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Low boost/High compression setup?

Joined
6 June 2011
Messages
808
Location
Okinawa, JP
Has anyone ran boost with high compression pistons? Seems like a way to make more power and have the benefits of a faster throttle response from compression. I'm not talking about crazy numbers here but could you get away with say... 11:1 compression (same as an s2000) on pump gas @6lb of boost? I saw an s2000 running 15lb of boost on a stock block with 93 octane (ill advised but still ran). So it may not be unreasonable to run a 6lb whipple on higher compression. Thoughts?
 
It can definitely be done, but most s2000 guys run it because thats how they come stock. Once building the motor most drop the compression unless they are running e85 then they can stick with stock or even go higher. My buddies s2000 made 900+whp and he either went with stock compression or .5 higher I forget but was always using E85 or race gas.

It all comes down to the gasoline that you are using, the type of forced induction, and the cooling capabilities of that FI system. The biggest reason FI setups can make more power with the same octane gasoline is because you compress air, cool it, then compress it again. That cooling in between keep chamber temps down. Running more compression counteracts this advantage. Typically(not always) more boost is the safer solution to get more power with safer temps because you can cool the charge air before entering the cylinder. Not all aftercooling systems are equal though, roots S/C often done have the best or any aftercooling systems and may produce a lot more heat with more boost. I would think 6lb pulley on the whipple on 11:1 would likely be fine on pump gas, but I'm not a supercharger expert.

When I build the block on my NSX I'm going to go with 10:1 compression so similar to stock, I have no E85 in my area or I would go higher.
 
Great insight, the idea popped in my head for the CA guys who are running CTSC's and want to make a bit more power, but still want to pass visual inspection. I can definitely see IAT's being a limiting factor in such a build.
 
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