I'm trying to decide if it is worth the cost of a 3" exhaust system. I currently have a 2.5" thermal R+D and I was thinking of going to a 3" thermal. I'm running 1 bar of boost from the Apex'i kit on a B18B1.

Does anybody have any first hand experience of going from 2.25 or 2.5 to a 3"? What kind of numbers did it produce and was the in-car volume raised significantly?

Thanks

 

i went from a 2.5" to a 3" exhaust but i also took the cat out and gained 40 hp.

 

That sounds GRRRR-REAT!!!

I'm running a 2.5" test pipe too but...

My power really drops in the high revs. I'm hoping that back pressure is partially to blame.

 

Its not the exhaust that makes it drop in the higher revs, it is the small turbo.

You need a bigger turbo for the higher RPM's

3" is probally just going to make it worse.

Brian

 

Yeah, the IHI is pretty small but I don't see how going to a 3" could make things worse. See, my torque peak is in the same spot as a stock N/A ls so I'm thinking the torque drop has something to do with the nature of the stock motor as well.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TurbodCX &raquo;</TD></TR><TR><TD CLASS="quote">Its not the exhaust that makes it drop in the higher revs, it is the small turbo.

You need a bigger turbo for the higher RPM's

3" is probally just going to make it worse.

Brian</TD></TR></TABLE>
agreed!

but I personally would get a bigger downpipe and have it taper down to 2.5 full exhust.
**heres a though:..... keep your current exhust and just get a custom downpipe with an e-cutout