NefMoto

Hello guys, I've been crazy about this gear change for quite some time now. We see it a lot on new sportscars.

It is a kind of pop at gear change, I don't know how to explain it, so here is a video...

Have a look at this golf 7 R

https://youtu.be/Kb-qFcqa6B4?t=52s

We hear it a lot on this RS3 too

https://youtu.be/GPnvj0nqcws

Can someone explain how this works ? Is it something coded into the ECU or something that's "natural" with the exhaust turbo ...

The most important question, can this be ported to a ME7 (S3 BAM) ECU ?

Thank you guys ;)

It's DSG farts?

Is it specific to DSG gearboxes ? Because I think I saw on some manual gearbox cars ...

This is exactly what I'm talking about !!!

https://youtu.be/kXI78224lYY

The cars I heard it from, do iton gear change but also when you let go of the accelerator pedal after a heavy load ...

Would be nice to have something similar on the 1.8t or ME7 ecus...

here are a few other ones ...

https://youtu.be/BtANoW-7IXE

https://youtu.be/NBkJYuP6j2k

https://youtu.be/P_CYxLNkIqs

https://youtu.be/ulapBd4dq18

a late ignition angle make this effect

It's peculiar to the DSG boxes I'm sure.  Don't see how you could replicate this on a manual as the change speed will always be different.

"Dommage" as they say in french ...

Sorry for my bad engish  ;)
to shift you habe to reduce torque, the fastes way is ignition. So the gearbox change the ignition angle. In manual gearbox you have the chang is yourself.

All right, so this means that it could work with the clutch switch only right ?

Every time the engune reduce torque fast

It's called a fast path torque reduction. It's very common on motorsports sequential boxes. The fastest way to pull torque for a smooth gearshift like that is to cut fuel/timing so that's what they do. In motorsports we will frequently just do a spark cut which keeps the turbo going and spits a nice flaming fart out the tailpipe. You could sort of do it on a manual box by tying the clutch signal in for flat (no lift) shifting.

Difference is that you sometimes hear this sound even when drivers, just release the accelerator pedal, we can hear this sound too.

Here are some examples on ford focus rs with manual gearboxes (not only when accelerator pedal released...) ...

https://youtu.be/umkbehSxfHE

https://youtu.be/cDPsEtyq6NU

https://youtu.be/bf3UDRH9VOI

I was alaso wondering about something else. Excuse me for answering that many questions, but I like to understand how things work ... So it is about when you accelerate (while stationary or while driving) and release the accelerator pedal and you hear multiple "farts" on the exhaust (not necessarly  with flames ...)

THank you guys ;)

I hear what you're talking about now. I think you'll find it's excess fuel in the manifold that suddenly has some air to burn when you let off the throttle. The fast path torque thing is more with the throttle depressed. It sounds similar but the two are different. You can also make a car really farty by retarding the timing at low throttle. Some manufacturers do this on purpose to make the car sound more aggressive. Dodge with their SRT4 comes to mind.

Could it be the ecu monitors also the turbocharger intake pressure, instead of blindly cut spark or whatever?
I've no clue about A2l/maps, but when my wastegate got blocked in open position, i had a lot of farts from dsg. Even farting in N when fulltrottle reving up then releasing, engine was making small delay untill "accepting" my gaspedal release, then reving down with "machine gun" farts, like if ecu wanted the intake pressure to not go below xx value.

I think you're describing active antilag which is frequently used in motorsports. It is highly unlikely that you'll see any OEM using this sort of thing because it puts a _LOT_ of stress on the exhaust system and turbo. In rally we'd send the turbo(s) out for a rebuild after every race. Forget about warranty.

Yes, sort of "light" bang-bang effect, but my 1.4 tsi is a crap CAXXA model and not tuned at all, not sure if they were late ingitions (so less power to pistons but high exhaust flow, if i'm correct), i've no knowledge at all about this stuff, i just observed the engine didn't do a quiet revdown, instead it seemed to want more pressure in intake but faulty wastegate was blocked in open position, so the machinegun farting timedout after 1 second. I was just wondering if the dsg fart (which i've observed to be similar if not same) could be increased by lowering up the map value related to such "min intake pressure", if such variable exists.
About stress on exhaust and turbochargers, i think vw engineers have found a solution: "tell customers the turbocharger got broken for no cause, never occurred before, this is first time we see such problem" ;D

Are you sure this just isn't a delay between lifting off and the on-set of the over-run fuel cut taking place?

The stuck open wastegate would bypass the turbine blades and you'd have a more "naturally aspirated" engine as such.  Turbo's kill a lot of noise.

I'm thinking that the stuck open wastegate is allowing the exhaust to be more vocal, and you're hearing a small over-run fuel cut for one second.