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The APR Valveless Catback Exhaust System is Here! (MK7/MK7.5 Golf R)

Funtuzzi

Passed Driver's Ed
Location
Canada
Watched the video and sound clips on APR website. Why is there no pronounced DSG "farts"? At the end of the clip, we can hear a small DSG burp. All other parts of video shown from inside and out of car, with multiple shifts, cannot hear any DSG farts. Sounds like any other car shifting.

Does the Helmholtz resonator eliminate the "burps"? Or is this video clip not the best representation?

Honestly, the full exhaust system with mufflers sounds louder and meaner on the APR video clip? Shouldn't the straight pipes be louder? Just poor video/ mic, or editing?
 
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TrinivdubOG

Ready to race!
Location
Caribbean
hopefully they don't sell it with a bunch of faulty clamps, like the ones they sent with my valved system. Ended up just welding Vband clamps instead :rolleyes:
 

Arin@APR

GOLFMK7 Official Sponsor
Location
Auburn, Al
Car(s)
B8 S4, MK7 GSW TDI
Why is there no pronounced DSG "farts"? At the end of the clip, we can hear a small DSG burp.
When you launch the car, the transmission enters into AMAX mode, which eliminates the fart between shifts (because it's faster without them).

The other car (valved exhaust) had our pops and bangs software installed too, so it has a loud crack. I seem to recall it was actually a manual.
 

Funtuzzi

Passed Driver's Ed
Location
Canada
Thanks for the education Arin.....Now I'll have to launch my car and have a listen to my exhaust. Never knew there was a difference in shifting and sound.
 

gotahave

New member
Have a 16 R and at stage II+ and want to get the APR valveless cat back system. I don’t get on the car much but the people down here(fla.) say it’s really to loud for street( APR salesmen) and unless racing it’s just to loud. Is it really though. I don’t want to be known as the guy with the obnoxiously car. It’s on sale now so a great buy. Not a great buy if everybody hates your overly loud car. Is it to loud for street or not?
 

ATR

Drag Race Newbie
Location
Baltimore
Car(s)
'17 Golf R 6mt
Have a 16 R and at stage II+ and want to get the APR valveless cat back system. I don’t get on the car much but the people down here(fla.) say it’s really to loud for street( APR salesmen) and unless racing it’s just to loud. Is it really though. I don’t want to be known as the guy with the obnoxiously car. It’s on sale now so a great buy. Not a great buy if everybody hates your overly loud car. Is it to loud for street or not?
Ummm, yeah with a downpipe it's VERY loud... The standard APR exhaust gets my vote if you're at all concerned about noise.
 

The Fed

Old Guys Rule
Location
Florida
When you launch the car, the transmission enters into AMAX mode, which eliminates the fart between shifts (because it's faster without them).

The other car (valved exhaust) had our pops and bangs software installed too, so it has a loud crack. I seem to recall it was actually a manual.
Please elaborate.
 

ATR

Drag Race Newbie
Location
Baltimore
Car(s)
'17 Golf R 6mt
Please elaborate.
From here:
https://www.audizine.com/forum/showthread.php/766796-What-is-AMAX
Amax uses both clutches simultaneously and slips between the gears.

A normal shift de-rates the engine by telling the ECU to pull timing. It does this to prevent free-revving and to lower the torque at the clutch to make shifting easier. It has the engine de-rate while it's opening the first clutch. The engine free-wheels for 50ms or so while the second one is being closed and then the TCU tells the engine to bring back the power. That de-rate timing retard is what causes the DSG "farts" you can hear on videos.

Amax doesn't work like that. When in this mode, the TCU keeps the beans on the entire time. There is no de-rate at all. It controls the engine RPM by having both clutches engaged in the linear (slip) region together while it transitions between the two. The upshot of this is that there is no de-rate, the engine is making full power the entire time and is transmitting it to the ground even during the shift. The downside is that it's extremely delicate. If the transition time is too fast, the clutches won't slip enough, will be working against each other and will rip themselves out of the transmission. On the other side, if the transition time is too slow, the engine will free rev, hit the limiter and de-rate via the rev limiter. It comes back as soon as the clutch closes a bit more and pulls it off the redline, but it still spent some time in de-rate.
 
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