Hey guys i just gutted out my cat and it feel great but the sound is kinda rasby..lol..by doing this will it help out performace wise in my R?will it gain a bit power?plmk..thanks

 

I'm glad I don't live in California.

 

how did you gut it?

 

Becareful if you gut all too much your check engine light will come on.
You probably gain abotu 3 hp.

 

Am I the only one who prefers to keep the air clean with a cat? Growing up, I remember the days in the early 80s when the smog was so bad they would cancel P.E. classes and warn us not to run around too much during recess. You could see it in the air, and it would actually hurt your lungs and make you cough when you took a single deep breath! Now I am thankful that the smog never gets anywhere near that bad nowadays, thanks to smog control devices such as catalytic converters. I believe that technology is wonderful in allowing us to make power without the pollution in modern cars.

 

I would suggest you weld a pipe inside the cat to help exhaust flow. The reason is that the pipe preceeding the cat is probably about 2", the flow then enters the cat which is about 3"-3.5" creating the turbulence effect. For better performance, you wanna have laminar (smooth) flow. So if I were you, I would take the cat off and have the muffler shop weld a piece of pipe inside the cat. I did this to my 3rd gen Prelude, I wanna do it to my current Prelude too, but there is a freaking secondary O2 sensor and the check engine light would come on.

 

You need to get rid of the R exhaust and go with a hi flow cat and at least a 60mm system. The stock R exhaust is only good for stock cars and it probably hurts them too.

 

How much power do you think there is to be gained from an aftermarket exhaust with AEM and JDM 4-1 with 2.5" carsound cat?

 

It depends on the exhaust. I'm not sure how many 60mm systems are available but I know of at least two, Tanabe and the Mugen. I know for a fact that the Tanabe has a restriction and I'm about 90% certain that the Mugen has a restriction. Plus we all know that it goes down to 2-1/4" in the twin pass muffler. So, I think both systems need to be modded to get the most out of them. Jason will have some dyno numbers, after this weekend, of his modded Tanabe system, he has already said that he can feel a difference so we'll just have to wait and see how good his butt really is.

When we installed RStoR's 2-1/2" mandrel bent cat back system there was a very noticeable improvement in power and response, but I honestly can't tell you how much. We don't have any numbers on his car after he installed my header with the modded stock B pipe but we'll have numbers with the header and 2-1/2" system together. If I can talk him into it we'll do a test of his Jeg's cat versus one of my CarSound units.

 

I'm pretty sure the Apex'i N1 is 60 MM with no restrictions (Maybe one right before the axleback) any input on that one?

 

If it is 60mm the whole way from the B pipe flange to the exhaust tip, it sounds pretty good. Are you sure there is no neck down at the B pipe flange? How much does it neck down at the axle back section? Is the muffler and resonator straight through? Tanabe uses some dog ear arrangement of the inner tube (resonator) to help promote sound control and these dog ears could cause some restrictions as compared to a straight/smooth through resonator.

I'm using 2-1/2" tubing in my initial kits which has an inside area of about 13% more than 60mm and 25% more than 2-1/4" tubing.

 

I also installed the SMSP b-pipe adaptor on my tanabe racing medalion, along with JDM DC and carsounds cat. The difference is very noticable. I also love the louder, meaner tone the car makes now. It is really loud! I have a video of a WOT pass, if anyone would care to host it.

The mid-range is greatly improved, top end as well......

 

sup guys..well this is how i gut the cat out..first i took it off, and when it was off i took the 02 sensor out so i wont damage it..I stuck a long metal rod down into the cat core and pound it out with a malet..And do it continuelly till it basically hollow..after i just got a high pressure hose and spray it out..you cant believe what was in the cat ..and that stuff they put in it,alot of restriction ..you wont throw a check engine light on because the 02 sensor is in front of the cat air just go thru it from the headers and it pass the 02 sensor and then into the cat..so no check engine light..

 

Here are some pics of it, hopefully they'll answer your questions. all your feedback is appreciated, as well as info on your new exhaust coming out, i'm in the market for one and can use all the help i can get.





[Modified by xjohnx, 10:23 PM 7/10/2001]

 

I hope you were wearing a good mask and didn't breath to much of that dust in. The catalyst material is very good for our air when used but very bad for our bodies when inhaled.

 

lol..i inhaled alot of it.. not good..lol..

 

what exhaust system sould i put on it?i dont want a catback cause i am goin to get the SMSP header soon and dont want to cut and modified the expensive catback piping..plmk what muffler to get cause imma just have the muffler shop custom madrel bent made the pipe..thanks..

 

Can't really tell from those pictures.

The initial release of my kit won't be for everybody since it will only include the parts to "build" a system and welding will be involved, however it will be 2-1/2" with no restrictions and the resonator and muffler will be straight through. I will also flared the inlet of the B pipe to have a 2-1/2" ID (vs the 2-3/8" of the 2-1/2" OD tubing), this way the B pipe will match perfectly with a 2-1/2" ID CarSound cat. Or any 2-1/2" cat, most if not all 2-1/2" cats are made to slide 2-1/2" OD tubing into either the inlet or outlet.

 

by gutting my cat out ..Did this gain me any HP?

 

Any idea on when it will be ready? Sorry to keep on you like this

Regards,

 

I should have kit prices today.

 

alrighty then

 

I agree! I think the HP gain is in your head. If your dead set on moding it go buy/make a simple straight through pipe. This can be changed later for when you have to SMOG it.

So how much does a new cat cost?