Gear Ratios

[Stick Insect]

On My Minor having changed from a standard 4.11 diff to a 3.9 diff and also a 3.75 diff I can assure you that all the performance goes from the bottom end. I tried a more powerful Midget engine which was all top end power and no torque. I now have a high torque engine which is greata with the 3.9 diff and high profile tyres, which are the same mph/rpm as the 3.75 with low profile tyres.

All I can say is it is horses for courses.

Most people would want an all round performer and not something which is beaten away from the traffic lights by a 2CV but will do 180MPH......

David

[quattro4Life]

I am not very knowledgeable on this subject, but in case none of you guys have seen it, HERE is a website that compares all the different 01E gearboxes. HTH

-b

[S2central.net]

Ben & others...

Maybe I'm being a bit thick today, but I cannot get that web based MPH calculator to work.

When I use the final drive ratio of 4.111 (37/9) and gear ratio of 0.585 (24/41) I just get silly numbers at 1000rpm with a rim diameter of 24.9 in.

:wacked:

Paul

Originally posted by s2avant
I found a website that calculates MPH/RPM. Going by the figures above, it comes out with 24.7mph/1000rpm on stock wheels(24.9in diameter) for standard RS2/RS4 gear ratios, thus agreeing with Lee's figure.

For the 1.9TDi 6th gear it gives 30.82mph/rpm. Am I correct in assuming that this would give a the theoretical max speed of around 215mph!!

Excuse my limited knowledge of ratios etc but how would a sixth gear like this be in normal driving? Would you need to push 5th gear to the red line before using 6th?

Ben

[s2avant]

I jusr tried it and it works ok. It does create a lot of decimal places though.

When you input the data above you get 30.81461364117653 as a result.

Ben

[S2central.net]

Stupid calculator only work on WinTel browsers... Obviously his code isn't written with open computing in mind. Turns out I wasn't being a bit thick after all (this time)


Paul

[S2central.net]

Built my own gearing calculator spreadsheet in Excel at the weekend - from first principles - what a ripping time that was. The values agree with the web based calculator linked earlier in this thread.

I got to playing with some other 01E gear and final-drive values (from RS4 and A6/All Road TDi engines).

The attached file gives you an impression of what is feasible - in theory at least - obviously mega power would be needed for the 200mph variant - but hey we can dream.

I'm happy to share this with anyone who has Excel and fancies a dabble - will also drop it onto S2 Central later this week... perhaps after some feedback from the learned community here.

Note the configuration of 1st & 2nd gear in standard config to get 0-60 mph in one gear change.

The tweaks I have shown here give a less 'short' spacing in the 6 speed 01E format - aiming for as near 1.5 gear spacing as possible. I also wanted to reduce the spacing between 1st and 1nd on the 'big change' format, but had to go for the lower diff ratio to achieve 60mph in 2nd - and of course that helps the lairy top end. I might have overdone it here, but its a useful tool I hope for those thinking of exotic gearing.

Who has a ready reckoner for HP needed to achieve max speed ?

Cheers,

Paul

[Silverboy]

will the A6 quattro rear diff fit onto a S2? if so I've did a little comparison of the std 3b gearbox and the tdi 6 speed gearbox.. (actually from the 180hp engine, but it's probaly almost the same as the 140 IL5 tdi box)
this is kmh speed at 7500rpm with 225/45/17 wheels


A6-TDI S2
1: 61 62
2: 112 118
3: 174 179
4: 248 242
5: 324 307
6: 411 **

So, if the rear diff from the A6 quattro fits, it would be a superb gearbox I think.. 110kmh and 2000rmp on the highway they are almost the same, exept for the "overdrive"

[caterpillar]

THE a6 diff WILL NOT fit direct on...and the code CKL have 3,889 ratio... ,but the rear end cron and pinjon wil maybee fit IT IS NOT FOR THE HOMEMEC TO TO DO... EASYER will be to use the urQ diff

[arazvan2002]

I know is an old thread, but I have a question. between gearboxes with 37/9 and 35/9 ratio, there is another difference in input shafts.
35/9 -> 8+17
37/9 -> 8+18.
I think it should be taken into consideration but I don't know how.

[Pirvu Eugen]

I know is an old thread, but I have a question. between gearboxes with 37/9 and 35/9 ratio, there is another difference in input shafts.
35/9 -> 8+17
37/9 -> 8+18.
I think it should be taken into consideration but I don't know how.

That input shaft nr. has nothing to do with the 6 speed ratio or final ratio.
Iff you have an 35.9 rear diff, you need 35.9 final ratio gearbox.

[90quattrocoupe]

You may want to talk to Mark Swanson at EFI Express. I have a S8 AKH motor in my Coupe and presently a ABY CGR 6 speed gear box. I always felt that the six gear was not conducive to cruising with the V8. The revs were a little high, and this was with 245/40-17s on the car. 245/40s are taller than +2 for the stock tire, which should have lowered the RPMs. 6th gear is .71.

So I picked up a 2002/3 3.0 A4 FYF 01E transmission and sent to Mark to be gone through. He installed the upgraded 1st/2nd gear collar and installed a .56 TDI 6th gear. I don't have the trans in the car at the present time, he is going to install it in April along with removing the 034 IIC and installing VEMS.

So if you have some questions, send him an email.

Greg W.

[arazvan2002]

Built my own gearing calculator spreadsheet in Excel at the weekend - from first principles - what a ripping time that was. The values agree with the web based calculator linked earlier in this thread.

I got to playing with some other 01E gear and final-drive values (from RS4 and A6/All Road TDi engines).

The attached file gives you an impression of what is feasible - in theory at least - obviously mega power would be needed for the 200mph variant - but hey we can dream.

I'm happy to share this with anyone who has Excel and fancies a dabble - will also drop it onto S2 Central later this week... perhaps after some feedback from the learned community here.

Note the configuration of 1st & 2nd gear in standard config to get 0-60 mph in one gear change.

The tweaks I have shown here give a less 'short' spacing in the 6 speed 01E format - aiming for as near 1.5 gear spacing as possible. I also wanted to reduce the spacing between 1st and 1nd on the 'big change' format, but had to go for the lower diff ratio to achieve 60mph in 2nd - and of course that helps the lairy top end. I might have overdone it here, but its a useful tool I hope for those thinking of exotic gearing.

Who has a ready reckoner for HP needed to achieve max speed ?

Cheers,

Paul

That input shaft nr. has nothing to do with the 6 speed ratio or final ratio.
Iff you have an 35.9 rear diff, you need 35.9 final ratio gearbox.

I know about rear diff, it has to be the same as gearbox.

I have a 1.9tdi AVF quattro with FYT gearbox and I want to install another one with longer 5th and 6th gears.

FYT (1.9tdi 131hp) 18+8 input shaft, 37/9 final ratio, 5th 27/37, 6th 24/41
DQT (from 2.5tdi 150hp) 18+8 input shaft, 37/9 final, 5th 26/39, 6th 23/41
GBB (from 2.5tdi 180hp) 18+7 input shaft, 35/9 final, 5th 27/38, 6th 23/41

I wanted to know if the input shaft has influence in gearbox ratio calculation.

[S2central.net]

Talk about finding an old gem - found this thread while looking for gear ratios on 01E gearboxes - my car was 11yr year old when I made that calculator in 2004 - here I am finding it again a further 14yr later. Holy smokes - my S2 will be 25yrs old this summer. I am going to have seriously get my finger out !

[kinaputt]

I bought my self a 01E gearbox from a Audi A4 1.9TDI quattro with code name GBC. I have found out that i have to swap over the 3 flanges and back piece that is screwed on the rear of the box and the reverse light switch. Does the gearbox bolt on the to engine and does the input shaft work with standard S2 clutch? Does anyone make brackets for the gearbox mounts to fit it to a S2, or do i have to make them my self? The bolt pattern is looking a bit like 03A, but i think they are not the same.