bigmikespec

What country are you in? I have had these on my car for 5 years, they are not new.

Brad did this get fixed?

Yes because of heat transfer through the pipe which is nothing to do with what I said. You have a 3.5" restriction, put it anywhere along the 4" pipe, it will do the same thing.

I don't mean to be seen to be picking on your posts but that is incorrect, it could be 4" all the way and have a 3.5" tip and that is enough to cause a restriction. Does not matter where it is along the pipe really.

Does anyone want to help out with turbo position? Here are some screen shots of billet T4 twin entry piece and merge collectors

For the record, compressor RPM and pressure are not related... at all.

Beautiful car and colour... I have the same. I want another one, hoping you still have it in a month or so!

Nice crank scraper! GTRPSI

Wow that is average for a race car... but was that built to class rules?

You will get reversion through the exhaust with the overlap too...

Yes. But I will wait for someone to say "oh they are old tech" without even quantifying (or perhaps understanding) what that means.

Parts arrived, very well packaged. Great seller! Thanks Joe.

That was the Hioctane R32 right? Not apples to apples really. How many tenths classify as spanked?

I can get the flanges made with what ever primary size going into it and a T6 one too... send me a PM. A more progressive merge and a waste gate port that is more in line with the merge instead of 90° is a lot better but I want to keep it compact and I am using twin 44mm gates so boost control should be ok.

They are not common due to a mixture of misinformation and people not using them as part of a complete package. They are a 'bolt on' turbo but personally to get them to perform properly requires more work. Guys like XKLABA have the right idea... didn't Paul Diemar push 500kW with these back in the day? That was on a 2.6 with a lot of head work.

Yes, definitely slow and steady though... What I wanted to be able to do is have a compact billet collector, makes it as cheap as possible. But also so that you can build a 3-1 tube merge and weld it straight on.

This is my collector effort so far... the T4 flange part is billet machined to get the transition from circle to rectangle spot on.

Photo of collector won't post

Can anyone help a brother out... I am drawing up my exhaust manifold .To save me measuring, anyone have a CAD file of a RB26 head flange for a single turbo manifold? Position of the ports and studs, etc. Here is the work so far, the T4 flange is billet machined to get the merge right and also space the two sets of 3-1 collectors appropriately. Means that the 3-1 are easy to make and transition from a circle port to the rectangle of the T4 is spot on. Any format is fine, thanks. Mike

Check out Burns Stainless, they do some pretty fancy merge slip on turbo collectors.

It seems crazy. Borci88, I don't know why you would persist with not porting the head (only if you could not afford it), you can make power through small ports but not efficiently. Put VCT on the RB26 head if you really want, done.

Go for it then, replace the guides with bronze ones (I got Nitto ones) and replace the valves with +1.0mm oversize, at least they can recut the seats so it is all perfect again. Maybe try the Nitto valves.

If the ports are not being opened up a lot I am not sure that bigger valves will do much for you. Does the head have any porting?

Supertech or if you can Ferrea, forget Naprec. Supertech make parts for Tomei. I think Nitto do valves too?