1983/84 Audi 80 Quattro 5th gear ratio??

Audi-Ant · 05-09-17, 05:14 PM

Hello, anyone know the answer to this???
I have just bought a 1983 KK Quattro, it does 17.5mph/1000rpm in 5th. I also have a KV engined type 85 90Q, and this does 20.5mph/1000rpm 5th...

Is that how the KK is meant to be? Or had it found the box from a 1.8 Quattro at some point??

SteveC · 05-09-17, 05:58 PM

Quote:

Originally Posted by Audi-Ant

Hello, anyone know the answer to this???
I have just bought a 1983 KK Quattro, it does 17.5mph/1000rpm in 5th. I also have a KV engined type 85 90Q, and this does 20.5mph/1000rpm 5th...

Is that how the KK is meant to be? Or had it found the box from a 1.8 Quattro at some point??

From what I remember my '83 80q was about 20mph/1000rpm in 5th

quattrodave · 06-09-17, 08:05 PM

From this site, loads of info for US models, can;t see UK being different

http://www.motorgeek.com/viewtopic.php?t=8293

B2-4kquattro -1984-tranny style 016-locker center differential
1st-3.600
2nd-2.125
3rd-1.458
4th-1.071
5th-.829
final- 4.11:1

B2-4kquattro - 1985-87 tranny case 016- locker center differential
1st-3.600
2nd-2.125
3rd-1.458
4th-1.071
5th-.778
final-4.11:1

I know that the 20v B3's have the 3.89 final drive ratio, same as S2, exactly same box and rear diff in 90 20v quattro and S2, tyres make the difference in MPH per 1000 rpm on these.

mikes2 · 07-09-17, 07:38 AM

Quote:

Originally Posted by quattrodave

I know that the 20v B3's have the 3.89 final drive ratio, same as S2, exactly same box and rear diff in 90 20v quattro and S2, tyres make the difference in MPH per 1000 rpm on these.

I know it's not related to the original question, but this is all wrong. It's 37/9 for 5 cylinder B3 cars.

quattrodave · 07-09-17, 01:54 PM

Quote:

Originally Posted by mikes2

I know it's not related to the original question, but this is all wrong. It's 37/9 for 5 cylinder B3 cars.

My mistake you are right 37/9 is 4.11 if you do the maths thats for the 10 and 20 valve 5 cylinder B3 cars audi 90's and coupe's, I'm also sure the 4 cylinder B3 quattros had the 4.11 ratio.

The other ratio 3.89 is on the 6 cylinder cars doh !, I should know as I dropped a diff and gearbox in my dads b3 10 90 quattro from a 95 6 cylinder coupe and it totally buggered up the acceleration.

The reason the S2 has the same ratio 4.11 as the 90 is that the 20 valve engine revs to 7000 peak giving around 155 mph in the S2 and 140 in the 90 20v quattro (smaller radia tyres) in the coupe 10v the top end is around 132 and in the saloon 120 due to the 10v engine maxing out at 6000 rpm.

msh · 07-09-17, 03:19 PM

There was also shoter ratio, 41/9, for small engined A80q's. Sole A90q gearbox was AKU, but you cannot find it in CQ, as the bigger wheels would make engine rev lower - therefore audi made another gearbox, basically the same, but with even shorter fifth gear, to keep the same rev/speed ratio. S2 certainly used higher fifth gear than both, as S2 maxes out sooner than 20v and all of these engines maxes out at around 6k; it doesn't matter where rev limiter is if the engine doesn't breathe at that point.

I recently had a chance to take for a quick spin A80q with a 1.8 mono in it, found that speed/rev ratio is still the same 20 mph/1k, since it has short ratio diffs, apparently that is being compensated by taller fifth gear.

Audi-Ant · 18-09-17, 09:20 PM

Quote:

Originally Posted by msh

There was also shoter ratio, 41/9, for small engined A80q's. Sole A90q gearbox was AKU, but you cannot find it in CQ, as the bigger wheels would make engine rev lower - therefore audi made another gearbox, basically the same, but with even shorter fifth gear, to keep the same rev/speed ratio. S2 certainly used higher fifth gear than both, as S2 maxes out sooner than 20v and all of these engines maxes out at around 6k; it doesn't matter where rev limiter is if the engine doesn't breathe at that point.

I recently had a chance to take for a quick spin A80q with a 1.8 mono in it, found that speed/rev ratio is still the same 20 mph/1k, since it has short ratio diffs, apparently that is being compensated by taller fifth gear.

So the box in my KK wouldnt be exactly the same as my mates 1.8Q??
I wondered if someone had killed the original gearbox, gone to scrappies and got given abox for a 1.8Q

Audi-Ant · 19-09-17, 12:08 PM

Quote:

Originally Posted by quattrodave

My mistake you are right 37/9 is 4.11 if you do the maths thats for the 10 and 20 valve 5 cylinder B3 cars audi 90's and coupe's, I'm also sure the 4 cylinder B3 quattros had the 4.11 ratio.

The other ratio 3.89 is on the 6 cylinder cars doh !, I should know as I dropped a diff and gearbox in my dads b3 10 90 quattro from a 95 6 cylinder coupe and it totally buggered up the acceleration.

The reason the S2 has the same ratio 4.11 as the 90 is that the 20 valve engine revs to 7000 peak giving around 155 mph in the S2 and 140 in the 90 20v quattro (smaller radia tyres) in the coupe 10v the top end is around 132 and in the saloon 120 due to the 10v engine maxing out at 6000 rpm.

I have a torsen diff gearbox from a 1989 coupe quattro 2.3 NG...
So according to the the info above, i could put the gearbox straight in the KK quattro and not have to change the rear diff for the one from the coupe??
If all the final drives are the same 4.11.1???
That would save the 'ball-ache' of the flange seals being different on the back etc

Audi-Ant · 19-09-17, 12:41 PM

Quote:

Originally Posted by quattrodave

From this site, loads of info for US models, can;t see UK being different

http://www.motorgeek.com/viewtopic.php?t=8293

B2-4kquattro -1984-tranny style 016-locker center differential
1st-3.600
2nd-2.125
3rd-1.458
4th-1.071
5th-.829
final- 4.11:1

B2-4kquattro - 1985-87 tranny case 016- locker center differential
1st-3.600
2nd-2.125
3rd-1.458
4th-1.071
5th-.778
final-4.11:1

I know that the 20v B3's have the 3.89 final drive ratio, same as S2, exactly same box and rear diff in 90 20v quattro and S2, tyres make the difference in MPH per 1000 rpm on these.

Just worked this lot out on an online calculator...
1984 gearbox 20.2mph/1000rpm in 5th kk quattro
1985 gearbox 21.54mph/1000rpm in 5th 90 quattro

on 195/60/14 tyres

slammedAudi · 19-09-17, 05:27 PM

The 1.8 gearbox used in the 80q is for a 4 pot engine, and the bellhousings are different 4 versus 5 cyl, so that couldn't be the case.....

06-09-17, 08:05 PM	#3
quattrodave Grown up member Classic Audi Club Member Join Date: Dec 2010 Location: Bingley Posts: 634	From this site, loads of info for US models, can;t see UK being different http://www.motorgeek.com/viewtopic.php?t=8293 B2-4kquattro -1984-tranny style 016-locker center differential 1st-3.600 2nd-2.125 3rd-1.458 4th-1.071 5th-.829 final- 4.11:1 B2-4kquattro - 1985-87 tranny case 016- locker center differential 1st-3.600 2nd-2.125 3rd-1.458 4th-1.071 5th-.778 final-4.11:1 I know that the 20v B3's have the 3.89 final drive ratio, same as S2, exactly same box and rear diff in 90 20v quattro and S2, tyres make the difference in MPH per 1000 rpm on these. Last edited by quattrodave; 06-09-17 at 08:10 PM.

07-09-17, 03:19 PM	#6
msh 4 ring whore! Join Date: Jun 2008 Location: Rucava, Latvija Posts: 3,816	There was also shoter ratio, 41/9, for small engined A80q's. Sole A90q gearbox was AKU, but you cannot find it in CQ, as the bigger wheels would make engine rev lower - therefore audi made another gearbox, basically the same, but with even shorter fifth gear, to keep the same rev/speed ratio. S2 certainly used higher fifth gear than both, as S2 maxes out sooner than 20v and all of these engines maxes out at around 6k; it doesn't matter where rev limiter is if the engine doesn't breathe at that point. I recently had a chance to take for a quick spin A80q with a 1.8 mono in it, found that speed/rev ratio is still the same 20 mph/1k, since it has short ratio diffs, apparently that is being compensated by taller fifth gear.

19-09-17, 05:27 PM	#10
slammedAudi Grown up member Join Date: Jan 2013 Posts: 104	The 1.8 gearbox used in the 80q is for a 4 pot engine, and the bellhousings are different 4 versus 5 cyl, so that couldn't be the case.....