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20B semi pp EFR9180 1.45 AR

Old 06-05-18, 05:11 PM
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20B semi pp EFR9180 1.45 AR

Semi pp/street port, stock intake and throttle body (semi pp runners added to lower intake), EFR9180 1.45 AR, Link Xtreme ecu, IGN-1A coils, 93 pump gas. 580rwhp @ 12psi, 650rwhp @ 17.5psi. Peak power occurs at 7000rpm, falling over by 7500. The engine is not yet run in so the tune is relatively conservative. There will be more power in it at a later date if need be but to honest there isn't much point pushing it hard as at 7500rpm it's out of compressor anyway. It might make 24-25psi in the mid range, but 17-18psi is it at the top end.

20psi is reached at 3000rpm, and by loading it on the dyno 12psi is reached at 2000rpm at 70% throttle. Anymore throttle opening than this and the engine bucked and surged badly due to the relatively high overlap. Because of this dyno pulls had to be started at 40 or 50% throttle at 2000rpm and gradually increased until full throttle was reached at 3500rpm.

Borg Warners matchbot indicated the turbo was going to be on the small side for a 20B but I didn't expect it to be quite this responsive. Of course the dyno isn't the real world and it will remain to be seen how the engine responds on the track. This is an amateur drift application - when planning the build target power was around 650hp with a wide powerband and not too much peak rpm. The 9180 with 1.45 does this perfectly. Coupled with the TTi sequential 6 speed trans this should be a fun, reliable car.
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Old 06-06-18, 02:19 AM
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Awesome. I knew this setup would be RAD!
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Old 06-06-18, 06:08 AM
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Thanks for sharing
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Old 06-06-18, 09:34 AM
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Originally Posted by JZG View Post
Anymore throttle opening than this and the engine bucked and surged badly due to the relatively high overlap.
Isn't this compressor surge?
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Old 06-06-18, 10:51 AM
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Quote:
Originally Posted by JZG Anymore throttle opening than this and the engine bucked and surged badly due to the relatively high overlap.
Isn't this compressor surge?

Sounds like it.

Bucking from overlap is a low load condition that goes away when you give it full throttle.

Then again, it is the high overlap that is powering the turbo to spool up to that psi at that low engine rpm- so the statement isn't wrong- just misleading.
and by loading it on the dyno 12psi is reached at 2000rpm at 70% throttle. Anymore throttle opening than this and the engine bucked and surged badly due to the relatively high overlap.
Dyno loading more than weight of car can load the engine on the road. My guess is 12psi @ 2,000rpm isn't going to happen on the road unless you are in 5th gear with the brakes on.
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Old 06-11-18, 12:44 PM
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Excellent. We're actually seeing similar trends/numbers in our side port 20B/9180 config. I think when its in the chassis it'll drive like a V8.
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Old 06-11-18, 01:11 PM
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With the bucking at low rpm, it can reflect two things:

1) Compressor surge. You'll probably be able to hear it. "chug chug chug" sound is often what it is.
2) Unstable combustion. This can often be corrected by advancing spark.
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Old 06-20-18, 04:41 AM
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Originally Posted by arghx View Post
With the bucking at low rpm, it can reflect two things:

1) Compressor surge. You'll probably be able to hear it. "chug chug chug" sound is often what it is.
2) Unstable combustion. This can often be corrected by advancing spark.
It may have been surging, I didn't bother with a speed sensor so I don't know for sure. I couldn't hear surge but it was hard to hear anything over the exhaust note. I didn't bother trying to tune it out as the engine will never be heavily loaded up under 3000rpm in the real world.

Heres a vid of the cars first outing on the track. Novice driver, it'll take him a little while to get used to it.


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Old 06-20-18, 08:24 AM
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Looks fun
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