01E long 6th gear swap- 0.56 or 0.6?

[B2Boy]

Has anyone on here put a long cruising 6th gear into an 01E box?

There options are 0.6 and 0.56 ratios.

0.6 would be safe, I was considering the longer 0.56 but I am worried the engine will come off cam / off boost.

Any real world experiences out there?

[Zoig]

I had 01E Diesel box in my UrS6, 0.56 6th gear. Swapped it to V8 01E box with 0.68 final gear.

It really depends on your average speed limits. At 100km/h the 0.56 was suitable when max 2 people in the car and no cargo. Around 120 km/h was quite decent (my local speed limits dont go any higher). I guess if there is a lot of motorway with sustained 130-140km/h the 0.56 would be ok.

If the common speed is 100km/h and rarely goes to 120km/h like in Estonia, i would rather go with 0.6.

[quattrostyle]

But if you drive a B2 as your name suggests it might be okay since you will run (much) lower profile tyres meaning higher RPM's at the same speed than say an S2 or S4.

[speeding-g60]

i had an RS2 (CRB) gearbox sent over to the US from UK.

we took the 3/4 gears out and put them into an 01E TDI gearbox (.56 6th gear) for my friends cruiser car.

stupid side story; i put the RS2 trans back together, with a .87 4th gear and .86 5th gear (i drink sometimes, out in the shop, see)

i just gotta take it back apart partially and put a different 5th gear on it, or skip 5th gear completely lol.

[quattrostyle]

LOL

[B2Boy]

Zoig – thanks!

speeding-g60 - That must be the world’s closest ratio box!

quattrostyle - It is a B2 but its being built with an S2 drive train and rolling radius of the tyres will only be out about 0.5% from stock S2, so it should be a good comparison.

[speedfr38ky]

Tried a longer gear in my 01e rs2 box for my UR Quattro. even when running it in running no boost it felt horid and was too big a drop so had the standard 6th gear put back in.

[Thuppu]

B5 S4 0.68 could be good.

[B2Boy]

Tried a longer gear in my 01e rs2 box for my UR Quattro. even when running it in running no boost it felt horid and was too big a drop so had the standard 6th gear put back in.

speedfr38ky - Which one did you try? .56? or .6?

I have an RS4 box, which has the .68 ratio in it at the moment.

The car is being built so I don't have a reference to work from. I am about to re-build the box, and don't really want to have to pull it out again later on....

I will be using it mostly in the UK, but also across France and so don't want it screaming its head off on long motorway runs at 70-90 .... or even Germany at uhum 100+

[speedfr38ky]

.6 is what I had.....your call entirely but unless you really want to have a longer ratio specifically for long cruises I wouldn't bother it felt wrong....the drop in revs was considerable.

[B2Boy]

.6 is what I had.....your call entirely but unless you really want to have a longer ratio specifically for long cruises I wouldn't bother it felt wrong....the drop in revs was considerable.

Hi speedfr38ky. What BHP were you running?

[Error404]

I agree, longer 6th needs at least a longer 4th and 5th to spread the ratios, and a lot of torque low down in the rev range...
0.68 will still get you to 200mph with a sensible rev limit, not sure really why you'd want anything longer?

[B2Boy]

I agree, longer 6th needs at least a longer 4th and 5th to spread the ratios, and a lot of torque low down in the rev range...
0.68 will still get you to 200mph with a sensible rev limit, not sure really why you'd want anything longer?

It really wasn't top speed I was after, I just wanted a long cruising gear for motorways and autoroutes.

MRC used to do a .641 which would give the same rev drop as 3-to-4 and 4-to-5. Shame they don't do it anymore.

[Error404]

Another option to consider is swapping to 3.889 diffs which will reduce your overall ratios and increase road speed in every gear.

[B2Boy]

Another option to consider is swapping to 3.889 diffs which will reduce your overall ratios and increase road speed in every gear.

Good thought, though I have mapped the rest of the ratios as is and they look good with the 4.11.

Thanks all for the thoughts everybody!

I think the consensus is that .6 is just too high.

I think I will build it with .68 and see what happens.

If its not high enough, I might have a custom 6th ratio made up. It wouldn't be hard to a 0.641 26/38 made up. There seem to be enough companies out there making Audi gearsets to find one who will do a custom 6th.

Cheers!