Discussion
For racing I would think that a plate type diff would be better (Titan or ZF if you can find one). The Quaiffe diffs are torque biasing (I believe) and will therefore spin up the inside wheel if it leaves the ground e.g. bumping over a curb.
I swapped from an AP Suretrack torque biasing diff to a Titan plate type and it was a big improvement. You might get some initial understeer in some corners but this can be dialled out with suspension set-up or driving technique.
Phil at Road and Race transmissione should be able to supply and fit one for you.
I swapped from an AP Suretrack torque biasing diff to a Titan plate type and it was a big improvement. You might get some initial understeer in some corners but this can be dialled out with suspension set-up or driving technique.
Phil at Road and Race transmissione should be able to supply and fit one for you.
I'm running the Quaife ATB on track and it works well but wouldn't disagree the comments about a plate type diff. Just to correct, the ATB will stay locked up as long as drive is applied - even if it's just one wheel on the ground (after all that's the purpose of the LSD). The problem with curbs occurs when either both wheels leave the ground or you lift. Then it can switch between the two sates which can be a little hard on the gearbox - OK for trackdays, but for racing maybe not ideal.
DCL said:
I'm running the Quaife ATB on track and it works well but wouldn't disagree the comments about a plate type diff. Just to correct, the ATB will stay locked up as long as drive is applied - even if it's just one wheel on the ground (after all that's the purpose of the LSD).
I was told by an expert on transmissions that the Quaife ATB isn't a limited slip differential. Apparently when one wheel lifts it will spin the power away rather than locking up like a plate LSD. I don't have personal experience of ATBs, but bought a Titan as a lot of people recommend them for Sevens.downsman said:
I was told by an expert on transmissions that the Quaife ATB isn't a limited slip differential. Apparently when one wheel lifts it will spin the power away rather than locking up like a plate LSD. I don't have personal experience of ATBs, but bought a Titan as a lot of people recommend them for Sevens.
Sorry, but an airborne wheel does not spin the power away with an ATB diff . . . The Automatic Torque Biasing diff is designed to Limit the Slipping of the Differential. It uses a series of inter-meshing helical rollers to provide the differential action. The rollers are housed in a cage, and when drive is applied to the cage, friction reduces the amount the rollers rotate (depending on the torque being applied).
The key point when comparing the two types is the range of 'limited slip' action in the ATB diff is far greater, going from almost zero to fully locked up depending on torque being transmitted - exactly what's required in most cases. That's not to say modern plate type diffs don't also have a torque element, it's just that they do it another way which could be argued to be better suited to racing applications.
This picture show half the diff rollers. Another inter-meshing set are on the other side. The drive is applied to the outer cage, through the rollers, and to the inner shaft. When no drive is applied the rollers are free rotate allowing the differential action. Provided that torque is applied, and at least one wheel is providing a load, then there will be a reduction in the amount of differential action.
I have just changed from ATB/ Quaiffe to a 'friction plate' diff. The reason was it was spinning the wheel with no resistance/ off the ground in a couple of corners at the track i race at, this was loosing me time as i would have preffered some power oversteer. Speak to Quaiffe and they tell you to stiffen the back/ ARB. The spinning of the wheel feels like the clutch is slipping the revs rise but the car doesnt go forward or oversteer.
Quaiffe ATB's are very good and come with a lifetime guarantee, we have fitted this to a CSR 200 and it works well for track days. I have yet to try the friction plate diff in anger but going on all who race and talking to R and R this is the favoured choice.
.........then i spoke to another race guy, very experienced and he reckoned the ATB was the best choice?!! you hten have to go into the realms of your own personnal R and D as everyone has a difference in driving style and priorities......R and Race though are the key players to maybe biase any descision of the diff to try first.
Quaiffe ATB's are very good and come with a lifetime guarantee, we have fitted this to a CSR 200 and it works well for track days. I have yet to try the friction plate diff in anger but going on all who race and talking to R and R this is the favoured choice.
.........then i spoke to another race guy, very experienced and he reckoned the ATB was the best choice?!! you hten have to go into the realms of your own personnal R and D as everyone has a difference in driving style and priorities......R and Race though are the key players to maybe biase any descision of the diff to try first.
I have experienced what you describe, but also record wheel speed sensors and have looked at what was happening. When the diff is hot, and torque is momentarily lost it can switch off the LSD action and this can be slow to recover making the drive away from the corner as you describe.
My point was that this was being blamed on one wheel becoming airborne when in fact it was the whole rear axle that needed to become airborne.
Edit: Here's an example of an ATB diff switching off at Clarks in Knockhill. The car goes light enough to lose traction on both wheels before spinning up a wheel on the exit.
http://youtu.be/B3dtadCKJK4?t=3m32s
My point was that this was being blamed on one wheel becoming airborne when in fact it was the whole rear axle that needed to become airborne.
Edit: Here's an example of an ATB diff switching off at Clarks in Knockhill. The car goes light enough to lose traction on both wheels before spinning up a wheel on the exit.
http://youtu.be/B3dtadCKJK4?t=3m32s
Edited by DCL on Saturday 21st April 14:28
The rear inside wheel (that had the least resistance)was spinning on exit of the chicane at Croft, no loss of torque no loss of throttle input but as the cars centre of gravity moved to the offside front on exit and the least weight being over the rear nearside of the car the rear wheel lost traction and spun. It done this from the start of the race untill the end, also happening on exit of hairpin, with no relation to heat build up.
The most popular and the one caterham use in the race cars (as per Phil R and R) is the 30-90 titan, forgotten the pre-load, although he is of great help and worth a call
The most popular and the one caterham use in the race cars (as per Phil R and R) is the 30-90 titan, forgotten the pre-load, although he is of great help and worth a call
Gripper also do a plated type LSD diff which would be suitable. Its apparently very simialr to the ZF. I run one in my Westfield and Clio. Been fine so far. Titan wasnt available when I bought mine, I'd definately go for one of those over an ATB.
I spoke to lots of racers who said ATB and lots who said plated. Really couldnt get a firm view one way of the other really. My Gripper plated in action
I spoke to lots of racers who said ATB and lots who said plated. Really couldnt get a firm view one way of the other really. My Gripper plated in action
Edited by Porkie on Thursday 26th April 09:55
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