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Johann · Joined: 07 Aug 2016 Posts: 240 Location: Netherlands

What setup are you running with regards to your exhaust Carrera RSR? I am looking to replace mine this winter and could use some European based advice

Carrera RSR · Joined: 08 Jan 2010 Posts: 2309 Location: Somerset, UK

Its a custom Haywood & Scott stainless system first used on BassGT's race car some years ago. Expands to 3.5'' off the turbo and tapers slowly down to 2.5'' at the connection to the rear section. No centre and only one small silencer/muffler in the rear section to reduce back pressure as much as possible
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1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
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canyonblaster · Joined: 20 Aug 2012 Posts: 391 Location: Denver, CO, USA

Fast Eddie....

AFR is 14-15 at idle, AFR fattens up to approx. 11 when boost is peaking at 10 psi. The CIS seems to have just have adapted w/o anything special.

Thx!
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PCA Licensed Club Racer & Driving Instructor Current P cars: 1981 931
Past P cars, 1985 944, 1987 951, 1990 911 C4, 2002 Boxster S, 2005 996 GT3, 2013 911 C2S
Daily Driver P cars: 2008 Cayenne GTS, 2013 Cayenne GTS

Carrera RSR · Joined: 08 Jan 2010 Posts: 2309 Location: Somerset, UK

Usually with CIS, if your AFR is 14.5 at idle and cruise it will be 10 on full boost. Any adjustment to lean off AFR on boost will conversely lean off idle and cruise, not ideal. Hence Brian Leasks boost enrichment kit which I emulated on my car. I keep 14.5 on idle and cruise, once boost is built the signal is blocked from reaching the WUR and AFR is in the 11's. But once the boost signal is triggered at 4800rpm then the AFR jumps back to 10. Which is needed to help cool the combustion and EFR on 1.0+ bar boost at extended high rpm's. So somehow you are very lucky to see 14.5 on idle/cruise and 11's on boost.
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1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
Now www.924board.org/viewtopic.php?t=34690
Then www.924board.org/viewtopic.php?t=31252

canyonblaster · Joined: 20 Aug 2012 Posts: 391 Location: Denver, CO, USA

I can't turn a wrench other than wheel/tire set swap, brake pad swap & bleed, pressures, etc. I'm a driver. But I can write a check. Local CSI guru tuned it early on in the project. This intercooler was a gift to the car and myself after "everything" ? was done. No idea why I'm lucky but the car is strong & fun. More fun than my sweet 951 was in so many ways! If I really want to go out and boil the B roads I jump in the GT3

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PCA Licensed Club Racer & Driving Instructor Current P cars: 1981 931
Past P cars, 1985 944, 1987 951, 1990 911 C4, 2002 Boxster S, 2005 996 GT3, 2013 911 C2S
Daily Driver P cars: 2008 Cayenne GTS, 2013 Cayenne GTS

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11724 Location: PacNW

In the US that's a cat.
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3