Jimmy-D

I would just like you to clarify because I am getting lost - Those that are using Racing Headers w/o a tune may be prone to throw a CEL??. The tune will eliminate this propensity??

BGB Motorsports

When you remove the cats the mixture is going to fatten up and the ECU is so intelligent these days that it's going to throw codes for mixture too rich. If you don't find a way to get the O2 sensors in the stream because the manifold doesn't have a pre and post cat O2 bung, you will get faults for your rear O2s not working UNLESS you use the tune.

BGB Motorsports

I have had Cargraphic add post cat O2 bungs to all over axle pipes for race systems. Minicats last about 12 track weekends and then they go poof. If i had Cup mufflers like you, i would not have this issue.

Yes. I also read a note on another thread you posted. For the record, I have Cargraphic race manifolds on my GT4 mated to the OE PSE mufflers. OE manifolds and Cargraphic Sport manifolds with cats have 2 O2 sensors while the race exhaust systems have manifolds with 1 sensor and the 2nd O2 sensor on the corresponding race axle pipe.

Yes sir. If you want to avoid a tune, you're only leaving about 6hp and 6lb/ft on the table if you do Sport Manifolds vs. Race ones.

user1029

most importantly I think I may be giving up 0.5db of loudness possibly? I like LOUD NOISES

jmartpr

...more noise is just an exhausts system swap away...

jmartpr

John...I see in your future a CG Cup Exhaust system!

kitwetzler

Not as of today. Durametric can read overrevs, etc, but cannot do coding of the 991 or 981 yet.

BGB Motorsports

We just completed a scratch build of a 981 that's running everything possible for Porsche Club Racing and on it are the Cup mufflers so that he can make sound at most tracks in the U.S. that would otherwise not allow the race mufflers. The Cup mufflers are nice. They definitely are more quiet but having talked to people in Germany, they definitely make more power than the stock PSE. Do you have a dyno run of your car yet?

jmartpr

I do but it's useless.......it was done on a Mustang dyno and I'm a bit skeptical on the results due to variations all over the place.....too many variables and most dynos posted here are done on DynoJet. Mustangs are notorious for outputting the lowest power numbers of all dynos so not much use unless we test 2 cars same day at the same time on the same dyno.

Jimmy-D

I think the aftermarket exhausts for the GT4 you have to target weight loss and upping the sound factor because the increase in HP/Torque are negligible

user1029

which makes completely removing the exhaust the best option for weight savings, noise, and power

user1029

how bad is the drone with the Cargraphic bare bones race-x exhaust?

jmartpr

That's a good question. The Race Exhaust with mufflers is perfectly fine with Sport headers.....My guess is with Race headers it could be a bit too much. The Race exhaust with resonators (the one with the X cross tips) should be even louder.....John (BGB) has a video of a Cayman with that exhaust and race headers......

BGB Motorsports

That will save the most weight but may be too loud for the street.

The drone i not bad but that's because the entire system is rather loud. You won't hear a drone as much as with a more restricted system.

It's rather loud. I have more and more video clips now. Jose, i spent all weekend with a car at the track with race manifolds and the Cup mufflers you have. the sound is great, definitely a bit loud for the street but as far as loud on track, it's rather quiet. That system was chosen for tracks that have decibel limits in the mid 90s.

jmartpr

But must sound awesome at WOT......the combo of the Sport headers and the Cup with mufflers is just perfect. It has changed a lot in terms of tone and volume. Everybody loves the sound and if you are careful with the throttle it's fine for the street. Also love the weight savings.