i have a mini me y7block/y8 head, so the compression ratio is already a little higher, but i was wondering what are the disadvantages to increasing CR even more?

Do i need to do anything to prep for higher CR?

Detonation: if this is the main concern, do you have to dyno to prevent this or can you garage tune it and successfully avoid it?

Is there a limit that id want to avoid (CR)?

I saw on ebay some pistons for the ZC that would increase my compression a bit more than current setup, the price was reasonable so i ve started to wonder about CR.
they were specifically: 75mm p29 High Compression dome Pistons made by NPR in Japan.
says also: D16Y7/8 Block and Head get a CR of 12.89:1 with these..


also i have a dc sports 4-1 header, a cheap intake and a lightened flywheel/clutch.

(im not interested in putting a turbo on this engine ever, so i realize if i were wanting that, i d want to get a lower CR...)

Purpose of a switch like this: to learn more about my engine, to get a bit faster acceleration (pretty good now), and thats about all...

Also, im bitten by the swap bug like everyone else, but at the moment im not goin that route, i need to buy a house first. A b16 or b18 will have to wait. Though once i get one i will probly want to do some CR alterations as well.

 

Increasing compression increases the chances of preignition/detonation. It also results in higher nitrogen oxide emissions.

 

how bad is that?

 

You don't want preignition/detonation.

If you want to pass emissions, higher nitrogen oxide emissions will not help.

 

your gonna have to run higher grade of gas.. with the prices these days, thats definatly a con!

 

Look who's talking lol!

 

you could tune it in a garage as long as the person tuning knows what there doing. Also depending on where you live you need to be careful on your inspections. Chances are you will not pass.

 

higher octane, higher emissions (NOx)

 

how exactly are you going to accomplish that, unless you meant in a garage with a dyno!