The gearbox would have ND0 020 stamped on the underside - the '020' denotes the LSD. A 225 non LSD box would just have ND0 000 on the underside. No idea if thats the part number - aftermarket LSD's are around £700 for a Quiaffe IIRC - 'ianplymouth' went down this route. Demon Tweaks / JJC stock them. Personally I would email JOnny at TrackfocusDirect - his service is second to none, and although he doesn't list them(only diff's for ST's) , I have used him for sourcing parts that are hard to find, and it turned up 2 days later. He is active on this if you pm him also - http://www.trackfocusdirect.com/
If I had to choose between the stock R26 LSD and a Quaife for the same amount of money, I would definitely go with the Quaife unit. Higher clamp force and faster response. This is closer to a motorsport item where the GKN (original) one is more suited for the normal driver. But this is just my opinion. S.
You have any personal experience with both? i'm having to decide between the 2 atm. By hand the gkn does feel way less aggressive than the quaife in my 02m
Hey Tutuur, just seen your message. Yes, I had multiple experience with both of them and other different diffs in various cars. If we speak about M2RS, the GKN doesn't do too much until you have a pretty high speed difference between wheels (usually a tight roundabout and WOT, all weight shifted to a side) where Quaife kicks in even on straight line if you WOT and you feel each wheel gripping more or less through the wheel. Is not something that my mother would like to experiment, but definitely something I would like. Also I fitted a GKN unit in my M2RS diesel (from a M3RS cup) and I have a lot of experience with that. It very weak and I would love more friction inside the diff. I also tested in snow or hardest condition of snow on one wheel and talmac on the other and the results are just ok-ish but not wow. You may say GKN is a good unit unless you never driven a clutch-plate diff with preload and ramp angles. Then you will realise how mild it is. And because I'm coming from some proper racing environments with rally cars and drag cars, I would love the wild one. On the other hand, even the GKN one can be modified to be more aggressive and is just a question of finding the correct friction washer with higher friction. If you want, we can discuss more about this. So, personal opinion, for a track only car I would go with a clutch and plate but for a mix of daily driver and track, I would go with the best helical one. And my absolute preferred option is the Wavetrac (not an option for M2RS unfortunately). S.
Good to finally find someone with experience using both! i've had a 02m (vag 6sp) with Quaife before and it was awesome! when i had the wheels in the air and rotated one side, the other side would rotate with it, with the gkn i can just turn them with my fingers in the gearbox itself. Hence why i thought the gkn is much less aggresive. i'm fitting a 225 engine in my car with nd020 atm so will probably fit a quaife in the normal gearbox which i'll be fitting to my uprated engine. don't think shimming the gkn would help much as it doesn't change anything to the helical gears cheers for your input, helped me alot!
Happy I managed to help. What ratio do you want to run in the gearbox? Stock Megane ones? Stock Final Drive Ratio? I know you said you are doing the ECU tuning on yourself and I'm also looking into building a Clio with Meg engine, I'm pretty curious of what are you looking of doing. S.
Lets be clear what is being discussed here, helical gear type torque biassing differentials ala Quaiffe or Limited Slip Differentials? LSDs use friction plates pushed together by belleville washers to limit the speed differential between the wheels, there is no such mechanism in the various other differentials without some form of friction plates (wavetrac being an interesting hybrid).
We where discussing atb's, atleast i was. and yes bulardas, i'm doing the immo swap and mapping myself standard final drive ratio, pretty long by itself anyway!
But that is not how torque biassing differentials work, you were talking about "clamping force" which sounds very much like what one does with an LSD by putting bigger/stiffer belleville washers in to push the friction plates together with more force, or by changing the friction disks such as using the GT3 race car disks in the Porsche road car ZF LSDs. An ATB doesn't have any friction plates or similar to directly limit speed differential (excepting the odd wavetrac thing). If one completely unloads one side of an ATB it will stick out all of the engines power through that wheel just as it will with an "open" or conventional differential. http://www.guardtransmission.com/tech_faq.html Two completely different types of differential that work in very different ways, if one ATB feels like it has more friction than another I wouldn't read too much into that itself as its not like trying to turn an LSD where you can feel the effect of the friction plates.
I know the differences between the clutch type and helical type, but even the helican relies on friction to block the side gears agains the housing in order to block the main gears (so the car wheels). So, the ATB differential LSD's are torque sensitive limited slips with a torque biasing ratio. This is the result of the friction generated by the thrust forces on the gears against the housing and within the gear mesh between the pinion and side gears. If you open it, you will find there some shims and modifying the friction coeff of the shims or housing or gears, you can change how fast the differential starts to lock. If one wheel is in air, the diff with still be open, but as long as you still have some load on both wheels, you can tune how fast it going to react. So the ways you tune this differentials are the amount of friction there which changes at what speed difference the side gears starts to block and also what is the maximum blocking force. If you make the side gears to block still, then your wheels will have 100% lock. I'm struggling to find the pictures of a GKN diff opened with the shims I'm speaking about. There are some small ones on the sides of the side gears. Hope it makes sense what I'm saying. S.
Good to speak to you yesterday mate and see your R26! I could only find you in here and on the clio forums!
