Gas of course They're called Porsche Braps.


Sent from AutoGuide.com Free App

 

So what causes/makes the "brap"?

 

It's from the ECU quickly pulling fuel then dumping it again once the gear is engaged.

 

Thanks Syn, so the "Brap" sound is actually a bi-product of a performance purpose? Or is it intentionally programmed in the ECU just to simulate the sound of a "race car"?

 

The "backfires" as Porsche call them in the owner's manual are only active in Sport mode or in Normal if Sport Exhaust is activated (for cars with PSE). I have PSE in my car (14 C4S) and there are NO pops/crackles/backfires in Sport plus mode at all. In normal mode with PSE switched off, there are also no such noises. However, activating PSE in Normal mode brings along these sounds and changes the character of the sound significantly. This is a much quieter car in normal mode; almost too quiet. Personally I like these sounds and I feel they add to the excitement of the whole experience. However, if you don't like them, then you need to avoid Sport mode if you don't have PSE, and if you do have PSE then you can switch it off even in Sport mode. This should be the same for the Macan, perhaps someone can chime in and confirm!

 

This brap was quite evident when I was at PEC last week. Most every car on the track made the sound. The Macan GTS I was in also did it and mine also does it. I like these sounds and at an endurance race where there lots of P-cars, you'll hear it a lot.

 

@synergize had it almost 100%. The "brap" is common with turbo charged cars. And as @synergize also commented it truly is very close to a fuel dump.

When the turbo pressure psi caused by an immediate accelerator-driven need for additional fuel, air and instant horsepower, that turbo pressure builds for that maximum "need" (according to that RPM), then when the car changes gears and momentarily loses RPM the wastegate opens and releases "extra" unnecessary pressure and some fuel ('brappppp") and then begins the "build" pressure process again.

It was not originally ECU driven in early cars, but may be assisted by the ECU in modern technology.

That's not the full technical answer, of course. I back away from those detailed diatribes because we have some engineers here on the Forum --

 

Thank you W Tiger and MacWhite, I am relieved, from your explanations, to learn that the Blap is not just an artificially induced ECU "race sound copy" (maybe just a little accentuated by the ECU programming?), but an actual performance byproduct of the turbo. As I stated above, I have an AWE Touring exhaust system installed, so the Brap fart can be quite loud when accelerating and shifting aggressively! As this is my first Porsche Turbo, I have never heard anything like this in all the previous cars I have owned. So thank you for the explanation.

 

Obviously you have magic.

 

The backfires definitely exist without PSE even in normal Drive but only upon hard acceleration. They are not loud but certainly noticeable (and enjoyable) to me.

 

Agreed 100%



The noise is definitely not tied to PSE. I find my S does this in the 2-3 shift under semi hard acceleration. When in sport it is noticeable under almost all shifts and now with the Cobb tune it definitely has the bite to go with the bark!>

 

The PDK definitely does not "fart" under normal mode with PSE off.

The DSG fart on the S4 was louder stock and with an AWE exhaust you could hear the pop a block away.

That was a sports car sound

 

The PDK definitely does not "fart" under normal mode with PSE off.

So the PDK will NOT "fart" in normal mode with PSE off, in cars that HAVE PSE, but it WILL 'fart" in normal mode in cars that DON'T HAVE PSE at all? That doesn't make sense to me.

 

Gotta love that Brap Fart!! With the AWE exhaust, it's quite an event, I must say. It sounds quite loud inside the car, wish I could here it from outside. Learnin' to love it!

 

next time you drive in a tunnel or under a overpass, make Brap Fart sound, it'll echo and sound twice as loud, lol, so much fun

 

My humble S braps under acceleration in standard or sport. It's just more noticeable in sport under aggressive acceleration.

 

Want more Brap? Get an AWE Touring exhaust system installed. Gurgles, farts and braps galore! Especially in Sport mode.

 

@grim, but a C4S is not a turbo-charged car and so it is true that there are no "braps" or "farts". In turbo-charged cars, that sound is produced by the wastegates (exactly as they are titled).

And when there are "gurgles" in a normally aspirated car, those sounds are not exactly (but similar to) a fuel "dump" -- it is because excess gas is burning but does so without an actual need for that fuel. The car is decelerating and the engine is slowing by the reduced momentum -- there is no true need for fuel yet some fuel is still being fed to the cylinders and thus burns and create those pops because of greatly reduced compression in those cylinders.

Unequivocally, in a Porsche the sounds are not "fake" -- what does happen in some models is that a "sound plenum" is used to redirect some of that exhaust sound back into the vehicle interior. It's not a fake sound, just a process so that the driver gets to hear it better.

 

If the OP is talking about upshifting, I was talking about decelerating. The deceleration or lifting is artificial. The ECU dumps excess fuel on purpose. That is fake. Its not necessary. Its not piped in over speakers like a BMW but not needed (hence fake). Its programming into the ECU from what I understand. Customers WANT those fake sounds. If he's not talking about lifting, then I agree about the BRAP. Maybe we are talking about two different sounds.

 

I am talking about the Brap when accelerating hard on upshifts. The fart between upshifting from one gear to the next.

 

When I was in Santa Monica last summer I got a BMW 640i convertible instead of the Mustang GT convertible I had rented... as a guaranteed model! (yes, I was a tourist in LA; any problem? ) In sport mode that car made numerous and very artificial braps ("brap-pap-pap-prrrr" would be a fairly accurate transcryption, I believe) every time I was lifting the foot from the throttle, even at low speeds and low revs (driving up and down those parking houses on the 2nd street ou can't go fast or rev up). Rather than impress me it just made me miss the Macan GTS that was waiting for me back in Geneva.

I love the GTS PSE's braps, farts and pops.

And yes, we all know what kind of gas @WHT TGR was referring to.

 

Nice! Next time you may get a 911 vert as a guaranteed model. >

 

Hey guys,

Sorry I'm a little late to the thread with the answer to this but the backfires/pops/farts/braps heard during a gear change is from the engine temporarily reducing torque by means of cutting ignition and fuel delivery. This helps to limit load on the trans when the next gear us engaged.

Here is a quick datalog of what is happening during a 4th->5th gear shift under full throttle that you guys can play with if you like:

datazap.me | jhebbeln | Macan S 4th -> 5th Shift


Thanks!

- Jon

 

I heard this on up and downshifts and it's mesmerizing. I have the S. I was just on the nurburgring and heard it from my car about 100 times slowing down on the turns and accelerating out of them. I was focusing on the road, so didn't look at the tach.

Does anyone know at what rpm does this happen on up shifts when accelerating?

 

On my Turbo, it is most pronounced when upshifting when accelerating hard, around 5-6,000 rpm.