i have 8:1 compression with 7 lbs of boost is taht gunna be drivable?

 

Are you sure it's not like 8.8:1 or something similar? 8:1 seems a tad low. What pistons? Regardless, you can't drive without a tune.

 

p07 pistons

according to the calclulator 8.22:1
thats with the thinnest head gasket there is .025


i have a tune for my stock d15z1 which is 9:1
thet only diff is i am changing the head but the cc volume is bigger so it drops comp some. the guy at the head shop said these honda heads cant be shaved much and that even if he did my comp wont bump much

 

Yeah I wouldn't mill the head. If you tuned for 9:1 and your running 8.22:1 then your tune is going to be off a little. How much? Hard to say. But 8.22:1 still seems really low. What fuel are you running?

 

pumpgas at this point i think i have to use a d16z6 block that i also have laying arround....that fixes my compression problem

 

drivable? yes....safe? probably not, your engine has to be retuned no matter what you do to it unless you would rather run the wrong a/f mixture and incorrect timing and melt pistons

mechanix619, it's possible to have a very low compression ratio, though i'm not sure about the p07 pistons, but i run vitara pistons with stock length eagle rods in a y8 and my compression ratio is around 7.8:1, still very drivable though, just not as torquey as the stock 9.6:1 y8 compression ratio

 

I would get a new tune and just up the boost. That is the easiest way to get more power. I wouldnt bother trying to raise the compression unless your gonna do a built bottom end. Just up the boost by a couple psi and you will be fine.

 

but with that low of compression are you running something other than pump gas?

 

Nope 93 octane, high compression is where you need race gas