I have a b20b drag turbo setup with thermal 3 inch exhaust...

Would a 3inch "high flow" cat REALLY hurt my performance? My horsepower goals aren't that high. I'm more of driveability nut, but I do like performance. So would the cat hurt my power too much.

 

nope shouldn't, plus it's ozone friendly

 

bump, I'm curious about this too. I have a 3" carsound cat with my 3" thermal.

 

<----- also curious

 

cats are one of the biggest ristrictors in your exhaust sys., replacing it w/ an aftermarket will help but not as much as ditching it altogether, I say save some money by just putting a 3in pipe in it's place and put you stock cat back on when emmisions time comes

 

i also say ditch the cat...

Unless you have an ob2 car and hate to see that CEL

 

i don't need to worry about emissions, I already have a straight pipe right there...but I'm looking at the noise level, that is my main concern. I had a resonator put in, but it didn't really help.

 

Look at it this way, my car won't pass inspection, ever. No biggie. But if you get caught without a cat...hello double digit fine.

And no, a high flow cat should only take away horsepower in the single digits from what I have seen. I've been running one for over a year. My car is still loud as hell, and I too have a resonator.

 

so it didn't really make it difference in noise level?

 

would a 2.5" catless with just a muffler on the end flow the same as a 3" with a cat and resonator and muffler?