Turbo header length
#102
Just in time to die
iTrader: (1)
Running dual wastegates allows you to do a few things one is keep the manifold completely divided. It also allows you to run a more efficient(for lower boost) valve to diaphragm ratio. This offers better boost control. I think most people go over board on wastegate size. If it were me on your set up I would run on 44mm and be done. It is a good happy medium. Big enough to control lower boost settings and small enough to work with 38lbs. Dual wastegates are cool but not necessarily needed.
-S-
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#103
Pineapple Racer
iTrader: (1)
Ok, so lets start talking prices. How much money are we talking for a manifold that has roughly 2" ID tubing, 16-18" long, equal length, setup for a single wastegate, etc. Safe to say 1k+?
Hmmmm, maybe I should see if Ralph or Rob has one laying around. All this talk about faster spool, and more power sounds good.
CJ
Hmmmm, maybe I should see if Ralph or Rob has one laying around. All this talk about faster spool, and more power sounds good.
CJ
#104
development
Originally Posted by Zero R
Running dual wastegates allows you to do a few things one is keep the manifold completely divided. It also allows you to run a more efficient(for lower boost) valve to diaphragm ratio. This offers better boost control. I think most people go over board on wastegate size. If it were me on your set up I would run on 44mm and be done. It is a good happy medium. Big enough to control lower boost settings and small enough to work with 38lbs. Dual wastegates are cool but not necessarily needed.
-S-
-S-
maybe I'm way off base here, just the way things work in my head. I have to think dual WG and true fully divided has more to offer than just "cool". If the efficiency is seen at low boost, that's creating much more under the curve power. Maybe it's not so important in drag racing, I don't know...I'm just thinking at loud, if I'm misunderstanding something, please clue me in. Might be just as hard to fit dual WG's as it is equal WG runners
#106
Just in time to die
iTrader: (1)
Ideally you would want to keep everything as equal as possible. Equal secondary runner length, equal length up to secondaries etc. This is a very hard thing to do when you are limited by space etc. You more than likely will have to mount them in different positions on the primeries. If done (located)correctly backpressure differential would be minimal. Is there some benefit? Yes. Is it worth the added mess and wieght under the hood? Not really. It's minimal. Ask your self how many pro built cars in most any form of racing are using more than one wastegate per manifold.
#120
Believe it or not that was a stock port with a less than optimal midrange tune. At idle it purrs like a kitten but just barely crack the throttle and it goes to lopeing. I figure it is the fact that it has such a large intake and throttle body.
You can really tell on the dyno.
http://www.youtube.com/watch?v=Re_QuvMnR28
Here is a thread with the pics of the aftermath though.
https://www.rx7club.com/rotary-drag-racing-167/can-factory-reman-motor-run-9s-713563/
You can really tell on the dyno.
http://www.youtube.com/watch?v=Re_QuvMnR28
Here is a thread with the pics of the aftermath though.
https://www.rx7club.com/rotary-drag-racing-167/can-factory-reman-motor-run-9s-713563/
#124
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Join Date: Dec 2007
Location: san diego
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another thing to think about when choosing runner length is egt temps going into the turbo and also the wastegate. a shorter runner manifold will have much higher egts on the face of the wastegate valve as well as the turbo. rotaries already tend to run very conservative ignition timing which increases exhaust temps. temperature kills everything so whenever you can keep temps down its a good thing.
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