Si or GS-R transmission

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labe lincoln

New Member
I am swapping in a B18a into my 95 civic. I do not have my transmission yet because im not sure which i want. I will have about 200hp+ n/a and then about 300 with nitrous. Im not sure whether i should go with an si tranny or gsr tranny for my combo. About where would an si top out on the highway. How do they compare?


Supa Mod
i say GSR, SI has better gears but the GSR tranny has a stronger differential .. and the gearing isnt too much different, slightly longer gears.. better for nitrous

SI tranny at 80mph/5th sits at 4400 rpm , GSR sits at 4k rpm...


werd. being 400 rpm's lower during cruising makes all the difference for noise. Take it from me, I used to drive a 99 si, and now have a gsr hatch. Idk if it's the lower gearing, but I also get better mileage (3-4 mpg better on the highway) now than with my old civic.