I'm looking to buy the JDM 4-1 2.5" header with a 2.5" carsound cat, and also the itr b pipe + muffler. What size is the b pipe? I've searched all around to no avail!

 

Its 2.25

 

Yep. You'll need an adapter if you want to use the stock b-pipe. SMSP sells them, I believe.

 

Not if I'm going JDM 4-1/Carsound

 

It will bolt on, you're right but your cat outlet is 2-1/2" ID and the inlet to the ITR B pipe is 1-3/4" ID. Big time bottle neck.

You've got pictures in the mail.


[Modified by SMSP, 9:07 AM 12/5/2001]

 

What about the JDM B-pipe ?? Is it 2.25" as well ?? Once, I heard it was 2.5" but I never had a chance to confirm.

 

Question: Why would you want to run the ITR B-pipe if you are using a JDM 4-1 and carsound cat? Ran out of money to get a full 2.5" exhaust perhaps?

 

Well, money is always an issue when buying stuff for the car. In my case, I simply want to keep it as Honda OEM as possible. I also want to go with the sleeper look. While I accept the fact that there are better-flowing mufflers out there than ITR stock, I want to keep the stock look as long as possible. So, my exhaust setup would look something like this: JDM 4-1 header, carsound cat, 2.5" B-pipe, OEM ITR muffler. Don't flame me, I know I have strange ideas sometimes but it would be a kicker to find a quality, 2.5" B-pipe ... JDM ?? maybe ??

 

Well, I'm with iperez, I don't want a really loud exhaust and OEM is always best for me. Going from 2.5" -> 2.25" inch isn't that bad for a really good system!

 

I was told from nick@import-specialists.com that I can get a 2.5" inlet for my carsound cat, and 2.25" outlet, the ITR B pipe I thought was 2.25"... Not 1 3/4

 

What do you mean by quality b-pipe?

I think crush bent 2.5" pipe will still be larger than stock muffler diameter. No need for quality b-pipe if you are mating it to a smaller diameter muffler. Save your money.

You will also have to cut off the flange from your stock b-pipe and weld it to the new 2.5" pipe, because a 2.5" tube will not work directly with stock muffler. Stock muffler donut will not fit over 2.5" tubing.

CB

 

Stock cat outlet is 2" O.D. and the b-pipe infront of the resonator is 2". Only after the resonator does it become 2.25 O.D. I am almost positive of this.

CB

 

SMSP just said the inlet was 1 3/4", then the pipe becomes 2 1/4", minus a couple more bottlenecks along the way

 

Well I'll be damned then.

Nick told me that the JDM 4-1, Carsoundcat and the stock ITR bpipe/muffler would be a perfect fit with no modifications.

?

 

So you guys are saying that using the ITR b pipe/muffler isn't good with the JDM 4-1 and Carsound cat..because of the bottlenecks, might as well get a full 2.5" exhaust?

Aren't there a lot of people on this board running this setup?

 

I have a Mugen header I just had modified to 2.5" running through a 2.5" test pipe into a Mugen exhaust which is 2 3/8" The sound isn't that loud at all, not buzzy, but you can here the test pipe under the car, kind of an air rushing sound that wasn't there before. The car revs more freely, and I haven't confirmed on the dyno but it feels like my power band has moved further up the rev range. It pulls right to redline, I have bounced the car off of the rev limiter by accident because it is still pulling.

Mattj