21 replies to this topic

[Almond-1]

Ok folks here's the issue & I'm sure some one will know the answer (or I hope so).

 

I'm currently running 10 x 6 ultralight wheels with a -3 ET over Mini sport 7.9" 4 pot alloy calipers. Machined down vented discs, Mini 8.4 drive flanges, Mini Hubs / steering arms. Although the calipers run close to the wheel with this setup, they do miss due to the negative ET.

 

However I'm Not happy with the the large offset of both the front / rear wheels & feel that this is causing handling issues.

 

What I need to know is, has anyone else used another alloy wheel with a more positive ET over these calipers ( looking at the Mini Lite with a +8 ET). Or do I need to go back to the Cooper S setup i.e 7.5 disc, drive flange & caliper setup?

 

Thanks in advance.

 

[imack]

I'm looking for pretty much the same answer, same brake 7.9" setup as you but with KAD calipers and trying to find out if the non deep dish 6x10 minilites ('s' offset according to minispares site) with 100mm backspace clear the calipers.
Did ask the question on hear some time ago but got no answers.
Have read somewhere that modern genuine minilites clear 7.9" calipers, forget whether it was minisports or KAD's, but it didn't state whether it was all modern minilites or just certain width/offsets.
Kad send you a template to print off to offer up to a wheel to check clearance, don't know if minisport do similar.
Have you contacted minisport in case they know if certain wheels clear or not.
Kad would only say try the template.

[Almond-1]

imack, thanks for the reply. Not contacted Mini sport, but may be worth a try. Unsure how much difference there is between the KAD & Mini sport calipers regarding the dimensions.

 

May be worth trying to get the internal dimensions of the Minilites as a comparison. 

 

What wheels have you tried, if any yet?.

[imack]

I'm currently running my old 5x10 GB's that I bought in the 1980's, these have plenty of clearance, but I want to replace them as they're very worn around the stud holes from years of being removed/ refitted and I fancy a 6x10.

[Almond-1]

The 5 x 10 have a positive 14 mm offset & the 6 x 10 have a 8 mm positive offset, obviously taking a bit more towards the wheel arch. 

 

Does the wheel cover all the caliper & if not would it if was wider?

[Cooperman]

I have never understood why anyone would want the 4-pot brakes with any non-racing Mini, especially when 10" wheels are wanted for the overall ride and handling benefits they give.

The offset required for the big 4-pot brakes will increase the mean track and thus degrade the steering due to the then incorrect scrub radius. The difference in the track to wheelbase ratio will also make the car less stable.

Most owners accept that the 10" wheels with the 7.5" Cooper 'S' calipers are about the optimum and with Carbon-Metallic brake pads there will never be any braking problems, even if racing. With less wheel offset using 10" wheels, there is no need for wheel arch extensions, which can only be a good thing. I have used up to 5" wide wheels on my 'S' with the standard offset and don't use arch extensions.

[Almond-1]

Appreciate your comments cooperman, This is exactly what I am trying to cure & yes this is a race car.

 

I have had various race cars all using 10 x 6 wheels & the usual 7.5 setup with no previous  issues. However I have gone down the road of using the four pot alloy setup (yes I should have stuck with the standard 7.5 setup) But I don't like being defeated, Hence why I'm trying to cure these issues.

 

Any information on the technical dimensions of the various 10 x 6 wheels would be appreciated.

[imack]

The GB's have et21 cast into them but I've done my best to measure the off set to compare them with the 6x10 minilites that minispares quote as back space 100mm and 74mm hub face to outer edge, I make that et13 if I'm working it out correctly.
The GB's I make et13.5 by measuring in the same way, so the minilites should have an additionl half inch inboard and outboard over the GB's.
Cooperman, these 7.9" setups shouldn't increase the track oner a 7.5" S setup as the discs are modified to be able to be fitted using the 8.4" mini disc drive flange, not the metro ones that I know increases the track and messes up scrub radius. I might be wrong but I've always thought that the track of the 8.4" mini set up was the same as the 7.5" S set up.

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[imack]

Appreciate your comments cooperman, This is exactly what I am trying to cure & yes this is a race car.
 
I have had various race cars all using 10 x 6 wheels & the usual 7.5 setup with no previous  issues. However I have gone down the road of using the four pot alloy setup (yes I should have stuck with the standard 7.5 setup) But I don't like being defeated, Hence why I'm trying to cure these issues.
 
Any information on the technical dimensions of the various 10 x 6 wheels would be appreciated.

I also went to this set up to reduce scrub radius due to some interesting moments.
I'd previously been running turbo drive flanges, ground down metro 4 pots and wheel spacers.

[Almond-1]

imack, I believe that you're correct with the calculations regarding the ET.  I was also under impression that the track remained the same by using the 8.4 drive flange.

 

I'm trying to locate my geometry readings & see if it includes the track readings to confirm.

 

 

Yes, the handling can be fun some times, especially when you're trying. 

Edited by Almond-1, 21 May 2018 - 08:32 PM.

[rww]

imack, I believe that you're correct with the calculations regarding the ET.  I was also under impression that the track remained the same by using the 8.4 drive flange.

 

I'm trying to locate my geometry readings & see if it includes the track readings to confirm.

 

 

Yes, the handling can be fun some times, especially when you're trying. 

 

 

  I'm very interested in your observations concerning the handling with large offset wheels. In what way do you feel the handling has been effected - understeer, oversteer etc ? 

[imack]

Lots of weaving and tramlining on any heavily cambered road surface or where road surface repairs had been carried out or even white lines under hard acceleration, could be very scary overtaking a car as you cross the crown of the road and the camber then goes the other way. Mine was made worse after fitting an lsd. Much better now I've got rid of the wheel spacers and the metro drive flanges. 7.9" discs don't have quite the bite of the 8.4" but the handling is much more tolerable.

[rww]

   Thanks for that. Are you still running a lsd ?

 

 

Lots of weaving and tramlining on any heavily cambered road surface or where road surface repairs had been carried out or even white lines under hard acceleration, could be very scary overtaking a car as you cross the crown of the road and the camber then goes the other way. Mine was made worse after fitting an lsd. Much better now I've got rid of the wheel spacers and the metro drive flanges. 7.9" discs don't have quite the bite of the 8.4" but the handling is much more tolerable.

[Almond-1]

I agree with imack comments. I have slowly reduced the effect by replacing the Metro drive flanges with Mini ones, different wheels & LSD. Although I currently run a ATB diff.

 

Still doesn't handle to what it should be or what I'm used to.

[imack]

   Thanks for that. Are you still running a lsd ?
 

 

Lots of weaving and tramlining on any heavily cambered road surface or where road surface repairs had been carried out or even white lines under hard acceleration, could be very scary overtaking a car as you cross the crown of the road and the camber then goes the other way. Mine was made worse after fitting an lsd. Much better now I've got rid of the wheel spacers and the metro drive flanges. 7.9" discs don't have quite the bite of the 8.4" but the handling is much more tolerable.

As per Almond-1, I'm also usind the quaife atb so pretty tame compared with a plate type diff but it still made the squim/weave in a straight line something that could be quite unnerving, scary enough to make me try and do something about it and considerably worse than with the previous twin cross pin and identical suspension set up. It is great fun in tight corners though where the application of throttle pulls the nose in tighter just at the point you would normally expect understeer to creep in.