jspeceg

caught up in the r/s ratio debate. on my current build i have a r/s ratio of 1.49 in a gsr block. i have heard that 1.75 is ideal and have a line on a different crank (which would require different rods obviously) that would give a r/s ratio around 1.67. so do i roll with what i have or look to change? i would be giving up about .2 liters in the process which i dont really care about.

is a 1.49 r/s ratio safe (and reliable) for a daily driven supercharged vehicle?

raene

Forget about rod/stroke ratio. Focus on keeping a lower redline with a bigger displacement and make more reliable power. High redline kills parts. R/S ratio has to be the most overrated (in terms of importance) spec of an engine.

Schister66

I agree. Honestly, this is something i've never even considered while building a setup for FI

jspeceg

ok. thanks!

solo227

its more important in smaller engines...B16s when going all motor...

Cuz your trying to spin the motor higher than it was built to go... Its only gonna matter in a engine thats revving to 10k+

Tony the Tiger

Unless you are greedy, and you want a turbo that spools around 5000RPM with a useable redline of 10000RPM, just like my Integra. That's when I think R/S is important, but to a regular guy, it may not mean anything.

locash

Screw the R/S ratio. We run the 84mm bore B18 motors to 10500 all the time, with 30-50 psi boost. They aren't coming apart from over-revving. Keep in mind, these are drag cars, not daily drivers..