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2007 chevy
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207 Posts
Discussion Starter #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: [email protected] MPH w/2.373 60ft...Launch at about 1800 RPMs, upshifting before 5000 RPM's

Third run: [email protected] MPH w/2.333 60ft...delayed and sputter in 3-4 upshift due, upshifting at 6050 RPM's

Fourth run: BEST RUN of day [email protected] MPH w/2.374 60ft..reduced TQ Management, 2000 RPM Launch, upshifting at 6200 RPM

Fifth run: [email protected] w/2.579 60ft...4WD launch and run (video 1)

Sixth run: [email protected] 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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Basic Vendor- Skid Plates
2007 chevy trailblazer_ls
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3,700 Posts
Cool!

Yeah, I gather the 5.3 and 6.0 only go like 3/4 throttle in first gear with all the torque management...

Mike
 

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2007 chevy
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Discussion Starter #4
Yeah that throttle thing made me waste too many runs..the tune was set to trigger WOT setting at 97% TPS...which of course our TB's never achieve.

You'd be amazed how much resistance them big ol' dumbo ears offer.:raspberry lol
 

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2006 gmc envoy_denali
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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.
 

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Cool!

Yeah, I gather the 5.3 and 6.0 only go like 3/4 throttle in first gear with all the torque management...

Mike
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.
 

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2007 chevy trailblazer_ls
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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:
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I'm sure you've looked at it, being that you've got the tuning software and an SS, but wow... I trounced on an SS at low speed a few times, and was unimpressed; and I watched Big Ed (5.3L Extended with a CAI, tune, and cat-back, with big, heavy wheels) stay next to a couple of stock SSs until maybe 1/2 way through 2nd, last year...

I had thought I was unimpressed with them because of the huge amount of TQ management I had heard they had in 1st and 2nd, but if they don't have any (while in gear, not during the shifts)... well...

Mike
 

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Discussion Starter #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.
 

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I'm sure you've looked at it, being that you've got the tuning software and an SS, but wow... I trounced on an SS at low speed a few times, and was unimpressed; and I watched Big Ed (5.3L Extended with a CAI, tune, and cat-back, with big, heavy wheels) stay next to a couple of stock SSs until maybe 1/2 way through 2nd, last year...

I had thought I was unimpressed with them because of the huge amount of TQ management I had heard they had in 1st and 2nd, but if they don't have any (while in gear, not during the shifts)... well...

Mike
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.
 

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2007 chevy trailblazer_ls
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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.
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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Northwest Chapter
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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
It is my understanding GM went from a combined PCM (engine + trans) to a seperate ECM and TCM in order to use them on more vehicles.

They communicate a lot with each other, you cant flash whatever TCM tune in and have it work, some do but most do weird things like take away the shift indicator and report you're going 255mph at a stop.

Yes, the TCM and ECM both have limits in them that can reduce power if they determine too much is being made. These tables are commonly maxed out when installing a built engine and/or super/turbocharger otherwise you'll be in 2nd gear at 80% throttle and the ECM will be closing the throttle and possibly pulling spark. It even can happen on stock cars sometimes, Ive had my 02 pull timing and close the throttle with the stock tune in it when I was beating on it.

Im not explaining this very well I know, hope you can understand my rambling. :duh:
 
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