Civic EX '90 into a '91 CRX Si

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ssl2k

Senior Member
Okay, here is the deal.

The syncros were going out in my car when i had bought it and I took it to a tranny shop and the mech said that it was syncro bearings that were going and it seemed like the forks were bent slightly. I bought the car from a kid that was about 20 so I'm guessing it is from jaming gears and racing around. No big deal. I hadn't planned on keeping it in there for long anyways. Well as I was racing around I missed 3rd gear thinkin it was all the way in and it wasn't. There went the tranny. I picked up a tranny from a 1990 Civic EX. The guy who sold it to me swears by a money back promise that it will work perfectly with my 1991 CRX Si. Which I don't see why it wont, they are both d16a6 engines. The only thing he said, was that the gearing ratios would be different. I found the gear ratios here https://hondaswap.com/forums/index.php?showtopic=29829 and according to this, 1st through 5th are the same, but FDR (final drive?) is different.

What exactly is final drive?
Does this mean my top speed will be decreased compaired to my old Si tranny?
Any does anyone know for sure that this will work? I will be putting the tranny in on tuesday (tomorrow, march 09/04).
I'm guessing that the cluthc isn't going to matter cuz I've been lookin them up but they seem to come up with the same model clutch for the 90-91 civic and 90-91 crxs.

here are the gear ratios from that link for the 2 models:
Car Name Years Engine Counterpart Type LSD? 1st 2nd 3rd 4th 5th 6th Reverse FDR
Civic EX 1988-1991 cable no 3.25 1.894 1.259 0.937 0.771 0 0 3.888
CRX Si 1988-1991 D16A6 cable no 3.25 1.894 1.259 0.937 0.771 0 0 4.25

Thanks!
nathan
 
Final drive, is kinda like the rear end gear in a RWD car.

the EX with the lower final drive will give a higher top speed (if the car had enough power to take it to redline in 5th)

the Si with the higher final drive will have quicker acceleration through the gears, but will have a lower top speed (again, power to redline in 5th dependant)

it should be a bolt-in affair, with no worries about anything, other than a little better gas mileage, and a little slower acceleration.
 
How much of an acceleration lost am i lookin at?

=/ this sucks kinda i guess...

where is the final drive gear located in the tranny and is it easily swapable?

nathan
 
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