Pat's Ebay Turbo Compound Boost Build
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Also muffler came in today, jesus christ this thing is gigantic. It's not 5x11, it's 6x11.25. This thing is going to hang very low in the rear, I'm afraid it's gonna drag the ground if I launch too hard.
If it were my setup, I would run a pair of O2s, one in the normal end-of-DP location, the other 6" behind the rear turbo. Measure backpressure next to the first O2, compare readings for a better idea of what true AFRs are under cruise/boost.
Then again, I think I would just run a 7163, make similar power, and have it spool much better
Then again, I think I would just run a 7163, make similar power, and have it spool much better
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I'll check, but 99.8% sure that won't work.
Magnaflow said this was a 5x11 muffler, uh.
Thanks, I thought about doing that with the O2's, but I don't have two widebands.
Are you running a 7163, and making similar power and spooling much better? What are your numbers?
Magnaflow said this was a 5x11 muffler, uh.
If it were my setup, I would run a pair of O2s, one in the normal end-of-DP location, the other 6" behind the rear turbo. Measure backpressure next to the first O2, compare readings for a better idea of what true AFRs are under cruise/boost.
Then again, I think I would just run a 7163, make similar power, and have it spool much better
Then again, I think I would just run a 7163, make similar power, and have it spool much better

Are you running a 7163, and making similar power and spooling much better? What are your numbers?
Last edited by curly; Feb 23, 2016 at 10:38 AM.



Turns out however that BMW's use little cute electric scavenge motors on their cars, tiny gerotor pumps. They didn't flow enough to produce pressure for my application, but would probably work great here.
No, but Soviet made similar power (484/404 Dynojet uncorrected) with better low end (200ft.lb@3100rpm IIRC), and he did it on an unported '99 head, and that was an EFR6758, which has about 75whp less compressor than the 7163 does.
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Yes, at 60 PSI base (dropping to about 5 PSI from that at 38 PSI) I'm at 100% duty on 5 1,000cc injectors. With 17.9* of timing. 500ish indeed.
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I made one for ~$50. Honda streetbike gerotor pump and razor scooter motor. I made mine to prime the engine with oil before starting, but it would work well for scavenge with a much smaller motor.



Turns out however that BMW's use little cute electric scavenge motors on their cars, tiny gerotor pumps. They didn't flow enough to produce pressure for my application, but would probably work great here.




Turns out however that BMW's use little cute electric scavenge motors on their cars, tiny gerotor pumps. They didn't flow enough to produce pressure for my application, but would probably work great here.

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EDIT: Just realized you quoted uncorrected (bigger) numbers and a different turbo too.....
Last edited by patsmx5; Feb 23, 2016 at 12:20 PM.
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Already answered that, but yes when it's sorted and the track is dry I'll be there. I had some parts come in yesterday I need to install to fix an oil leak in the rear turbo. Hopefully be there friday.
Don't laugh, I've heard of this: Do you think orienting all of your plug tips a certain direction would help with your spark issue? Might be a better direction than another in the combustion chamber turbulence....
Pat != avg cheap turbo miata owner (1800 hrs of welding experience, anyone?)
There are ways to turbo a miata cheaply, and there are ways to turbo a miata effectively. The number of people who can do both is extremely small.








