i have a 93 civic with a GSR turbo swap, and it still has the cat on it, if i cut it off will it boost more?? and if so how much more?? I know it should spool quicker.
any help is appreciated... thanks

 

It should not boost more. I was boosting 10psi on my stock 2.25in exhaust then I went with a full 3in exhaust and it boosted the same but spooled faster. I did not have it retuned after I did this and the ringlands went out on all of the pistons. I was making 280 at 10psi with a 60trim. With the 3in and new motor it was making 320 at 10psi so you can see how much a restriction it was and why I needed to retune.

If you tuned the car with the cat on make at least make sure the air/fuel is fine after you take it off.

 

ok thanks..
the car was tuned with the cat on it. its tuned at 9psi with a T3/T4 on crome.
What do you think the HP is??

 

it wasnt tuned on a dyno?

 

If it was street tuned then make sure you have your tuner check things over again.

 

No it was Street tuned.
He did a Good Job