The inlet manifold on the track car is currently off, and I've also broken the standard intake pipe (snapped a boss off), so now would be an ideal time to upgrade if they're worth the money.

Basically, the car has a td06-20g billet turbo at present (the old style sc42) on a 2.1 with std new age wrx heads.

The question is basically, does anyone have any back to back (or close to) measurements of standard intake pipe vs a silicone inlet pipe at around the 400bhp mark? I'm not planning on taking the power further on this car, hence I don't want to splash out on an expensive part that might not give any benefits at this sort of power level (and indeed be detrimental if collapsing under vacuum).

I see there's now 4 ply versions on ebay for not a lot of money, but I'm a bit wary of buying them in case they collapse (which doesn't seem to be limited to just the cheap ones).