Quote:
Originally Posted by driftflo
i did not do any further research on the osg because i did not have any hope to make it better then a standard rebuilt zf unit. so i sold it to a guy who wanted to try it anyway... never heard anything about it again.
i will stay and continue with zf and drexler based units as i came to the conclusion these are the best units out there.
after ~1.300 lsd cores i built to date, i am looking at nearly no customer complains about zf/drexler units as well (compared to much more problems and complains with all other units/brands i sold) i decided to stop offering other parts/brands to my customers.
i want to use the best hardware to create setups that perfectly fit, perform and last!
it was a long journey, but i learned a lot and i am pretty convinced now!
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I understand. I guess if something works don't change it. I know one company in the Netherlands which works with OS-Giken units - they are differential specialists and custom set up the units for racing, but its a lot of work to learn a new mechanism and set it up properly etc.
My view of the OS-Giken is - it could be good for drifting in the dry if setup correctly and good if you have a squarer line on track (think of MAX or Vettel's driving style compared to Sainz for example in F1). I need to be really aggressive on the brakes for the diff to lockup on deceleration and wrestle the front end in the corner and I need to straighten up as quick as possible and get aggressively on the gas for it to grip out of corners, which causes oversteer on the way out - as when it locks - it LOCKS up too quick. Once you get used to it and manage that oversteer right after the apex - you know what it will do and when, and you can just keep a much tighter racing line with later braking, lower turn-in speeds, hard accel out of the bend and less ability to crash I guess. On the Out-In-Out standard racing line it just feels like an open diff on decel and has sudden locks mid-corner on tight bends. It is good on long swooping bends though - as it just doesn't lock up much if any and I don't get understeer. Its hard to get used to in the rain though. It will stay open when decelerating and then lock to 100% out of nowhere when weight transfers mid corner and I just would spin on throttle. I need to again pull off a MAX Verstappen in Brazil type of driving, where I just run as square of a line as possible so that I almost don't trail-brake, but I brake in a straight line, lift off before the apex and turning, and when I accelerate my wheels are always going forward, and then - it is good - it just puts the power down well as it locks so quick. I think it just is a 0 or a 100% diff kind of. It locks up probably 30-40% quicker than normal clutch type diffs with a preload shim instead of the springs. It does create less heat that way and if you change your driving style - it works, but if you don't like the square racing line and you don't like to straighten your line after the apex, mash the gas, force it to lock-up and then manage the oversteer on corner exit - it might not be the best option. If you like that - then it is okey. Maybe lower ramp angle on acceleration and softer neg-preload springs, so that I don't need to force it to lock-up, but once it does I can manage it by it locking up at a slower rate due to the ramp angle. In the rain it can put you in hard situations where it behaves like an open diff on decal and locks up on rotation and if you get on the gas too hard and the inside tire slips, you are still steering, lock up mid corner - you run out of steering lock in the opposite direction and spin. Maybe the 2 way Spec-S is the way to go, not the 1.5 Way so it locks up more while actually stopping. I don't know.
I know its maybe a lot to ask, but is there a trusted place you know which can build me some custom LSD friction plates with molybdenum coating in Europe? I want to try out a few things with the OEM Viscolock unit and the OS-Giken I have too.
Also is there somewhere where I can buy the stock ZF unit new, or is it just breakdowns of old M5's which were crashed for example. I like to tinker with stuff in my free time
then break my car on track and start all over again... its a money-pit hobby I guess. If I manage to modify the OSG to a place where it works well I will update the thread. I will get a conventional LSD too for comparison and tinker with that too.
There is so hard to make a compromise between rebuild intervals, locking operation and locking potential. Conventional diffs with a preload shim start to slip within 25k km sometimes. OSG and CUSCO's with springs and lower preloads on the other hand behave differently and can catch you out unprepared. There is no Win/Win/Win
