Straight Cut Drop Gears and ATB

[Fanfaniracing]

Hi Folks

I am looking for ATB Diffs but the Swiftune/Quaife is not In stock for a wile now and neither Swift or Quaife can give a Date when they are back again...

Also has Swiftune taken out their Straigth Cut Drop Gears of their Shop.

My questions are: is there an other ATB Diff which will work well?

And are the MED S/C Drop Gears good quality?

best regards

[Supersonic]

Hi Folks

I am looking for ATB Diffs but the Swiftune/Quaife is not In stock for a wile now and neither Swift or Quaife can give a Date when they are back again...

Also has Swiftune taken out their Straigth Cut Drop Gears of their Shop.

My questions are: is there an other ATB Diff which will work well?

And are the MED S/C Drop Gears good quality?

best regards

I can only answer your last question, the MED Engineering S/C Transfer Gears are top quality

Hard on the ears nonetheless

Alan

[wantafaster1]

MED stock an alternative differential to the Quaife, it works on the same principle

[Oneball]

I’ve got MED drops in my race car. Had them for years. No issues except noise but that’s normal for SC

[imack]

MED roller bearing drop gears here, no issues.
As already mentioned, MED now sell their own version of the Quaife ATB.

[wantafaster1]

Except it isn't their own, it's supplied to them.
I have used one, nothing wrong with it.

[Fanfaniracing]

So i think i will go the MED Road.

Unfortunately their ATB 's are also out of Stock...

[Spider]

I have used many Quaife ATBs and absolutely love them, I won't ever go back to an open Diff again.

It's great that MED, or who ever it is that makes theirs, has stepped up to the plate though, nice to have options and alternatives. Maybe it'll bring the price down a little ?

Except it isn't their own, it's supplied to them.
I have used one, nothing wrong with it.

Thanks for the feedback on them, good to know.

[850man]

I have never liked Quaife diffs. Having driven hundreds of Minis with them fitted I prefer the std diff.
We have removed them from a number of cars here in our workshop, one being a twin cam big HP car, with the quaife it torque steered and was a dog to drive. Don't let the hype get in the way of real time experience.
Most of the decent race cars here in Aus use a Salisbury LSD. They are well proven and preferred by the guys with the quickest cars.
Quaifes are usually loved by the Motorkhana drivers, they seem to work far better in the dirt than on the Tarmac.

Straight cut drop gears are great if you can find a genuine BMC made set. Others I have used are either too hard, too soft or made of Chinese cheese and usually fail with decent HP engines.
An advantage they have over the helical gears is they dont try to seperate and chew out the thrust surfaces under load in race conditions. The tapered roller sets are excellent as well, though I have not seen any std idler bearings fail with the std straight cut set up.

[Mini-geek]

Correct setup is crucial with an ATB you need to do several other modifications to allow the ATB to work it's best..

[GraemeC]

850man - I think you're in the minority there.
I've competed 3 cars with ATBs and never excessive suffered torque steer as long as both wheels have grip. And yes, at least two have had considerably powerful motors. The biggest downside over an LSD is that if one wheel has no grip at all then they don't help.

Mini-geek - Correct setup? Never done anything other than checked clearance in the casings (had to relieve one very slightly) and bolted up -what other 'mods' are needed?

[Spider]

Mini-geek - Correct setup? Never done anything other than checked clearance in the casings (had to relieve one very slightly) and bolted up -what other 'mods' are needed?

Graeme, 'bolt them up' is pretty much all I've ever done too and been very happy, but if there's more to learn here, then I'm interested to hear what Mini-geek can shed some light on

[Oneball]

Never experienced torque steer with an ATB either. They’re far more forgiving than a plate type unit, about 4 secs a lap slower round the GP circuit at Silverstone but better than a standard diff by about the same amount.

[Mini-geek]

Can only talk about my own experience but I found that with rubber mounted tie bars the torque steer made the car virtually impossible to drive.

Obviously this depends on the power you're putting down and wheel offsets etc, I considered taking it out until I changed tie bars


Wasn't talking about installation into the box

I'd highly recommend one when running over 100bhp I don't think there's much point below that

[wantafaster1]

I think I know what you mean.
Torque steer was terrible but I suppose the clue is in the ATB name. What was very disconcerting was how it would constantly "hunt" from side to side on a steady light cruising throttle.

I didn't find enough grip and changed to a plate diff.

[Spider]

Cheers for your experiences mini-geek and wantafaster1.

Most I have fitted have been in cars that have been sub-100 HP. There's been a couple though that have been on and over that mark, and I gotta say, we didn't find that issue, infact in one car, it actually settled the torque steer somewhat, though, in regards to torque steer, I don't believe it comes from the method of drive, but as you pointed out here mini-geek, front end set up.

I run one in my Moke and my fellow travels do too. Many years back, prior to ATB's being available, I tried an LSD and I couldn't take it back out fast enough. In the Race Car, it was great on the track, but in a road car, it was dreadful. Before running the ATB in the Mokes, we found when off-road, we have to often run low tyre pressures (22 to as low as 12 PSI at times) to increase our footprint, however, with the open diffs, torque steer and wheel spin occurred often and worn & bust diffs were commonplace. Since going over to the ATB, we've found that the torque steer in these conditions has gone and I can't recall getting wheel spin, we're also able to drive through many more places, particularly in soft sand, than we ever were. They have been a game changer for us. I'll add here to that we all only run bone standard 1275's so power levels aren't at all high, circa 60 HP.

In the Minis, I find them much more sure footed and again, it has removed wheel spin, particularly in tight corners.

Definitely one of the best things to ever come available and I have to thank Matt Read (Mad Matt) for putting me on to them. He also loves them.

[Oneball]

I had uprated tie bars with rubber when I had my ATB, no torque steer but I had significantly more caster. Maybe the caster makes a difference or maybe it’s the thicker bars. That was with 998cc with 100bhp.

[wantafaster1]

I really removed it because of wheelspin in tight corners.

[imack]

No complaints with my Quaife ATB.
Obviously not as effective or as aggressive as a plate type diff but in my opinion far superior to an open diff.
It does seem to highlight or magnify any suspension or wheel offset issues you may have. Mine hooked up / weaved badly under power on joints in the road or severe cambers in narrow lanes when I had metro turbo drive flanges and spacers to give the wheels clearance with the calipers. Once I removed the spacers and fitted mini drive flanges and smaller calipers the weave and hooking up on poor road surfaces under power all but disappeared. The ATB certainty puts the power down better out of the corners and seems to pull the nose in tighter with the application of power through the corners.
No downsides for road use in my opinion other than initial outlay.
I've never experienced a plate type diff for comparison.

[850man]

I think I know what you mean.
Torque steer was terrible but I suppose the clue is in the ATB name. What was very disconcerting was how it would constantly "hunt" from side to side on a steady light cruising throttle.

I didn't find enough grip and changed to a plate diff.

Exactly my experience. I could never keep the car in a straight line.
Now, as others have said, it did have an adjustable front/rear end with a fair amount of negative camber and around 200hp so the Quaife was removed and a open diff fitted. Problem solved.
I suspect suspension settings are a major factor when using a Quaife.

We have 3 Mini specialists in our workshop and the discussion yesterday was 2 of us agreed that they are horrible, and the other said he loves the Quaife in his road car.

You either like them or you don't.