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polizei polizei is offline
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Join Date: May 2007
Location: Collegeville, PA
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Originally Posted by RarlyL8 View Post
If not having an intercooler vs putting an intercooler in an unusual spot is your goal then you should design your engine to that limitation.
Start by finding the most efficient ball bearing turbo for the pressure island you will have. Optimising the turbo will significantly reduce discharge temperature. Add twin plugs, good gas, exact cam and ignition timing, and you may not need water/MeOH injection.
Give Marty (copbait73) a holler. He is an expert at this application.
Thank you for your response, Rarly. I have been wondering if all of those factors you listed could make it possible that no IC is needed. I think that I'm on the right track in terms of your list. I'm going to be running a ball bearing Garrett gt35r modified by Precision to flow even better. I'll call Precision to find out what kind of heat I could expect at 10PSI. I've already got the twin plug ignition in place, and I'll be running a Protomotive chip optimized for twin plugs. I'm entirely ignorant on how to adjust cam timing. I know that my wrench buddy set the cam timing to the exact specs of an '87 Carrera, as indicated by the Bentley manual. Finally, I have 93 octane gas readily available.

Unless the overwhelming majority comes back and says "something is better than nothing" in regard to having or not having an IC, I will start out with NO IC and monitor the intake temps. I'll relay those temps here. Regardless, I'm still curious to hear what kind of efficiency you guys think I could get out of a small IC with low ambient air flow.

One other thought is that Protomotive has had a kit out there for a while for running .5 BAR on a Carrera with 9.5:1 compression and NO intercooler. If you check out this graph which Marty posted a few months back, the net compression on that Protomotive setup would be 12.0:1. I'll be running .7 BAR on 8.0:1 compression, resulting in a net compression of 11.5:1. In addition to that, I'll be running twin plugs with a more efficient turbo.

Andy - 1987 911 Carrera Coupe
Old 08-16-2008, 04:46 AM
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