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Compression with boost

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Hello,

What CR pistons would you recommend for a supercharged Honda B16B for track use with 10psi of boost? I was aiming for something higher than stock. Fuel used will be VP SV05 and E85.

Thanks

Mark

I'm not familiar with the VP fuel however with such modest boost levels on E85 you're very unlikely to be knock limited. My understanding is that the stock CR is around 10 or 10.2:1 and I wouldn't necessarily go much higher than this. Often the decider as to which CR to choose is more around what is available off the shelf than what may actually be the 'perfect' ratio for you. For example if there is a 10:1 piston built for a turbo application but nothing higher, then I'd go with this CR. Note that often in the Honda world you may have higher CR options but they will be often designed around an N/A build and may not be strong enough for a forced induction build. Getting a higher CR piston made is certainly possible but the added cost for custom pistons is unlikely to be worthwhile in my experience.

As Andre alluded to, the piston may work from a theoretical compression/boost viewpoint but have insufficient crown strength - especially with potentially higher combustion temperatures further weakening the crown.

I'm a big believer in learning from other people's mistakes rather than repeating them myself, so I'd suggest having a good look through the Honda forums and see what they are doing.