is the Itr cat already high flow or would a aftermarket one better with
new exhaust?

 

aftermarket

 

You changing exhaust diameter? 2.5" collector header perhaps? I'd just keep the stock one unless you need the larger one.

 

Why not replace cat with a tube? Cheap and effectve. Anyone done this?
My friend did so on a 240sx turbo (euro), suddenly he could hang (well sort of) with me.

Expected hp gains?

 

The cat for the ls/rs/gs and ITR is the same. On my ITR with a Mugen header and Mugen exhaust, the Carsound cat was good for 5hp and 5 pd ft @ peak, The best part was 15pd ft and 12hp @ 4500 rpm I didn't go with a straight pipe because I'm a stuborn bastard and do things my way.

Mattj

 

So a straight tube should at least get the gains you got from the carsound cat?

what is the price for that cat.? Sounds like a nice mod.

 

I wouldn't bother swapping the stock cat with a Carsound cat if you still have your stock header. An 60 mm straight pipe helps a bit with your stock header. You have to remove a bottleneck also.

 

Hi,

I did replace my cat by a tube and all is fine.
I didn't notice particular change because I did it
a month after I bought the car
(not used to the car )

 

Ok, I need a header then, what is best for the euro R? (Besides Mugen)

Aslo any other problems if I decide to replace cat with straight tube?

 

You won't pass the annual emission test. If you put a straight pipe now, you will have to modify it if you buy a JDM header. The DC JDM 4-1 is a good one for the price.
If you get the header, your stock cat won't fit anymore (for the annual emission test)!!!

 

Ok, let's say I want to keep the cat. or get the carsound cat and a header, is DC the way to go on euro R's then.
Maybe header first, then cat?
Or header, straight tube, then stock cat when emission tests come around. (Only every 2. year in Norway!)

What fits with what?

 

USDM ITR engine is not very different than the Euro B18C6. We have a higher compression and other small things (closer to JDM).
So, if a header is good for the USDM B18C5 then it's also good for us..

DC JDM 4-1, Carsound cat = 2.5 inch flange.
Stock header, stock cat = 2.25 inch flange.
You can make a 2.25" or 2.5" or 60 mm straight tube or any size you want.....

 

USDM Mugen or JDM Mugen? What diameter collector and cat?

Test pipe = illegal in most, if not all, (US) states.

 

ive got JDM header to 2.5" test pipe, reduced to stock cat back... i love it, only draw backs are
a)illegal
b)brown residue buildup on back lower bumper

 

I used to study in Blacksburg!! Loved to street race there. Got pulled over once in my charged crx for squealing tires coming out from a light!! hahaha