I understand "optimal" exhausts for turbo and non-turbo are quite different. Specifically, turbos benefit from not having an exhaust at all - you want the least restrictions possible. Drag racers run dumps on F/I cars to ditch the exhaust path. But N/A cars are more difficult, with some back-pressure being beneficial.

Isn't this correct?

Basically I'm echoing AudiOn19s opinion that a proper before/after dyno sheet is the only way some of us can get over our fear of decreasing performance.

We have customers reporting approximately a 10 Hp gain going to the same X-pipe with high flow cats on the NA 996. If you look at most of the high performance exhaust systems used on 996 GT3 cup cars or race cars that have made more power on the 996 GT3, they all use a high flow design, very similar to what we have done, many eliminating the restrictive cats all together, such as on the Porsche FIA GT3-RSR race car, which uses an open exhaust with NO cats.

Many years ago when cars did not have computers (ECU's) a car could lose power with too much flow (reduced back pressure) because it would change the air/fuel mixture and the car could not adjust to a proper mix. With new modern engines, the ECU's adapt to increased flow and send more fuel, making more power. Our opinion is that back pressure is not required here - increased air flow and increased fuel is the key to unleashing more power.

I am extremely confident of the gains this exhaust will provide, therefore, I am willing to guarantee a HP increase, on top of the huge weight savings - not to mention the great sound! If you are not satisfied with the power after installation and/or a before/after dyno, I will allow a return for a full refund of the purchase price.

Nice to see people still developing parts for the 996.

Many of you have asked for a picture of our 996 GT3 exhaust. Here is one configured as if it were on the car. It also has the OEM muffler connection pipes pictured...

This is a system we recently built for a customer. It weighed in at 27 lbs. complete...the same weight as just the OEM cat pipes on the 996 GT3.

https://www.6speedonline.com/forums/...ine=1368919094

Close-up of our newly designed 996 GT3 "Le Mans" style mirror polished tip.

http://gallery.rennlist.com/albums/S..._jpg.sized.jpg

http://gallery.rennlist.com/albums/S...d_crop_jpg.jpg

These are made to order - we are going to be producing one of these systems in the next few weeks - anyone want to add on to the production run?

Here are pictures of two systems just shipped this past week -

X-Pipe with Hi-Flow Cats for aftermarket mufflers
https://www.6speedonline.com/forums/...ine=1368919336

Complete SpeedTech 996 GT3 X-Pipe Exhaust System
https://www.6speedonline.com/forums/...ine=1368919336

Vince,

The system passed at Tremblant this past week. The driver was not bashful with the throttle and did some WOT passes right by the sound person at multiple locations throughout the day!

Also, the weather was overcast with low clouds, which makes passing even more difficult.

The same customer drove 2.5 hrs. one way to the track with his wife. He was concerned and asked his wife how the new exhaust was and she said it was fine, sounded good and did not bother her at all....they both enjoyed the sound!

That's the latest update.

Also, the car did not require the turn down track tips to pass either - it was running our straight "Le Mans" style polished tips (which got their name from debuting on a customer car at the Circuit de la Sarthe, Le Mans, France)

Here is a video from the front straight at Mont Tremblant:

Another good video of this system - identical to the one that passed Mt. Tremblant

Hi All,

Any before and after dyno runs? what sound levels have you measured - Calabogie has a 98Db requirement and LCMT is a bit lower?

TIA

Ray

This system has passed sound testing at LMCT on a few cars...so no problem's there...Our design car owner did not want us to dyno his car, so no dyno on this one...

Just completed this 996 GT3 full catless "RACE" system with complete ceramic coating today!

https://www.6speedonline.com/forums/...ine=1380082225

https://www.6speedonline.com/forums/...ine=1380082225

https://www.6speedonline.com/forums/...ine=1380082225

We recently sold a system and the customer wanted the headers ceramic coating in a brilliant silver/chrome. We were able to do so and customer was very happy with the results.

Ceramic coating is available in multiple colors, not just black. PM for options if interested.

We just completed fabrication of a lightweight "FULL RACE" 996 GT3 system for a customer. It has cat bypass pipes, muffler bypass pipes and simple lightweight outlet pipes (no tips with polished outer layer). Here is is packed and getting ready for shipping.

https://cimg0.ibsrv.net/gimg/www.6sp...501ff1f089.jpg