Thursday, July 8, 2010

Holset update

Well, I've been running the Holset for a while now and I'm really enjoying it, but I've hit a wall with tuning. I really can't run more than 20psi with my setup. The 2.3L stroker engine that I'm running has higher compression Wiseco pistons which bumps me up to 8.9:1 which is limiting the amount of boost I can run on crappy CA 91 octane. I've pulled timing way back. I run about 5 degrees at peak torque, and ramp it up to 10 degrees peak timing. I could pull some more timing, but as it is I'm already seeing really high EGTs from partially combusted mixture shooting out my exhaust. If I pull the timing any more I'll just be wasting energy. I'm going to try turning down the boost and adding some timing, but running an HX35 on such low boost is almost pointless. Another option is running meth or e85. Since there's hardly any e85 in SoCal, I'll probably end up going with a meth setup. For now I'm keeping the boost around 20psi. If I had it to do over again I would have had the stroker built with 8.5:1 pistons.

Also, I've noticed my Holset spools a little late for being paired up w/ a stroker. I was expecting it to spool up by 3,500rpm, but it really doesn't reach full boost until about 3,800. That's still pretty good for such a big turbo, but I need to do a boost leak test and do some more tuning to improve spool up. I'll keep you posted as I see results. I'll try to get to the track sometime soon too!


Anonymous said...

I have read and read your write up on the Holset and it helped me tremendously with my install. My problem now is it made only 303 awhp on a mustang dyno on 22 psi??? Any ideas why such low numbers ? U can contact me via email @ Thanks in advance

miley swan said...
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