I am running an O2m ( audi s3) box in my mk1. I am concerned that it will be tooshort in the gears, 80mph is about max in 3rd in an s3 with 17" wheels and 45 profile tyres. My wheel and tyre set up will have a much smaller circumference circa 580mm as opposed to around 630mm on the audi. I reckon 70mph max in third. I have heard about swapping the final drive for a diesel one. Does anyone know what I need to get? Thanks MIke
Probably is a solution to it but i wouldn't worry,just change gear as you'll have plenty gears left. I've said it before,but i think the 02M is over rated & more suited to a 16v N/A engine,my leon has one and i'm always 1 higher gear than 5 speed so i don't see the point,(its just more gearchanges) I have a feeling that a TDI FD will be too tall,so have you thought about a 5 speed? ratio's & FD's a plenty!
Definitely want to change it. If it will only do 70 in 3rd, I will need to do 3 gear changes in maybe 6 or so seconds from a standstill. It will make it slower due to the time changing gear. Any more thoughts?
What do you mean by two final drives? Two are available or there is another one in the box that can be transferred? If so, how do you swap it?
just the one crown wheel, I had a box apart couple days ago.. isn't a diesel one on a stock car/power be far too long?
there is a 6 speed 02m gearbox in a 400hp jabba octavia with a deisel 02m final drive in it for moterway and high speed cruising. so it is possible to swap the gears around, from which model and how compatable each gear is im not to sure,as to the power of the car relating to the final drives i would hazard a guess it might be to long.
Yes, gearing with diesel final drive and petrol gear ratios is very long geared indeed Put it this way, Jordy in Rocco and Andy in mk1 4x4 drag cars use above combination, 4th gear is good for 150mph at under 8k revs!
This may help you understand 02M boxes, have a read http://www.clubgti.com/forum/showthread.php?t=203192
I had spoken to DS motorsport about Andys box. I imagine on that he was wanting limited gearchanges for 150mph as this is his normal terminal. Mine will be in a different league to that of course but would like a sixth gear of say 25 mph per 1000 rpm
Then just a standard diesel 02M box will do you fine, ERF and DRW are couple of codes that spring to mind Only problem is big-ish drop in revs from 1st to 2nd gear as 1st is shorter then petrol boxes Diesel ratios, aprox 1st....3.8 2nd...2.1 3rd...1.3 4th...1.0 5th...1.0 6th...0.8 Petrol ratios are simmilar 2-6 but first gear is longer at 3.4 i think Obviously final drives are taller, may be to tall, depends how much power you gona have I will be running DRW box in my A3 but will also run big 26" drag radials to further lengthen ratios
Are the diesel boxes four wheel drive? I have the s3 box already, I really wanted to lengthen slightly all the gears. I do not fancy big drops in revs between gears. I used to run a gemini cable box with the 1 to 6 gearkit and the ratios were lovely. At say 7500 I had 50, 70, 95,115,135 and potential say 155 is. The revs hardly dropped at all and the car would easily pull the longish first gear.
Just looking at my previous comments, starting in second will have same effect as second will prob only run to 50mph... bingo! Sambo, will you be running the diesel 4wd box in the a3?
No im running my A3 quatro in FWD mode for few months with diffed up diesel 02M whilst mk2 golf has been caged and prepped for this engine/box thats gona be used as drag car, then A3 will be rebuilt as 4WD again, not sure what box il use tbh
