Having a rebuild done, and currently have full 2.5 decat (H&S), will this hamper my performance.

Looking around for 3 inch or bigger but will mine do for now


The headers are ported OE items


Cookie

 

Circa 350bhp I believe mate, if my recollection of prev threads on the subject is accurate. I don't think it's set in stone though!

Ns04

 

Hope not as the build is a 400+ one

 

2.5 litre??

Ns04

 

built 2.0 with MD321t

 

Nice!

I'm sure there are other factors that determine how far you can go on a 2.5 inch exhaust mate. David knows what he's doing and will no doubt advise if it's gonna be a problem.

Ns04

 

the 2.5" can cope (if the design is good) at 400+. 3" ones just make it slightly easier to obtain as far as i know.

 

Cookie

I went for a 3" system....you know it makes sense mangetout, mangetout !!

Shaun

 

but my credit card

Oh go on then

 

Will ported o.e headers take 400+?

 

I bladdy hope so

 

Andy Forrest advised me in the early days while I searched for 380 bhp on a stock Sti 2 litre.

Over 350 fit a 3'' (Revolution makes a very good one)
Stock headers are fine, Stainless headers are good for top end bhp, ported headers are great for mid/low end torque with a little off the top bhp.

David does ported headers for little $$$ so fit a set!

You biggest question must be De cat or Sport Cat?

Graham.

 

I think to get the most out of a 321T you'll have to change the headers.

John Banks is the one to ask about the 2.5" system, IIRC on a thread of his a 2.5" coped with 400

 

I had a 2.5" Firestorm system on my car before the rebuild and it was rolling roaded at 382 bhp,It's for sale at the moment,it's on the shelf next to your car mate