Any 3 inch exhausts in development?
 

I know that most aftermarket companies are sticking close to the stock exhaust diameter or only stepping it up slightly, but are still producing decent results. I'm wondering if there is anyone that is developing a 3 inch catback exhaust or has messed around with that size piping yet.

Reason being is for years in the S2000 community there had been many people sticking to the theory of backpressure being needed to help with torque causing the aftermarket to stick with smaller diameter piping. More recently as the popularity of turbo kits started rising so did the aftermarkets exhaust piping diameters. Some people tried using the bigger piping exhaust on their NA cars and found that they gained power througout the entire powerband. It is well known that the F20/F22 flows very well, and I'm assuming that the FA20 would be pretty similar especially being alot newer.

Are there any manufacturers that might consider the possibility of an NA 3-inch catback exhaust?

I have a lightweight 3" Exhaust System!

So what's the verdict on the back-pressure theory?

Basically it has dispelled the "NA cars need smaller piping" myth. These are threads from just the s2000 and honda tech forums documenting no loss in power and gains throughout the entire rev range with the larger diameter piping. In fact it is now quite common in the K-series world to see 3 inch exhausts on NA setups. Here's some threads for reference.
http://www.s2ki.com/s2000/topic/8960...-inch-exhaust/
http://www.s2ki.com/s2000/topic/8132...-dynos-inside/
http://honda-tech.com/showthread.php?t=2341715
http://forums.clubrsx.com/showthread...ghlight=3+Inch

I'm very curious for results around here, especially since it is a very new platform. Just figured I'd throw out some food for thought:party0030:

Don@accelerated: Were you able to dyno your 3-inch exhaust compared to other piping diameters? If so do you have any dyno plots? Do you have any pictures of the setup as well?

Still waiting on specs of this thing. Dyno? It looks mean...

I saw that earlier when I was browsing, looks and sounds awesome! Patiently awaiting dyno results ;)

:) I know I know..... I promise this week for sure. Small hiccup with getting our new dyno up and running but it's all good now.

Thanks for the interest.

- Billy

I have a 3inch exhaust on my 1.8 B18c5. I have 13:5 comp. Totally didn't under produce power with it. 2+ Liter K series engines LOVE 3inch piping.

I've done a 3" 316L system with 3 straight through magnaflow mufflers and hks burnt muffler tips for my turbo setup. Will be jigging it soon for production.

We will eventually have at least two exhaust systems to choose from, 3" being one of them. We designed and built it at the same time as the 2.5" system. Noise levels and price tell us the 2.5" one will be more popular so it will be available first then we'll move to the 3".

How much more noise does it generate?

It would be hard to have a 3" system without a turbo that would be in the legal noise range. I would imagine hp would be lower than running a 2.5" system without turbo application.

What makes you think that hp would be lower? Just out of curiosity.