ZC tranny vs Si tranny

im talking to a engine shop now, and they have a ZC with tranny for $675
and $100 for an 89 LS ECU

he says the ZC tranny is better than the Si but i would need bigger axles
i know id need the axles if i went with the ZC tranny, but i thought the Si tranny would work... so i guess my question is: Will the Si tranny work on a ZC engine. IF the ZC tranny is better than the Si tranny,
either way im gonna need a new clutch with the clutch type depend on the tranny? and which set up would be better

ZC DOHC w/ ZC tranny on an LS ECU with new axles and clutch

or

ZC DOHC w/ Si tranny on an LS ECU with new clutch

this is a car i drive everyday so i dont want any probs down the road
so which is the best way to go?


http://files.automotiveforums.com/uploads/313864fastcar.jpg

the zc tranny is geared closer, so it has better acceleration....the drawback is that it rev's pretty high at highway speeds and can get annoying.... the si tranny works fine and you dont have to deal w/ axles and an intermediate shaft and shit... the optimum situation is the zc tranny w/ the si final drive...

...so if ya drive on the highway alot, keep the si...IMO

If you want to see exactly what the difference will be, click here...
http://crx.honda-perf.org/math/index.html

Originally posted by marked001
the zc tranny is geared closer, so it has better acceleration....the drawback is that it rev's pretty high at highway speeds and can get annoying.... the si tranny works fine and you dont have to deal w/ axles and an intermediate shaft and shit... the optimum situation is the zc tranny w/ the si final drive...

...so if ya drive on the highway alot, keep the si...IMO

actually the ZC tranny is closer spaced for smaller rpm drops between shifts.. but the final drive is much taller than the Si tranny, so it will rev lower on the highway.

the best performance setup would be to use a ZC tranny (for the equal length halfshafts) using the Si final drive to shorten the gearing a bit for better acceleration


in terms of revving high on the highway, doesnt bother me

at 80mph the integra is spinning a hair over 4000rpm in 5th gear, and the nissan is spinning a hair under 4000rpm in 5th (the CRX spins under 2500rpm :( )

i had to get the USDM 86-89 integra tranny to bolt to the ZC motor in my 87 civic si. the 84-87 si tranny will not bolt to the zc motor.

is cruising at 2500 at 80 such a bad thing? fuel economy is up, noise down... win win to me! of course, my zc engine and si tranny (90)are in an '80 civic so mileage is up anyway