I going to get a greddy muffler and have custom piping from my cat back,I was just wondering what size piping should i get,I was thinking 2.25 or 2.5 what would give me the most gain.

 

2.25 is whats recomended

 

do you think i would lose low end toruqe if i use 2.5?

 

yes you will loose low end torque due to 2.5in piping...you will also loose a little with 2.25

 

Yeah you'd lose bottom end torque but gain some top end. Get 2.25, that the best, considering all the good aftermarket exhaust makers use that diameter.

 

Depends what you already have on your car.

I've got SRI, headers, downpipe, and added a catback this weekend. I've got 2.5" and can't say I lost anything. But then again, I've got headers and dp.

 

I couldn't agree more. I have the same mods and I have 2.5" piping from the downpipe (RPW) back. There is definitely a loss of low end power, but by the time 3500 rpms comes around, it's worth the wait. Plus it's all part of a turbo setup anyway, and generally bigger piping is better.

 

Yeah once you go turbo i can see getting 2.5", on a NA engine it just depends when you want the power.

 

i have the rrm header,cold air intake,and rrm piggyback and plan on going turbo

 

If you already have headers and the PB on top of that I say definetly go with 2.5. Try to get your self a downpipe as well. If you're serious about going turbo you'll need the downpipe anyway.