engine and drivetrain Which Diff Ratio?

[76ohtwo]

so the 318i E36 case, is the same/interchangeable with a 02 ????

No, but I think in the articles section there's a guide to building one for an 02.

Matt

[Swiss 2002Tii]

Coming back to this topic, I see that many owners have switched to a 3.91 LSD.  What do most folks do with their speedometers in this case?  If sent for a speedo re-cal, do they change out a gear in the speedo, or just make it read correctly at a particular speed?

(Here in Switzerland they test at 50 kmh.  As long as that reads correctly, they accept the speed indication.)

[bento]

2 hours ago, Swiss 2002Tii said:

Coming back to this topic, I see that many owners have switched to a 3.91 LSD.  What do most folks do with their speedometers in this case?  If sent for a speedo re-cal, do they change out a gear in the speedo, or just make it read correctly at a particular speed?

(Here in Switzerland they test at 50 kmh.  As long as that reads correctly, they accept the speed indication.)

 

Can't answer your recalibration question, but can offer a potential alternative. 

 

I bought a new speedometer for a 1976 from Walloth & Nesch. They came with a 3.90 rear diff in the US. It reads dead accurate according to some of the radar signs I drive past. Not sure if there's a metric equivalent though. 

 

Speedo accuracy really doesn't matter here though. I'd imagine most just live with the 10% error. 

[ray_]

2 minutes ago, bento said:

 

Can't answer your recalibration question, but can offer a potential alternative. 

 

I bought a new speedometer for a 1976 from Walloth & Nesch. They came with a 3.90 rear diff in the US. It reads dead accurate according to some of the radar signs I drive past. Not sure if there's a metric equivalent though. 

 

Speedo accuracy really doesn't matter here though. I'd imagine most just live with the 10% error. 

 

What was the ratio on the front diff in '76?

 

[bento]

17 minutes ago, ray_ said:

 

What was the ratio on the front diff in '76?

 

 

Does that joke ever get old? 

[TobyB]

No.  But we do...

 

(I run a 3.46 up front.  Helps with tire wear...)

 

t

 

[dhr.vdw]

Opened up my diff the other day and counted 42/10 on the gearing wheels. So that would make it 4.2 ratio on the diff right? And that would make it a diff for higher top speed? Correct me if I' m talking nonsense this makes sense to me lol.

The guy also welded these things on my diff:

Feelsbadman it's no LSD, was really hoping for it haha!

 

JP

 

[NickVyse]

5 hours ago, dhr.vdw said:

Opened up my diff the other day and counted 42/10 on the gearing wheels. So that would make it 4.2 ratio on the diff right? And that would make it a diff for higher top speed? Correct me if I' m talking nonsense this makes sense to me lol.

The guy also welded these things on my diff:

Feelsbadman it's no LSD, was really hoping for it haha!

 

JP

 

 

I think you might want to do a recount - probably 41:10, which is a short ratio better for acceleration than top speed. 

[dhr.vdw]

6 hours ago, NickVyse said:

 

I think you might want to do a recount - probably 41:10, which is a short ratio better for acceleration than top speed. 

Haha I really thought it was 42, but then I guess I am wrong indeed. Oh I thought high speeds but what you're saying makes sense tho. So the big wheel makes a 360 degrees turn and the smaller one(s) turn like 4.1 time then.

Maybe I should've studied something technical or at least do my homework before buying my car, my knowledge is useless when it comes to cars.

JP