What size pipe should I use when I build my turbo manifold? It is for a GSR. I figured about 1.75 so I could flatten it a little till I get the oval shape or should I just use 2 & leav it round? Also what thinckness whould I use? sch 40???? Please let me know so I can get this project on the road. I am takeing a short cut though Im buying a used cheap header & use the flange from that instead of spending 60 for the exhaust flange. Do you see a negative in this?

 

sch10 seems to work just fine as long as the prep is good, and your welds are good (enough filler, penetration, be sure to backpurge, enough heat but not too much etc. etc...) The material usually isnt the weak link, its the fabricator

 

1.5" schedule 10 or schedule 40. That is what everyone makes manifolds out of. ID is actually closer to 1 5/8" with an od of 1.9x"

 

oh and don't re-use a header flange. Won't be thick enough anyways. If you need one I've got a couple left over you can buy for $35.

 

Ill definatly be hitting you up real soon about the flange.... Oh I have another question what is the advantages & disadvantages of useing a ramhorn vers a log style??

 

KJ and ICC covered most of it. Except I prefer filler and backpurging on everything. Even dump tubes

My old One-Fabrication exhaust manifold. No filler, backpurging, penetration, etc. And my new exhaust manifold

Fusion welds > !@#$%^&*()_+

 

Also. A log exhaust manifold is going to spool the turbo a couple hundred RPM quicker but the ramhorn is going to make more power. Depending upon the setup about 15whp all the way to 60whp have been seen

 

 

My setup is a 96 gsr 81.5, cp pistons 9.0/1, block gurad, ferrah ss valves & valve sprins, titanium retainers & stock gsr cams. everything new with the exception of the cams.