Throttle aceleration/deceleration
Thread Starter
Instructor
Joined: Feb 2006
Posts: 148
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From: Saratoga Springs New York
Throttle aceleration/deceleration
Have a question on throttle response. All my experiences with perfomance come in the form of motorcycles where throttle response is instant—both on aceleration and deceleration. What I find with my 2006 C6 (manual trans) is when I gradually take off from a traffic light the acceleration is immediate and proportional to throttle position just like what I'd expect BUT when I suddenly come off the gas, the engine momentarily maintains throttle and then gradually decels feeling like it’s delayed. I’m talking 1st gear in the range of 2000 to 2400 rpm’s.— I also notice it when gently reving the engine in neutral. The engine revs up quickly but gently returns to idle.
Did Chevy do this purposely? Can this be reprogrammed out? Or is this flywheel effect (I have stock powertrain)?
I can use some insight on this?
Did Chevy do this purposely? Can this be reprogrammed out? Or is this flywheel effect (I have stock powertrain)?
I can use some insight on this?
Last edited by BobST1100; Sep 30, 2006 at 09:10 PM.
Race Director
Joined: Sep 2001
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From: Between a rock and a hard place, S.E. PA
Electronic throttles are not as responsive as linkages. I think they were able to save money and "complexity" but they sacrificed the responsiveness that a sports car deserves. It's still better than my Jag's throttle control.
Drifting
Joined: Oct 2005
Posts: 1,549
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From: Roanoke Virginia
No, BobST1100 is correct. It is software programming that gives slow RPM decreasing. I have reprogrammed my starting flare, throttle response, etc, but can't get at the RPM decel. Does anyone know how to do this?
I think it has to do with the DFCO, but I can't seem to adjust it right.
I think it has to do with the DFCO, but I can't seem to adjust it right.
Safety Car
Joined: Dec 2005
Posts: 4,157
Likes: 37
From: North Carolina
St. Jude Donor '07-'08-'09-'11-'12
From what Ive read and been told, GM did do some things to try and keep the car "safer".
For ex, from the factory, putting the pedal to the floor only gives you 85% throttle. The gas pedal positon does not directly equal throttle position (I dont remember the default values, but 1/2 pedal gives you like 25% throttle or something like that). Good tuning software like HP Tuners and EFILive shows the default values, and some of them are really surrprising to see. Here's some links to get more info:
http://www.gmhightechperformance.com...lash_scanning/
http://www.hptuners.com/products/vcmsuite.php
http://www.chevyhiperformance.com/te...rtrain_module/
A good tuner can tweak and adjust the car more to your liking. I had my car tuned by Chuck at Corvettes of Westchester, and he got rid of all the pesky software annoyances. Not only does the car feel much more like a throttle cable instead of drive by wire, the resultant performance is amazing.
For ex, from the factory, putting the pedal to the floor only gives you 85% throttle. The gas pedal positon does not directly equal throttle position (I dont remember the default values, but 1/2 pedal gives you like 25% throttle or something like that). Good tuning software like HP Tuners and EFILive shows the default values, and some of them are really surrprising to see. Here's some links to get more info:
http://www.gmhightechperformance.com...lash_scanning/
http://www.hptuners.com/products/vcmsuite.php
http://www.chevyhiperformance.com/te...rtrain_module/
A good tuner can tweak and adjust the car more to your liking. I had my car tuned by Chuck at Corvettes of Westchester, and he got rid of all the pesky software annoyances. Not only does the car feel much more like a throttle cable instead of drive by wire, the resultant performance is amazing.
Safety Car
Joined: Jan 2006
Posts: 4,598
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From: Miami FL
2020 C6 of the Year Finalist - Unmodified
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16,'17,'18-'19-'20-'21-'22
Thanx to all, particularly Craigster, for the information. I do not like the way the revs hang on during shifting of my MN6, when I am trying to be smooth and conservative.
Since I plan on getting the mail order tune from CoW, as soon as I get the 160F thermostat installed, I will be sure to ask Chuck to give me throttle control like he gave Craigster.
Thanx again
.
.
Since I plan on getting the mail order tune from CoW, as soon as I get the 160F thermostat installed, I will be sure to ask Chuck to give me throttle control like he gave Craigster.
Thanx again
..
Thread Starter
Instructor
Joined: Feb 2006
Posts: 148
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From: Saratoga Springs New York
Thanks Craigster05---Kelp, I had a feeling it was GM programming. I test drove a new Porsche Carerra 4 and 03 Turbo yesterday and immediately felt the difference in throttle response and $ticker!
I assume Corvette of Westchester was able to tweek the decel -- right now this is my main complaint 'though now that you mention Chevy concervatively maps out throttle response I'm curious how they mapped out my car.
Does anyone know how conservative Chevy's been?
Has anyone used the software mentioned in Craigster05's links?
Where is the computer interface on the car?
I assume Corvette of Westchester was able to tweek the decel -- right now this is my main complaint 'though now that you mention Chevy concervatively maps out throttle response I'm curious how they mapped out my car.
Does anyone know how conservative Chevy's been?
Has anyone used the software mentioned in Craigster05's links?
Where is the computer interface on the car?
Race Director
Joined: Oct 2004
Posts: 10,089
Likes: 13
Originally Posted by BobST1100
Have a question on throttle response. All my experiences with perfomance come in the form of motorcycles where throttle response is instant—both on aceleration and deceleration. What I find with my 2006 C6 (manual trans) is when I gradually take off from a traffic light the acceleration is immediate and proportional to throttle position just like what I'd expect BUT when I suddenly come off the gas, the engine momentarily maintains throttle and then gradually decels feeling like it’s delayed. I’m talking 1st gear in the range of 2000 to 2400 rpm’s.— I also notice it when gently reving the engine in neutral. The engine revs up quickly but gently returns to idle.
Did Chevy do this purposely? Can this be reprogrammed out? Or is this flywheel effect (I have stock powertrain)?
I can use some insight on this?
Did Chevy do this purposely? Can this be reprogrammed out? Or is this flywheel effect (I have stock powertrain)?
I can use some insight on this?
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Former Vendor
Joined: Nov 2005
Posts: 11,792
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From: Ossining New York
St. Jude Donor '07-'08-'09-'10-'12-'13-'14
Totally Not Correct....
Originally Posted by C5pilot
Electronic throttles are not as responsive as linkages. I think they were able to save money and "complexity" but they sacrificed the responsiveness that a sports car deserves. It's still better than my Jag's throttle control.
Thank god for electronic throttle! Properly managed, you can have amazing throttle response that is actually BETTER than a cable or linkage. It can actually be faster than a cable too. Want a car with a big cam to idle good....ELECTRONIC THROTTLE!
When you program it right....it's AMAZING!
Stay TUNED,
Chuck CoW
Former Vendor
Joined: Nov 2005
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From: Ossining New York
St. Jude Donor '07-'08-'09-'10-'12-'13-'14
To Clarify...
Originally Posted by kelp
To clarify the 85% throttle idea, the tuners are logging the "throttle position", not the "ETC TPS Position" which gives you 100%. That's where it came from.
TO CLARIFY....The opening of the throttle (0-100%) and the travel of your foot (0-100%) are not the same.
If your electronic throttle corvette was a 1 to 1 ratio (same as cable or linkage)....you would not be able to drive the car as the low end power and responsiveness would overcome the tires every time. You could not paralell park or start off from a dead stop....Your car would jump like a frog! Believe me I tried it....I thought it would be great....But, you can't even drive the car.
The way I tune my cars is a TREMENDOUS imporvment! Ask CRAIGSTER! It took alot of work to get it right, but I have the combo for a really responsive throttle that's smooth to drive....
BY THE WAY....AN LSx based electronic throttle is limited, and unless tuned properly...will NEVER open more than about 85% even though your foot is burried to the floor....How much does that suck?
Give it a try!
Chuck CoW
Safety Car
Joined: Dec 2005
Posts: 4,157
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From: North Carolina
St. Jude Donor '07-'08-'09-'11-'12
Originally Posted by Chuck CoW
BY THE WAY....AN LSx based electronic throttle is limited, and unless tuned properly...will NEVER open more than about 85% even though your foot is burried to the floor....How much does that suck?
Give it a try!
Chuck CoW
I saw Andy yesterday too. His comment "Man, were you right about the tune...I cant believe the low end power now..."
Former Vendor
Joined: Aug 2004
Posts: 166
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Originally Posted by Craigster05
Until you get through with it my friend....I swear, after the Vararam install and the tuning tweak last week, it felt like you could pull the front wheels off the ground during the test drive. I am still amazed at how now while riding at 70 a quick stab of the throttle has you over 100 in a couple of seconds. Im enjoying the car 10 fold since you made it come alive.
I saw Andy yesterday too. His comment "Man, were you right about the tune...I cant believe the low end power now..."
I saw Andy yesterday too. His comment "Man, were you right about the tune...I cant believe the low end power now..."
Drifting
Joined: Oct 2005
Posts: 1,549
Likes: 1
From: Roanoke Virginia
Back to the orig question of throttle response. Some quickness of throttle response can be programmed in, but not the decay. At least I haven't seen anything. Maybe the professional tuners here can confirm or deny if these parameters exist?
I tried adjusting it via the DFCO, but that did not work, and haven't gotten any answers yet on the tuning forums for our models. I would like to simulate the engine responsiveness of a lighter flywheel.
About the logging parameters: again, logging the Throttle Position vs. ETC TPS Position results in 85% vs 100% on the graphs.
A good tune will not only net you a good 20+ HP at WOT, but will adjust all the nice touches to your liking so it will feel more powerful, yet much more drivable. That seems to be the basis of the great enthusiasm.
BTW, a handy tune to have around is a valet tune. When you take your car in to be serviced, etc, you can load it in to limit performance substantially so no hot dog repairman can beat it up for his entertainment. Tunes are quite versitile.
I tried adjusting it via the DFCO, but that did not work, and haven't gotten any answers yet on the tuning forums for our models. I would like to simulate the engine responsiveness of a lighter flywheel.
About the logging parameters: again, logging the Throttle Position vs. ETC TPS Position results in 85% vs 100% on the graphs.
A good tune will not only net you a good 20+ HP at WOT, but will adjust all the nice touches to your liking so it will feel more powerful, yet much more drivable. That seems to be the basis of the great enthusiasm.
BTW, a handy tune to have around is a valet tune. When you take your car in to be serviced, etc, you can load it in to limit performance substantially so no hot dog repairman can beat it up for his entertainment. Tunes are quite versitile.
Thread Starter
Instructor
Joined: Feb 2006
Posts: 148
Likes: 2
From: Saratoga Springs New York
I will look into the possibly having my throttle remapped BUT my original question is concerning deceleration.
Chuck Cow....can the rate of deceleration be reprogrammed. Kelp appears to have tried but couldn't. As much as I would like better performance, I also want better throttle decel. My instincts are if you can do one you should be able to do the other BUT I don't know....
Chuck...I'll pick this up with you on Monday...if you have time to talk.
Chuck Cow....can the rate of deceleration be reprogrammed. Kelp appears to have tried but couldn't. As much as I would like better performance, I also want better throttle decel. My instincts are if you can do one you should be able to do the other BUT I don't know....
Chuck...I'll pick this up with you on Monday...if you have time to talk.
Former Vendor
Joined: Nov 2005
Posts: 11,792
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From: Ossining New York
St. Jude Donor '07-'08-'09-'10-'12-'13-'14
Yes
Originally Posted by BobST1100
I will look into the possibly having my throttle remapped BUT my original question is concerning deceleration.
Chuck Cow....can the rate of deceleration be reprogrammed. Kelp appears to have tried but couldn't. As much as I would like better performance, I also want better throttle decel. My instincts are if you can do one you should be able to do the other BUT I don't know....
Chuck...I'll pick this up with you on Monday...if you have time to talk.
Chuck Cow....can the rate of deceleration be reprogrammed. Kelp appears to have tried but couldn't. As much as I would like better performance, I also want better throttle decel. My instincts are if you can do one you should be able to do the other BUT I don't know....
Chuck...I'll pick this up with you on Monday...if you have time to talk.
Chuck CoW
Thread Starter
Instructor
Joined: Feb 2006
Posts: 148
Likes: 2
From: Saratoga Springs New York
Thanks Chuck...I stopped by during the week of Oct. 2nd and we chatted about this at some length. You were working on tuning a modified Yellow C6.
Right now I have my hands full with other things. When things settle down, we can talk more.
Thanks again.!
Robert
V yellow C6
Right now I have my hands full with other things. When things settle down, we can talk more.
Thanks again.!
Robert
V yellow C6
Originally Posted by Chuck CoW
YES, for sure you can change the throttle decay....A good tuner with good software can make that car do almost anything you want...
Chuck CoW
Chuck CoW
Safety Car
Joined: Dec 1999
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From: Roxbury NJ
Originally Posted by Chuck CoW
YES, for sure you can change the throttle decay....A good tuner with good software can make that car do almost anything you want...
Chuck CoW
Chuck CoW
Drifting
Joined: Oct 2005
Posts: 1,549
Likes: 1
From: Roanoke Virginia
You are correct. The throttle follower decay for cannot be done for the LS2 or LS7.
Originally Posted by Flareside
I'd love to know how you are doing this. Beta version of HPT or another program? In the current version (2.1.12), I can modify the throttle follower decay for LS1, but not for C6 LS2.
Safety Car
Joined: Dec 1999
Posts: 4,148
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From: Roxbury NJ
Originally Posted by kelp
You are correct. The throttle follower decay for cannot be done for the LS2 or LS7.
)?In my car, when the LS2 gas pedal is to the floor, the PCM says it's at 88%, but the throttle plate is 100% open. The 88% stuff is just a PCM calibration, you cannot gain any hp by modifying it.
Safety Car
Joined: Dec 2004
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From: stafford country, va. Avatar: Me on turn 3 @ Bristol (The World's Fastest Half-Mile)
Originally Posted by clevitekid
...the way the revs hang on during shifting of my MN6