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911nut 911nut is offline
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Join Date: May 2001
Location: Michigan
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Quote:
Originally Posted by Speedy Squirrel View Post
The "effective compression ratio" is not a factor. The final temperature at the end of the compression stroke is strictly a function of the temperature of the mixture in the cylinder at the beginning, the compression ratio, and the ratio of specific heats.
I would tend to agree that ECR won't help us make a judgement in this case but it gets us into the ballpark. It's more about temperatures and efficiencies. The stock turbo and intercooler aren't winners. As soon as Porsche could go to more efficient components, they did (the K27 and full bay intercooler of the 965).
ECR is a theoretical term that's not unlike horsepower. It is a design tool. It keeps people from making stupid mistakes like spec-ing out an engine with an ECR of 21, for example.
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'91 964 Turbo
Port matched, SC cams, K27/K29 turbo, Roush Performance custom headers w/Tial MV-S dual wastegates, Rarlyl8 muffler, LWFW, GT2 clutch & PP, BL wur, factory RS shifter, RS mounts, FVD timing mod, Big Reds, - 210 lb
Old 04-27-2014, 04:26 AM
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