Too cheap to buy a catback, how much will that hurt? I'm running Jet-Hot Long Tubes, and will build a custom Y-pipe, and probably an electric cutout. But, I'm talking about with the cut-out closed...running through the exhaust.

 

I would say you'd be able to notice a definite sotp feel from going closed to open cut-out, especially since going to an aftermarket exhaust on a stock engine will net you some gains. I'm guesstimating, here, but based on your power levels it should be 20-30 hp? maybe more since you have headers...

 

I should be right at 500fwhp, and I'm running an electric cutout, but I haven't dyno'd closed vs open yet. Based on some racing though, its a pretty good amount of difference.

 

Probably 40 horses or so lost with a stock catback.

 

Damn this is an old thread.

I ended up getting a Magnaflow Cat-Back from I forget where for $280 shipped, just have to get a Y-Pipe now.

 

I did end up dyno'ing back to back runs and their was a 13rwhp difference. I do believe if I made 3 pulls each it would've been closer to a 20rwhp difference. This was when the car wasn't running right either and it only put down 378rwhp open and 365rwhp closed. I got the graph somewhere.