What's the difference between Y1 and S1 transmission on B16A JDM motors?

 

Y1 = 90-1 CRX/Civic SiR with 4.266 final drive but close gearing also optional LSD (so possiblity that it could be LSD)

S1 = 90-1 integra XSi = 4.4 final also close ratios but no LSD found in any. also S1 was found in 90-1 USDM integras

 

Thanks, that is exactly what I was told.

 

Here are the various trannies offered with the JDM first-gen B16A swaps:
1. J1
2. S1
3. Y1

They are all cable-type clutch trannies, so you will need a HASport or Place cable-to-hydro conversion kit. It works, but it doesn't feel as positive as the real hydro trannies.

The cable trannies are notorious for having grinds and just overall shittyness from being old. The problem with them is that once they go bad you're screwed because there are no rebuild parts offered here in the U.S except for one or two guys on -H-T that can get the synchro kits for $350.00 or so. Add the labor and trouble to do the rebuild and you should have just bought a true hydro second-gen B16A swap to begin with.

The J1/S1 has the same 1-4 gears that the USDM ITR S80 tranny has, but the 5th gear is shorter. Combine this with the 4.400 FD and you have a really nice tranny for all-motor or near-stock motor, but it has really high freeway cruising rpm.

The Y1 has taller gearing and the 4.26 FD. It's not as good for all-motor or near-stock motor. The only plus for these is the rare optional LSD. To me it's simply not worth the trade off for the LSD to have taller gearing and the 4.26 FD.

WARNING!!!

There were also U.S spec cable B-Series trannies, and one of them is also an S1 tranny.

This is easily confused for the good JDM S1 tranny, but it has the tallest/shittiest gearing of all the B-Series trannies and also has the 4.26 FD.

Some slick people swap the JDM lower mileage S1 tranny for the shittier USDM S1 tranny and you get screwed while they sell off the JDM S1 for a premium price.

So bottom line:

If you want to do a B16A swap in a 1992-1995 Civic and you absolutely will not buy the correct hydro trannied swaps, get a swap with the J1 tranny. It's the only one you know for sure that has the good gearing and 4.400 FD.

 

Nice explanation!!!

 

If I can help, I will.