I know smsp makes the reducer for the b-pipe, but Iam not sure if he sells it. I e-mailed him and I got no reply. Can any muffler shop make me one with a flange on it? How did you get your 2.5 inch cat or test pipe to work with your stock b-pipe. I want to lose the 2 inch bottle neck so having a 2 inch cat is not a option for me.

thanks

 

if you are running a stock exhaust manifold (or even a basic DC 4-2-1 etc.) you don't a high flow cat as large as 2.5". a 2-2.25" is sufficient and everything will bolt up maintaining a constant diameter tube. try a 2.25" sized cat with more side area for greater flow through the cat without excessively inlargening the inlet and oulet of the cat. if you are using a 2.5" catback exhuast system then using the 2.5" cat will help exhaust flow.

oh yeah, don't use a testpipe. it can get real nasty with the sound as well as the fumes.

later

 

BTW the stock header has a collector of 2" OD.

 

Ok, I guess I didn't explain it well enough. I want to get a DC JDM 4 into 1 and a 2.5 carsound cat. I want this all to bolt on to my R B-pipe. Meanwhile, I want to remove the 2 inch flange on the B-pipe and replace it with a 2.5 flange.

Here are some pics from this thread.
https://honda-tech.com/zerothread?id=204632





This is the adapter I want


Can any muffler shop make this adapter? I think smsp makes this, but I don't know if he sell it. I tried to e-mail him, but I got no response. How can I get this adapter???

Thanks for your replies


[Modified by Mac8008, 8:56 PM 8/13/2002]

 

ttt

 

I just installed my "Dave (SMSP) CAT and flange special" that you speak of.
The important note here is not just the match-up difference in size (see pic above) but the immediate bottleneck right behind that stock b-pipe flange. The part is sold for $55.00 which does not have any internal restrictions.

 

that's the one i plan to order as well.. there's still the bottleneck further down the b-pipe though(on the the stock)..

for now, you can just bolt up the 2.5" cat end to the stock b-pipe, it's just going to be a restriction until you get it fixed..

 

In talking with some, they believe that relieving restrictions closer to the engine are more crucial than those further back. Although no restrictions are best.

 

I'm running what you speak of... get the reducer from SMSP $55 stainless... Have not seen one from a muffler shop yet that was half as good as his...

 

i'm currently in the middle of installing my new JDM DC header/Carsound 2.5" cat setup. the header is on but i don't have the collector gasket yet to install the cat so it's on hold for a bit.

i take it you want to install the 2.5" cat now (with the flange adapter shown) with your stock header until you get the JDM 2.5" header?? i'm not quite sure what you mean.

i had the cat for a while until i got my header but i just waited it out to do it at one time.


[Modified by sweet, 2:40 PM 8/20/2002]

 

Leave Dave (his username on here is SMSP) am h-t im. He gave me all the info I needed the other day via im. I currently have a JDM DC 4-1 and am going to purchase the 2.5" cat and flange shown above. Dave at SMSP will get you everything you need.