I've got a 3" HKS Hiper back and centre section on a P1 currently. Which Hayward & Scott downpipe is for me, the 3" straight through or the 3" to 2.5"?

I'm guessing the 3" straight through but is their any advantage to restricting it a bit?

 

Mickle check this thread out here

 

After you've slogged through that lot, you want a 3". I'm guessing that the point of reading all the text is to see that the H&S technically isn't the best design, but practically the H&S gives realiably good results (you may get better from elsewhere, but the advantage of the H&S one is that it isn't at all particular about what you connect it to, whereas many of the twin-dumps - for example - are). Personally I like the BPM twin dump - it works well for me, but it's expensive & very 'particular' to its environment!
H&S is a good choice.

 

Cheers nom, currently I'm running on a HKS downpipe which I know isn't the best design hence wanting a change. People seem to rate the APS one which I've never heard or seen.

It always comes down to size in the end

 

Why exactly is the 3" HKS Pipe thought of being not ideal?

Just interested
Best wishes
Steve

 

Not too sure, I'm setting my car up for a TEK3 upgrade and I was told I needed a H&S downpipe as the HKS is restrictive at the top end. I'm just going on advice...

8)

 

The HKS downpipe is niether open neck or twin dump, it simply has a slightly larger bore near the turbo on the exhaust turbine side, and blanks the wastegate side of the turbo off. Therefore the only differences compared with the standard, are, bigger bore and not cat or silencer.

 

...and you really want the wastegate opened up for the Tek2 (or similar) to do its stuff.
Bit of a wierd design to me, the HKS one. They sort of got it half right

 

an interesting read
http://www.scoobynet.co.uk/bbs/threa...hreadID=168580