Bad Acceleration...

[Dacomputernerd]

Hey, Today me and my dad were going to the dentist office and we were late... so my dad is driving rather aggressively. We are about to go onto the on-ramp, so my dad floors his foot. I hear the engine roar and glance at the tach racing past 5500rpm and the truck wasnt accelerateing very fast! :confused: My dad has a habit of keeping the TrailBlazer in 3 for city driving (thats what he did in the 2001 Impala), but today it was in D.

Is it just the nature of the truck? With the V8 I would think we would have better acceleration! If he keeps it in 3 for aggressive driving, would it accelerate better?

[deathbynosleep]

was it up hill by any chance?

[02EnvoySLE Guy]

you MIGHT get better acceleration in 3, it does take the transmission some time to "spool up" if you jab the throttle thanks to that wonderful thing called "Torque Management."Also, remember this: ITS A DAGGONE HEAVY TRUCK!! It isn't going to accelerate or handle like a camaro no matter what you do to it. :raspberry

[MoJoe]

Well if it revved and did not go it may of been TQ conv slip. Maybe the computer had a hickup. Did it feel like a slip, if so I would let a tech check it out.

[Dacomputernerd]

when he first floored it, i thought it was slipping, but then i could feel the accel. So its just sluggish because it weighs almost 5000lbs?

Ouch, i wonder how it would be with a I6 :duh:

[MoJoe]

when he first floored it, i thought it was slipping, but then i could feel the accel. So its just sluggish because it weighs almost 5000lbs?

Ouch, i wonder how it would be with a I6 :duh:

Then Charlie sounds correct with TQ management.

[Dacomputernerd]

Then Charlie sounds correct with TQ management.

K thanks everyone

[triz]

It also accelarates quite differently in cooler and hotter temps. :m2:

[Jman423]

I've been shocked as hell lately at how good my acceleration is, I have to do the whole launch sequence thing to get out of the complex that I work in, which is located in the middle of the Turnpike, so when you merge into traffic, you are merging into the fast lane, and the speed limit is 70MPH, so traffic is generally at 80MPH. As soon as I hit the straight part of the ramp, I nail it, and by the time I get onto the road, I could be doing 90MPH. I refuse to pull onto any highway going slow, thats an insurance claim waiting to be filed!!

The only things that I have done to the truck that could remotely affect take off is synthetic oil and a K&N air filter. I have 3.42's by the way.

[sallen]

i have driven both, and the I 6 has way better acceleration imo, i have only floored mine a few times and when i do it pulls me way back into my seat,

shay

[Dacomputernerd]

@shay- Both I6 and V8 in the EXT?

[sallen]

yes, when i test drove when i was buying mine i drove the ext in both options, something about the inline just produces smoother power imo

shay

[02EnvoySLE Guy]

yes, when i test drove when i was buying mine i drove the ext in both options, something about the inline just produces smoother power imo

shay

I would agree that it's "smoother" but I disagree that its as fast. Unless you're used to the feel of a V8 and automatic transmission paired together, the torque followed by the "jerking" may be deceiving. :m2:

[Dacomputernerd]

Do you think if you tryed accelerating in 4WD HIGH it would accelerate faster?? or would it be slower since your moving more of the drivetrain?

[Ricciard]

I have recently purchased a 05 TB EXT with the 5.3L (and I am also a new member!) and compared to the I6 I test drove, the V8 has much better acceleration and passing capabilities. Plus, you can't beat the sound of a small block at wide open throttle :D .

[Dacomputernerd]

I have recently purchased a 05 TB EXT with the 5.3L (and I am also a new member!) and compared to the I6 I test drove, the V8 has much better acceleration and passing capabilities. Plus, you can't beat the sound of a small block at wide open throttle :D .

Welcome :D Is your TB an LS or a LT?
Yep, cant beat that small block sound :D

[ylab]

It might be possible that the I6 felt quicker than the V8 on his test drive. If the V8 had 3.42 gears and the I6 the 4.10 (not available with V8 btw), the I6 might have been on par with the V8 but smoother.....especially if he was comparing throttle response when the truck was already moving. (The I6 loves to rev)

The other possibility is that the truck with the I6 had been driven enough that the PCM had adjusted to the drivetrain, while the V8 may have still been a virgin and the pcm hadn't fully adjusted.

Just some food for thought.

[MoJoe]

Do you think if you tryed accelerating in 4WD HIGH it would accelerate faster?? or would it be slower since your moving more of the drivetrain?

That is how I had to launch my last Silverado with the turbo. It would not hook up in 2wd. My with the 4wd systems most GM have, they have all the parts spinning, just the front unlucked in 2wd. It should run the same, if not better due to no spinning :m2:

[Dacomputernerd]

That is how I had to launch my last Silverado with the turbo. It would not hook up in 2wd. My with the 4wd systems most GM have, they have all the parts spinning, just the front unlucked in 2wd. It should run the same, if not better due to no spinning :m2:

Ok, but no matter what my dad trys he said he cant squeel the wheels. I said, lemme drive and you watch the strips of rubber on the ground, cant squeel the wheels HA :D :D :D

[02EnvoySLE Guy]

Ok, but no matter what my dad trys he said he cant squeel the wheels. I said, lemme drive and you watch the strips of rubber on the ground, cant squeel the wheels HA :D :D :D

Yeah, good luck with that. If you drive it, I think you'll learn really quickly what we all complain about; GM programmed the truck to prevent wheelspin. The only time my truck doesn't "instantly" lock-up is on sand or gravel. Torque Management destroys my fun the rest of the time. :(

[MoJoe]

Yeah, good luck with that. If you drive it, I think you'll learn really quickly what we all complain about; GM programmed the truck to prevent wheelspin. The only time my truck doesn't "instantly" lock-up is on sand or gravel. Torque Management destroys my fun the rest of the time. :(


:rotfl: To me TQ management is like hearing you have the flu, it is one of those sucky things I have learned to hate :mad:

[Jman423]

I have recently purchased a 05 TB EXT with the 5.3L (and I am also a new member!) and compared to the I6 I test drove, the V8 has much better acceleration and passing capabilities. Plus, you can't beat the sound of a small block at wide open throttle :D .
Congrats on your truck, and welcome to the site!!

:rotfl: To me TQ management is like hearing you have the flu, it is one of those sucky things I have learned to hate :mad:
Agreed!

[Dacomputernerd]

Isn't there some sort of work around or chip to disable torque management?

[Dacomputernerd]

I found THIS (http://www.kennebell.net/accessories/PiggybackReplacement/Piggyback.htm) site, would this work for the 5.3 V8s?

[Jman423]

Isn't there some sort of work around or chip to disable torque management?
There are a few chips available, but the one that everyone wants to get their hands on is the Wester's Custom Tune.

Check this thread out:

http://forums.trailvoy.com/showthread.php?t=792&page=2&pp=40

[Dacomputernerd]

Will Westers get rid of torque management?

[Dacomputernerd]

Just an idea...
Heres a quote from diabloSport.com

"
1) Torque Management
PLEASE NOTE: Disabling torque management will put greater stress on your drive line.

TM Abuse Mode time limit= This is the time in abuse mode as a function of temperature. Turning it off in conjunction with Upshift Torque reduction and %Torque Reduction vs RPM will eliminate torque management. However we have noticed that the shift feel when disabling the upshift torque reduction in trucks and SUV's is reduced and therefore recommend leaving it ON for trucks and SUV's.


%Torque Reduction vs RPM= Torque reduction as a function of RPM, turning it off in conjunction with TM abuse mode time limit and upshift torque reduction will eliminate torque management. However we have noticed that the shift feel when disabling the upshift torque reduction in trucks and SUV's is reduced and therefore recommend leaving it ON for trucks and SUV's.


Upshift Torque reduction= Torque reduction control for each individual gear, turning it off in conjunction with TM abuse mode time limit and %Torque Reduction vs RPM will eliminate torque management. However we have noticed that the shift feel when disabling the upshift torque reduction in trucks and SUV's is reduced and therefore recommend leaving it ON for trucks and SUV's. "

[Jman423]

Will Westers get rid of torque management?
Thats the claim, but I don't have one yet, so I can't say.

Check it out, go to the GM Trucks section near the bottom of the page.

http://westers_garage.eidnet.org/scprice.htm

[Dacomputernerd]

I checked Westers site and they dont have a tune for the V8 :confused:

[Envoy Fan]

I checked Westers site and they dont have a tune for the V8 :confused:

Yes they do, unless its DOD, and I'm not sure about DOD availability. (Do you have DOD? Look in glovebox lid at RPO code label, if the codes DOD are in there you have DOD.)

[MoJoe]

Yes, you rarely want TQ disabled completely, on a stock tranny dropping it about 60% or so would be fine, on a built tranny, you could take around 80% out of even completely delete it, you just better have a well built trans. Wester's or Nelson's can explain it to you far better than I can. :)

[Dacomputernerd]

Yes, you rarely want TQ disabled completely, on a stock tranny dropping it about 60% or so would be fine, on a built tranny, you could take around 80% out of even completely delete it, you just better have a well built trans. Wester's or Nelson's can explain it to you far better than I can. :)

OIC thanks :D

Yes, i have DOD :D good for gas, bad for tuning?

[02EnvoySLE Guy]

Yes, you rarely want TQ disabled completely, on a stock tranny dropping it about 60% or so would be fine, on a built tranny, you could take around 80% out of even completely delete it, you just better have a well built trans. Wester's or Nelson's can explain it to you far better than I can. :)

:yes:

[Dave]

Yes they do, unless its DOD, and I'm not sure about DOD availability. (Do you have DOD? Look in glovebox lid at RPO code label, if the codes DOD are in there you have DOD.)

I think DOD also started as a standard feature on the 2005 V-8 models.

[Dacomputernerd]

Ya, i guess i'll have to live with torque management caz theres no way my dads gonna let me reflash the computer

[Dacomputernerd]

What about the "B&M Racing ShiftPlus" i found it on the 21st page of this (http://forums.trailvoy.com/showthread.php?t=1110) catalog that Tommy scanned.

[Dacomputernerd]

Hey, yesterday my family and I went on an all day road trip, to check out a motorcycle my dad wanted to buy and i observed a few things about the TrailBlazer.

1. At higher speeds, torque management seams very minimal

Example. We were on our way home and it looked like it was going to rain, and i remembered i had left a couple of windows open on our trailer :duh: We didnt want the trailer to get wet inside because its all pressboard and we'd have a big mess. We were going 110KPH (68MPH) on a flat county road (2 lanes) and we were aproching some slow moving cars, so my dad looks over into the other lane, and floors it! Wow, we passed 3 cars in like 4 seconds, and when we merged back into our lane we were going 145KPH (90MPH). Of corse going this fast, we ran into another set of cars very shortly after, but at that time we were going about 140KPH (87MPH) because my dad let off the gas. So he floors it again and we pass another 3 cars and we merge back into our lane and are going a little over 160KPH (100MPH), and then the engine felt like it stopped trying (i guess a speed limiter). And my mom and sister were like holding on to those roof handles and me and my dad were just laughing :D Man that was fun!!

So my conclusion is that when accelerating while already going fast in a TB EXT V8 is almost like driving a muscle car. (my best buddy's dad has a Chevelle 454-But that thing has no torque management:D (it burns rubber from a standstill takeoff)

2. Even with the roof rack cross bars, it is loud in the third row of seats at speeds over 110KPH(68MPH)--I sat in the third row for most of the trip up there. :yes: I bungie'd the second row seat up to the front row (cord through 2nd row LATCH system, and hooked onto front passenger side headrest bars.) so i could sit with my feat kicked out :D

[Windy City]

As someone who spent a LOT of time tuning my LS1 in my Camaro with both LS1 Edit and HP Tuners, TQ Management does not affect acceleration other than the shifts.

Microseconds before the shift it reduces timing and stops reducing timing just after the shift. It becomes more severe after a high-stall converter is installed and the best way to describe it is it feels like the car just falls on it's face during the shift but kicks right back in after the shift.

The 5.3 really needs a converter if you want it to perform well. I know first hand how weak the LS-based motors can feel without a good stall. An associate of mine had a '00 Camaro Z28 that wouldn't hardly spin the wheels and my '02 didn't do so well either. Both cars, when equiped with 3200+ stalls would smoke them on command. The LS-based motors like to rev to make power and typicaly don't make any serious power until 3,200 - 3,400 RPM. The stock stall is in the range of 1800, when the motor isn't making much power. It does give it a "smooth" feel but you loose a lot of performance (not unusual for f-bodies to loose a half second in the quarter with just a good converter).

HP Tuners is working on support for the 5.3 in the TB/Envoy and they have my VIN for research. As soon as I know anything I'll pass it on.

[Dacomputernerd]

Great thanks :D please keep us posted :D

[Envoy Fan]

I think DOD also started as a standard feature on the 2005 V-8 models.

Except not in SWB Envoy Denalis. No DOD for them.

[Envoy Fan]

HP Tuners is working on support for the 5.3 in the TB/Envoy and they have my VIN for research. As soon as I know anything I'll pass it on.

Please do keep us posted on the progress of HP Tuners :yes:
What is a contact for HP Tuners? Website or phone #?

[Windy City]

HP Tuners (http://www.hptuners.com/)

They're getting ready to release 2.0 which will include LS2 support. Once they get the new release out of the way I would hope they get a chance to start working on the I6 code and I can't imagine it would take much to support the 5.3 since they already support it in the larger SUVs and trucks.

[Dacomputernerd]

ya hopefully we'll see a unit for the TB/Voy

[spearenvoy]

For all of you that want to know what Wester's tune will do for torque management this was Brian's answer to my question. I do believe that the I6 torque management settings is what makes the truck feel sluggish from start. Well, I will let you judge on your own. They also claim a 4-5MGP increase. Sounds good to me......Homer
----------------------------------------------------------------
Brian..... Will your custom tune modify the annoying retarded timing that the stock programing has off the line?

Absolutely...that's one-half of torque management, and it's the half that isn't needed. GM refers to it in some vehicles as "traction control," or at least they used to a few years back. The other half is tranny TM. On the '99-'05 Vortec trucks with the 4L60/65/80 trannies, we usually remove 100% of the engine TM and about 75% of the tranny TM. We've never had complaint one about premature failure of the tranny due to reduced TM. It's our belief that GM overengineered the TM to extend what really amount to 10-15 year old tranny technology. Couple that with the high output engines, and you're just asking for a tranny failure!

The continued support of the folks on this forum have really helped to get this ball moving. I drive a 5.3L (two of them, actually), but I've heard a lot of good things about the 4.2L engine. It's about time you all got a tune.

--Brian

[envoy62]

Hey,

These engines are run also by a electronic throttle at least the I6 but i guess that the V8 uses the samer system. What that means is that if you step on the accelerator and floor it, the actual throttle is not going to wide open instantly as on teh old systems with a bowden cable. But the PCM is opening up the throttle at a speed that optimizes fuel consumption and eventually also reduce the torque peak ythe transmission sees.

This might explain also if sometimes the acceleration feels sluggish at take off.

Regards

[Dacomputernerd]

Wow! so even the throttle is computer controlled?? Man that sucks. Ya i thought that it couldnt all be Tranny TM. I defenately need to get a Wester's Tune, caz off the line it feels like a civic

[Windy City]

Interesting. Luckily on the f-body we didn't have to deal with any engine TQM and only transmission TQM. Sounds a lot like the damn TQM Ford uses with the new Mustangs.

My HPT scanner should work with my Envoy but I haven't tried it yet but I think I need to. Not that I doubt Brian's comments but I want to see first-hand how much timing is being pulled on acceleration and how well the electonic throttle control follows actual pedal input.

[Dacomputernerd]

@Windy- Good idea:D please keep us up-to-date :yes:

[Banzai]

Yep...just picked up the new ride ..she's a dog off the line, very limp till the revs kick in, but not bad by any respect.

Throttle response is lack luster....chips please!!!
EXt i6, loaded..



Wow! so even the throttle is computer controlled?? Man that sucks. Ya i thought that it couldnt all be Tranny TM. I defenately need to get a Wester's Tune, caz off the line it feels like a civic

[sallen]

i just figured its a suv, its kinda big, its going to be a little dog off the line, i am happy with mine as stock, ;) but i am not a picky person tho,

shay

[jnicklo]

The way I look at is, if you want off the line power, buy a GTO or Mustang.

Granted the I6 produces a very good amount of power, the TB/Envoy wasn't made for get up and go. The power can be utilized in the form of towing or hauling.

[Dacomputernerd]

Well my parents TB is a V8, and i would have expected it to at least squeel the wheels off the line, but as others have said, its Torque Management that holds it back.

[jnicklo]

People seem to always assume that "V8" means its going to be powerful. I think in this case the I6 is not much worse off then the V8 in the TB/Envoy...

Like I said, you want speed get a GTO or a Stang. :m2: :D

[carbonvoy]

People seem to always assume that "V8" means its going to be powerful. I think in this case the I6 is not much worse off then the V8 in the TB/Envoy...

Like I said, you want speed get a GTO or a Stang. :m2: :D


The I6 is a great motor and not "much worse off than the V8." However, acceleration (at the low end) is more about tourque than it is about horsepower and the V8 has 20% more torque than the I6. More is more. :)

Your point about if you want more speed, get a Goat or Stang is well taken, but a little tough when you have to routinely haul the wife, kids, and all their stuff. The next best thing is to get all you can out of the vehicle your forced to drive. Besides, when I really want more speed, I take the Ducati. :D

[Windy City]

Like I said, you want speed get a GTO or a Stang.

Yeah, and be just another fast GTO or Stang. :rolleyes: I'm not trying to flame you but that's the fun of hot rodding. :D

I tried to connect my HPT but because my Envoy is an '05 I can't. It uses a new ECM similar to the LS2 and HPT requires a new cable to communicate with it. The new cables "should" be released soon and I'll be one of the first in line to buy one.

[Dacomputernerd]

Im gonna update this thread here and say that after about 15k Miles, the engine has REALLY broken in. Along with switching to synthetic oil, and running 87 Shell gas, the acceleration in this thing has really suprised the heck out of me! :yes: And thanks to tips from the SS guys, it is now easy to powerbreak launch and do more then chirp the tires! (although we dont do this too often, because we dont wanna mess up the tranny)

[Envoy Fan]

Im gonna update this thread here and say that after about 15k Miles, the engine has REALLY broken in. Along with switching to synthetic oil, and running 87 Shell gas, the acceleration in this thing has really suprised the heck out of me! :yes: And thanks to tips from the SS guys, it is now easy to powerbreak launch and do more then chirp the tires! (although we dont do this too often, because we dont wanna mess up the tranny)

Get a Vector tune and you will really appreciate that V8 :yes:

[Dacomputernerd]

Get a Vector tune and you will really appreciate that V8 :yes:

If we buy out the truck, that is on the mods list! I dont think vector has a transfer policy like westers, so if we return the truck, we wont get a discount on a new tune. :no:

[Envoy Fan]

If we buy out the truck, that is on the mods list! I dont think vector has a transfer policy like westers, so if we return the truck, we wont get a discount on a new tune. :no:

Send them an email and ask them :yes:

[runzwitsisors]

Its all about horse power to weight.. The V8 only runs 1/10 of a second 1/4 and 0-60 faster than the i6. The v8 puts out 300 hp but weights about 200lbs more. The i6 is 290 hp but is 200 lbs less. The i6 should be faster but it lacks bottum end grunt of the push rod V8. But its high rpm HP helps it catch up. From a dig the v8 would be faster but from 30mph to 100 my money would be on the i6!


Anyone live near Saginaw MI with a non SS V8 trailBlazer with no or minor mods wanna race me in my i6? I'll give you 10.00$ for gas to meet with me.

:undecided I think I'll win :D I'm in ATL GA till the 19th of june but will be back in MI after that.

[Dacomputernerd]

Its all about horse power to weight.. The V8 only runs 1/10 of a second 1/4 and 0-60 faster than the i6. The v8 puts out 300 hp but weights about 200lbs more. The i6 is 290 hp but is 200 lbs less. The i6 should be faster but it lacks bottum end grunt of the push rod V8. But its high rpm HP helps it catch up. From a dig the v8 would be faster but from 30mph to 100 my money would be on the i6!


Anyone live near Saginaw MI with a non SS V8 trailBlazer with no or minor mods wanna race me in my i6? I'll give you 10.00$ for gas to meet with me.

:undecided I think I'll win :D I'm in ATL GA till the 19th of june but will be back in MI after that.

Lol, the 5.3L V8 is pushing 330+ Ft.Lbs stock. What is the I6 rated for?

[ScarabEpic22]

Lol, the 5.3L V8 is pushing 330+ Ft.Lbs stock. What is the I6 rated for?
Yea, but you have an EXT (600lbs more) and a heavier engine. I bet a SWB I6 would walk you man, sorry.

What I really want to see is a SW V8 take on a SWB I6 (both completely stock, down to the air filter and bother running either syn oil or non-syn). That matchup would actually be pretty close I think, but the engines must be broken in (at least 10-15K on the ODO). I dunno, the I6 doesnt have as much down low, but it has one of the flatest TQ curves Ive ever seen and continues to make power to 5800rpms, which I know the V8 doesnt. I think if GM had 6spd tranny, the V8 would have more of an advantage because it has more midrange and the 6spd would definately keep it in the power band all the time.



I6 is 275ft lbs and then 277ft lbs depending on year.

I still dunno, I love the I6 for the power it puts out, but in a apples to apples bone stock race, I dunno. A V8 in an EXT vs. I6 in SWB, the SWB would walk it.

[ieatglue]

Kelvyn, if you're ever in Toronto, Pm me before you go and we could try racing, you can try convincing your dad into racing us :D

[Dacomputernerd]

I was talking EXT vs EXT ;)


Your on glueboy :D

[ScarabEpic22]

I was talking EXT vs EXT ;)


Your on glueboy :D
That works too, I just want to see EXT 5.3L V8 vs. EXT 4.2L I6 or SWB V8 vs. SWB I6 to make sure the extra weight isnt an advantage for the shorter wheelbase TV.