Drive by wire poor throttle response

Tech discussions on the L77 6.0L V8.
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9C1fanatic
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Drive by wire poor throttle response

Post by 9C1fanatic »

Ill try to keep this as short as I can.

Over the last few years, my department switched from Ford to Chevrolet for our fleet. We got Tahoes first for a few years to give the Caprice a few years to be out and see what service issues they have. Well I must say as much of a GM enthusiast I am, I was really disappointed with the performance of the Tahoe PPV. These were also the first GM vehicles I had ever driven with the 6L80E trans and I expected them to feel much quicker than the older models. My dads 07 Suburban with the 4L65 feels better in the low end. Both vehicles are drive by wire and I assume that had something to do with it. As I have driven more late model GM vehicles with the 6 speed trans I have noticed they all have the problem one way or another. Even the Caprice.

Now the Caprice does not feel quite so sluggish due to its less weight and more powerful engine as compared to the Tahoe but you can tell it has some severe torque management going on as my 2014 wont even spin tires a little bit when taking off full throttle from a stop with the Stabil trak, traction control turned off, on dry pavement. It has to be in the programming. It seems the 2011 Caprices I drove during the Chevrolet ride and drives felt more responsive than the 2014s we have now.

I don't have a lot of experience with the drive by wire stuff but my 06 Pontiac GTO with the 4L65 E trans has it and that car has almost instant throttle response and will smoke the tires at will. It seems like the first drive by wire vehicles had better response but the newer vehicles with the 100000 mile powertrain warranties and the 6L80E trans with the steeper first gear have a ridiculous amount of delay.

Upon doing a little bit of research I found on one GM truck forum that this is a point of major disappointment for GM truck owners that have upgraded from an older truck. They talked about fixing it with HP tuners in regards to throttle settings such as "tip in" (in regards to how much the throttle moves in relation to what your foot is doing on the gas pedal) and "max rotation" settings which from the way they were talking made it sound like in most of these GM vehicles with the 6L80E trans, the throttle does not even open up 100 percent in first and maybe even second gears with the factory settings even if you have it floored.

My question is for any of you guys that have had your cars tuned (stock or not) have you messed with this? Does anyone know what the factory max rotation and tip in settings are on the Caprice with the L77? I know there is more in this car even without installing a single bolt on. I expect this car to be more responsive with the 4.0something first gear ratio and larger engine than my old LT1 Caprice but for now the old Caprice is way more responsive in the low end.

Maybe it affects gas mileage a little but I bet the main reason for this poor programming is additional insurance to GM that more vehicles across the board make it to 100,000 miles without a major component failure and also to keep the traction control from kicking in more often which could be a complaint from average drivers who mistake the TC for some type of engine hesitation.

Thanks.
Garner Ames



1975 Pontiac Grand Am L77 - 14.82 @ 92.89
1991 Chevrolet C1500 L31 Vortec/5 Speed
2002 Chevrolet Suburban 1500 LM7
2014 Chevrolet Caprice 9C1 L77 - 13.60 @ 105.87
2019 Chevrolet Express 3500 L96
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GTObert
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Re: Drive by wire poor throttle response

Post by GTObert »

After removing torque management this becomes a non-issue. My Caprice is at least as responsive as my GTO at this point.
2011 9C1
2005 GTO
9C1fanatic
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Re: Drive by wire poor throttle response

Post by 9C1fanatic »

That's good to know. I guess the extra grandma programming is due to increased gear ratio in the caprice first gear and party due to the fact they know the cars are destined to have a hard life in fleet usage. I'm not sure about the diff, which looks a lot different in the GTO than the Caprice but the Caprice suspension and rear axle shafts look a lot beefier than the GTO.
Garner Ames



1975 Pontiac Grand Am L77 - 14.82 @ 92.89
1991 Chevrolet C1500 L31 Vortec/5 Speed
2002 Chevrolet Suburban 1500 LM7
2014 Chevrolet Caprice 9C1 L77 - 13.60 @ 105.87
2019 Chevrolet Express 3500 L96
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GTObert
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Location: Jordan, MN

Re: Drive by wire poor throttle response

Post by GTObert »

As you said before, the warranty lasts 100k and they need to reduce costs. Taking all the balls out of the car really reduces stress on the driveline.
2011 9C1
2005 GTO
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elc32955
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Re: Drive by wire poor throttle response

Post by elc32955 »

Actually the best person to answer this question is Chris Henry since he tunes these cars & is a forum member, I'll see if I can give him a nudge to weigh in on this topic. I know in HP Tuners that there are a number of settings (such as adjusting the Torque Management settings) which will definitely improve your driving experience specific to the 2011 cars. I seem to remember that one setting in particular (believe it's labeled as Hysteresis) when set to 0% will allow instant response to the throttle command, eliminating the normally delayed response with your application of throttle to the motor vs. when the engine spools. You push and it GOES with no lag!

There are so darned many variables in tuning these motors. BTW if I remember correctly I was also told you never want to turn Torque Management completely off... just adjust it. It'd be interesting to look at a dump on a 2014 vs. a 2011 to see how many modifications were made. I don't know with HP Tuners if 2011-13 will be a separate class by itself because of the changes with the car electronics for the 2014MY or not. Never checked into this yet since I don't have a 2014....

Just for general info... the tuning board on the LS1 forum is really good for these discussions as well. Lot of folks with tuning experience out there.

http://ls1tech.com/forums/pcm-diagnostics-tuning-7/

Eric
System Manager and your tour guide for the day. 2015 Caprice w/LFX, former NC DPS staff car. Partial hybrid G8/SS/Camaro SS interior mods, SS MyLink radio upgrade, 2016 Camaro V6 rims, GMPP Malibu chrome exhaust tips, otherwise bone stock for now.
9C1fanatic
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Re: Drive by wire poor throttle response

Post by 9C1fanatic »

Thanks, that is really good information. That makes sense about not turning tm completely off as I'm sure it does lots of things such as reducing torque during upshifts and such. I'm really interested to know where these things sit from the factory. I want that throttle crisp like the old drive by cable systems.
Garner Ames



1975 Pontiac Grand Am L77 - 14.82 @ 92.89
1991 Chevrolet C1500 L31 Vortec/5 Speed
2002 Chevrolet Suburban 1500 LM7
2014 Chevrolet Caprice 9C1 L77 - 13.60 @ 105.87
2019 Chevrolet Express 3500 L96
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storm9c1
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Re: Drive by wire poor throttle response

Post by storm9c1 »

Drive-by-wire is part of the reason that 99% of my own cars still have a mechanical throttle cable. I still deplore the thought of "asking" the car what to do with my foot and having it "allow" response when it feels like it. The same applies for some of these newer cars with electric steering. We aren't playing video games here! We are DRIVING. Moronic drivers may need all of their inputs buffered, but the buffer delay can cause an experienced driver to be "surprised" to say the least, especially if the power kicks in AFTER the apex of a turn.
Tom (AKA: Storm)
2011 Caprice 9C3: L77, 8K miles, first-owner, purchased July 2011.
1995 Caprice 9C1: LT1, 178K miles, summer car.
1995 Impala SS: LT1, 21K miles.
1995 Caprice Wagon: LT1, 62K miles.
1995 Caprice Wagon: LT1, 128K miles. Rust In Pieces
1994 Caprice 9C1: LT1, beater winter car.
1969 Chevy C30: 383ci stroker, 4L80E, rollback car hauler.
1972 Chrysler Newport: 400ci big block, survivor 27K miles, 2-door hardtop.
1969 Dodge Charger: 383ci big block.
CrashTestDummy
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Re: Drive by wire poor throttle response

Post by CrashTestDummy »

The biggest issue we had with our '10 PPV when we got it was that 'stumble' at throttle tip in when pulling away from a stop. The guy that did the tune on our PPV said that GM pulled almost all of the timing out at throttle tip in, which caused that flat spot. He tuned that out of our truck and it's 1000% better.

The thing already ran pretty well, considering it's heft, but he made things better by tuning it for 93 octane fuel and playing with the shift points/firmness a bit. It's a real hoot to drive now. I'm dreading that flatspot at throttle tip-in when we get our Caprice, but do know what to do with it. 8-)
Gene Beaird,
Pearland, Texas
2012 Caprice 9C1
1992 B4C 1LE Camaro
2018 Tahoe PPV (her car)
1995 DGGM Impala SS
1985 Firebird - 310 LS1 C Prepared autocross car.
1980 Bluebird Wanderlodge
And some others
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