gearbox ratio

[joan131]

Hello, I have a gearbox with reference 131AB1A1005 4417988, I have disassembled and I counted the teeth of various sprockets, have a very long relationship, it is possible?
1 - 2.846
2 - 1.611
3 - 1.068
 4 - 0.787
 5 - 0.685
It is possible?thank you

[131 Lover]

Hi Joan!
Are the question if this is the gear ratio on you car? What model and engine do you have?
This is the ratio from -81 to -84 according to fiats own service manual,
1st gear 3,612
2st  2,045
3st 1,357
4st  1,0
5st  0,834
Reverse 3,244

Hope this will help you!
Regads
Alf

[miro-1980]

Hi Joan

Never seen such ratios.

It looks like someone tied to get a very high top speed.

I plugged thesw ratios into my setup on a 3.9 diff and got a top speed of  325 km/h at 8000 RPM (mine is 255 km/h).

 It is around the 747 take off speed (181 knots). For this speed you'd need BIG wings...

Maybe this is a diesel gearbox.  At 4000 RPM the speed would be 162,6 km/h  

I am awaiting resolution to this question...

Miro  
 

[joan131]

Hello, I was looking for a relation closed with fifth long to circulate along highway, recorde that I had the gearbox in the garage. Remove the gearbox, I told the teeth of every pine kernel and the corresponding pine kernel, them divided and I obtain these relations, they seem to be long enough for many speed. I will count again the teeth of the pine kernels. Thank you.

[TfP-Motors]

131 gearboxes have straight 4-gear, and power goes from primary reduction gears when you using 1,2,3,5 gears.

maybe you only calculate sprocket teeth?s?

So you have multiply these with primary reduction ratio  ~1.27. This method is not fully exact, because crucial thing is contact diameter of the sprocket, not teeth?s number.

1 - 2.846 ~ 3.614
2 - 1.611 ~ 2.04
3 - 1.068 ~ 1.356
4 - 0.787 ~ 1
5 - 0.685 ~ 0.87

classic mistake

[joan131]

Ok, thanks for the clarification. Anyone know the result of selling gearboxes for lada and fiat 124? Are 6 speed,and diferents close-ratio. I think it could also fit in the 131.
Greetings.

[Walezy]

get yourself ford type 9 gearbox with close ratio gearkit and it will work fine. Quaife and TranX make them. In order to install the gearbox you will have to make an adapter plate between Fiat gearbox bellhousing and ford gearbox. pretty easy to do as i did it in one day.
You can go further and install sequential gearbox based on type 9 gearbox from quaife
here is how it goes
http://www.youtube.com/watch?v=Sc0mGUmobyU&list=UUCa2_jIssG1P3RSeej3iR5w&index=1&feature=plcp

[miro-1980]

Thanks TfP-Motors

I new there was something wrong with Joan calculation.

Good to know how to do it.

The box Jan has  is a standard 131 with 5 gear.  I have few of those . They never seem to brake.

Miro  

[sentrentu]

Ok, thanks for the clarification. Anyone know the result of selling gearboxes for lada and fiat 124? Are 6 speed,and diferents close-ratio. I think it could also fit in the 131.
Greetings.

Very interesting is whether it is feasible to mount the gear box of 131 or possibly mount the changing of the Lada with elongation of the spacer shaft.
Here are some links about it:
http://www.abarth-gmr.be/forum/index.php/topic,3980.0.html

http://www.racedandrallied.com/rally-cars-for-sale/rally-cars-parts-for-sale/new-6-speed-fiat-124-gearbox-sale