Topic: Detroit TruTrack Differential

[Main One]

Knock on wood, my rebuilt transmission has lasted longer than my first rebuild, thanks at least in part to not programming it via the Powertrain Control Module to shift faster than stock.

I decided to compare how this tranny, with the 3200 stall converter, and now with the supercharger, performed compared to last time, which didn't have the supercharger but did have the same converter.

Looking back at my posts and truck computer data in the fall of 2010, I saw that I was regularly getting tire spin off the line, as well as some spin when hitting second, due to the PCM's faster shifting programming as well as the hardware improvements made during the rebuild, which were included in this rebuild.  This was a bit surprising, as I'm not getting the tires to spin off the line now.  Of course the temps were much cooler in October/November of 2010 than they've been the last month or so this summer by far, but I'm now sporting a supercharger, and even with the low boost I'm currently running, I thought I should be getting results at least as good as before!

I considered tires.  I've now got Bridgestone Dueler H/P Sport summer tires in the back, before BF Goodrich g-force TA KDW summer tires, which I would guess to be at least as sticky as the Bridgestones.

I then considered the effect of having put in the Detroit Tru Track differential this spring, a top of the line locking differential, as compared to the locking G80 Eaton diff that my Z66 came with from the factory.

I decided to put my GTech meter to the task of comparing the truck's current performance with runs I had made shortly after installing the first rebuild and high-stall converter.

I've attached to screen shots from the GTech software.  Black line is a run last month, ambient temps in the 70s.  The other runs are from October of 2010, temps in the high 50s.

You can see where in the pre Tru Track runs where the off the line g-forces would peak at around 0.55 gs, then after a dip come back up close to that again.  This shows the rear breaking loose at 0.55 gs.  The black line is showing peak acceleration of over 0.7 gs, with no dipping.  Even though I was breaking the rear loose before, it seems as if it is holding a higher g-level than what I was able to acheive before.  I may be wrong, but I attribute this to the Tru Track.

Also looking at the first screen shot, you can see a bigger "bump" when hitting second gear in the 2010 runs.  The peak gs there aren't as high, but that is probably due to getting a bit of wheelspin there.  Looking at the second screen shot, which shows speed versus time, it appears as if I may have been getting a bit more boost from the faster shifting with the wheel spin compared to what I'm seeing now, but hopefully between not hitting hard enough to spin the tires there, as well as having put into this tranny an output shaft that is supposedly 57% stronger than stock, I'll not grenade this one any time soon.

As far as jumping off the line, I'm quite pleased with the Tru Track.  I'm wondering if I'll be pleased with how well it pushes my 2-wheel drive Z66 through snow and ice come winter.

Stay tuned.

[Main One]

I was also going to mention that from the acceleration plot (first pic) I am disappointed with how close the new run is to the old runs after hitting 2nd gear.  I'm attributing that to needing to get an intercooler on this thing.  I think the intake temps, which get about 70 degrees above ambient when the supercharger is pushing hard, got up high after the shift and really cut down the amount of power the supercharger was able to provide.

[MonstaMonsta]

Awesome read Main One Just awesome