Reason I ask is that on my stock shortblock I was running roughly 11.3-11.5:1 compression. With all of the same components (well a different spec cam for the turbo), on a forged 6.0L I am running 8.8:1 compression. I'm just curious how much the compression drop would affect my NA RWHP. Losing around 2.5 points of compression the new engine feels a lot stronger then what I was expecting.

-Sly

 

I remember some old rule of thumb like "for every 1 point compression you gain 4% efficiency".

Can anyone back me up on this one?

 

I have always used the 4% rule.A while back one of the magazines performed a engine dyno test,with the same motor,and changed the compression in 1 point increments.The test turned out to back up the 4% rule of thumb.

 

Cool, thanks guys that's right on with the RWHP numbers I was figuring I had based on the previous setup.

-Sly

 

i was told about 7hp by agostino racing.