pnd4pnd

has anyone tried this to solve the problem? :
https://www.sprintboosterusa.com/c-413-dsg.aspx

Vijay

In fact, it can make the lag seem worse, as the there is so much more power when the boost does come on.

DD1546

This gadget looks really interesting, though I'm not sure how it works on a technical level (what's really inside?). I would definitely pay $300 to get rid of the lag, though I do wonder whether or not the latest TSB might do the trick (assuming I can get my dealer to install it).

With regard to Sprintbooster: Is it likely to leave a footprint that will be detected as a chip alteration - thus voiding the warranty? And, of course, does it actually work to get rid of the lag or does it just improve overall responsiveness? I note there are two dealers in NJ not too far from me.

GiantEli

Not sure why you would screw around with this, given that there are multiple long-standing members of this forum who say that the TSB fixes the problem. I'd take the audi fix (even if it took some haggling) over a $300 internet device that only claims to change the output signal from the accelerator, which may even exacerbate the problem (if the controls engineering guys earlier in the thread are right).

MalibuCANE

The latest from my dealer is that they heard back from AoA and they said that eligibility for the update is determined by VIN and my car is not eligible. They have asked me to drive and replicate the issue with the service manager and the Audi rep. I told them I would pay for it and that I just want the latest update. I'm not interested in wasting time so they can just tell me that my car is not eligible for the update. Not sure if I should bother.

hayasa

All the Sprintbooster does is adjust the throttle % via changing the electrical signal. Nothing magic; works well on cars with a laggy throttle and no "sport" mode. Won't do anything in regard to the tranny.

Richard Solomon

So let's see - the throttle on a drive-by-wire car is nothing more than a device which provides a voltage proportional to the pedal position. So any delay in opening the actual throttle(s) is controlled directly by the ECU based on what it "sees" coming from the pedal. (Note that it was known even back in C5 days that Motronic looked at the rate of change of the pedal position as well as the absolute pedal position.)

So a "laggy throttle" is at best what you perceive based on the ECU's *outputs*, and since these devices sit on the *inputs* of the ECU, they can't directly make the throttle more or less "laggy", all they can do is simulate what happens when YOU press the throttle pedal.

For simplicity's sake, consider it this way: Pedal position can vary between 0-100% and the pedal output voltage can vary between 0-100%. Generally speaking the pedal installed in your car is directly proportional, so 50% pedal yields 50% output voltage, 10% pedal 10% output, 100% 100%, etc. (Actually IIRC, the C5 pedal produced 0-110% voltage with 110% meaning you'd pressed past the "kickdown" switch which was nothing more than a rubber dome to give that "kickdown" feel, but I digress.)

The most "Sprintbooster" could do is provide higher voltage for a given pedal position - meaning that when you press the pedal 10%, the $300 box could make it look like you pressed the pedal 50%. Let's give it the benefit of the doubt and say it even ramps the voltage up very quickly to 50% instead of tracking your pedal position.

Whoopty-doo. You could just quickly press the pedal to 50% instead of 10%... In other words, you could drive your drive-by-wire car the same way we old farts learned to drive turbo cars with throttle plates connected to the pedal. Namely, flooring the pedal to get as much airflow going to spool the turbos up as quickly as possible and then backing off the pedal as the power builds (unless of course you really want full power in which case keep 'er matted and Katie-bar-the-door). Of course the mechanism is different, since we're not trying to feed the turbos air as much as we're trying to tell the ECU that we seriously want power and NOW! Believe me, it's programmed to understand that - if it weren't then even a pedal booster wouldn't be able to affect change.

So IMNSHO, the device is a very clever invention - for separating folks from their money. Anything it can do simulating pedal movement is something you can do by ... moving the pedal.


Disclaimer: I have no personal experience with this or the other similar devices which have preceded it, nor have I disassembled or analyzed the guts of one, but only analyzed it based on the documented interface.

DD1546

Re your comments on driving old turbo cars: That's exactly how I drove my 87 Chrysler Conquest Turbo (nee Mitsubishi Starion). Loved to drive it at 3 - 4K RPM on the highway and floor it.

SMK_RS4

This is pretty much exactly what it does. After reading pages and pages of positive comments on R8Talk I bought one for my R8 with the expectation that it would be a joke. However, I was pleasantly surprised. It does make a huge difference and makes the car "feel" much faster. Depressing the throttle only slightly brings on the power much sooner, making the car feel quicker and more powerful. One caveat though is that I find it more difficult to drive the car smoothly, especially starting from a standstill where it is difficult sometimes not to rev the engine too quickly to pull away smoothly (this is for a manual).

I don't think it would help with our throttle issue.

Ruger280

I am having a similar problem: I can take off just fine until I get the pedal half way down, then it just bogs plum out!! I can barely go up these mountains in WV-- 20 MPH tops. Another thing is my A6 2.7 biturbo is over heating after about 20 minutes of driving. I'm afraid to drive it anywhere because of the over heating issues. Any help is Greatly Appreciated. BTW, the nearest Audi dealer is 100 miles away