FastestBusaAround

Why did GM build in this dumb mapping on a 650 HP supercharged monster? What's with the slight hesitation/ bog when NOT hammering and just cruising and some part throttle? I bought this car because I wanted power - not lag. I have driven a few A8's and they all do this, so I know it's not an issues specific to my car.

My supercharged FGT, and my 991 TT/S don't do this. Both are FI cars...and when you throttle, light, hard or anywhere in between, they don't hesitate / lag etc...they just go! So WTF was GM thinking?

If I wanted a car that got great mileage and was grandpa friendly, I'd have bought a fu.cking Prius, not a 650 HP super monster!

Someone tell me it can be written out in a tune, please!

Another dumb bug...I had my A/C on yesterday, and the driver and passenger systems were definitely in SYNC mode...meanwhile passenger side is blowing 120 degree heated air with the driver's side blowing ICE COLD A/C. It took me 10 minutes of fu.cking around to figure out how to get the system working properly...and it consisted of putting the system into heat mode, then back to A/C.

Seats don't get very cool either with the seat ventilation on...but I believe there is a software update for that.

Android Auto integration sucks...with no dial pad once you reach a number and have to hit digits to access something. Only way is to hit Home>>Phone>>Keypad...all while the phone is ringing or waiting for user input. How is that safer than NOT having it, which is the entire point of Android Auto?

Other than that - and having to seriously pay attention to NOT smash the spoiler by bottoming out, car is fantastic!! LOL

sTz

You have a couple different options to remedy the throttle lag. Not sure how many miles you have on it, but it does get a littler better... AC and seats, meh. Auto integration- get an iPhone... JK. You're not the first to have Android sync issues. Maybe a reflash? Not sure if any software updates are available yet...

FastestBusaAround

Why, is Apple Car Play much better? LOL

The throttle lag issue doesn't really get better with the Vitesse...if that's what you were going to suggest. Is there something else that can eliminate it? I'm all ears!!

383vett

Try a ported throttle body. Worked for me.

ZenicaPA

I have none of these issues. I do have the TC issue and headlights that seem to be mounted to the fender and not the frame because tapping the fender will make the headlight beam dance.

I'd trade my headlight issue for your seat issue.

FastestBusaAround

Have the headlight issue as well...thanks for reminding me!

ZenicaPA

J. Gary

My goodness, there might be something wrong with your Z. My 2015 A8 gives me heart palpitations every time I get cheeky with the throttle. I've had her serviced at Moran Chevrolet (Michigan) since I bought her. Never got "cheeky" until I had a couple thousand miles on her. I am unable to detect any lag in street use where full throttle applications are rare. Not enough real estate to keep on the gas for long. Perhaps when tracked it becomes apparent? So far my biggest issue was the rear license plate light went out, Moran found it when she was in for service.

Ducdriver

I have similar issues with my Z06 ('15). The problems seem to be worse when the car and tranny are cold. Occasional annoyance.

VitesseMotorsports

GM and most other car manufacturers build some delay into their Throttle response.

Here are a few reasons:

• To make powerful cars safer to drive on public roads

• To pass emission tests

• To make the cars more fuel efficient

The lag will also prevent the average driver from wrecking their car (If it has lots of power).

Our Controller will allow you to dial the exact amount of response to match exactly the way you want the car to feel.
From 9 different settings, you can change it even while driving.

Lots of customers say it feels now more linear, as if it was a hard cable controlled Throttle.

davepl

Well so far:

- My car didn't overheat at the track (A8)
- My car doesn't have a TC issue (A8)
- My headlights don't shake
- My throttle is responsive and crisp

Now my rear end did fail, so it's not all roses and cherries.

The worst lag I've ever had was on my Mercedes CL65 BiTurbo V12. The scary part was that AFTER you lifted it would continue to accelerate at full boost for about 1 second, which can be scary at 600+ horsepower. I thought it might be turbo related, but I'm pretty sure it was just a slow-to-respond electronic throttle body.

My son's new Silverado however has a very sluggish throttle. I presume that's for economy reasons.

Before I trust my life (quite literally) to a piece of aftermarket electronics, I'd be curious as to how the Vitesse throttle controller works. Is there a doc or web page I can read? I wouldn't mind remapping the linearity of the response, even if it's already OK (more is better and better is more!)

For example I have no idea if it's just remapping tables in the ECU or if it's actually changing the physical link between your pedal and the stepper motor(s) in the electronic throttle body. So how does it work? What's the failsafe to protect the consumer if there's a defect (ie: if I close the throttle, and you've got a bug, what guarantees the throttle will still close and that failing to open, not close, is my worst possible case?)

Thanks!
Dave

VitesseMotorsports

Let me explain how the Controller works

The Gas pedal sends a signal to the Throttle body blade asking it to open and close depending on how much you have pushed the accelerator.... It's usually never a 1:1 ratio in Stock mode.

The Controller when connected between the 2 sensors of the Gas pedal and the Throttle Body, will alter that signal, with 9 different settings, you can choose how linear you want that response to be

Ex:
SP0 ( Stock mode ) 50% Accelerator ---> 30% Throttle Body Blade open
SP3 50% accelerator ---> 40% Throttle Body Blade open
SP5 50% accelerator ---> 50% Throttle Body Blade open ( This will feel more linear )
SP9 50% accelerator ---> 70% Throttle Body Blade open

The Lag ( Delay between the time you step on the Gas pedal and the time the car starts accelerating ) is also modified depending on which setting you choose. The higher the setting, the less Lag you will feel.

The controller only alters that signal between the APS and TPS , it does not modify anything on the ECU.

Yes, it has a fail-safe mode on top of what the corvette has, just like every other "Drive by wire" system.

The ECU keeps checking the voltage between your APS ( Accelerator Pedal position Sensor ) and your TPS ( Throttle Body position sensor ). If it detects the slightest difference between these two, ( 5% difference or more ), it will simply default to "Limp mode" or in our case for GM cars: "Reduced Engine Power" the car will not accelerate even if you have your gas pedal pushed all the way.

On top of this, our Controller also checks for any malfunction and if it detects anything wrong: Voltage difference / no voltage / loose connector... it switches automatically to SP0 ( Stock mode ).

tzoid9

I asked that same question on this Forum regarding a slight throttle lag when the engine is cold...I have a '16 Z06 with M7 trans. Vitesse actually responded to it and said that their throttle controller could not help this issue. I just have to be careful when the engine isn't warmed up....it will bog down in 1st gear when letting the clutch out unless you have more than normal RPM's. Seems like we both have the same type of issue.....

FastestBusaAround

I drove more than 2 of these 16 Z's...and they all exhibited the same symptoms. I am guessing that those who don't feel it think it's normal on supercharged engines, but it's not. Blower cars are generally not known for laggy throttle response...not in the slightest. Even my 911 TT/S - which is a turbo, has better throttle response. My Ford GT with a 4L Whipple blower has very crisp throttle response - as crisp as an old school carb'd muscle car, if not more.

@ J Gary ...don't get me wrong...when you put your right foot into it, it goes like a bat outta hell...but when you're cruising and apply light throttle, and it doesn't just go right then...that's GM building software in it to create that lag...as Vitesse says.

Throttle response has nothing to do with power, but has everything to do with power delivery.

My ZX14 Ninja had the same thing with dual throttle plates where top one would not open until after 3500, limiting TQ in a big way at low RPM. I removed the secondary throttle plates - tuned for better AFR's and picked up IIRC, something like 40 LBS of TQ under the curve. No doubt it was designed to keep the rider safer.

@ Vitesse...as I understand it, you're amplifying the voltage at a given throttle position, but this doesn't dial out the lag...it only makes the throttle more sensitive to input, where it was less sensitive before. So if at a given physical throttle position, where we had say 2 volts before the Vitesse install, you basically applying a higher voltage at the same exact pedal position? That's what I understand anyway...

Not really sure that will help me today...so, knowing what I'm asking for, is the Vitesse the answer or part of the answer?

I was thinking mapping when I change to a Whipple 2.9 --- just haven't talked to a tuner who knows about this yet.

VitesseMotorsports

We don't simply amplify the signal, we also change it in a way to reach the Throttle Body Blade a lot faster than Stock, this is translated to the "Quicker response" you are looking for.

Other Controllers on the market only amplify the signal, they don't eliminate Lag.

davepl

How do you shorten the path? What delay/lag circuit are you removing? I'm not going to run out and build a competing unit, honest... but this is a sensitive part of the car obviously so I'd like to understand how it works before entrusting my safety to it.

Now that you've clarified you're not just remapping the same slow signal, I'm intrigued.

VitesseMotorsports

We're not shortening the path, we are just eliminating or I should say decreasing that "Built-in Delay" to make the signal reach the Throttle body instantly.

I'm sorry but I wish I could give you more details.

ZenicaPA

If I'm "goosing" the throttle for fun, mainly because my 3 year old loves it, I experience this delay between lifting off the accelerator and the engine RPM coming down. In fact, it continues to climb and accelerate for a few tenths of a second.

Higgs Boson

I don't think that's what he said, just my "interpretation."

The signal isn't slow, electricity flows the same speed through the same resistance, right? So the signal is the same.

The stock computer simply takes a demand from the driver through the pedal and decides what to do with it.

Read this:
https://www.hptuners.com/help/vcm_ed...vanced_e78.htm

There is a smoothing function built in as well. Gone are the days of cable actuated instant pedal to throttle body relationship. It's all a manipulated signal now.

sTz

I've had two late model GT500s and they both had throttle lag- Nothing a SCT w/tunes couldn't fix, but delays nonetheless. Whether it's normal or not, SC'ed cars "can" have throttle lag for reasons mentioned earlier.

Maybe you shouldn't be comparing your Ford GT w/4L Whipple (nearly twice the size of OEM), which I presumed was custom tuned. Even without the 4L mod, the Ford GT would have been factory tuned a lot differently 10 years ago than SC'ed cars are tune today with all of the CAFE crap... Awesome car BTW