Losing power after 8000 rpm
#1
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Losing power after 8000 rpm
Well I went to get my VAFC II tuned and it was a disappointing experience. I baselined at 195.7 on a dynapack. After tuning I was only able to get 204.3 @ 8241rpm. We couldn't figure out why the loss of power. No CEL and A/F ratios were w/in norm with the VAFC and without. We even disconnected the vafc and harness. My tuner said I was losing a good 20hp because of the unknown problem. I'm running 4.57's, Mugen cooling mods w/ hondata gasket, intake/test pipe/exhaust, and denso IK24's gapped at .44. I do have a wiredspeed 02 sim that is propery wired up. I even cut it off for one run, but still had the problem. I also have a yellow box, but that is propery wired up as well. We came to the conclusion it's some sort of electrical problem, but because i'm not throwing a CEL, we couldn't pull codes. HELP!!!!!!!!!!!!!
#2
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Did you try the MAP whack? I don't want to start using that as a "fix-all" suggestion, but that seemed to help me when I had the following dyno:
Some of my problem in that dyno could've also been attributable to heat soak. Notice how my torque started dropping off after 7K RPMs.
What did your A/F ratios look like?
Some of my problem in that dyno could've also been attributable to heat soak. Notice how my torque started dropping off after 7K RPMs.
What did your A/F ratios look like?
#3
I've been getting this issue for awhile. i've changed O2S, valve adj., comp. test, engine oil change, reset ecu many times.... some are related and some are not but I was hoping... I also do have yellow box but not sure if that's cause..
#4
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I added the A/F plot. At the time I didn't think about the MAP whack, because I was almost sure it was a potential wiring issue with the 02 sim or yellow box. I guess I'll break out the rubber mallet...
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