Rear Disc Conversion

[Phaeton]

Jason, just re-read the post, there are a lot of photos hidden in links in it, used to do them that way then people could load images if they wanted. But this one

Probably gives you the best idea of how/where the carriers fit & where the metal has to be removed from..

Alan...

 

[jason_l]

Thanks Alan thats perfect!! Just confirms exactly what i thought i needed to do.

Already picked up some disc front hubs, just have to strip off all the other crap thats attached and then im going to shot blast them

Jason

 

[Mini Mad Max]

Aye! I have a fair bit to do aswell! The guy on the rallydesign may have a point about 13" wheels being slightly too small because the golf mk4 calipers have them fins on whereas the early steel/iron ones didn't because alloy is slightly weaker and conducts away more heat. But if you're moving the calipers in on the hubs, this may not be a problem, especially if the old ones fit under 12" steel wheels! Plus the mini hubs are a lot smaller than the cars with intended use.

Thanks for being so snap happy when doing your conversion alan, it is really helpful  !!

Max

 

[jason_l]

It wasn't the guy that stated they wouldn't fit 13's Max, it states it in the Rally Design Catalogue. If you look at Alan's calipers they look roughly the same size, i think the fins sort of grove into the caliper, rather than stick out. Im sure we will be fine Max.

Oh and don't forget, the race is still on!!!!! ;D

 

[Lime&Orange]

Whats the all in weight of these?

Just wondering if they are heavier than the standard drums.

 

[jason_l]

Not sure of all in weight, i have just weighed one of the calipers i have and its 2.5kg and the disc weighs 2.9kg. The ones me and Max have are Alloy versions of the golf ones. Im guessing it will be roughly a little more, although weight really isn't a worry in the freestyle  ;D

Once i get all the old Drum setup off the car i will get it all weighed up and then we will have a definate answer

 

[Phaeton]

Jason, When you got your hubs, did you get a set of driveshafts as well, the disc version use a larger one than the drum version.

Alan...

 

[jason_l]

I picked up the hubs form my mates house. I have the hubs,discs,camber arms, top arms etc but i don't think i have the driveshafts.

Do you mean the driveshafts themselves or the end part with the castle nut on? And whats the difference in size, if its the length it won't matter.

Jason

 

[Phaeton]

They are physically a bigger diameter of shaft, where they go into the CV is a different diameter to a drum shaft.

Alan...

 

[jason_l]

So the end part that goes through the hub and has the castle nut on is a larger diameter as well then?

If thats the case i may need to get hold of some, not sure if my mater has them or not???

Jason

EDIT: Have found the pics online and i see what you mean, completely different part that goes through the hub. I wonder if the driveshafts themselves are the same???

 

[Lime&Orange]

But the rear brakes do very little on a buggy anyway.

Mine are dialed as low as the MOT allows.

As for weight, lighter is faster  ;D

 

[Phaeton]

I wonder if the driveshafts themselves are the same???

Nope quite a bit bigger.

Alan...

 

[jason_l]

But the rear brakes do very little on a buggy anyway.

Mine are dialed as low as the MOT allows.

As for weight, lighter is faster  ;D

Max was talking about the rear drum rakes not being very good for handbrake test ??? and the fact i will have 200bhp i think i may need some decent brakes

I wonder if the driveshafts themselves are the same???

Nope quite a bit bigger.

Alan...

I need some Disc driveshafts then  ;D Will have to see if my mate has them, i don't think he does though.... :-\

 

[Lime&Orange]

But the problem is, disc's may grab quicker at the back than the front due to engine weight, now that would be intresting.

I am watching this with intrest.

 

[Phaeton]

But the problem is, disc's may grab quicker at the back than the front due to engine weight, now that would be intresting.

I am watching this with intrest.

L&O I have had no issues, even without the bias valve fitted, the Mini MC has some limitting on for the rear brakes.

Alan..

 

[Mini Mad Max]

You must remember it's a 1 pot sliding caliper set up as well so aren't as good as the traditional 2 pot calipers on the front.... the main reason for the conversion is to have a handbrake that works because the minni handbrake wasn't designed to have all that weight over it from the engine and so the drums are pretty rubbish.
Max

 

[mud68]

Alan, I have just tried to bleed my Mk2 rear conversions for the first time but can't get any pressure on the pedal. Got fluid coming thro' & no air bubbles, the fronts are working (can't turn by hand) and the handbrake works - so I know the pots are moving.
Wondering if the MC is faulty or the fact I still have the brake bais valve fitted?
Could it be because the rear now needs more fluid to move the calipier and its not getting the volume because the bais valve is restricting it?
Any help appreciated.
Thanks Shaun

 

[Phaeton]

Shaun,

I don't have a bias valve fitted so not sure it that will hinder or help, you have also got to make sure you have the front & rear pipes connected at the MC the correct way round. This will depend on the MC in question, but it you get them the wrong way round you will not be able to get the rears to work correctly. The other thing that may cause an issue, is on mine I have the calipers upside down, so it is not possible to bleed them whilst fitted, I take them off, lock the piston back with a clamp & turn them over to bleed

Alan...

 

[mud68]

Alan,

Mine are on upside down as well, I will have to take them off to bleed them. Makes sense when you think about it -the bleed nipple is at the bottom and the air is trapped at the top.
Thanks for your help.
Shaun

 

[jason_l]

Right, planning on getting on to this conversion this month.

Been speaking to a mate and he knows someone who might be able to do the hub mods for me and im hopefully seeing him this weekend.

I have printed off the pictures that Jamie posted up and i have shown these to my mate as they give a really good idea of what needs to be done. My mate said that rather than drilling out the holes and having a cast piece pressed in would it not be easier to fill the existing holes with weld and then redrill the holes in the correct position? My question is if its ok to do this? I think it would be stronger than having the cast piece simply pressed into the hub but am i being stupid???

Thanks if anyone knows, Phaeton?  ;D

Jason