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flashgordon64 flashgordon64 is offline
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Join Date: Mar 2010
Posts: 507
Originally Posted by Tonger View Post
This is a purposeful and serious looking build. I especially like the angle of the wastegate piping from the secondaries - it shows a lot of thought and craftsmanship. If you don't mind, I have a few questions.

* Headers are unequal length but look larger diameter. Does it matter in the twin turbo setting? When is the boost all in? How does your motor behave off hoost?

* I may very well be wrong, but I think I see four wastegates. The lower ones that come off the secondaries and dump into the smaller dump pipes look conventional. What do the ones that go into the IC above the engine tin do?

* I know you have a very large IC but would there be any benefit to moving the air intakes/filters to a cooler spot and ducting them to the turbos to try to minimize heat soak? Maybe it doesn't matter, the packaging in the bumper is very space efficient but I imagine it gets quite hot down there.

I'm definitely not criticizing, your build is off the charts - thanks!
Hey Tonger, I'll try my best

1. Headers are 1-5/8". I don't find that the unequal length effects boost at all. These are small turbos so it doesn't take much to get them lit. They are GT28 housings with 58/57 billet wheels(ceramic ball bearing). So in affect they equal to GT30's. The best thing is they're all in @32-3500rpms As far as off boost, it's fine. A lot of guys complain about how doggy high hp builds are off boost. I don't find that to be the case. It's all in the tuning.

2. There are 2 wastegates(either side of the turbos). What you're seeing above the tins are the blow-off valves. In the older pics I only had one and it was located behind the IC. I've kinda added a couple things and moved things here and there this time around.

3. There's just not enough room in the engine bay for air filters so I had to come up with this solution. On a side note they were surprisingly clean when I removed the bumper so....and never had any indication of heat soak.

Take a look my engine builder doing some light revs from a few years ago :

1986 930 Guards Red
Too much to list...Lot's of HP
Old 05-03-2018, 07:19 PM
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