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Anyone have any experience or info relating to a higher compression motor with low boost? I understand it’s not the normal way and may not make sense. But it’s for a specific application with a specific reason. Throttle response and good drivability out of boost. Whereas you get lag and a lazy motor out of boost with a normal setup. By high I mean 14:1 and by low I mean 5-10 psi.
 

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What is the application?
I have not run into anyone running that level of high compression at any turbo boost honestly.
 

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What is the application?
I have not run into anyone running that level of high compression at any turbo boost honestly.
off-road car. Throttle response crispness is the most important. But you know turbos sound cool and trying to scratch the hp itch.
 

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I'd scratch it carefully. IMO, e85 isn't near the free intercooler than methanol is, nor is it as tolerant to the high cylinder pressures. That compression ratio is off every chart related to boost for a reason. The tuning window is non existent....well very small. Add to this the normally smaller cam profiles used in turbo applications, and you have a combo that wants to eat itself. My methanol combo is 12.5:1, and has very good throttle response....with a loose converter.
I'm that guy that has done the unusual turbo combo. But I wouldn't try 14:1.
Also, in an off road car where every ounce isn't a premium, I would certainly put an intercooler on it. My rail runs under load for 7 seconds. I imagine off road would be much more taxing and loner periods.
Throttle response isn't out of the question with turbos. They get a bad name in this area because of cars that are going for big numbers, and thus run very big turbos on relatively small engines. So they are fickle at low rpm. Go drive a new bmw. NO turbo lag at all. Very well matched turbos for the application.
Another advantage with the turbos really is that you don't need and shouldn't have enormous cams. This often will give you better throttle response down low and will build boost a little quicker. Now you have a valvetrane that lives, and an engine that makes power and is fun to drive.
But I'm sure the real experts will be here soon to tell you the right information.
 

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Comp doesnt mean responsive. You can have 14:1 motors designed to make power from 6000-9000 rpm and be a turd below that, basically being unresponsive lol it all depends what you want and how you size all the components.

you can have a good running NA motor and add large turbine turbo and tight converter and have a slow spooling combo that makes killer power once lit but all way up in rpm range. Or you can size everything around the rpm range you want to operate in and make it respond how you want, be it 9:1 or 14:1. Where do you want the power?
 
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