Nistune Forums

just thought id share my custom twinscroll external wastegate manifold i made, and man was it a project lol spent a lot of time on this top mount manifold but it allows for my hx35 to sit perfectly under the hood and it allows for me to have ac which is something i like to be able to turn on if need be the picture i have now is before i welded the wastegate flange to it but it is divided all the way to the wastegate piston so its true twinscroll. im not the best welder but the ugly parts are because i had to do some real custom crap bc of fitment. let me know what you think, and if you have something similar how does it perform, also i spent about 120 on the manifold for all the material and downpipe stuff, compare that to a 1500 dollar manifold cant beat that!

and another picture

what material and wall thickness ?

its mild steel galvanized coating. the coating made it difficult to weld on but in the end as i got better at welding the material it didnt bother me.

as for the wall thickness, i cant remember exactly as i order the material long ago but it is thicker than my previous aftermarket manifold that cracked on me. I didnt buy the pre made cuts of 45's and 90's i cut everything myself i just bought a bunch of u bends.

and i have just now got the car running again with this manifold and a hx35 turbo. the boost response is much quicker than i thought it would be, i believe the twin scroll helped significantly, also the use of making my electric boost controller force the wastegate completely closed helped a lot. so far i am really happy with the end result and cant wait to give it more heat cycles before i go and get the mani ceremic coated!

not bad for stick welding. looks like you only have a few spot leaks to fill.

since going Ex-gate.. put it on the exhaust housing not the manifold.

Just letting u guys know. The manifold seems to be working magically. Quick spool. No leaks. No boost creep. So far im loving it. Im running a shitty tune currently on a low boost setting (.8)bar and im estimating 325 hp. I have a friend with a newer vette that makes 375 ish. We did some highway pulls last night I had him in 3rd by half a length and in forth we were dead even and in fifth he oulled away about half a length. I never ran it passed 6 grand and the motor (sr20det) is built to rev to 9 safely. I cant wait to turn up boost to 28. Then ill be running e85 looking at 500+hp daily.