Ysi maxed out?
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From: ny
Ysi maxed out?
Just finish my build lsx 427 with ysi. 2.7 upper 8in lower. Made 21psi. Problem is peak power is at 5900 and fell for pretty bad after that. Cam was degree by engine builder. Tuner thinks blower is just done. Anyone who has maxed out a ysi what does it look like on the dyno.
Last edited by jacked cobra; Dec 17, 2017 at 12:33 PM. Reason: Add graph
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Fueling afr was 11.5 across the board. Timing was 18 degrees we tried 20 and it lost 2 hp and still peaked in same spot. Leaning toward the valves floating if it's not the blower. This was on a mustang dyno. So 920 on it is about 1050 on dyno jet
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Le Mans Master
Joined: Apr 2011
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From: Montreal
St. Jude Donor '13
YSI on a 402. 19.5 lbs and less timing than your running. Valve float would show as fluctuating on the dyno. Something doesn't seem right there, but would need a log to try and see what.
Last edited by realcanuk; Dec 17, 2017 at 05:14 PM.
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Joined: Apr 2010
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From: ny
YSI on a 402. 19.5 lbs and less timing than your running. Valve float would show as fluctuating on the dyno. Something doesn't seem right there, but would need a log to try and see what.
Attachment 48236140
Attachment 48236140
Le Mans Master
Joined: Apr 2011
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From: Montreal
St. Jude Donor '13
Originally Posted by jacked cobra
Tuner wasn't saving logs. So I don't have any. I'm thinking it's either the blower or float. I talked to Josh at a and a he thinks blowers done. Might try stiffer springs and go from there.
Doubt it's springs. Don't see how blower could be done, but I guess anything is possible. I would still think belt slip first. Would have thought more than 21 PSI with a 2.70 pulley, but there are a lot of variables to boost so don't know for sure.
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How can a tuner not be saving logs to look at after a pull ? Thats just dumb.
Doubt it's springs. Don't see how blower could be done, but I guess anything is possible. I would still think belt slip first. Would have thought more than 21 PSI with a 2.70 pulley, but there are a lot of variables to boost so don't know for sure.
Doubt it's springs. Don't see how blower could be done, but I guess anything is possible. I would still think belt slip first. Would have thought more than 21 PSI with a 2.70 pulley, but there are a lot of variables to boost so don't know for sure.
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St. Jude Donor '13
Dunno. Mine only a 402 but with good heads and mild cam. Is the cam spec'd for the setup?
All my numbers are with filter on. Never tried with it off.
As far as the tuning, I just can't see why he wouldn't save the log to look over carefully if he sees the power falling off like that.
Maybe Nick (unreal) will chime in. He's running a similar combo to you I believe.
All my numbers are with filter on. Never tried with it off.
As far as the tuning, I just can't see why he wouldn't save the log to look over carefully if he sees the power falling off like that.
Maybe Nick (unreal) will chime in. He's running a similar combo to you I believe.
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From: Baton Rouge LA
St. Jude Donor '14, '16
He was logging the pulls making changes then logging the next run. Just not saving them. It's got big cam ported heads and it's a 427 so boost will be lower. Honestly I thought 21 was a lot from what I see on 427 ysi builds. It made 17.5 with air filter on and 21 with it off
Last edited by sevinn; Dec 17, 2017 at 10:29 PM.