Hi All So as background I have a Mk1 which is getting a turbo late motor Should have more than 300hp, even though we run a 36mm restrictor, torque will be more important when it comes to breaking stuff, though light weight will help give an easier time on everything Car is for a race series and the rules specify the driver can only select a maximum of 5 forward gears and it must be H pattern (this doesn't preclude a late 6 speed box, it just means the I can lock out one selection) In everyone's opinion which gear box is the best basis to start with? I have a couple of 020's, obviously they live in the car so it is going to save me time and effort right now. 02a's are currently cheap, I am fitting a pedal box, so the hydraulic's will be easy Late TFSI boxes are already designed with the turbo torque in mind, you you think they have the greatest safety margin, but weight for benefit having to carry around an extra gear and 2 final drives, will this make changing to a different ratio hard, or could I build it so it only selects 1 ratio at a time so I effectively have to complet boxes in 1 set up for the long and short tracks I do (there is a thought!) In the future I will most likely fit a dog box because I know what ever I start with will not be strong enough long term, so the ability to get a new gearset is important. Are there any case problems that I should know about, in my experience most of the time broken gears can be tracked down to case flex, so which cases are proven to be the best? The question is am I better with (for example) an 020 with a good gear set, an 02a, or some thing completely different like an 02q (and if someone could educate me on how those double final drives work It could be handy!) Thanks in advance
no mention of 02M boxes, they are strong - 6 speed though, weigh about 60kgs so pretty heavy but i can't see you breaking one with 300hp
Don't you hate writing a big detailed response on mobile only to lose it! Anyway, home now so take 2: Sorry that is supposed to be 300 Nm, not HP For all intensive purposes I thought the 02M and Q were the same sort of design, just as a 02A and J, been out of Golfs for a long time so easy for me to be wrong! I have read the FAQ and that is not what I want, as I said the ratio's themselves are not the important bit what is important is the basis of a box going forward. Metallurgy of the gears are usually fairly constant so what I am looking for as an indication of strength is case design and gear width, and what sort of power they handle. An example: The sort of thing I am talking about is illustrated by the Mazda G series box, they have a pretty poor bearing carrier between 4th and 5th so when subject to a side load (as in helical cut gears) they tend to push the gears away with predictable results, you can either re-enforce the bearing carrier or if you have a straight cut box you do not have any issues because the box is OK in that direction. You are still going to shred gears at 400Nm, because the gears are just not wide enough (ironically helical cut gears are always stronger than straight cut, but straight cut will often handle more power because of the case forces) So the sort of thing I want to kno: If we have examples of an 020 breaking at 200Nm but when fitted with a straight cut happy at the levels I am talking about then there is no need to go any heavier If there are 02a's that are running the torque, but marginal in an 1100 kg chassis then they could be fine for my use A box for a Mk5/6/7 TFSI you would expect to work because those cars are close in torque, but importantly 400kg heavier, but the weight (of the box) and carrying a unused gear (and final drive!) is not ideal, so best avoided unless it is the only thing that does what I need. Even better if these examples are in a motor sport environment
020 in a motorsport application is a no go, from 170-180 hp Upwards....unless you accept it to break every now and then ... and certainly will not withstand 300 Nm and the c-c distance of the shafts is to close to put any serious forces trough them ( 65 or 70 mm iirc) 02A or 02J (has a stronger casing ) but both have the same issue as the Mazda box... 4/5 bearings that get pushed apart. The bearing bulkheads are just not strong enough. This with helical and straight cut gears. Here c-c shaft distance is now up to 75 mm ( iirc) I would go for 02Q ( Mk6) this is stronger than a 02M (Mk 4- 5 ) This is pretty bulletproof and can handle serious TQ levels altough its a 3 shaft design and quite heavy
I run a 02A and about 360 lb ft. I've lost 4th gear before but that was on an old box. 2nd to 3rd shift can be tricky at high revs. Will swap out to a 02J with custom ratios in time, principally for shifting. Can't say which box is "best" as I've only ever driven 02A/J but I would have thought they would be up to the job with your power/torque.
Excellent information, thank you both! IIRC 360 ft lbs is around 450 Nm to my metric mind (I'll check in a sec) so I would think that is a reasonable safety margin Does the late 02m/q box fit a mk1 without chassis mods, just thought of that, I can only drill holes for the passage of lines, not for clearence, either way I am buying a pedal box with a hydraulic clutch tonight :-)
My 02M has not done very well with 515nm , was fine before i started sprinting and auto tests and ring trips. Did bend a wheel on one event so that shock load may have caused an issue. But then had a simular issue on a A3 when sprinting long time ago. Never had any problems with my quaife boxes which are based on 02A boxes . but those are mk2`s with less BHP and power 240 bhp and 300bhp. These boxes would have been rebuild with new bearings kits .I prefer the shift of a 02A over a 02M , using the same shifter. Clutch and flywheel options may put you off a 02M as its about 1k for decent flywheel and clutch, the standard DMF on the 02m is so heavy , not for race use i think The 020 boxes can be rushed and can be over shifted , i am sure you will have seen people run end stops to prevent the shifter pushing to far on over zealous gear shifting on rod shift, i certainly had this problem when i ran 020 boxes . I think i have the terminology correct there. Hotgolf is the man for showing common failures for all the above box types, i bet he has seen every failure possible know to man on a VW box
