Final drive ratio
 

Hey guys just wondering how much you think I would have to spend in order to get the final drive of a vx transmission lengthened or a longer 5th gear (probably at a shop) to save just that little bit extra on gas. Thanks so much guys!

race teams have gears custom cut for their ratios and they are really expensive. I would say in the thousands of dollars.

not really worth it to save a few bucks in gas plus it will limit when you can shift into top gear (the minimum speed for that gear) so you may not save anything.

Research the transmission, find out everything it was ever installed in, every manufacturer it was ever licensed to and what later models were derived from it. From all that you might get an idea about ratio swaps, either final drive, 5th gear or output shaft pinion. Some vehicles you could do the swap in a day with the tranny in the car, for the cost of junkyard parts, a bit of RTV and a fill of transmission fluid. Others need the tranny completely pulled and stripped down.

Just off the top of my head, I'd take a guess that Odyssey minivans with bigger wheels might have had a different final drive on similar transmissions.

Look for something with a V6. It's possible the ring and pinion gears are the same(except for ratio) between different transmissions. It makes production cheaper to do that.

Unfortuneately the VX/CX tranny has the lowest final drive for compatible hydraulic transmissions.

The CRX HF tranny has a lower final drive but is not compatible on hydro trannys. But what is compatible is the HF gearing which is slightly longer than the VX's. In my opinion it's not worth it.

Stock VX Tranny @ 2500rpm
1st....3.25......15.96mph
2nd....1.761....29.45mph
3rd....1.066....48.64mph
4th....0.853....60.79mph
5th....0.702....73.87mph

VX Tranny with HF Gearing
1st....3.25......15.96mph
2nd....1.650....31.43mph
3rd....1.033....50.2mph
4th....0.823....63.01mph
5th....0.694....74.72mph

Hasport makes "hydro to cable" (not to be confused with the "cable to hydro") conversions for b-series engines. You should contact them and see what it takes for them to make a "hydro to cable" conversion for the d-series engine... if they can make one for you then you can run the straight HF Tranny.

Yeah, that doesn't look like a good place to spend money. There have to be way better bang for the buck mods. Such as a proper exhaust or for the cost of changing gears like that, an aftermarket tune.