Technical MPI Abarth & Schumacher have lower gear ratios - do they?

[jiminwatford]

Does anyone know the ratios involved?

Today i learned the MPI boxes have different ratios as they came with 14" wheels as standard. Whereas the SPI Abarths didn't as they were 'Abarthed' later down the line (at the dealer for example)

What do you do to determine if a gearbox is MPI Abarth / Schumacher or not?

If it involves counting teeth on a gear, how do you do that?

Thanks

 

[jiminwatford]

Does anyone know how to check the final drive?

 

[P1T0L]

MPI's or SPI's(ABARTH's or SCHUMIE's) sportings always has been fitted with shorter gear ratio boxes by factory to make them keep up with normal sportings........
Simply as "1,2,3" or "3,2,1" U should find out....?????
At least fancy to count a teethe's????
All best))

 

[jiminwatford]

Was there an answer in there?

Anyway, if the box is out of the car, i have learned that by putting it in fourth gear and counting how many turns of the input shaft it takes to make the driveshaft do a complete turn will give a guide

Compare this number of turns with another box to see which has the lower gearing

The one with which turns less (i think) has the lower gearing and is from an Abarth / Schumacher

 

[cc1]

According to the workshop manual.

Mpi/Spi Sporting and Schumacher have the same C.514.5.13 gearbox.
Non Sporting C514.5 gearbox.
Mpi/Spi/Sporting, 3,909 2,158 1,480 1,121 0,829. Final drive is 3,867 with 58/15 diff.
Spi, 3,909 2,158 1,345 0,974 0,766. Final drive is 3,562 with 57/16 diff.
Not certain how to tell them apart as of yet apart from the cable/sender type speedo drive.
Also not certain about dealers fitting kits for the Abarth version as there are quite a few parts to change including spraying, which would be very costly.

 

[jiminwatford]

Yeh, it's never really been an issue before. Generally people just want a 1.1 gearbox to get them going

I had a pm asking specifically for a Schumacher gearbox as 'it has the 4.071 final drive'

I got some information from J333EVO on this thread about MPIs having different ratios https://www.fiatforum.com/cinquecento-seicento/129083-seicento-abarth-gearbox-what-fits.html

On this basis i will collect together all the MPI boxes i have and see which has the lowest ratio. At this stage i can't recall which car they came from so some testing required

If they're all the same i guess that is inconclusive :shrug: