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FINALLY Took the LH6 5.3L 6L80 TBRS to the track.

14K views 11 replies 5 participants last post by  ssilveronyxx 
#1 · (Edited)
No wonder no one likes to tune these....there are crazy amounts of torque management parameters in there. First time at the track since the install to tweak the basically factory ECM and TCM tunes.

First run was a "no time" error in the tower:

Second run: 15.503@90 MPH w/2.373 60ft...Launch at about 1800 RPMs, upshifting before 5000 RPM's

Third run: 15.376@92.14 MPH w/2.333 60ft...delayed and sputter in 3-4 upshift due, upshifting at 6050 RPM's

Fourth run: BEST RUN of day 15.218@93.09 MPH w/2.374 60ft..reduced TQ Management, 2000 RPM Launch, upshifting at 6200 RPM

Fifth run: 15.523@92.12MPH w/2.579 60ft...4WD launch and run (video 1)

Sixth run: 15.227@93.65MPH w/2.477 60ft...almost all torque management removed, massive one wheel spin out at line. (video 2)

Not what I expected/wanted, but not too bad for a 110,000 mile rental abuse motor, bone stock engine injector/air/spark parameters, factory exhaust w/resonator delete, full tank of gas, open 3.42 gears in differential and 20" wheels 275/45R20.

With tune, better 60ft, and exhaust...it's a low 14's truck.



 
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#6 ·
Maybe the 5.3s, the 6.0 has the throttle opening rate tables maxed out from GM. The TCM limits the power, but not nearly as much as you'd think, its mostly on the upshifts. But alas, a decent tune fixes that and more. :cool:

was this run with a tune? cause i ran my 2006 envoy denali with 5.3 and ran a 15.9 literally BONE stock with 20"s and 275's.
And a 6L80E trans... with some transmission tuning.
 
#8 ·
The TM varies from year to year on the SS's. I believe the '06's were the most liberal. Additionally, the 'learning' curve of the transmission plays a significant role in performance. After driving my SS like grandpa for a few months it ran like a dog when I finally tried to jump on it.

Picking on a 5.3L TB/Envoy is risky business as the 5.3L has a range of optional gears and the TM limits are probably rarely reached, so the computer has little reason to interfere. The SS's gearing and power have the computer's stock tune always interfering and therefore pulling back power. So when the 5.3l is still pulling, the SS is in and out of power.
 
#10 ·
Im just saying the throttle opening rates arent limited, there is still transmission TM active but the engine side seems to be wide open.

I can see a tuned 5.3 staying with a stock SS for a bit, the transmission can still be pulling spark on hard downshifts whereas I dont believe the 5.3s are setup that way. Plus the factory settings for TM ramp-out are slow, so timing is pulled then added back gradually. Tuning helps it not intrude as much plus ramp the timing back in faster.

I will say that I havent driven my SS with the stock tune in 15mo, maybe Ill flash it back and see how it feels. I know its gonna shift like crap, I hated the way it shifted when I bought it.
So you guys will have to help me out... All of my schooling on automotive electronic control was based on what was mostly out in 2001-2002 (when I was doing my specialization), so a "PCM"... On the seperately controlled ECM/TCM, what's the deal? It sounds like the TCM says "you're making too much power for this gear/range, stop that" and tells the ECM to pull timing (or I assume, partially close the throttle), even when there is no shifting happening (or rather, not because of a shift)?

Thanks,
Mike
 
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