Alex's R32 GTST Stainless Steel Downpipe

I've had a decat and APEXI stainless exhaust on the GTSt for a while now and fancied something new and shiny. Apparently a fat downpipe gives good hp gains. So I plumped for an ebay special. For about half the price of a Jap big brand downpipe, I bought a SS turbo elbow and a 3 inch downpipe from the US of A. Incedently it seems there are now a decent number of people fitting RB20/5DETs to 240SXs etc in the US which can only be good for the price of RB engine performance bits.

Downpipe looked pretty much spot on. Though the elbow need a fair bit of work on the flow divider between the waste gate and the main outlet which fouled the wastgate preventing it from opening! Luckily I found this out during a trial fitting! Otherwise it could have resulted in some nasty noises. Anyway I think I've got it to the point where it would work fine, but I've decided to hold fire on the elbow and just fit the downpipe for now. That was the plan after all, before ebay distracted me with cheap shiny stuff! The old downpipe came off easily, this may have been due to my unusual patience in coating the bolts with plus gas several days before trying them. Fitting the new one required a little twisting and shoving of the exhaust system to get it all lined up but the fit was pretty good. There is a support which joins one end of the cat (or decat in my case) and the gearbox mount. This need some holes slotting a fair amount to allow enough adjustment to get it bolted back up.

As you can see the clearance is pretty tight to the chassis. About half of what you get with the stock pipe which is pretty thoroughly heat shielded. And pretty much as you'd expect this results in quite a lot of heat getting transfered to the passenger footwell which is directly above it. After a quick test drive I decided that I wasn't happy to use the car without sorting out some heat shielding. So I bought some adhesive backed combined reflective and insulating material and cut it to size and stuck it on.   As you can see the heat shield is pretty flexible, the shiny side is somewhere between thin aluminium and chunky baking foil and the backing is a few mm of fibre glass type stuff.   Well it certainly sounds good and the proof of any hp gains will be on the dyno, but I'll need to look at the fueling again using the SAFC 2 before that, so as to get the most benefit from it.