Quote:
Originally Posted by JET
One thing to think about, with high compression via static compression it does not get cooled. If you add "compression" via boost, then you run it through the IC and it gets cooled down. So lower compression has more potential for power and be safer on the engine, but the higher compression will have better low end and spool the turbo a little faster.
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I agree:
Miller cycle.
While I think that the stock 1g compression is far too low, I think that right at around 9:1 is about perfect. You can negate much of the knock issue with high boost and higher compression by just having more timing retard. Now, at first glance you may assume "well you're still trading up: timing for compression". But a higher CR raises the burn rate which makes MBT, the ideal timing, much later. So you need to have more timing retard to get good timing; since timing is about *
timing* and not about advance. If you new at what point the fuel would preignite (different from detonation), then you can run as much CR up to preignition, as long as you know that you'll have to dial in more timing retard for the faster burn rate. There comes a point where the thermal efficiency increase doesn't merrit the cost of more CR.
As well, a higher boost will raise burn rate, and later timing with higher boost seams to do very well. Buschur does something like this with his pump gas builds. MAD timing retard, huge boost. All the fuel/air is still burned. All the fuel/air is still ignited at a point where it will put the most torque on the crank.
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Matt
Bolton Holset H1C w/ external gate, fp2X cams, DSMLink, 3" exhaust, FMIC, water injection
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