compression ratio
 

Hello people, tell me please what i need to make compression ratio 10 or 9.5? What parts i must to buy? Are there kits aviable for this action? (sorry for my english)

If you want to lower your CR you have to get a new set of pistons.

Your power goal should be known if you want to lower your CR.

What about connecting rods?

there are a few ways... even a thicker head gasket can lower compression... pistons are the way to go.

definitely replace the rods too
the stock items are weak and very variable in strength as they are a sintered part

Does anyone know how lower compression pistons affect emissions? I think I'd like to use lower compression pistons but I'm concerned that I'll no longer be able to pass a smog. California CARB is a PITA.

You shouldn't lower your compression ratio without first consulting your tuner on the benefits and cons for both keeping stock compression or lowering it, also for the amount of power you want to push out of the engine.

Personally for my build i'm staying with the stock compression with some (Custom CP Pistons, and Carrillo H Beam rods) because I don't think the trade offs you get with lowering your compression is worth it.
i.e. Lower gas mileage, lower grade fuel(usually), and etc.

But if you want to lower it, all you need is some low compression pistons from either (CP, JE, Arias, Manley, and etc just to name a few) just to name a few.

Or you can just run a stock internals with not a shitty tune and be fine to 450whp with e85 and 18psi. You should be blowing trannies before blowing blocks.

450whp won't last forever, no matter how good your tune.

200 won't last forever either.
@Reaper

13:1 or gtfo.

We have 2 cars locally racing time attack and still street drive. One is stock rods 13.5-1 at 400+whp and the other is all stock 450whp for 27,000 miles. Lots and lots of broken transmissions right now. Not much racing until sequentials come in.

Dont do it, unless you want to lose power.