Exhaust Help!

[quickmr2]

Hi Guys!,
I got this exhaust that is 3" straight pipe to a Greddy Ti-C. I was told by a friend that 3" is to big for non turbo. That I will lose power. Okay, so if this is true, what size do I need to go down to? Also, how much power do I lose? Please guys can you help me.

 

[quickmr2]

Hi Guys!,
I got this exhaust that is 3" straight pipe to a Greddy Ti-C. I was told by a friend that 3" is to big for non turbo. That I will lose power. Okay, so if this is true, what size do I need to go down to? Also, how much power do I lose? Please guys can you help me.

Actually I messured the inlet to be 2and a half inch. It is straight through to. So it is probably the same all the way. Is 2.5 inch to big for n/a?

 

[2oo1Dc2]

i just went through all of this. I did a lot of research and got a lot of tips from a lot of people before i had my exhaust installed granted mine was just test pipe. What i ended up doing was doing 2.25 straight pipe all the way to the S bend at the gas tank and right there it jumps up to 2 5/8th's all the way out. i was going to just do 2.25" but i was given that exhaust so i had it welded up. 2.25 is perfect for a N/A build or a motor with less than 190bhp. 2.5" may be a little too big.