Topic: Upping the line pressure?

[bluedevil]

Upping the line pressure?   When is this done?  How is this done?

Last year i replaced the Torque Converter for the TrailBlazer one.  Did i had to do this then?


Reason i ask is,  every since i did this along with the Shift-Kit, it seems that the AV hesitates to switch to 2nd gear. At launch,1st gear obviously is fine,...is the transition to 2nd gear that bothers me.  It seems that im missing about a second or less in changing gears time.

Am i making any sense?   lol

[oHIobellboy]

You can adjust that with the predator BD, I've tightened up my shifts a little.

[bluedevil]

You can adjust that with the predator BD, I've tightened up my shifts a little.

Yeah...i seen it but havent bothered it yet.  I did long time ago when i had Hypertech.  I guess i should try again.

but my question is,.....the new torque converter & shift-kit the reason of this?

[oHIobellboy]

stupid question but someone has to ask it. Did it just start doing it after you got your SC back or has it been doing it since the TC change?

[bluedevil]

stupid question but someone has to ask it. Did it just start doing it after you got your SC back or has it been doing it since the TC change?

since the TC change over a year ago.

[oHIobellboy]

I'd try  the pred and see what you come up with. simple instructions are in that book that came with it or online at the pred site.

[MyBigToy]

You can do it with the Predator but I don't think it's the line pressures that's the issue. It's more likely that adjusting the shift time will help. Between the shift kit and the servo your line pressure and holding power is already higher than stock.

I'd suggest, if Main One comes, that you see if you can rope him into using your HPTuner to adjust the shift. There's a lot more flexibility in the programming there than in the Diablo and you should be able to take care of the issue.

FWIW, my 1-2 shift has been lazy ever since I installed the Magnacharger. I've adjusted the line pressure up a very little bit and the shift times down almost all I can. It's helped a lot on everything except a WOT shift and it's still lazy then.

[bluedevil]

You can do it with the Predator but I don't think it's the line pressures that's the issue. It's more likely that adjusting the shift time will help. Between the shift kit and the servo your line pressure and holding power is already higher than stock.

I'd suggest, if Main One comes, that you see if you can rope him into using your HPTuner to adjust the shift. There's a lot more flexibility in the programming there than in the Diablo and you should be able to take care of the issue.

FWIW, my 1-2 shift has been lazy ever since I installed the Magnacharger. I've adjusted the line pressure up a very little bit and the shift times down almost all I can. It's helped a lot on everything except a WOT shift and it's still lazy then.

Thats how mine is.  Lazy between 1-2 at WOT.

[KY_BOB]

IMO, MBT is on the right track as to shortening the desired shift time.  Also, has the TM been removed?  It will make a truck stumble a little during and just after the shift due to the timing being pulled out.

[bluedevil]

IMO, MBT is on the right track as to shortening the desired shift time.  Also, has the TM been removed?  It will make a truck stumble a little during and just after the shift due to the timing being pulled out.

TM is removed 100%

[KY_BOB]

TM is removed 100%

Do you have the original servo in it or a Vette servo?  That will firm the 1-2 shift a little.

[Main One]

Blue, if you could, I think it would be helpful to do a scan while driving such that you experience the issue you want to address, and log as a minimum the following parameters:

RPM
Throttle Position
Vehicle Speed
Time of latest shift
Trans fluid temp
Trans current gear
Force Motor Line Pressure
Force Motor Actual Current

Dynamic Airflow, Calculated Load, and Delivered Trans Torque may also be interesting to look at.

After doing the scan, you can email it to me, along with your current tune.  Bob may be willing to take a look at it too.  I'll give you my email address if you don't already have it - give me a PM.

My scans are often around 30 minutes.  If you send a long one, it would be good to have an idea where in time you might have experienced an unsatisfactory shift.

[bluedevil]

Do you have the original servo in it or a Vette servo?  That will firm the 1-2 shift a little.

I have the vette servo from that group buy couple yrs ago.

Blue, if you could, I think it would be helpful to do a scan while driving such that you experience the issue you want to address, and log as a minimum the following parameters:

RPM
Throttle Position
Vehicle Speed
Time of latest shift
Trans fluid temp
Trans current gear
Force Motor Line Pressure
Force Motor Actual Current

Dynamic Airflow, Calculated Load, and Delivered Trans Torque may also be interesting to look at.

After doing the scan, you can email it to me, along with your current tune.  Bob may be willing to take a look at it too.  I'll give you my email address if you don't already have it - give me a PM.

My scans are often around 30 minutes.  If you send a long one, it would be good to have an idea where in time you might have experienced an unsatisfactory shift.

Sure thing.  Im loading a new version of hptuners on my new puter tonight.

[Main One]

Sure thing.  Im loading a new version of hptuners on my new puter tonight.

You're as bad as Bob.  Now I'm going to have to load a new version too.   

[KY_BOB]

You're as bad as Bob.  Now I'm going to have to load a new version too.