[alfonsos]

Originally Posted by Mustang Fanboy

And again, that isn’t lag…that is intentional throttle mapping done to aide everyday drive-ability (modulation). What you want is something that intercepts the stock signal and outputs another, effectively reducing modulation…especially at tip-in. A tune can obviously change this, but isn’t this exactly what the Vitesse does? We have something similar in the mustang world to help those who prefer an on/off switch.

I don't think this's quite right. I watched a video by a guy reviewing the 2016 Camaro 2SS M6 ("subaruwrxfan", I think). He complained about the lag in his moving review. He even demonstrated it: he hit the gas pedal several times quickly, all the way to the floor - you could hear it. He even said, "hear that? That's me hitting the gas repeatedly". There was no response from the engine; he was doing it fast enough such that the engine/electronics couldn't respond fast enough. If he had done this with a throttle by cable car, this wouldn't happen. Lag and throttle mapping are 2 different things; subaruwrxfan demonstrated lag. The Vittesse (sp), for example, alters throttle mapping.

[Mustang Fanboy]

Originally Posted by alfonsos

I don't think this's quite right. I watched a video by a guy reviewing the 2016 Camaro 2SS M6 ("subaruwrxfan", I think). He complained about the lag in his moving review. He even demonstrated it: he hit the gas pedal several times quickly, all the way to the floor - you could hear it. He even said, "hear that? That's me hitting the gas repeatedly". There was no response from the engine; he was doing it fast enough such that the engine/electronics couldn't respond fast enough. If he had done this with a throttle by cable car, this wouldn't happen. Lag and throttle mapping are 2 different things; subaruwrxfan demonstrated lag. The Vittesse (sp), for example, alters throttle mapping.

If there is a system lag caused from pixies moving from point a to point b too slowly, you’re not going to be able to fix it….I’ve said this all along. I seriously doubt GM programmed in a delay parameter to induce lag, as this is typically controlled using a throttle mapping which limits response during certain areas. Unless someone throws a scope at it, ya’ll aren’t likely to find out.

[alfonsos]

Originally Posted by Mustang Fanboy

If there is a system lag caused from pixies moving from point a to point b too slowly, you’re not going to be able to fix it….I’ve said this all along. I seriously doubt GM programmed in a delay parameter to induce lag, as this is typically controlled using a throttle mapping which limits response during certain areas. Unless someone throws a scope at it, ya’ll aren’t likely to find out.

This may throw light on causes:

http://www.chevelles.com/forums/169-...eliminate.html

Re: Drive By Wire hesitation...can you eliminate it?
Bob , i understand now what you are talking about most people do not pick up on this and again i have not had a major issue with customers not accepting this feel on the fby systems ...GM explains its reason why you feel this ...
Service Information
Home Publications Number Search New Bulletins Bulletin Search Feedback Help
2007 Chevrolet Silverado - 4WD | Sierra, Silverado VIN C/K Service Manual | Document ID: 3940199
#PIP4112P: Normal Characteristic - Sag Or Hesitation On Acceleration - (Jun 26, 2014)
Subject: Normal Characteristic - Sag Or Hesitation On Acceleration


Models: 2008-2012 Buick Enclave
2010-2011 Buick LaCrosse MH7
2010-2013 Buick LaCrosse MH2, MH4
2011 Buick Regal MH7
2006-2009 Cadillac XLR, XLR-V
2006-2011 Cadillac STS, STS-V
2007-2012 Cadillac SRX
2007-2015 Cadillac Escalade, Escalade EXT, Escalade ESV
2008-2015 Cadillac CTS
2013-2015 Cadillac ATS
2006-2015 Chevrolet Corvette
2007-2013 Chevrolet Avalanche
2007-2015 Chevrolet Silverado, Suburban, Tahoe
2008-2011 Chevrolet Malibu MH8
2008-2013 Chevrolet Malibu MH2
2008-2012 Chevrolet Equinox MH2, MH4
2009-2011 Chevrolet Equinox MHC, MH7
2009-2012 Chevrolet Traverse
2011 Chevrolet Cruze
2012 Chevrolet Cruze MH9
2010-2015 Chevrolet Camaro, Express
2011-2015 Chevrolet Caprice
2012 Chevrolet Captiva Sport MHJ, MHK
2012 Orlando
2012 Chevrolet Sonic MH9
2012-2013 Chevrolet Impala
2014 Chevrolet SS
2007-2015 GMC Sierra, Yukon, Yukon XL
2008-2012 GMC Acadia
2010-2012 GMC Terrain MH2, MH7
2010-2011 GMC Terrain MHC, MH7
2010-2015 GMC Savana
2008-2011 HUMMER H2
2007-2010 Pontiac G6 MH2
2009-2010 Pontiac G6 MH8
2008-2009 Pontiac G8
2008-2009 Pontiac Torrent MH2, MH4
2007-2009 Saturn Aura MH2
2009 Saturn Aura MH8
2008-2010 Saturn Outlook, Vue MH2, MH4
Equipped With a Gasoline Engine and Automatic Transmission

This PI was superseded to update Models and Model Years. Please discard PIP4112N

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern

Some customers may comment on a sag or hesitation when accelerating under the following conditions:

When coasting at low speeds of less than 15 miles per hour with a closed throttle and then aggressively applying the throttle. Examples of this maneuver include a rolling stop or a lane change maneuver. In this type of maneuver, even though the accelerator is applied aggressively, the throttle blade is opened slowly for up to 0.7 seconds to help minimize drive-line lash and clunking.

Also in a vehicle equipped with a six speed automatic transmission when making a hard, complete stop with a closed throttle, immediately followed by an aggressive throttle opening the transmission down-shifts may not be completed by the time the throttle is opened. As a result approximately 0.5 seconds of ″zero″ torque may be commanded to allow the shift to first gear to occur.

Recommendation/Instructions

Both of the above conditions are a result of Torque Management and both of these conditions should be considered normal and no repairs should be attempted.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

-----------------------------------------------------------

It appears that the lag is engineered in and is normal.

[Mustang Fanboy]

Originally Posted by alfonsos

This may throw light on causes:

http://www.chevelles.com/forums/169-...eliminate.html

Re: Drive By Wire hesitation...can you eliminate it?
Bob , i understand now what you are talking about most people do not pick up on this and again i have not had a major issue with customers not accepting this feel on the fby systems ...GM explains its reason why you feel this ...
Service Information
Home Publications Number Search New Bulletins Bulletin Search Feedback Help
2007 Chevrolet Silverado - 4WD | Sierra, Silverado VIN C/K Service Manual | Document ID: 3940199
#PIP4112P: Normal Characteristic - Sag Or Hesitation On Acceleration - (Jun 26, 2014)
Subject: Normal Characteristic - Sag Or Hesitation On Acceleration


Models: 2008-2012 Buick Enclave
2010-2011 Buick LaCrosse MH7
2010-2013 Buick LaCrosse MH2, MH4
2011 Buick Regal MH7
2006-2009 Cadillac XLR, XLR-V
2006-2011 Cadillac STS, STS-V
2007-2012 Cadillac SRX
2007-2015 Cadillac Escalade, Escalade EXT, Escalade ESV
2008-2015 Cadillac CTS
2013-2015 Cadillac ATS
2006-2015 Chevrolet Corvette
2007-2013 Chevrolet Avalanche
2007-2015 Chevrolet Silverado, Suburban, Tahoe
2008-2011 Chevrolet Malibu MH8
2008-2013 Chevrolet Malibu MH2
2008-2012 Chevrolet Equinox MH2, MH4
2009-2011 Chevrolet Equinox MHC, MH7
2009-2012 Chevrolet Traverse
2011 Chevrolet Cruze
2012 Chevrolet Cruze MH9
2010-2015 Chevrolet Camaro, Express
2011-2015 Chevrolet Caprice
2012 Chevrolet Captiva Sport MHJ, MHK
2012 Orlando
2012 Chevrolet Sonic MH9
2012-2013 Chevrolet Impala
2014 Chevrolet SS
2007-2015 GMC Sierra, Yukon, Yukon XL
2008-2012 GMC Acadia
2010-2012 GMC Terrain MH2, MH7
2010-2011 GMC Terrain MHC, MH7
2010-2015 GMC Savana
2008-2011 HUMMER H2
2007-2010 Pontiac G6 MH2
2009-2010 Pontiac G6 MH8
2008-2009 Pontiac G8
2008-2009 Pontiac Torrent MH2, MH4
2007-2009 Saturn Aura MH2
2009 Saturn Aura MH8
2008-2010 Saturn Outlook, Vue MH2, MH4
Equipped With a Gasoline Engine and Automatic Transmission

This PI was superseded to update Models and Model Years. Please discard PIP4112N

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern

Some customers may comment on a sag or hesitation when accelerating under the following conditions:

When coasting at low speeds of less than 15 miles per hour with a closed throttle and then aggressively applying the throttle. Examples of this maneuver include a rolling stop or a lane change maneuver. In this type of maneuver, even though the accelerator is applied aggressively, the throttle blade is opened slowly for up to 0.7 seconds to help minimize drive-line lash and clunking.

Also in a vehicle equipped with a six speed automatic transmission when making a hard, complete stop with a closed throttle, immediately followed by an aggressive throttle opening the transmission down-shifts may not be completed by the time the throttle is opened. As a result approximately 0.5 seconds of ″zero″ torque may be commanded to allow the shift to first gear to occur.

Recommendation/Instructions

Both of the above conditions are a result of Torque Management and both of these conditions should be considered normal and no repairs should be attempted.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

-----------------------------------------------------------

It appears that the lag is engineered in and is normal.

You're gong to hate me, but it's still reduced modulation.

Regardless, this sounds like something that must be adjusted in a tune...which has the probability of voiding your warranty.

On a side note, my mustang has a shitload of drive-train clunking that ford decided not to tune out. Many people complain about it, but it is what it is.

Thanks for the heads up, very informative!

[shaffe]

All I can say about the throttle lag from drive by wire is that it blows lol.

Best light I ever cut in my 04 mustang .009 I was normally good for a .100 - .199 in my 04

Best light in my 07 was around .199 or something. Most of them were in the .200 to .300 range. Lost a lot of races at the tree lol

[2SSRS@Gen5diy]

Originally Posted by Techn9cian805

same difference. Lag in throttle response is lag, weather its called "modulation" or not. I know its purpose and all, but its still annoying. I like my throttle response to work instantly in correlation to the pedal's depression, like the good ol' cable throttles.
Friggin fun-killing gov. regulations...

Its not only gov. regulations, its GM to, i think i was one of the first to complain of this more then a year ago, we added a CAI intake, that helps a lot with the delay, but if you do that then they void your warranty, some much fun, As they pulled my warranty after the first weeks, we did it on the car, and it helped a lot, but if your holding out hope for the GM CAI we wish you a speedy recovery, and dont forget with there intake they mane you do a tune, if that tune is what we think it will not fix the lag.

Originally Posted by Marty McFlew

Mine is manual, but don't notice lag in any mode.

Think that is do to your driving more then the car, IMO your not driving hard to see what it does, one day you will feel it.

Originally Posted by Mustang Fanboy

You're gong to hate me, but it's still reduced modulation.

Regardless, this sounds like something that must be adjusted in a tune...which has the probability of voiding your warranty.

On a side note, my mustang has a shitload of drive-train clunking that ford decided not to tune out. Many people complain about it, but it is what it is.

Thanks for the heads up, very informative!

if you call it lag or modulation its still the same thing and it can make for a miserable drive in a car with this bad of lag/modulation.

On a side note we still have some but not a lot of lag/modulation and when you let off at the right time car keeps going faster for what seems like 1 sec, its done this at 55 mph and at 125 mph at the track, needles to say we got off the track that day and never went back with this car, think this has more to do with the TB, we are getting a new one (on our own) think we know why and will try to find out.

[crankaholic]

From the GM explanation it sounds like exactly what I was thinking... the computer (traction and/or stability control) decides that you're giving too much throttle for what the chassis is programmed in to handle and opens the actual throttle body as fast as the car could theoretically handle it.

I found this to be much less pronounced when going into competition mode... so that's how I drive most of the time these days.


As for lag vs modulation, here are my $0.02:

Modulation is how much pedal travel correlates to throttle body opening; this can mean only 25% of pedal travel controls 100% of throttle opening, like if you have one of those pedal controllers set to a very aggressive mode; or it can even mean that the first 10% of pedal travel does almost nothing while the other 90% controls the actual throttle opening, like tour/sport modes by default. There is also a curve between the pedal and throttle, which makes things even more confusing. I would ideally prefer a 1:1 relationship.

Lag normally refers to how long it takes the engine to react to a change in throttle position... normally this is determined by intake design and fueling, but these days it also includes computer intervention between pedal and throttle (ie. that 0.7 seconds the computer takes to slowly open the throttle up to the pedal position). This is separate from the pedal to throttle relationship.


So in an ideal world when I press the pedal 75% of the way down, the throttle opens up to 75% as fast as the electric motor on the throttle body can move.

What happens in tour mode - I press the pedal 75% down, the throttle is mapped to open about 50% (modulation) and the computer decides it's best to take a second or two to get the throttle to 50% (lag).

[tcal780]

[2SSRS@Gen5diy]

Originally Posted by crankaholic

From the GM explanation it sounds like exactly what I was thinking... the computer (traction and/or stability control) decides that you're giving too much throttle for what the chassis is programmed in to handle and opens the actual throttle body as fast as the car could theoretically handle it.

I found this to be much less pronounced when going into competition mode... so that's how I drive most of the time these days.


As for lag vs modulation, here are my $0.02:

Modulation is how much pedal travel correlates to throttle body opening; this can mean only 25% of pedal travel controls 100% of throttle opening, like if you have one of those pedal controllers set to a very aggressive mode; or it can even mean that the first 10% of pedal travel does almost nothing while the other 90% controls the actual throttle opening, like tour/sport modes by default. There is also a curve between the pedal and throttle, which makes things even more confusing. I would ideally prefer a 1:1 relationship.

Lag normally refers to how long it takes the engine to react to a change in throttle position... normally this is determined by intake design and fueling, but these days it also includes computer intervention between pedal and throttle (ie. that 0.7 seconds the computer takes to slowly open the throttle up to the pedal position). This is separate from the pedal to throttle relationship.


So in an ideal world when I press the pedal 75% of the way down, the throttle opens up to 75% as fast as the electric motor on the throttle body can move.

What happens in tour mode - I press the pedal 75% down, the throttle is mapped to open about 50% (modulation) and the computer decides it's best to take a second or two to get the throttle to 50% (lag).

But it does it in all modes some not as bad as others, but still does it in all 4 modes.

[Marty McFlew]

Why not go back to the dealer and tell them to reinstall your factory tune. It will probably be an updated vers. of the original tune to fix bugs and may fix your lag.

[crankaholic]

Originally Posted by 2SSRS@Gen5diy

But it does it in all modes some not as bad as others, but still does it in all 4 modes.

That's true...

The only real way to eliminate lag is to get an aftermarket EFI/ignition controller and tune the car. I wonder if that's even an option for the LT1.

[Marty McFlew]

Originally Posted by alfonsos

This may throw light on causes:

http://www.chevelles.com/forums/169-...eliminate.html

Re: Drive By Wire hesitation...can you eliminate it?
Bob , i understand now what you are talking about most people do not pick up on this and again i have not had a major issue with customers not accepting this feel on the fby systems ...GM explains its reason why you feel this ...
Service Information
Home Publications Number Search New Bulletins Bulletin Search Feedback Help
2007 Chevrolet Silverado - 4WD | Sierra, Silverado VIN C/K Service Manual | Document ID: 3940199
#PIP4112P: Normal Characteristic - Sag Or Hesitation On Acceleration - (Jun 26, 2014)
Subject: Normal Characteristic - Sag Or Hesitation On Acceleration


Models: 2008-2012 Buick Enclave
2010-2011 Buick LaCrosse MH7
2010-2013 Buick LaCrosse MH2, MH4
2011 Buick Regal MH7
2006-2009 Cadillac XLR, XLR-V
2006-2011 Cadillac STS, STS-V
2007-2012 Cadillac SRX
2007-2015 Cadillac Escalade, Escalade EXT, Escalade ESV
2008-2015 Cadillac CTS
2013-2015 Cadillac ATS
2006-2015 Chevrolet Corvette
2007-2013 Chevrolet Avalanche
2007-2015 Chevrolet Silverado, Suburban, Tahoe
2008-2011 Chevrolet Malibu MH8
2008-2013 Chevrolet Malibu MH2
2008-2012 Chevrolet Equinox MH2, MH4
2009-2011 Chevrolet Equinox MHC, MH7
2009-2012 Chevrolet Traverse
2011 Chevrolet Cruze
2012 Chevrolet Cruze MH9
2010-2015 Chevrolet Camaro, Express
2011-2015 Chevrolet Caprice
2012 Chevrolet Captiva Sport MHJ, MHK
2012 Orlando
2012 Chevrolet Sonic MH9
2012-2013 Chevrolet Impala
2014 Chevrolet SS
2007-2015 GMC Sierra, Yukon, Yukon XL
2008-2012 GMC Acadia
2010-2012 GMC Terrain MH2, MH7
2010-2011 GMC Terrain MHC, MH7
2010-2015 GMC Savana
2008-2011 HUMMER H2
2007-2010 Pontiac G6 MH2
2009-2010 Pontiac G6 MH8
2008-2009 Pontiac G8
2008-2009 Pontiac Torrent MH2, MH4
2007-2009 Saturn Aura MH2
2009 Saturn Aura MH8
2008-2010 Saturn Outlook, Vue MH2, MH4
Equipped With a Gasoline Engine and Automatic Transmission

This PI was superseded to update Models and Model Years. Please discard PIP4112N

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern

Some customers may comment on a sag or hesitation when accelerating under the following conditions:

When coasting at low speeds of less than 15 miles per hour with a closed throttle and then aggressively applying the throttle. Examples of this maneuver include a rolling stop or a lane change maneuver. In this type of maneuver, even though the accelerator is applied aggressively, the throttle blade is opened slowly for up to 0.7 seconds to help minimize drive-line lash and clunking.

Also in a vehicle equipped with a six speed automatic transmission when making a hard, complete stop with a closed throttle, immediately followed by an aggressive throttle opening the transmission down-shifts may not be completed by the time the throttle is opened. As a result approximately 0.5 seconds of ″zero″ torque may be commanded to allow the shift to first gear to occur.

Recommendation/Instructions

Both of the above conditions are a result of Torque Management and both of these conditions should be considered normal and no repairs should be attempted.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

-----------------------------------------------------------

It appears that the lag is engineered in and is normal.

I suspect this was normal until hopefully they came out with an updated factory tune to fix the issue. They will not advertise the upgrade.

[2SSRS@Gen5diy]

Originally Posted by Marty McFlew

Why not go back to the dealer and tell them to reinstall your factory tune. It will probably be an updated vers. of the original tune to fix bugs and may fix your lag.

who do you think F up the tune, this was all done by the dealer that then went to GM to tell them to pull the warranty, WE did not tune the car, IT was all done by the dealer that did not know how to fix the car, not going over the 80 MPH, a MRC problem with the BCM.

And i have the paper work to show any one that wants to see it.

[brianhj]

Originally Posted by brAnd7onX

I got a ported throttle body on my 2012 SS and my throttle response was night and day compared to stock...

Do you have to get a tune for that? CEL?