I didnt' want to jack his thread, so I thought I'd post a new one instead.

I still have my stock cat in my 95 LS-Vtec turbo. I got it dyno'd / tuned yesterday and found out that my cat is restricting quite a bit of boost for me. At 7500rpm, I'm at 3.7 lbs of boost when I'm supposed to be boosting at 7 lbs.

I reach full boost at 3500rpm @ 5.6 lbs., and the pressure steadily decreases as I continue to rev.

Given the information in the test pipe article about fines and what not, would it be worth it for me to just remove my cat entirely? or should I get some kind of high-flow cat? Is there a dramatic difference in power gains betweenthe two? The thing is, I recently "passed" smog, so in terms of emissions, there shouldn't be a problem. I guess the question is, how easy would it be for a cop to notice if I were to run some kind of a straight pipe with a resonator?

The "projected" power gain (by Shawn Church @ Church's Automotive) with my setup and getting rid of the cat is between 10-20hp. Not to mention now the allowance of higher boost.

Any advice would be greatly appreciated. Thanks!

 

imo it restricts airflow. cops arent goign to notice. theyre not gonna crawl on the ground looking to see if you have a cat or not. not the ones ive ran into

 

I would just get a high flow cat, that way you can have a clear concious that your not killing the world

Also you won't have to worry about cops and emissions like that. The difference is very minimal between a test pipe and high flow cat.

 

well if u still have the stock cat, i would think its the size of the opening thats killing u not the cataylist. Get a high flow with a 3 or 2.5 inch in and out. Itll allow less back pressure and better turbo spool. But if you must you can use a test pipe and make a bit more power.

 

Ahh.. thanks for the info.. I think I'm just going to just go to a muffler shop (one that might be willing to remove my cat) and have the test pipe installed and welded. That sounds like the best thing for increasing power.

 

i've had all my cars straight piped and only got one ticket for it. instead of welding the test pipe, just bolt it on, and for any reason your car has to be inspected by a ref, you can always put the stock cat back on...hope this helps...

 

well.. I know of a place that can cut and weld the test pipe on for $25, whereas to get the test pipe and make the flanges for it would cost a helluvalot more.. given this, would you still recommend the bolt-on instead? The same price should stick for removing and installing the cat, meaning in case of inspection, I can get that sucker put back on for $25.

 

test pipes are less than 50 on ebay, but are around 75 to a bill at tuner shops. i'f you don't mind going to the muffler shop and waiting than cool beans, but with a test pipe you can swap them out when you need to...