q90 B2 type 85-can you change cogs to lower revs?

[20vcqdriver]

Chris (Jogi730) has the best idea, Don't waste money now when you are going to fit 6 speed eventually anyway. And using the diesel box with our size tyres and wheels is the perfect solution as it makes the 1st 3 gears the same as a 6 speed S2 with 4th slightly taller and 5th and 6th usefully taller
The 6 speed CGR in mine reduces the revs in 6th but only to around 3400rpmat 80mph. Ideally I would like to be doing 3000rpm at 80 to help economy, but I'm happy at present.
And how does anyone get 42mpg out of the KV? As the best I ever achieved was 38mpg on long motorway trip, was normally around 30mpg. Still better than the 15mpg I get now though when in lead foot mode which I admit is most of the time

[BIGGYIN]

Originally Posted by jogi730

Karl,
I did a fair bit of delving around looking into gearboxes after I changed to the 20vt engine. I actually ran the standard 90 g/b when I had the small turbo and it was surprisingly good despite the short gears. Swapping cogs around is a fairly expensive and time consuming exercise. Therefore instead, if you want slightly taller gears, I would consider trying the 016 turbo boxes. The 'weak' S2 five speed would be more than capable and strong enough to handle the torque of your N/A engine. THese boxes can also be picked up fairly cheaply. How the car would perform remains to be seen as I am not aware of any BTDT.
Better still, if you are going to all this trouble, just go the whole hog and fit an O1E six speed ready for your future 20vt swap
If you can wait until next year, I can let you know how I get on with the diesel version I am fitting where I hope that 6th gear will act as an overdrive for motorway cruising etc.
HTH
Chris

Thanks.
I will wait until you,re up and running,then decide what to do.

[BIGGYIN]

Originally Posted by msh

Of course fifth gear is for road/motorway use, not for torturing engine in city. As far as I know, despite shortness of B2q gearboxes, at redline [6200 rpm] usually is around 200 kmph. So u are torturing your KV @ 1,2k in city?

[BIGGYIN]

Originally Posted by Puglife

Torturing would be attempting acceleration in 5th with wide throttle. 1200rpm around town is no problem... You can utilise that low down torque and if need be use 4th for acceleration.

If you did want to swap gears (not a small job, or one i'd want to do for a daily economy reason) then you could use any 016 gearbox (Theres a few variations between the UR turbo and also KV CQ etc.) providing its a Quattro with hollow drive gear shaft. I have a fair few photos from Gearboxes i've dismantled/rebuilt. Gears should still be available from audi (chaching... about £150 each from memory?).

But a more sensible route would be a full box change (match the FD to your 4.11 rear diff though).

Thanks,for the info.
Sounds like too much hard work and cash.

[BIGGYIN]

Thanks,for everyones input.(As I hadn,t a clue.)
I,m alittle wiser now,which makes me look a bit foolish.
If you don,t ask,you don,t find out.

[jogi730]

I think I have a ur 3.89 diff lurking about somewhere if you decide to go down the ur g/b route

[msh]

Originally Posted by Puglife

Torturing would be attempting acceleration in 5th with wide throttle. 1200rpm around town is no problem... You can utilise that low down torque and if need be use 4th for acceleration.

For acceleration in city is second gear
Of course 1200 rpm under load that's not first or second gear is torturing. Even diesel is intended to be used in 1500-2500 rpm range. It's not pleasuring to change gears all the time, it's not healthy for the engine in long term, NA petrol engine doesn't have much torque below 2k [my NG develops 130 nm @ 1k, that KV should be even less], and actually I'm surprised to find that someone can even save some fuel by doing this - usually it's completely otherwise - because when engine is run at such low revs, usually lack of torque must be compensated with throttle - by running rich.
My grandfather also believes that smaller engine = economy & lower revs = economy. He's driving 1988 1.3 carb golf - on road 70-80 kmph [but that car has 4 speed gearbox], in city 40-50 kmph, torturing that 1.3 sewing machine. Once I had to calculate average fuel consumption - after I had done it, I started to laugh. Why? Because he driving in that mushroom style was doing 7l/100 km [40 mpg]. While I got from my A80's 3A 8-9l/100 km [31-35 mpg]. From 45% bigger engine, in 30% heavier car, being driven in city 50-60 kmph, switching to forth @ 50 kmph [because worn out main bearings, so crank started to rattle @ 2k, otherwise I would switch to 4th gear as intended - @ 70 kmph], on road @ ~100 kmph, sometimes getting some adrenaline [in city] by turning full tacho with 2nd and 3d gears and sometimes when going home, testing, how fast my A80 is able to go. And enjoying the ride. And only thing my A80 had better than that golf was aerodynamics. So, is it worth to drive, thinking about pennies and getting, usually nothing, instead of driving, thinking about driving and enjoying it? I don't think so. Ok, I know that there's some people, who simply can't enjoy driving - I can see that from my mother, she can't.

Originally Posted by 20vcqdriver

Chris (Jogi730) has the best idea, Don't waste money now when you are going to fit 6 speed eventually anyway. And using the diesel box with our size tyres and wheels is the perfect solution as it makes the 1st 3 gears the same as a 6 speed S2 with 4th slightly taller and 5th and 6th usefully taller
The 6 speed CGR in mine reduces the revs in 6th but only to around 3400rpmat 80mph. Ideally I would like to be doing 3000rpm at 80 to help economy, but I'm happy at present.
And how does anyone get 42mpg out of the KV? As the best I ever achieved was 38mpg on long motorway trip, was normally around 30mpg. Still better than the 15mpg I get now though when in lead foot mode which I admit is most of the time

I don't remember, who was installing 6 speed diesel gearbox in B2 with turbo engine - was that you or someone else, but I remember, when I checked gear ratios for that diesel gearbox and compared to my A90q's gearbox gear ratios, I was surprised to find out that diesel gearbox is so short. The same diff, the same first four gears, fifth slightly shorter and sixth slightly taller. Probably that was u, as u are saying, that u have short 6 speed gearbox - short because typical B3 4 pot engine is mated to 5 speed gearbox, that enables engine to rev 3k @ 75 mph. But ok, B2 has it's brick aerodynamics, and quattro means more power loses that should be compensated with higher revs. That's why B2q stock gearboxes are so damn short. My A90q's NG should rev 3k @ around 68 mph with it's stock 5 speed gearbox.

[20vcqdriver]

Originally Posted by msh

I don't remember, who was installing 6 speed diesel gearbox in B2 with turbo engine - was that you or someone else, but I remember, when I checked gear ratios for that diesel gearbox and compared to my A90q's gearbox gear ratios, I was surprised to find out that diesel gearbox is so short. The same diff, the same first four gears, fifth slightly shorter and sixth slightly taller. Probably that was u, as u are saying, that u have short 6 speed gearbox - short because typical B3 4 pot engine is mated to 5 speed gearbox, that enables engine to rev 3k @ 75 mph. But ok, B2 has it's brick aerodynamics, and quattro means more power loses that should be compensated with higher revs. That's why B2q stock gearboxes are so damn short. My A90q's NG should rev 3k @ around 68 mph with it's stock 5 speed gearbox.

The 6 speed in mine is the CGR from an S2. As you say the diesel box with series 2 running gear has similar ratios as mine but with taller 5th/6th. In an S2 the mph/1000rpm is 24.7. But due to the wheel and tyre combo on the series 2, 6th in mine equates to 23.1mph/1000rpm , comapred to 21mph in 5th on the 5 speed, a useful increase but the torque on the 20Vt is such it could easily be taller.
I noticed this very low gearing on the diesel box of my 3.0TDi and which are frankly ridiculous, 5th and 6th are about right but the lower raitios are far too low geared and find I start in 2nd most of the time.