I took a notion to measure the size of my up pipe and it came out at 65mm OD which, allowing for wrapping and wall thickness, equates approx to a 60mm ID. My car is a MY98 with VF23, APS CAIK and FMIC, 550s, GruppeS headers (the up pipe came with these), Apexi PFC & AVCR etc etc. The reason that I'm asking is that I drove a P1 t'other day and noticed right away that power came in much earlier and stronger than on my car where it tends to come in more sharply at approx 3500 rpm and I wondered if the up pipe was killing gas speed considering that I've only got a little VF23. If it is too big what would a better size be? I'm also planning to fit a TD05.18g some time so what would be the best size to use with that? Thanks

Raymond

 

Anybody?

 

alrite mate. ive been askin the same question as u, ive read through sum old threads and they reckon that about 46mm is the largest to go for an up pipe because it slugs the spool up of the turbo. mine is a 50mm which i think isnt to bad and it drives ok but i think a 60mm one is a bit big. thats all i know mate,youl probly get another reply tmoz of sumone who knows a bit more about them.

 

60 mm if it is 60 mm is way too big for a VF23 or similar. You will find a big improvement in spool and probably no loss further up with an up-pipe of 46-48 mm maximum.

 

50mm is big enough for 500hp. 60mm will not be doing you any favours.

 

Thanks for the replies. I've just acquired a 20g and i suspect that my up pipe is going to be too big for that as well