3 inch for later

[FooFighter]

I'm building up my engine next spring but, wanted to get a few basic parts now, one of which was an Apexi N-1 catback. My car will be turboed next spring so I figured on getting the 3 inch piping. How will that affect my n\a performance? Should I get the gst option?
Will I need a flange or couplink to link the 3 inch piping to smaller stock pipe? (I own a 99gs)

 

[Johnny Spyder]

That large really isn't necessary until you start making around 300hp, and I would think in your case it would actually hurt lower end torque. 2.5" would be ideal.

 

[Eclipse96Ryder]

johnneyspyder, maybe u didnt understand his question...so to your question. I think that its a good idea to get the 3" now, yes i do believe u should get the GST option. Although this will hurt ur low end power like crazy right now, but when u get ur turbo u will be lovin it. But why go buy a 2.5" exhaust right now for $500 when ur just gonna turn around in a couple months and buy a 3". I say buy the 3" right now and dont install it until you get the turbo, also u said ur building ur engine up for a turbo, so im assuming rods pistons cams, all that fun stuff, so the 3" will be the way to go.

 

[dsmrunnah95]

If you're still running the stock cat, it wont damper performance too much. I've ran an open cat before and it was twice as loud but the power felt about the same, not like everyone makes it out to be.