Topic: Best Bolt On's for performance?

[worm25]

Just wondering where to start to get the best bang for my buck with some performance mods.  The only performance mods I've made to date is a K&N cold air induction system and magnaflow catback exhuast.  I see things like superchips, TB spacers, ect. but I'm really not sure what route to take.  Someone let me know how I can feed a little more juice to the ride..........  maybe some combos you are running would be nice as well.

Thanks,

Jamie

[Main One]

Programmers (or a custom tune) are good, especially as you add bolt-ons.

I wouldn't bother with a TB spacer.

Headers are good.

Underdrive pulleys are good.

A bigger cam is good, and will probably give the most noticeable improvement.

A higher stall torque converter will give you more punch off the line.

Some may say iridium spark plugs and low resistance plug wires - I'm not sure how much they are helping me.

[MyBigToy]

My first choice, after the basic mods you've done, would be a higher stall torque converter. It will give you the biggest measurable performance increase. You'll need a programmer to tweak the shifting; I'd recommend the Diablosport Predator or you could take the truck in and have a custom tune done.

If you plan to stay naturally aspirated I'd probably go with a 3000 stall; if you might add forced induction at a later date I'd probably go with a 2600, depending on the type of FI you choose. I can give you some torque converter brand suggestions if you'd like. I see you've got an 08 so If you have the 6-speed auto (I don't remember when the 6-speed came about) the stall choice may be different than for the 4-speed auto, which is what I've got.

Beyond that, you could do headers and a cam. Forced induction will give you a big boost but it's also big $ and once you add it you have to start beefing up other things like the tranny. We like spending other people's money almost as much as we like spending our own! 

Whatever you do, keep your ultimate goal in mind and make sure you pick items that will complement each other and will work with your ultimate combination. Do your research before you pick anything so that you don't regret it because you made the wrong choice.

BTW: my mods are in my signature; I've spent way too much money on my "baby"!  Good luck and have fun modding.

[Ski Edition]

How indepth is a cam change and what other parts would need to or should be changed during the process?  What would a cam change do for a basic stock AV (mine)?

[MyBigToy]

How indepth is a cam change and what other parts would need to or should be changed during the process?  What would a cam change do for a basic stock AV (mine)?

Pretty much the whole front of the engine and the radiator have to come off, as well as the valve covers and fuel rails. You don't technically have to take some things off but it makes it easier to do the install. Aside from the cam you'll need new compatible springs and most times it's recommended to go with hardened pushrods because replacement cams typically have faster lobe ramp rates and higher lift. You may have to replace the spring seats and retainers also but most times it's not absolutely necessary. Depending on how many miles you have on the truck you may want to consider replacing the timing chain and gears while you are in there. You could also consider changing out the water pump if you have a lot of miles on the truck. You'll also need assorted replacement seals and gaskets for everything you remove from the engine.

What would a cam change do? It typically gives you more horsepower and torque over a wider rpm range than a stock cam. Proper cam choice is critical for how you use your truck; since you tow you don't want to go with a cam that has mostly high rpm power. You could reasonably expect to see an increase of anywhere between 20-50 horsepower depending on the cam. You could go with a slightly higher-stall converter to allow you to go with a slightly higher rpm cam but again, a high rpm converter is not ideal for towing. You could get away with a 2600 stall like I've got but I personally wouldn't go any higher than that; I tow occasionally and the main place I noticed the difference was when backing the trailer up. You have less-precise control of the movement of the truck/trailer combo. I liken it to a rubber band effect - you step on the gas, the rubber band winds up and reaches enough tension to start the truck moving, then it starts moving. By then you've let off the gas and start the cycle all over again.

That should give you a pretty good idea of how involved the job is; you could do the change in a hard weekend with some help that's done it before. I see guys posting on PT.net that they can do a change in 4 hours but that would be someone who does it all the time and taking shortcuts that I personally wouldn't want to risk taking.

[Main One]

I did mine having never done it before but with a real good write-up that someone did when changing the cam on an LS1 powered Trans Am.  It took about all of a 3-day weekend.  (I did go to church Sunday morning.)  Also helped KY_Bob put his in after doing mine.  It took us a 2-day weekend, but we had a couple of issues: 1-his cam came with the alignment dowel missing which we had to track down a suitable replacement, and 2-he dropped a cam gear bolt into his oil pan which took about an hour of fishing with a magnet to pull out.

Pretty much what you need to do:

Pull the radiator - not too bad of a job but need to deal with the fluid.

Remove the valve covers - not too bad.

Remove the rockers - not too bad.

Remove the pushrods - at this point a piece of cake.

Remove the front crank pulley.  This thing is really torqued down.  I locked the crank via vice grips in the bell housing inspection opening on the flexplate and needed a breaker bar and iron pipe extension to break loose.

Remove the water pump - not too bad.

Remove the front engine cover - not too bad.

Spin the cam to get the lifters up.  Very easy.

You can assume the lifters will stay up before you get the new cam installed to save you from having to pull a head(s) or do like I did and use 16 magnets to hold them up.  There is also a couple of openings in the front of the block that you can remove plugs from and insert a rod that will hold up the lfiters.

Remove the cam gear - not bad but stick a rag into the gap exposing the oil pan so you don't do a KY_Bob and drop a bolt into the pan.

Remove the cam.

I also replaced the pushrods (about $150) and upgraded the valve springs with dual springs.  A cheap valve spring compressor works great with single springs, but was a real PITA with the duals, but after about 6 hours I managed to get them all installed.  I think I also changed valve seals, but it has been a long time.  I did not change valve retainers - titaniums are available for higher RPM applications.  I also purchased about a dozen spare valve locks as these are very small and easy to drop and loose.  Other than dealing with the dual springs, which would have been MUCH easier if I had spent another $200 for a better spring compressor, this wasn't too bad.

Now you just put things back together.  I reused the water pump gaskets but replaced the front main seal that I took off of the front cover.  The pulley crank nut is a 1-time use item that you will need to replace.  I spent the extra money on an ARP nut that is reuseable vice a GM one, mainly since the place I bought it from was out of stock of the GM nut.

Then you reinstall the things that you took off.  Oil the cam up well before reinstalling.  With roller lifters, you only need to use regular engine oil on the cam, but assembly lube works ok too.

After the install, unless you went with a cam with such a little amount of change that it would hardly be worth the trouble of installing it, you will need a custom tune, primarily to bump your idle speed and corresponding airflow.  Stock, my idle speed was 550.  With my cam, I need an idle speed of at least 700 rpm in order to keep it from setting misfire codes due to the rougher idle at lower idle speeds.  I also changed the settings of how much the airflow was bumped with my foot off the the pedal at higher rpms due to the truck not wanting to slow down with my foot off the gas on the freeway.  (Stock it was adding some airflow - I've got it set now to just give the engine the idle airflow at all engine speeds when I lift my foot off the gas.)  You may also want to tweak some your tranny shift points and where the torque converter locks due to a different power range from the engine.

I went with a 216/224 degree at 0.500 inch lift intake/exhaust duration, 0.551 inch max lift with stock rocker ratio cam which is supposed to add power over stock from 1500 up to 6000+ rpm.  (Rocker lift is supposed to occur at 6600 rpm so you don't want to go above there.)  I really notice a difference above 3000 rpm.  Comparing my dyno sheets to others with basically stock trucks, I've got a pretty flat torque curve from about 3800 rpm up to about 5800.  Stock cams don't have a very flat torque curve, with max hp about 5200 rpm, my hp peaks around 5700.  More reason to hold gear a little longer at WOT and hence do a custom tune.

My cam makes enough of a difference in my naturally aspirated truck that after MBT rode in it at Bratfest last year, he decided to put one in his supercharged truck.

If I were to do it again, I would probably do a slightly bigger cam.  I don't tow though, and that should be taken into consideration.  I don't notice any loss at the low end with my cam, but I might if I was towing.  I doubt though that you do much towing running the engine below 1500 rpm.

MBT mentioned changing the cam timing gear and chain.  I did that later after doing the cam install.  To do that, you may have to pull the oil pump, if you are changing the crank sprocket to go to a double chain or a timing adjustable setup, which is what I did.  The GM tech manual instructs to drop the oil pan to do an oil pump change, although it is possible to do by only loosing the pan bolts allowing the pan to drop a bit.  It is a BIG PITA to get the oil pickup tube screws back into the pump unless you drop the pan.  Dropping the pan on 4x4's is a BIT PITA because you have to drop the front differential, etc.  The stock cam timing setups are supposed to be pretty good.  Unless you have a lot of miles, like over 200,000, I'd not try to pull the oil pump, but that's me.

[Ski Edition]

Sounds like a plan--when is your next open weekend??   

[MyBigToy]

Sounds like a plan--when is your next open weekend??   

BRATFEST! 

[Ski Edition]

Maybe a little too much to do in the park.

[Richie_Rich]

I only live a few miles from the park and have a garage full of tools.

[MyBigToy]

I only live a few miles from the park and have a garage full of tools.

Sounds like we have another volunteer.

I was just yanking your chain about doing it in the park. This isn't the type of mod I would want to start on when I'm away from home for a short weekend trip. You might get stranded if something out of the ordinary happened.

[Ski Edition]

Fowlhunter and I already have a mod that we need to work on Saturday (if it is ready to go by then) and then the ballgame Saturday night.  I appreciate all the help offered though.  MBT and MO, I will be picking your brains in the coming days on this cam deal!  I think a lot of my power issues are the result of my 4.56 gears (should have gone to 4.10's).  Lots of low end, but lacking at the top.  Thanks guys!! 

[Main One]

If more power on top is what you are looking for, short of forced induction, a cam is the way to go.  It is cheaper than forced induction, but at least as involved as far as installation goes.  Plus, your truck just sounds meaner just sitting there idling!

I could possibly be talked into a road trip to help a brother out with this job.  Would require lots of pizza, beer, etc., as an inducement.   

[Ski Edition]

Have plenty of extra beds and garage, but lacking adequate tools. How about plenty of homemade Mexican food and margaritas?

[Main One]

I have tools, and greatly enjoy Mexican food and margaritas!!!

[Ski Edition]

I have a chef I imported from El Paso and you can't get any better Mex food in Nashville. I need to do some more research on specific cams and get a parts list. You have a grandbaby coming, so I'm sure your spare time will diminish soon.

[Main One]

Granddaughter came Friday night!  My son and I were/still are planning on going to Gatlinburg first weekend in August.

Do your research.  See what's available.  I got my cam used off of ebay.  I've got about 100,000 miles on it now!

[Ski Edition]

Congrats on the new granddaughter!!  They are great.  Mine is 2 1/2 and a holy terror.  I'm ready to go as far as wanting to do it.  I just need to do my research and get the parts in (and go to the grocery).  I thought the 4.10's would be the way to go, but I think the cam will serve my purpose much better. 

[Main One]

You may want to take a ride in my truck at Bratfest before you pull the trigger.

[Ski Edition]

You may want to take a ride in my truck at Bratfest before you pull the trigger.

I'm sure, from what I hear, that I will be impressed with how she runs.  My research may take that long (probably not).  I've read a lot about what the outcome of a cam swap is and I think that is what I'm looking for!! 

[Main One]

I found this write-up to be extremely helpful.  This will better let you know what we'll be getting into.  Moving the AC compressor is not required on the trucks.

http://www.ls1howto.com/index.php?article=23

Also, when doing Bob's truck, dealing with his supercharger took extra time, and we also installed his flexilight fans at the time too.

[MyBigToy]

Congrats on the new granddaughter!!  They are great.  Mine is 2 1/2 and a holy terror.  I'm ready to go as far as wanting to do it.  I just need to do my research and get the parts in (and go to the grocery).  I thought the 4.10's would be the way to go, but I think the cam will serve my purpose much better.

One thing to keep in mind; I don't remember whether you have one or not, but you will need some type of programmer to allw you to tweak the shifting parameters once you get the cam installed. You'll want to spin the rpms higher to allow you to take advantage of the additional power available higher up than with the stock cam. I'm currently shifting at 6200 rpm and the cam is still pulling like a raped ape at that point.

[Ski Edition]

I found this write-up to be extremely helpful.  This will better let you know what we'll be getting into.  Moving the AC compressor is not required on the trucks.

http://www.ls1howto.com/index.php?article=23

Also, when doing Bob's truck, dealing with his supercharger took extra time, and we also installed his flexilight fans at the time too.

Good article!!  I might be a little more educated now and if I had to do it alone, I would be scared half to death to do surgery like that on the engine.  I do find the different cams VERy confusing.  Which one will do this and which one will do that--not sure.  Back to the books.  BTW Joe, I have a Superchips handheld that I can change shift points, tire size, gears, etc.   

[MyBigToy]

BTW Joe, I have a Superchips handheld that I can change shift points, tire size, gears, etc.

That will at least give you a start. You'll probably need, at the very least, to get some type of mail order tune to really get all of the changes made that are necessary. You might try to find someone local that has a dyno and get a dyno tune or possibly find someone like Black Bear who travels periodically to different locations and does tunes. I had to make quite a few fueling changes, timing changes, and KR changes to my truck before I got it to run the way I wanted it to. Yours won't be as complicated because you aren't forced induction.

It seems the two most current favored tuners @ PT.net are Wheatley and Black Bear. I believe Wheatley sends a data logger and bases his changes on the logged file(s).

[Ski Edition]

That will at least give you a start. You'll probably need, at the very least, to get some type of mail order tune to really get all of the changes made that are necessary. You might try to find someone local that has a dyno and get a dyno tune or possibly find someone like Black Bear who travels periodically to different locations and does tunes. I had to make quite a few fueling changes, timing changes, and KR changes to my truck before I got it to run the way I wanted it to. Yours won't be as complicated because you aren't forced induction.

It seems the two most current favored tuners @ PT.net are Wheatley and Black Bear. I believe Wheatley sends a data logger and bases his changes on the logged file(s).

I figured that I would need to do more than the Superchips does.  It was just the basic model to get my tires and gears into the system.  OK Joe, shoot me some numbers on the cam I should go with and I'm sure you will give me an explanation why!     Thanks for all your help!!! 

[MyBigToy]

I figured that I would need to do more than the Superchips does.  It was just the basic model to get my tires and gears into the system.  OK Joe, shoot me some numbers on the cam I should go with and I'm sure you will give me an explanation why!     Thanks for all your help!!!

Here's a good start on one:

http://www.chevyavalancheclub.com/index.php/topic,1708.msg14710.html#msg14710

It's the one Ky_Bob put in his truck. It's a little smaller duration cam with a little higher lift than the one Main One and I have. To be honest, I don't think there would be a whole lot of difference in your truck between the two choices when each is tuned properly. The 212/218 duration cam should be a little easier to tune for. I know from talking to Bob that he's shifting at 6200 on his standard programming and a little higher than that on his haul a$$ tune.

I'm sure Main One will chime in here also. He's indicated he would probably go with a larger cam the next time around. It's really a matter of a ton of research and making an educated choice after that. I will say that the 212/218 high lift cam indicated above is one of the main ones that gets recommended time and time again for naturally aspirated engines; there has to be a reason for that. This cam will be a little cheaper to install because you can get by with using the yellow GM (Corvette) single springs. Dual springs are recommended for the cam M1 and I have.

[Ski Edition]

Actually, I was reading that thread as you posted this.  Thanks Joe!!

[MyBigToy]

Here's some more light research reading for you, Ski:

http://performancetrucks.net/forums/showthread.php?t=387763

[Ski Edition]

Here's some more light research reading for you, Ski:

http://performancetrucks.net/forums/showthread.php?t=387763

I read that one too.  It was actually in a signature of a member with 3 initials.  He had different links and this was under cams.  Keep em coming Joe!! 

[Main One]

Ski,

I certainly do not want to discourage your research - after all for me it is half of the fun.  But, whatever cam you choose, you will probably think, if I were to do this over again I'd go a bit this way or that.  Whichever it is though, as long as you don't go real big, you are most likely going to prefer it over the stock cam.

[Fowlhunter]

I would love to swap out the factory cam for something a little bigger, I'm not in it to create a quarter mile thrasher but I would love more low end power for pulling.  I don't pull anything hugh by any means but that would suit my needs better than upper end power, I think?  After reading some of the attached links I would probably be better suited to go with a set of shorty headers first.  I currently have 126,000 miles on the clock, would it be a good thing to swap out the cam with this many miles?

[Ski Edition]

I would love to swap out the factory cam for something a little bigger, I'm not in it to create a quarter mile thrasher but I would love more low end power for pulling.  I don't pull anything hugh by any means but that would suit my needs better than upper end power, I think?  After reading some of the attached links I would probably be better suited to go with a set of shorty headers first.  I currently have 126,000 miles on the clock, would it be a good thing to swap out the cam with this many miles?

What gears do you have??

[Fowlhunter]

What gears do you have??

I'm thinking they are 3.73?

[MyBigToy]

I'm thinking they are 3.73?

Yep, that's what you've got.

[Ski Edition]

I'm thinking they are 3.73?

My gear swap was a trememdous help on the low end side to the detriment of the top end.  Wish I had gone to 4.10's, but love the 4.56's when towing the camper.  Get those Edelbrock coated shorties and we can do them on that saturday too.  Not too bad of an install!!  Think it took me and my neighbor a couple hours tops!!  (I'm like MBT---I love spending other peoples money)!!   

[Fowlhunter]

There are several things I would like to do but the funds needed are pretty high.
Gear swap, 4.10 (probably)
Tranny rebuild
New cam, springs, push rods, locks, retainers, etc.......
Shorty headers
The list goes on and on!  My concern is with the miles on the Ole girl, should more attention be put on the lower end?

[MyBigToy]

There are several things I would like to do but the funds needed are pretty high.
Gear swap, 4.10 (probably)
Tranny rebuild
New cam, springs, push rods, locks, retainers, etc.......
Shorty headers
The list goes on and on!  My concern is with the miles on the Ole girl, should more attention be put on the lower end?

You really shouldn't worry about the bottom end on the GM engines; they are good for a lot of miles. Just ask M1 @ over 200k miles and I know he isn't afraid to run his truck hard.

I personally wouldn't do a gear change from 3.73 to 4.10; it's a lot of expense on a 4X4 for not a lot of change.

If you are looking for a little improvement on the bottom end I would suggest you think about going with a higher stall converter (2600 since you sometimes tow) when you rebuild the tranny.

[Fowlhunter]

You really shouldn't worry about the bottom end on the GM engines; they are good for a lot of miles. Just ask M1 @ over 200k miles and I know he isn't afraid to run his truck hard.

I personally wouldn't do a gear change from 3.73 to 4.10; it's a lot of expense on a 4X4 for not a lot of change.

If you are looking for a little improvement on the bottom end I would suggest you think about going with a higher stall converter (2600 since you sometimes tow) when you rebuild the tranny.

Oh yeah, good point.  That is a bunch of miles!

Are you saying don't do it at all or go with a steeper gear (4.56)?

Every time I hear someone talk about higher stall converters I think of my hot rod days.  Would that benefit me since I'm not working on a 1/4 mile truck?  You know me, pulling the duck boat, out on some logging road, etc...  So when I had the Ole girl locked in 4-low and in 1st gear on Sat when I was pulling a stump out of the ground this 2600 stall would have helped/benefited me?  Maybe my thinking is all wrong?

What about headers, shorties, long tubes or neither and leave the manifolds in place?

[Ski Edition]

May I suggest you change you sign-on name to "Stump puller"?

[Fowlhunter]

May I suggest you change you sign-on name to "Stump puller"?

Not a bad idea!!  You should have heard my son, he was pumped up!  He said, dang Dad you were spinning the front tires as well!  They were howeling and we left black marks on the driveway!!!   

[Ski Edition]

Not a bad idea!!  You should have heard my son, he was pumped up!  He said, dang Dad you were spinning the front tires as well!  They were howeling and we left black marks on the driveway!!!   

You're a stud!!!   

[Ski Edition]

Need to get this cam in--Black Bear in Indianapolis on 7/30-31.   

[Main One]

Not a bad idea!!  You should have heard my son, he was pumped up!  He said, dang Dad you were spinning the front tires as well!  They were howeling and we left black marks on the driveway!!!   

Sounds like you've got more than enough low end to me!!!

[Fowlhunter]

Sounds like you've got more than enough low end to me!!!

Keep in mind, the Ole girl was in 4 low and in first gear.
Shorty or long tube headers and why?

[MyBigToy]

Oh yeah, good point.  That is a bunch of miles!

Are you saying don't do it at all or go with a steeper gear (4.56)?

Every time I hear someone talk about higher stall converters I think of my hot rod days.  Would that benefit me since I'm not working on a 1/4 mile truck?  You know me, pulling the duck boat, out on some logging road, etc...  So when I had the Ole girl locked in 4-low and in 1st gear on Sat when I was pulling a stump out of the ground this 2600 stall would have helped/benefited me?  Maybe my thinking is all wrong?

What about headers, shorties, long tubes or neither and leave the manifolds in place?

I'm saying if it was my truck I wouldn't do gears at all; I've been in your truck. You've essentially got 33" tires and while 4.10s are probably the ideal gear for 33s, there just isn't enough difference in 4.10s vs 3.73s to warrant spending the money. And 4.56s, while giving you a good boost in off-the-line (and overall) acceleration, will kill your gas mileage.

In my estimation the 2600 stall would give you the small amount of boost you are looking for off the line while having a negligible effect on your everyday driving and gas mileage. And you can do a stall (Trailblazer I6 or Yank TT2600 or comparable Circle D model) for less than the gear change and tune it with your Predator. The stock stall is 1600 rpm so by allowing the rpms to go to 2600 you are getting the engine into an rpm range where it's already making more hp/torque; I've seen posted results of a 0.4-0.6 second improvement in 0-60 mph times with just this change. I can't speak for the Trailblazer stall but my Yank is pretty tight; in other words, when driving "normally" I don't notice it's there very much but when I put my foot in it it flashes to 2600-2800 rpm and then MOVES. You could also go to a 3000 stall and gain a little bit more but, based on my experience towing with the 2600 stall, it would make towing a little more difficult.

As far as headers, I don't have any experience with shorties but from everything I've read you only gain 5-10 hp max. However, long tubes are reported to hurt you off the line so that's contrary to what you are looking for. For shorties, from what I've seen, JBAs are supposed to be better than Edelbrocks. If you do decide to do it, don't buy anything except stainless or ceramic coated. You'll just have to decide if an additional 5-10 hp is worth the $300 price tag. If you aren't in a hurry you could always watch PT.net and try to snag a deal on a used set. I gave $250 for my Titanium ceramic coated TOGs (mid-lengths, which are inbetween shorties and long tubes) used but they had been returned to TOG for re-coating. If you would decide to go with long tubes you would probably have to turn your rear O2 sensors off with the Predator, based on my experience with the Dynatechs on the Vette as well as mucho other posts on long tube header installations.

That's the extent of my for now. I'm out the door for my birthday dinner! 

[Ski Edition]

I'm out the door for my birthday dinner! 

Have a great B-day dinner Joe and thanks for all your help!! 

[Ski Edition]

Here's an interesting article on cams.

http://www.superchevy.com/technical/engines_drivetrain/cams_heads_valvetrain/0406phr_gen3/index.html

[Fowlhunter]

I'm saying if it was my truck I wouldn't do gears at all; I've been in your truck. You've essentially got 33" tires and while 4.10s are probably the ideal gear for 33s, there just isn't enough difference in 4.10s vs 3.73s to warrant spending the money. And 4.56s, while giving you a good boost in off-the-line (and overall) acceleration, will kill your gas mileage.

In my estimation the 2600 stall would give you the small amount of boost you are looking for off the line while having a negligible effect on your everyday driving and gas mileage. And you can do a stall (Trailblazer I6 or Yank TT2600 or comparable Circle D model) for less than the gear change and tune it with your Predator. The stock stall is 1600 rpm so by allowing the rpms to go to 2600 you are getting the engine into an rpm range where it's already making more hp/torque; I've seen posted results of a 0.4-0.6 second improvement in 0-60 mph times with just this change. I can't speak for the Trailblazer stall but my Yank is pretty tight; in other words, when driving "normally" I don't notice it's there very much but when I put my foot in it it flashes to 2600-2800 rpm and then MOVES. You could also go to a 3000 stall and gain a little bit more but, based on my experience towing with the 2600 stall, it would make towing a little more difficult.

As far as headers, I don't have any experience with shorties but from everything I've read you only gain 5-10 hp max. However, long tubes are reported to hurt you off the line so that's contrary to what you are looking for. For shorties, from what I've seen, JBAs are supposed to be better than Edelbrocks. If you do decide to do it, don't buy anything except stainless or ceramic coated. You'll just have to decide if an additional 5-10 hp is worth the $300 price tag. If you aren't in a hurry you could always watch PT.net and try to snag a deal on a used set. I gave $250 for my Titanium ceramic coated TOGs (mid-lengths, which are inbetween shorties and long tubes) used but they had been returned to TOG for re-coating. If you would decide to go with long tubes you would probably have to turn your rear O2 sensors off with the Predator, based on my experience with the Dynatechs on the Vette as well as mucho other posts on long tube header installations.

That's the extent of my for now. I'm out the door for my birthday dinner! 

OK, Thanks a bunch for your input!!  The tranny could use some work anyway, she is starting to slip a little.     My money would probably be better spent there anyway.  When the time comes for the tranny I'll look into a stall converter, never thought I would be saying that when it comes to the Ole girl.  So you think the 2600 would be OK for towing? 

I did some reading today (should have been working) on cam swaps and headers!  The shorties is what I was thinking but I wanted another opinion.  I actually looked at the JBA shorties at Summit, $300 the all Stainless without any coating were around $400!!  The ceramic coated Stainless and the Titanium ceramic coated Stainless were over $500.     There were two different collectors listed but wasn't sure which was correct, I'll have to take a look.

Lets say I did a cam swap, had the tranny rebuilt with a 2600 stall converter and went with the shorty headers (in the future) could I use the Predator to tune things?

Thanks and enjoy your birthday dinner!!! 

[MyBigToy]

So you think the 2600 would be OK for towing? 

Lets say I did a cam swap, had the tranny rebuilt with a 2600 stall converter and went with the shorty headers (in the future) could I use the Predator to tune things?

The Yank TT2600 is specifically listed as towing-friendly. I'm sure the Circle D equivalent can be had in a towing-friendly design also. As far as I know the I6 Trailblazer converter is also OK for towing. The main difference between the performance high stall converters and the towing-friendly setups is converter diameter, anti-balloon plates, and many are billet construction (and are therefore much pricier). The performance setups are typically 9-1/2" diameter. The TT2600 is, I believe, 11-1/2" diameter versus a stock diameter of 12". The smaller diameter means less rotating mass and faster spool-up. There's also less surface area for clutch engagement so there's more slippage and more heat that's subsequently harder on the tranny. How deep do you want to delve into converters? You can also talk about triple and 5-disk setups in the performance converters. These setups are more rugged and stand up to more abuse.

One thing I forgot to mention yet; get a decent tranny oil cooler to provide additional cooling. They are very cheap insurance. Heat is your tranny's biggest enemy as far as longevity is concerned. IIRC, I believe you installed the GM cooler on your truck.

You could get by using the Predator to tune for the cam but you would not get the absolute most-full benefit versus some type of actual tune. It would work fine for tweaking the shifting characteristics and rpms to account for the converter. To account for the cam and headers we would have to work on the fueling and timing and do some driving similar to what we originally did when tweaking your factory settings. It would take longer to get things dialed in because the changes you are talking about are much larger than what we originally adjusted for. The best thing to do there would be for you to get comfortable tweaking the parameters by watching what was being done; the only problem there is that it's much better to have a second set of eyes to watch the parameters since you don't have logging capabilities (although I did it by myself when I had the Predator). Another alternative you might consider is to talk to OBB and see what you would have to do to be able to have MonteSS do a custom tune for you that could be loaded into your Predator. I know you had Nelson Performance do a tweak on your pcm for your e-fans; you might also talk to him and see what it would cost for him to do a tune; my guess is that this would be the least-hassle alternative and probably not at a very high cost since you've already used him.

I'll remind everyone again; there's a ton of information available out there via Google searches and performance websites such as PT.net. What I discussed in this thread is due to the research I've done and my personal experience based on the choices I've made. You should also do the same due diligence (which it already appears both you and Ski are doing) and make as informed a decision as you can once you feel comfortable making that decision.

[Main One]

I'm running the Trailblazer torque converter.  It flashes to about 2200 rpm, versus 1700 for my stock converter.  On light to mid throttle it runs about 1500 to 1600 rpm in 4th gear around 40 mph.

I was very tempted to do the Yank converter, but Bob talked me into the TB that someone was selling on performancetrucks.net.  He's running a modified TB converter which seems to flash higher than my stock one, although some of that may be due to higher torque being delivered through it on his supercharged AV.

I may be tempted to go to the Yank 2600 when I put my tranny back in after my rebuild and sell the TB converter.  Used TB converters go for about $150 if I remember correctly on performancetrucks.net, and I think a new Yank would run me $600+ but it's been a while since I priced them so I may be way off.

Don't worry that the 6 cylinder TB converter won't hold up.  I've got I'm guessing in the neighborhood of 60,000 miles on mine.  I did do some torque converter lockup retuning with it since I was getting some slipping around 45 mph until upping some pressures.  Don't know if that was due to wear or design differences.

[Main One]

I'm OK on the low end, but start to bog down at about 55-70, but will take off at 70+ when I get momentum.  Does that tell you what cam I would be looking for?

Ski,

I wanted to comment on something out of what you PM'ed me above.  You mentioned bogging down at 55-70.  I want your cam expectations to be realistic.

With my cam, torque is pretty flat from about 3700 rpm up to about 5800, and doesn't fall off too bad above 5800 rpm.  With my G-Tech, I can log vehicle acceleration and with my flat torque curve, the G-Tech shows some interesting things.

One thing it shows is that when I floor it from a stop, I get some good acceleration that after the initial launch transient and I get into the above mentioned flat torque area, my vehicle acceleration remains fairly constant until it shifts into second.  After the gear change transient, the acceleration is again pretty constant, but at a lower level than it was in first gear.  The same thing happens again when I shift into 3rd, although to tell you the truth, I've never taken her to redline in 3rd.  (The actual acceleration at 50 mph may be the same as at 75 mph, but it sure seems to be more at 75, maybe since I'm getting a whole lot more say at 35.)

My point is this:  A cam can only do so much, and you may be somewhat at the mercy of the wide gear ratio differences in the 4L60.  My truck seems to "bog down" where it's going too fast for first gear, but not really into a good torque area for 2nd.  I'm shifting around 6100 rpm, and the rpms drop to around 3500 at the shifts.  Tighter gear ratio differences would definitely help here, although a looser torque converter would as well.  Shifting later is an option as I'm still pulling hard at 6200 rpm, but shifting that high has resulted in lifter tick in the past so I have knocked the shifts down by 100 rpm.

An expensive option that addresses the wide gear ratio differences in the 4L60 that we haven't yet addressed is a Gear Vendors Overdrive unit.  This would essentially give you an 8 speed transmission.  It would keep you in the best rpm powerband region when you wanted power, and offer possibly better fuel economy when you weren't looking for the power.  The trouble is these units go for about $2500 new, and you don't see used ones for 4L60s on the market very often and when you do they go for a good price.

[Ski Edition]

I was doing some research on LS1 Tech and ran across a guy with a sign-on of Tim @ LPE that was giving out lots of technical advice.  Finally tracked him down at LPE and sent him an email asking about his suggestion to my specific application, giving him the particulars of my AV and this is what he came back with:

Hello,

 

Thank you for your interest in Lingenfelter Performance and our products.  What I would suggest is our GT2-3.  It is designed to work well in a heavy vehicle and will still have a good idle.  It is 207/220 .571/.578 w 1.7 rocker 118.5 CL, made for us by Competition Cams and sells for 386.95 and will need new valve springs.  Cam and springs together are $439.95.  Please let me know if you have any questions.

Thank you,

 Tim Dyer

 Sales Manager
 Lingenfelter Performance Engineering

 260 724 2552 x 1001

http://www.lingenfelter.com

[Main One]

I was doing some research on LS1 Tech and ran across a guy with a sign-on of Tim @ LPE that was giving out lots of technical advice.  Finally tracked him down at LPE and sent him an email asking about his suggestion to my specific application, giving him the particulars of my AV and this is what he came back with:

Hello,

 

Thank you for your interest in Lingenfelter Performance and our products.  What I would suggest is our GT2-3.  It is designed to work well in a heavy vehicle and will still have a good idle.  It is 207/220 .571/.578 w 1.7 rocker 118.5 CL, made for us by Competition Cams and sells for 386.95 and will need new valve springs.  Cam and springs together are $439.95.  Please let me know if you have any questions.

Thank you,

 Tim Dyer

 Sales Manager
 Lingenfelter Performance Engineering

 260 724 2552 x 1001

http://www.lingenfelter.com

Looking on their web page it looks like you could get by without needing a retune with that one.

[MyBigToy]

My truck seems to "bog down" where it's going too fast for first gear, but not really into a good torque area for 2nd.  I'm shifting around 6100 rpm, and the rpms drop to around 3500 at the shifts.

I guess this is where the TT2600 gains you over the Trailblazer converter. It limits rpm drop between shifts to 1700 or 1900 rpm; I don't remember which for sure. Because of this, I don't notice any falloff in performance at shifts. The one time I've really tried out the cam/smaller pulley off the line it boiled the tires all the way through first gear, through the shift (and I was cringing then), and all the way through second gear.

[MyBigToy]

I may be tempted to go to the Yank 2600 when I put my tranny back in after my rebuild and sell the TB converter.  Used TB converters go for about $150 if I remember correctly on performancetrucks.net, and I think a new Yank would run me $600+ but it's been a while since I priced them so I may be way off.

I'd say my post just previous to this one would be a really good reason to go with the TT2600. If you want to get really sick, I'm going to tell you that Yank ran a special last year on the TT2600 for $350.  I gave $300 for mine gently used and that was a he!! of a deal at the time. One thing I really like about the TT2600 is the rock solid lockup compared to the OEM converter.

If I was really serious about obtaining maximum performance out of my setup I really should be running at least a 3-clutch 9-1/2" billet converter. I've tried to balance a good-performing setup with a long-lived combination. I'm willing to give up the "ragged edge" performance increase for a setup that will hopefully run as long as I want to run it.

[MyBigToy]

I was doing some research on LS1 Tech and ran across a guy with a sign-on of Tim @ LPE that was giving out lots of technical advice.  Finally tracked him down at LPE and sent him an email asking about his suggestion to my specific application, giving him the particulars of my AV and this is what he came back with:

Hello,

 

Thank you for your interest in Lingenfelter Performance and our products.  What I would suggest is our GT2-3.  It is designed to work well in a heavy vehicle and will still have a good idle.  It is 207/220 .571/.578 w 1.7 rocker 118.5 CL, made for us by Competition Cams and sells for 386.95 and will need new valve springs.  Cam and springs together are $439.95.  Please let me know if you have any questions.

Thank you,

 Tim Dyer

 Sales Manager
 Lingenfelter Performance Engineering

 260 724 2552 x 1001

http://www.lingenfelter.com

And I'm sure you noted that's the second cam recommendation I gave you.  If you decide to go with it, I see them for sale used on PT.net pretty often. As a matter of fact, I pm'd Mick sometime last week with one that was for sale. It didn't last very long. I'm sure you'd be happy with either choice.

[Ski Edition]

And I'm sure you noted that's the second cam recommendation I gave you.  If you decide to go with it, I see them for sale used on PT.net pretty often. As a matter of fact, I pm'd Mick sometime last week with one that was for sale. It didn't last very long. I'm sure you'd be happy with either choice.

I have received a lot of good recommendations since I have been looking at cams.  I appreciate all your help MBT and MO!!  You're both a level or two or three above most of us.   

[MyBigToy]

I have received a lot of good recommendations since I have been looking at cams.  I appreciate all your help MBT and MO!!  You're both a level or two or three above most of us.   

I haven't noticed or looked; have you asked the question on PT.net? If so, what kind of recommendations have you gotten there?

BTW, I agree that M1 is a few notches above the rest of us in his knowledge level.

[Ski Edition]

I haven't noticed or looked; have you asked the question on PT.net? If so, what kind of recommendations have you gotten there?

BTW, I agree that M1 is a few notches above the rest of us in his knowledge level.

I haven't asked any questions over there, but I have done quite a bit of reading of the threads.  A lot of them lead back to the GT2-3 or 212/218 - .522/.529 w 1.7 rocker - 114 LSA (the one Bob has.  Those are the most popular by far. 

[MyBigToy]

.....212/218 - .522/.529 w 1.7 rocker - 114 LSA (the one Bob has.  Those are the most popular by far.

That's the low lift version, not the one Bob has. The high lift version has .558/.563 lift and 115 LSA.

[Ski Edition]

That's the low lift version, not the one Bob has. The high lift version has .558/.563 lift and 115 LSA.

My bad, then the low lift version is very popular.  XR265HR  There is a guy trying to unload his custom grind 269 with 30K on it asking $275 or BO. 

[MyBigToy]

The number on the cam Bob has is:

Grind Number: LS1 XR265HR-15

so it appears it's the same base part number.

[oHIobellboy]

 

OK Mr Wizards....what kind of cam do you think might be in this?  I 'd say he has a few bolt ons.

[Ski Edition]

OK Mr Wizards....what kind of cam do you think might be in this?  I 'd say he has a few bolt ons.

Through my thorough research the last couple of days, we're looking at the Vinci Hi Performance:
DUR @ .004"  294*/ 290*
DUR @ .050"  232*/228*
LIFT .600/.600
LSA 117*

              

[MyBigToy]

OK Mr Wizards....what kind of cam do you think might be in this?  I 'd say he has a few bolt ons.

That doesn't have a cam. It's a bike for sissies. 

[Ski Edition]

Interesting for my application!!

Comp Cams XTREME RPM XR265HR - 212/218 - .522/.529 w 1.7 rocker - 114 LSA

As opposed to this one.

DUR @ .004" 272* / 280*
DUR @ .050" 210*/ 218*
LIFT .531/.531
LSA 114* TOWING & PERFORMANCE
 POWER  RANGE  1700 TO 6000
PROVIDES  HIGH TORQUE, MODERATE LIFT, LONG VALVE SPRING LIFE
LIGHT CHOPPY IDLE

[MyBigToy]

Interesting for my application!!

Comp Cams XTREME RPM XR265HR - 212/218 - .522/.529 w 1.7 rocker - 114 LSA

As opposed to this one.

DUR @ .004" 272* / 280*
DUR @ .050" 210*/ 218*
LIFT .531/.531
LSA 114* TOWING & PERFORMANCE
 POWER  RANGE  1700 TO 6000
PROVIDES  HIGH TORQUE, MODERATE LIFT, LONG VALVE SPRING LIFE
LIGHT CHOPPY IDLE

That one also appears to be a decent choice. It's a little lower lift than the high lift 212/218 so you'd be giving up some "under the curve" power. I still think I'd go with the high lift 212/218 or the Lingenfelter. I didn't look at the specs on the GT2-3 again but as I remember it, I don't believe the ramp rate is as aggressive as on the Comp Cams XRs. It appears to me that you are getting pretty close on a final choice. Once again, I think you'd probably be happy with any of the three choices.

[Main One]

Once again, I think you'd probably be happy with any of the three choices.

I have to agree with MBT.  The cams you are narrowing down to I think would all be good choices, and there most likely won't be a difference between them that you could notice without running on a dyno.

If it were me, I'd be looking for deals on ebay or at performancetrucks for something in this range, unless you really decide you're ready to get hitched to a particular cam.

[Ski Edition]

Can someone please explain to me in basic layman's terms, what the difference in these 2 cams is?  I have heard I will gain nothing from a high-lift cam unless I go with a bigger rocker.  Thanks! 

Comp Cams XTREME RPM HIGH LIFT XR265HR -                212/218 - .558/.563 w 1.7 rocker - 115 LSA
Comp Cams XTREME RPM XR265HR -                                212/218 - .522/.529 w 1.7 rocker - 114 LSA

[Main One]

1 degree of LSA isn't a great deal of difference, and I forget the details of how that affects a cam performance.  With fuzzy memory, I think more separation gives better low end performance and a better idle, with better top end with a tighter separation angle.

It is news to me that you would need higher ratio rockers in order to see a benefit from the higher lift cam.  Sounds like urban legend material to me.

You may be able to get by with less expensive valve springs with the lower lift.

If you went with the lower lift cam and 1.85 ratio rockers, you'd end up with more lift than the high lift cam and stock 1.7 rockers.

The 1.85 rockers with the higher lift cam would give you 0.613 exhaust lift.  At some point you may run into the valves hitting the cylinders - I'm not sure if that would be the case with this cam and 1.85 lift.

As I noted earlier (maybe in a PM), stock heads don't flow much more once you get above 0.400 or so.  More important than total lift then, is comparably, how much more "open" are the valves in the angle space corresponding to 0.050 to 0.400 lift, or how quickly do they close and shut.  There are limits there driven by just how much force you can put to the pushrods, how stiff the springs need to be, and wear on the valve seats and rest of the valve train.

[MyBigToy]

Can someone please explain to me in basic layman's terms, what the difference in these 2 cams is?  I have heard I will gain nothing from a high-lift cam unless I go with a bigger rocker.  Thanks! 

Comp Cams XTREME RPM HIGH LIFT XR265HR -                212/218 - .558/.563 w 1.7 rocker - 115 LSA
Comp Cams XTREME RPM XR265HR -                                212/218 - .522/.529 w 1.7 rocker - 114 LSA

That's incorrect. You will gain, from what I have read the general consensus is, up to a lift of about .550 on the stock heads. The valves stay open longer so you are gaining the benefit of both longer intake and exhaust pulses. You won't strictly gain additional power with the lift that's over 0.550 but the valves are still open longer so you gain the benefit of that. The 114 LSA is supposed to give slightly more peak power than the 115 LSA but the 115 LSA supposedly gives better drivability.

I had this typed as M1 was adding his thoughts.

[Ski Edition]

Thanks guys. I'm about at the close of me research. M1, have tools will travel??  Juat need to do a little shopping first.

[Main One]

Have tools and will travel for a place to sleep and wash up, and all the good mexican food and margaritas I can eat/drink!  Can also bring the G-Tech and do a before baseline and afterwards assessment of what you've added 0-60, HP and Torque curves, etc.

Need to get my tranny a little bit buttoned up first.  About everything's been taken out of the case except for the servos.  Have started the tear down and modifications to the valve body - right now the 10 or so valve lineups are pulled out and lined up in the order that they will need to go back in - don't want to get those mixed up and or lost.  Last night drilled a hole to allow fluid flow where it wasn't originally designed to go per the directions with the heavy-duty 2-3 shift valve I'll be installing, and drove a couple of balls into where the foward accumulator piston's shaft was - will be replacing with a shaftless piston.  If it isn't too hot and I feel up to it tonight, will try to reinstall the valve lineups and get that buttoned up.  After that it will be open up the pump, install the 13 vane rotor kit, high rpm spring, upgraded valve, etc.

I know, you all want pictures.  Will generate another thread when I get around to it.  Been taking a fair number of pics - got some transfered over to the computer but need to resize them first.

Will be able to come down sometime after around mid-August.  Will be transfering to a different division here at work around then and need to get some loose ends wrapped up as quickly as possible, generating some overtime hours here lately.

[Ski Edition]

Sounds like a plan!!  We'll work around your schedule. In the meantime, that gives me a chance to shop around. I just couldn't pass up such a generous offer!!  Hot Mexican food and Margaritas are a staple at my house, so not a problem there!  Thanks again M1!!

[MyBigToy]

Sounds like a plan!!  We'll work around your schedule. In the meantime, that gives me a chance to shop around. I just couldn't pass up such a generous offer!!  Hot Mexican food and Margaritas are a staple at my house, so not a problem there!  Thanks again M1!!

  to Main One. Ski - you need to start hitting the for sale ads in PT.net every couple of hours. Had you decided this a week sooner you would probably now be the owner of a GT2-3 cam.

[Ski Edition]

I know!!  Guy had a feeler thread about selling his 269. A little bigger than I want to go. Let me know if you see anything. Thanks!!

[MyBigToy]

I don't know if you would think about it or not but you need to start checking out the parts for sale section for the C5 corvette on corvetteforum.com. There will be a lot of cams for sale over there; most will be on the large side for the Av but you'll also see lots of LS6 cams (a decent choice for the Av as I understand it) that were stock in the Vette (2002-2004 are the preferred years). I dropped in over there a little bit ago and there had been a GT2-3 cam posted over there; it was already sold. Things move VERY quickly over there.

FYI - specifications:

LS6 204/218-0.551/0.547-117 you can buy this one for $200 pretty often
GM PP "Hot cam" 218/227-0.525/0.525-112 probably not as good a choice for your application

[MyBigToy]

Here's a current eBay auction for the high lift Comp 212/218:

http://cgi.ebay.com/ebaymotors/LS1-LS6-LS2-COMP-CAM-CAMARO-FIREBIRD-GTO-6-0-XR265HR-/310230632013?cmd=ViewItem&pt=Motors_Car_Truck_Parts_Accessories&hash=item483b2fc64d

I'm not sure how great a price it is.

[MyBigToy]

2004 Z06 (LS6) cam for sale CHEAP ($150 plus shipping) on Corvetteforum:

http://forums.corvetteforum.com/c5-parts-for-sale-wanted/2637588-fs-ls6-intake-zo6-cam.html

Get a set of yellow Vette springs, new valve seals, and a set of hardened pushrods and you'll be in business.

If you decide you are interested ask for detailed pictures so you can see what kind of shape it's in. If you get to a point where you might want to close the deal and the seller has questions since you'll be a newbie, just let me know as I've been a member there since 2005. I haven't been really active since I sold the Vette but I have checked in from time to time. I wouldn't have a problem vouching for you.

[Ski Edition]

Been staining my deck and just got your messages.  I was interested in the LS6 cam and wanted to do a little research on specs.  I show it as a:

LS6 CAM - 204/219 .551/.548 117.5

Would that be a direct bolt?

Post below on the Vette forum fromJason Haines, Project Director
Lingenfelter Performance Engineering

And the LS2 camshaft has the same lobes as the 2001 LS6 camshaft (but doesn't have the reluctor wheel machined in the camshaft since the sensor was moved to the timing cover).

The 2002-2004 LS6 engines had lighter valvetrain (hollow intake and hollow/sodium filledexhaust) compared to the 2001 LS6 and the 2002-2007 LS2 valves.

GM may not have gone to the 2002-2004 LS6 exhaust lobe for emissions (overlap) reasons or it may have also been for cost reasons if they feel the 2002-2004 exhaust lobe requires the lighter (but more expensive) valves.

The 2002-2004 LS6 camshaft would be a power gain for a 2001 LS6 and for an LS2 engine. Probably only a small gain on an LS3 given the much smaller difference between the two (exhaust lobe). You could probably just switch to 1.8 rockers on the exhaust and get more gain.

BTW - you can put the older camshafts into the newer engines (Gen III engine camshafts into Gen IV engines) without any major changes needed. To go in the other direction (LS2, LS3 or LS7 camshaft into an LS1, LS6, LQ4 etc) would require changing the front timing cover, the timing gear and then getting an extension wire to go from the old camshaft sensor harness location to the front timing cover (these extensions are available).

[MyBigToy]

The specs you show are correct with the exception that it's 218, not 219.

As far as I know, it's a direct bolt-in proposition into the Gen3 motors. Don't take my word for it, though, make sure to verify this with someone who is certain regarding fit.

This would make a good cam for you and you could probably tune this one with your Predator.

[Ski Edition]

The specs you show are correct with the exception that it's 218, not 219.

As far as I know, it's a direct bolt-in proposition into the Gen3 motors. Don't take my word for it, though, make sure to verify this with someone who is certain regarding fit.

This would make a good cam for you and you could probably tune this one with your Predator.

Off to do my research on compatibility of this cam--Thanks Joe!!  Sent him a PM. 

[Ski Edition]

This thread at LS1 almost says that it will fit, but my question is, is this cam as aggressive as I was looking to go with?

http://www.ls1gto.com/forums/archive/index.php/t-114360.html

[MyBigToy]

.....my question is, is this cam as aggressive as I was looking to go with?

I'm pretty sure the lobe ramp rate won't be as aggressive as the Comp XR lobes and you have a 204* duration on the intake instead of a 212*. My guess is that this cam would be pretty comparable to the low lift 212/218 cam. It's just a half-a$$ed educated guess on my part but I doubt you'd give up more than 10 hp.

In my mind you just have to answer the question to yourself if saving somewhere around $150 outweighs the benefits of getting exactly the cam you currently think you want. 

[Ski Edition]

I'm pretty sure the lobe ramp rate won't be as aggressive as the Comp XR lobes and you have a 204* duration on the intake instead of a 212*. My guess is that this cam would be pretty comparable to the low lift 212/218 cam. It's just a half-a$$ed educated guess on my part but I doubt you'd give up more than 10 hp.

In my mind you just have to answer the question to yourself if saving somewhere around $150 outweighs the benefits of getting exactly the cam you currently think you want. 

Key phrase is "the cam you currently think you want"!  It's all good!  I do like the price! 

[Fowlhunter]

OK, I'm going to ask a dumb question here only because I know most of the folks and I don't give a rats  what anybody thinks!!     I've done my fair share of work on the older Chevy small blocks but nothing to speak of on the newer LS1 version.  What do I have in my 02?  LS1, LS2, etc???????         

[MyBigToy]

OK, I'm going to ask a dumb question here only because I know most of the folks and I don't give a rats  what anybody thinks!!     I've done my fair share of work on the older Chevy small blocks but nothing to speak of on the newer LS1 version.  What do I have in my 02?  LS1, LS2, etc???????         

It's an LM7.

[MyBigToy]

I'm off the get some sleep! Good night, John Boy! 

[Main One]

OK, I'm going to ask a dumb question here only because I know most of the folks and I don't give a rats  what anybody thinks!!     I've done my fair share of work on the older Chevy small blocks but nothing to speak of on the newer LS1 version.  What do I have in my 02?  LS1, LS2, etc???????         

Your 5.3L is based on the LS1 design.  The LS1 has about 25 more cubic inches and an aluminum block - just about all of the other differences are very minor.  The LS1, LS6, 4.8L and 5.3L without cylinder deactivation are considered the Chevy 3rd generation small block, or Gen III.  Parts are generally interchangeable in these engines, although of course there are cylinder diameter and stroke differences to accommodate the different displacements.  The LS6 was the souped up version with the hottest cam and some fairly exotic valves.

[Ski Edition]

Your 5.3L is based on the LS1 design.  The LS1 has about 25 more cubic inches and an aluminum block - just about all of the other differences are very minor.  The LS1, LS6, 4.8L and 5.3L without cylinder deactivation are considered the Chevy 3rd generation small block, or Gen III.  Parts are generally interchangeable in these engines, although of course there are cylinder diameter and stroke differences to accommodate the different displacements.  The LS6 was the souped up version with the hottest cam and some fairly exotic valves.

So what are your thoughts/concerns about putting a 2004 Z06 (LS6) cam in my AV?  Thanks! 

[Main One]

Your 5.3L is based on the LS1 design.  The LS1 has about 25 more cubic inches and an aluminum block - just about all of the other differences are very minor.  The LS1, LS6, 4.8L and 5.3L without cylinder deactivation are considered the Chevy 3rd generation small block, or Gen III.  Parts are generally interchangeable in these engines, although of course there are cylinder diameter and stroke differences to accommodate the different displacements.  The LS6 was the souped up version with the hottest cam and some fairly exotic valves.

So what are your thoughts/concerns about putting a 2004 Z06 (LS6) cam in my AV?  Thanks! 

I believe a Z06 cam with better pushrods and springs would perform very well, assuming you didn't push the rpms above what the stock lifters can take without starting to tick, which in my truck is about 6200 rpm.  It isn't as aggressive as some you have been looking at, and you probably don't HAVE to get a custom tune since it doesn't lope at idle.

You could do titanium retainers with it, but if you stay below 6200 rpm I don't think you'll need them.  I'm using the stock retainers with a cam that is supposed to float above 6600, shifting at 6100.

[Ski Edition]

I can't remember me driving my truck at over 4500 RPMs ever. Even towing!!

[Main One]

I can't remember me driving my truck at over 4500 RPMs ever. Even towing!!

OK.  I've got to ask the question, Why do you say you need more top end power, when you've never been there?

[MyBigToy]

OK.  I've got to ask the question, Why do you say you need more top end power, when you've never been there?

I was kinda thinking the same thing........IIRC, maximum throttle stock shift points are 5200 rpm.

[Ski Edition]

Good point!!  Maybe mid-range is what I'm referring to in your terms. 55-100+ is where I need help. Maybe I'm not utilizing what I have and not being hard enough on her!!??

[Main One]

Good point!!  Maybe mid-range is what I'm referring to in your terms. 55-100+ is where I need help. Maybe I'm not utilizing what I have and not being hard enough on her!!??

You may not be pushing her hard enough to stay in the engine's power range.

From the above post and others, it seems you are looking for more power around 55-70 mph?  Is this correct?

With your gears and tires, what rpms is your engine turning when you are on the throttle in this speed range and wanting more power?

[Ski Edition]

Correct and I'm in the 3200-3300 range and she is slow to pick up speed.

[Main One]

Correct and I'm in the 3200-3300 range and she is slow to pick up speed.

With your tires and gearing, do you know how many rpms you are turning at say 55 or 70 mph under light throttle, or conversely, how fast you are going at say 2000 rpm in 4th gear at light throttle?

[Ski Edition]

I know I run 72-73 @ 2500. When I kick it from there that is where I'm really disappointed.

[Main One]

I don't know, but suspect, that you aren't going to find a cam that gives you much more power over the stock one at 3300 rpm and below.

I'm thinking that your problem is gearing related.  If you're turning 2500 rpm in 4th with the converter locked up, the 4l60e gearing is so wide that unless you want to be turning around 6500 rpm, you are only going to get a downshift to 3rd.  With tuning, you could change your WOT shift points such that at say under 70 or so, you could hit 2nd, but by about 75 it would be shifting back into 3rd at 6000 or so rpm.

I'd say your best options, if this range is where you want more power, is to either go to say 3.73 gears, an overdrive unit that would give you basically an 8 speed transmission, or a looser torque converter such as MBT is running.

As a for instance, in my truck, I'm turning 2000 rpm at 70, so at 2500, I'd be turning running about 88 mph.  With my gearing and where I'm shifting into 3rd, I'm holding second gear until about 89 mph.  I've got decent power in the range from 60 to nearly 90, then drop off some when hitting 3rd gear.  I've got a bit of a low spot power wise, like you are describing, around 45-55, but it doesn't take as much power to accelerate through those lower speeds as it does around 60-70.

Gear Vendors overdrive units are very popular with RVs and trucks doing a lot of towing.  As I noted previously, they are not cheap and hard to find used for late model transmissions.  Additionally, you would have to add the cost of a shortened rear driveshaft and lengthened front driveshaft, since they sit at the output end of the transmission and would push the transfer case farther back.

One other option would be to install a 4L80e transmission.  These have much narrower gear ratio changes between gears.

Looking at the 4L60 and 4L80 gear ratios on the Gear Vendors web site, if you were turning 2500 rpm in 4th with the torque converter locked, and downshifted into 2nd, you'd be pushing 5900 rpm, with the 4L60e.  With a 4L80e and your current gearing/tires, at the speed you are now turning 2500 in 4th, you would now be turning 2680 in 4th, and if from there your 4L80 downshifted into 2nd, it would be turning under 5300 rpm.  This is without an external overdrive unit.

[Main One]

I'm thinking if you want to go with a cam, this one would be a better choice for your application/desires:

http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=1095&sb=2

[Ski Edition]

I think the root of my evil is the 4.56's.  I have the low end (with them), but I never got used to the higher RPMs at highway speeds.  I stopped by my tranny shop to get my reciept (warranty for rebuild) and my tranny man just happens to have some 4.10's out of a Yukon XL that I think will fit.  May do me a swap cheap and install if they fit.  He says they will.  If I change the gears, then I think that changes my cam direction.  We'll see. 

[Main One]

I think that will help a good deal.  May want to change your shift points with the superchips, but I'd think with the 4.10s you could be able to downshift into 2nd at 75 and hold it to at least 80.

[Ski Edition]

Sounds like you need to teach me how to drive too!!   

[MyBigToy]

I think that will help a good deal.  May want to change your shift points with the superchips, but I'd think with the 4.10s you could be able to downshift into 2nd at 75 and hold it to at least 80.

This sounds about right to me also. My tires are 32" and I turn about 2150 rpms at 70 mph; you'll turn slightly less than that with your 33s (that's what I remember you have). And don't forget to adjust your speedometer with a GPS unit.

4.10s are typically recommended for 33" tires. Maybe we got to the correct conclusion; try the 4.10s and then see how you like the towing. You might be less satisfied with the off-the-line speed after getting used to the 4.56s but there are other ways to address that if you decide you want to (converter; cam, not so much).

I still think a cam along the lines of what we originally recommended would be good but knowing you are reluctant to rev the engine up into its higher torque band makes them less attractive than the alternative that M1 posted. That one will gain hp/torque starting lower in the rpm range at the expense of the upper-rpm range that the original recommendations would give you. You would likely not have much luck finding that one used, though.

I think that's probably less of a concern than ultimately making the right choice, though. 

[Ski Edition]

Think I'm going to go the 2500 route.  Found an '05 low mileage one locally that I like.  It's black, but I can live with that.  Just have to reel in those folks that have offered to buy mine in the past.  Maybe by Bratfest!!??

[waz]

Think I'm going to go the 2500 route.  Found an '05 low mileage one locally that I like.  It's black, but I can live with that.  Just have to reel in those folks that have offered to buy mine in the past.  Maybe by Bratfest!!??

One of the most effective bolt on performance upgrades there is.
Unbolt the plate(s) and bolt it(them) onto a 2500 with an 8.1L. 

[Ski Edition]

One of the most effective bolt on performance upgrades there is.
Unbolt the plate(s) and bolt it(them) onto a 2500 with an 8.1L.

That's what I'm thinking too!!   

[Richie_Rich]

Think I'm going to go the 2500 route.  Found an '05 low mileage one locally that I like.  It's black, but I can live with that.  Just have to reel in those folks that have offered to buy mine in the past.  Maybe by Bratfest!!??

I'm happy with my 2500, but I bought it to pull our TT

[Ski Edition]

I'm happy with my 2500, but I bought it to pull our TT

That is one of the main reasons I was looking for a little more power.  I pull a TT also at around 5K loaded and we are wanting to take it out a more frequently. 

[Richie_Rich]

The 2500 is a towing machine.
It hardly breaks a sweat towing out 27'r
We have the 4.10 gears and extendable mirrors.
We did not want cloth seats, plus they only come heated with leather.
The extendable mirrors are great too.

[Ski Edition]

The 2500 is a towing machine.
It hardly breaks a sweat towing out 27'r
We have the 4.10 gears and extendable mirrors.
We did not want cloth seats, plus they only come heated with leather.
The extendable mirrors are great too.

Sweet set up Rich!  That's what I'm looking for!!  We have been looking at campers also and want to go a little bigger with a larger slide out.  Right now I'm limited with the 1500. 

[MyBigToy]

The 2500 is a towing machine.

If my tranny and rear end would hold up I bet mine tows better than a 2500.    You've only got 295 hp.  I guess I just need to bite the bullet and swap to a 4L80E and 14 bolt.  All it takes is lots of money.