38 replies to this topic

[mini-geek]

I'm fitting a Quaife ATB I'm just wondering if it worth while upgrading the shafts I'm still waiting to keep the CV joints but are thicker drive shafts going to be worth the cost?

Ps it's a 1380 track car

[imack]

Standard mk1 cooper S shafts on my quaife. Fitted with hardy spicer joints, late automatic mini 'knock on' hardy spicer output flanges and large bush cooper S diff side plates.
OK so far.

[nicklouse]

Not needed until you break the old ones.

 

often the standard ones can be quite resilient.

 

never bothered on special drive shafts.

[Tupers]

You’ll have to be running some pretty serious slicks and doing drag launches to really trouble most driveshafts.

[Spider]

I'd suggest sticking with the stock shafts.

 

The final drive and centre web in the gearbox case aren't the strongest of items and they do break. Keeping with the stock drive shafts is a bit like a fuse as they are fractionally weaker then the gearbox (usually!) and frankly, I'd rather replace a drive shaft than be looking for a gearbox case and final drive gears.

[DeadSquare]

In a race, there is only one second of strain as you drop the clutch at the start.

 

That strain gets somewhat proportionately less, the further down the grid you are, because more important than 6th or 7th position at the first corner, is avoiding a traffic incident due to torque steer or wheel spin/grip due oil/rubber.

[Cooperman]

With high powered Minis the weakness in the standard drive shaft is the machined groove where the circlip that acts as the stop for the CV joint.  The groove is the weak point and that is where the shaft can fail. I had a standard 'S' shaft fail at that point whilst leading a rally. I slid onto the grass and as I came back onto the tarmac the wheel was spinning - I had to keep full power on to prevent it from spinning - the shaft snapped I fitted the competition shafts as a replacement.

That is unlikely on a race car as the tracks are smooth, but I guess one could slide onto the grass. However, an LSD will spread the load over both shafts, so shaft failure is less likely. An LSD is not usually used an a rally car. Personally I have never been able to get comfortable driving with one in competition and I know I am not alone in saying that. 

[mini-geek]

Cheers I'll leave it as is then..

[mini-geek]

to be honest I really don't know if I'm going to like or if it's worth the cost of the ATB but a few people seem to rave about them so giving it a go.
I'm running out of things to do to it that don't involve very expensive cylinder heads

I understand ATB's are no good in rallying as they don't work when the wheel isn't in contact with the ground..

Great advice as always

[DeadSquare]

 

Mini cylinder head kit (K1100 16 valve) with all BMW parts

Pre-owned

£380.00

 

+ £12.90 postage

44 Watching

 

 

 

Is this too expensive ?

Edited by DeadSquare, 07 December 2019 - 04:55 PM.

[Ethel]

Nice, but there'd still be a shed load of block machining etc to pay for, unless you can do it yourself.

 

We have had the conversion written up in the projects section, but it's a fair old while ago.

[mini-geek]

Thanks well aware of what it all costs the head is the cheapest part of the build

Edited by mini-geek, 07 December 2019 - 05:27 PM.

[imack]

to be honest I really don't know if I'm going to like or if it's worth the cost of the ATB but a few people seem to rave about them so giving it a go.
I'm running out of things to do to it that don't involve very expensive cylinder heads

I understand ATB's are no good in rallying as they don't work when the wheel isn't in contact with the ground..

Great advice as always

ATB is one of the best components I've fitted to my mini. You don't really know it's there until you give it stick. Steering may be slightly heavier under normal driving but can get very heavy when accelerating through a corner, which is something you'll want to do as it puts a massive grin on your face as it just turns in tighter towards the apex of the turn, understeer seems almost impossible on dry roads.
Suspension needs to be well set up no silly wheel offsets or it will weave all over the place under power. Made a big difference on mine getting the scrub radius back to standard.
Traction wet or dry is miles better than with an open diff. No real down side in my opinion except for initial cost.

[mini-geek]

I've got 6x10's on not sure what offset they are not too extreme by mini standards..

[imack]

I'm on 6x10's too with 'S' offset & 7.9" vented KAD discs using mini drive flanges.
Previously had metro turbo drive flanges plus 1/2" spacers so total increase of 3/4" per side. Weaving and tram lining under power could get pretty interesting!!

Edited by imack, 07 December 2019 - 06:20 PM.