4G63 HIGH COMP TURBO

HELLO

We are in the process of rebuild our evo 8 drag race car .2.1 RUNNING PURE ETHANOL 3.1 BAR OF BOOST . 850 WHP MAILINE DYNO

i am thinking to go with higher compression pistons LIKE 11.5 COMP and bigger turbo ( PT7685 ) and 3.0 bar of boost .

so I've heard that I need to move to methanol instead of ethanol bcuz of this boost and this compression .

plz can you confirm and ?

what is the max piston comp ratio I can go with this setup .( boost and ethanol )

thank you in advance

Hi.

After some point you better off to decrease Compression ratio if you want to increase the boost level. It is additional displacement for air vs better thermal efficiency while thermal efficiency is good only to some extent. Please find the attached file that explains the process.

Shota has done a lot of experimentation with those engines, I would put a lot of weight on what he says!

hello

i forgot to mention , the pistons now is 87 mm

thank you

so as shown in the graph attached by mr shota 9.5 comp is the best , right ?

With CR 9.5 and 3 Bar of boost you will get 6 percent less power than with CR 7.5 and 3 Bar. Not much but it is just starting point. The higher the boost the bigger the difference will be in favour of lower CR. I'm running 3.2 bar of boost with CR 8.4 on E65. Next season I'll be running 3.7 bar of boost on pure ethanol with CR 8.2

THANK YOU SO MUCH

GOT IT