UK Decat Diameter

[simbasupra]

Hi guys

 

I've had a look at other threads and couldn't find an answer, so decided to post a new thread.

 

I have seen threads regarding jspec decat diameters but not UK spec.

 

From what I understand it doesn't matter what diameter decats you fit to a jspec as you have to fit a restrictor ring anyway.

 

I have a UK spec and was wondering if 2.5" or 3.0" decats made any difference.

 

Would there be performance differences?

Boost differences?

Reliability differences?

 

Thanks

[sideexitsupra]

3.0" will flow better than a 2.5" obviously.

 

I actually went from a 3.0" to 2.5" when I changed my exhaust and had to play with the boost controller to get it back up to 1.2 bar due to the decreased flow.

 

At BPU I don't think you would see much difference. Over BPU and it may effect exhaust temps I guess?

[SteveC]

Some will say that 2.5" is sufficient for BPU, but I went for 3" decats and an 80mm system - just over 3".

 

The more free-flowing the system the better (if you don't need a restrictor ring - as on a UK model), but obviously there does come a point with increased diameter where all you get is a loss in ground clearance.

[simbasupra]

Some will say that 2.5" is sufficient for BPU, but I went for 3" decats and an 80mm system - just over 3".

 

The more free-flowing the system the better (if you don't need a restrictor ring - as on a UK model), but obviously there does come a point with increased diameter where all you get is a loss in ground clearance.

 

in another thread i noticed you said your decats were from whiftbitz, but i can only find 2.5" decats from them.

 

where can you get 3" decats for a uk from?

[SteveC]

in another thread i noticed you said your decats were from whiftbitz, but i can only find 2.5" decats from them.

 

where can you get 3" decats for a uk from?

 

From Whifbitz. They're made up to order as opposed to being listed on the website. PM or phone Paul Whiffin for a price.