[img alt="Hello all I’m doing a pretty decent rebuild on my b16a2
And would like to future proof for boost and just need some help with choosing a piston compression ratio, the car will be daily driven on 98 pump gas.

I’ve read that 9:1 is the go-to ratio but I’m just wondering because it’s gonna remain n/a for a while.

Cheers 🍻 "]https://cimg2.ibsrv.net/gimg/honda-tech.com-vbulletin/920x2000/img_1985_f8d71a9c45c09a9a2ac1b8f6f3911fa23085e3d0. png[/img]
Hello all I’m doing a pretty decent rebuild on my b16a2 And would like to future proof for boost and just need some help with choosing a piston compression ratio, the car will be daily driven on 98 pump gas. I’ve read that 9:1 is the go-to ratio but I’m just wondering because it’s gonna remain n/a for a while. Cheers 🍻

 

No less than 10:1 unless you want more than 500hp.

9:1 is early 2000s mantra. Tuning is better now

In 2019 my b16 was 11:1 (cast nippon on forged rods, ebay buy), 14+psi on gtx30 (idk hp, never dyno'd), and could get 40mpg when driven easy. Tuned on neptune. Better tuning solutions exist to do even better in theory. Car is down for paint and upgrades. Prob getting haltech or similar once engine goes back in.

 

Would I need to get a tune if I drastically changed the compression ratio of my pistons? What are the advantages and disadvantages of dome pistons And flats?

 

Any time you change the way an engine breathes, intake, exhaust, engine internals that move air, you should get a tune.

​​​​​Compression ratio dictates shape.

 

If you were me and you had a choice between 9:8:1 or 11:0:1 which would you choose?

 

11:1

The #s are not 11:0:1 its 11.0:1 if anything. One colon. Gas gets compressed 11 times over atmospheric pressure. Hence compression ratio