LaZyB0ne

DT power in the UK just released a TCU tune a month or so. It's supposedly getting good feedback from the S4 guys.

https://dt-power.com/product/tcu-transmission-tuner/

I ordered mine today. Can't wait to try this out.

I don't have an ECU tune, but do have a piggy back and feel the same way. I feel there are times the transmission and engine are out of sync and cause some choppy feel. Especially hitting the pedal hard and shifting at high rpms.

ericrebates

Very useful info. So you agree that the stock throttle response is "horrible" but the APR yielded only a moderate improvement. I was beginning to think maybe the responsiveness issues don't affect all A4s which might be why people report different levels of improvement with the same ECU modifications. Of course without instrumenting the vehicle to collect actual data it's all pretty subjective.

I'm actually a fairly conservative driver and I'm usually not very aggressive on the accelerator. Have you experienced choppyness or other understandable side-effects in the more conservative operating regimes?

Thanks!

- Eric

cuke2u

I paid £285 for mine from DTUK...

SchwarzS6

ericrebates

Although I find the latency from a dead stop annoying, it's really most pronounced when on the highway at a stable speed, say 60, and you want to accelerate to say 70. Do you notice a lack of responsiveness there? I find that the only way to get the car to respond in a reasonable amount of time in such a situation is to over-correct and punch the throttle, which is a very uncomfortable way to get to 70.

- Eric

SchwarzS6

I do this frequently and have not noticed a lag. I probably push the throttle only enough for a single gear downshift so the tranny is probably preselected already. I will try next week when I head to work and press a little harder for a must-gear shift and see what happens. If multi-gear shifts are the problem the pedal box won't help, in this case the delay is probably due to the DSG method of shifting. A regular auto tranny can handle multiple-gear downshifts faster than a DSG but I think a DSG can handle single gear up and downshifts quicker than an Auto, and much quicker than a manual shift car.

I will post what I find next week.

superswiss

Lag when cruising on the highway and then stepping on the throttle to accelerate mostly comes from the transmission deciding to downshift if you give enough throttle that it thinks you want full acceleration. As mentioned above, multi gear downshifts can be slow with the DSG. It's why I primarily drive in manual mode on the highway, unless I have ACC engaged. I do dislike the tendency of automatic transmissions in general to downshift at the slightest throttle input. Usually I just wanna accelerate in the current gear and if I need a lower gear I will downshift myself. Today's transmissions are programmed to down-speed the engine and have more and more gears. Mercedes is now up to 9 gears and some other manufacturers have 10 gear transmissions. It's all in the name of fuel economy. Turbo charged engines are gas guzzlers on boost, so to get these advertised miles per gallon, the engine needs to be kept out of boost. That's the secret behind down-speeding. The longer the engine can be kept out of boost, the better the fuel economy, so modern transmissions quickly upshift to keep rpms low, but then need to downshift multiple gears to get a decent acceleration when you step on the throttle and the turbo needs to spool up, so that leads to these kinds of lags.

LaZyB0ne

Would a TCU tune help with the slow multi gear downshift of the DSG?

superswiss

I think they do speed up shifts a bit, but there are mechanical constraints responsible for this. Even my RS5 with a track tuned DSG has this lag if I just blindly mash the throttle from 7th gear. Engine howls, but the car doesn't move for about a second while the transmission is busy hunting for the lowest possible gear.

VipinLJ