Compression = H.P./TQ

[nismojunkie]

Does anyone have an educated guess on how much horsepower/Torque could be gained going from 8.6:1 to 9.1:1 pistons?
I am building this SOHC in an N/A config and with the block down at the machine shop, this is a good time to decide this. :mepoke:

[sepulchral]

stock comp on sohc is 8.6? thats really really low damn

[Jeff240sx]

1 point compression increase = 5% horsepower (or something.. maybe 10%? But that seems high.. 5% sounds more correct). Your .5 point increase will be 4hp or something on a KA-E
-Jeff

[nismojunkie]

Stock is 130 @ fly... so thats 6.5 hp @ 5%.

Quite a bit of money to spend (approx $325USD) for 6 HP, no?

With much headwork planned, will the higher compression pistons benefit me more significantly on the ported and polished head than stock? I mean will I get a bigger power increase from the later mods with the HiComp pistons than if I stuck with stock specs?

[orion::S14]

^^^ Yes.

And 9.1 is stil too low IMO...if you're gonna spend the $$$ (and stay N/A), get some 10:1 slugs and really make a difference. Still easy to do on pump gas, but better gains after other mods...

- Brian

[msaskin]

Hell, you could easily run it at 11:1 on pump gas (91 octane +)

~matt