Anyone have experience of driving a front wheel drive car on tarmac fitted with a plate diff and how that compares with a similar car with an atb / torsen diff ? I hear from people with serious laptimes that the plate-type is quicker but whats it feel like ? Cheers Rob
Vento Gareth has tried a VWMS box in his with a full on plated diff. said it was quite savage, and hard to drive at low speeds, but the grip was immense, a loads better than the Quaife ATB.
No personal experience but several guys (in Novas & Fiestas) that I hillclimb & sprint with swear by them. Do require more maintenance though.
i have a Kaaz plate diff in my mk3 using an FM mk1 box and 4:47 FD and its absolutely unreal, grip level in any corner is immense, only used it on the road and testing on an airfield at the mo tho. Its adjusatble so u can dial it in or out as u require and change how tight it is. i have mine quite viscious as im gonna use it for tarmac rallying and it took time to get used to @ first with the 4 paddle clutch but now i wudnt change it for the world.
the problem is that I hear conflicting arguments - some folk say their better and another, who makes plate diffs, reckons atb is pretty much as good on tarmac and less hassle to maintain the thing with atb is its fit and forget, no adjustment needed and no maintenance plate diff - could be better, could be worse, but rebuilding a gearbox isn't the easiest thing in the world to do and tbh, I'm not sure I can be bothered with several ins/outs to get it right if need be with gravel/dirt/snow there's no debate, plate diff is the way to go but tarmac......maybe its not so much of an advantage and I am wondering if the hassle/benefit factor is worth it more opinions please from people who have experience with them....
I'll let you know shortly m8 more people tell me its better for competition, than an atb, and they have previously run atb diffs. (saxo in combe saloons, sponsored by quiafe, but runs a plate diff reckoned he was 1sec faster with diff - relatively low powered saxo compared to class b cars) wondering how driveshafts and joints will bare up personally.
Dave - VR6T - has a few opinions on this sort of thing. Think his VR6 Turbo runs a plate diff (but not 100% sure)
Have put a few thousand miles with both diff types. ATB very good for what it does. Used it for hillclimbing in my old scirocco and it was CRAP but for everyday road driving you didn't really notice it. For fast twisty roads in the wet it worked well until one of the tyres lost traction, the diff will only transfer drive if you up set the car by turning the steering wheel hard left then hard right other wise the diff behaved like an open diff. The tyre that was spinning will just spin up even more. The best way to understand this is if you break a CV the car is stranded, the diff will not transfer drive to the good shaft. On MK1 drive train you usually find the short drive shaft tyre (LH side) with the standard open diff will ware faster than the long drive shaft (RH side) tyre. After 70K miles and 4 pairs of Yokohama A 539's using the ATB box the Long shaft (RH side) tyre wore faster than the short shaft (LH side) so the diff does do what is says on the tin. Now when I build the full all steel Gemini box for the VR6t i put in a VWMS plate diff, this is in a different league. My idea was to use the plate diff (current slip setting 100NM) to relive the stress on the syncro rear diff. The theory is that when you spin up the front end on the rallye you have to spin both front wheels, which the plate diff does consistently. The VC on the rallye does take quite a few revolutions of slip before it transfers drive to the rear open diff. I have to spin 3 wheels before the rallye stops moving with the plate diff. If i had used the ATB setup it would only require one front and then one rear to spin before it would spin up....... If you have driven a big BHP rallye/synco drive train car with open diffs you will be surprised how slow they can be to get off the line, they just spin up front wheel and then after what seems like an age the rear kick in and off you go. This doesn't happen with the plate diff set up. The science off plate diffs is quite interesting, you can specify loads of different ramp settings, it can be made so it locks on engine braking and on acceleration. You can have aggressive ramp contours or soft one, these all alter the the way car will behave on fast road driving or just heading down the shops. So to sum up you need to decide what you want your diff to do for you and then spec it to suit. But I would defiantly not use anything other than a plate diff in a large BHP 2 wd/4wd as long as your CV's are up to it. I have a few plate diff parts i will post up some pics of what i am talking about.
Hi fellas. From back when i used to race on the hills in my mk1 i had a ATB fitted in my car which drove nice and smoothly no real "tugging" at the wheel but under extreme conditions it could still be persuaded to let go. A friend of mine [some of you guys that have been around for years might remember him] Niheem Hussain who had the ex BRM built KVV 170Y had a VW motorsport plate diff. When i first drove it i was gobmacked by how much better it hooked up from a standing start and pulling through bends, far better than my ATB but it did pull the steering around a fair bit. It also if driven cack handedly could make the car terribly understeery. You had to set the plate diff up quite carefully to get great results, where asthe ATB was fit and forget.For my money i would say that if your car is used on the road quite a bit or not driven at its absolute maximum on track [its time to be honest with yourselves guys] or if you have any reservations about pulling your tranny out probably once or twice a year to sort your diff then a plate diff is best leftoff in favour of an ATB, however if you want the absolute maximum drive avaliable, and you are skillful enough to attain it. Plus you dont mind being covered in vile smelling tranny oil then a plate diff is the real deal. As always you need to look at what you require what your comfortable with in a very honest fashion to make the correct choice. Thanks, Dave Wetton.
The plate type diff is ajustable so you can make it as tame or aggressive as you like. The 02a diff that I had for the Lupo was far too tight when it was delivered from Ricardo, but I changed the ramps in it and it was superb. The only experience I have of a Torsen was in a Rover 200 GSi Turbo and it was useless and very unpredictable, it would start to lock midway through a roundabout and drag the car into the kerb.
I can vouch for the plate differentials , yes they can be a little too much for the average driver.... cracking, juddering and grinding at low speed cornering... but moderate to high speed corners is where it works at best. The more pedal you give it the better it works. As mentioned before it does put alot of strain on the g-box and drivetrain. I killed a few boxes, CV joints and driveshafts in the process.. but well worth the hasstle.
