Here we go. I used a big allen key, a 19mm socket, a pair of Hi Spec R-132 calipers, Hi Spec brackets for Cossie hubs and a set of Ferodo DS3000 pads. It took about 45 minutes for the first side and 15 minutes for the second side:

1. Original wheel with standard 2WD caliper


2. Wheel off to reveal newish disc and standard caliper


3. Disconnect old brake line and attach new braided line


4. Remove original caliper and compare to the HiSpec R-132 to see size difference



5. Compare standard size pads (above) with pads for R-132 calipers (below)


6. This bracket mounts the caliper to the hub


7. Turn the steering so that you can mount the bracket


8. Bracket on


9. Mount the caliper to the bracket


10. Attach the braided line


11. Put the wheel on to discover that it does fit but only just and I had to take the wheel balancing weights off the inside. Not sure what to do about this at the moment.


12. Go to the kitchen. Original Cossie caliper with pads weighs 5.3KG (scale has gone right round past zero)


13. Hi Spec brackets and DS3000 pads weigh 1kg


14. Hi Spec calipers weight 2.5kg



So there you go. I haven't raced on them yet - first race is in June - but they should do the business and they fit under standard wheels. It saves 1.8kg per wheel in unsprung weight, gives you a bigger braking surface area, should diffuse heat quicker and didn't cost too much.

Charlie

 

is it possible to use this set up on 4x4 saph cossie?thinner disc's on 2wd?or what kind of set up is used on them(4x4) with standard wheels?using redstuff pads at precent,no complaints tho,sorry to have changed the subject a bit,col93saphcos

 

looks good mate, great pics aswell, think im going to order up tuesday

 

so how much were the calipers and brackets then?? looks good

 

Cant you just use bang on weights to balance them now?
I had the same trouble with my 309 when i put big brakes on, i just didn;t balance them! lol

 

I paid 375 quid second hand for the calipers and brackets. The pads are around 100 I think.

Charlie

 

I'm not sure how essential balancing weights are. When I did the other side I noticed that the balancing weights must have fallen off on track. I haven't noticed any vibration.

Charlie

 

I'd like to try a Sharktooth alloy and a 3 door alloy sometime to see if they go over the brake calipers. Anybody near Surbiton have a wheel they fancy bringing over one day? No hurry.

Also if anybody fancies weighing a sharktooth alloy and a 3 door alloy (without tyres) I would like to know what they weigh. Lattice is 9.1kg.



Cheers,

Charlie

 

Very good piccies there Charlie, looks a very good upgrade within the confines of 15" wheel, are you limited to this size for class rules or anything ?
tabetha

 

Exactly. "you must be able to refit a wheel of standard size"

This restricts the fitting of large brakes

Charlie

 

It depends how far out they are, with good quality tyres its usually not too bad, but if you do get one a long way out, you will probably notice it, it doesn;t bother some people, others hate it.
I do alot of wheels for race cars at work, some people have to have them perfect, others dont have them done at all.

 

A 25g weight has fallen off 18kg of wheel and R888 tyre. Am I going to notice it?


Charlie

 

25g's, i'd say probably not, nothing unbearable anyway.

 

You will stand more chance of noticing with poly bushes that's for sure, on my old sierra with solid bushes in places a build up of dirt on the inside of the wheel could be noticed, personally it annoys the hell out of me.
tabetha

 

dirt can make wheels go out of balance in huge proportions.
did a car the other day that had lots of crap in the back wheels, they where over 200 grams out, cleaned the crap out, they came down to about 30 gram's!
Had it on my escort van, was so bad i thought the thing was going to fall apart (some more).

 

On my wheels, DS OPTICS, the dirt was just a slight ridge that built up on a seam, but when measured as out of balance it was over 15 gramme, cleaned the wheels as they were when fitted with weights, and less than 2 gramme.
tabetha

 

I note that theres bleed nipples top and bottom , i guess that these can be used trailing or leading then , if thats the case and they dont have Differential bore pistons you should be prepared for Wedge shaped brake pads and frequent replacement charlie !
.

 

Good write-up Charlie - looks like a cheap upgrade if you want to stick with std size wheels 15" - shame about the balance weights though - mine always need doing as i have poly TCA bushes.
Look a good upgrade for bigger wheels as well

 

I'll find out and let you know.

Charlie

 

It is so the same caliper can be used on either side of the car.
tabetha

 

realy intrested to see how these perform as i will be selling my wheels and brakes and going back to my standards

 

Right, just checked and these calipers have different sized pistons (good!). TBH I didn't check the calipers before I put them on (bad). I'll call Hi Spec tomorrow and check out the correct mounting.

Charlie

 

Spoke to Hi Spec who were very helpful and warned me about potential problems with heat dissipation. I may need to think about adding ducting and we had a good conversation about surface area, disc width and increased numbers of vanes in the discs.

Anyway, the smaller piston needs to lead so each caliper has the smaller piston at the bottom and the larger piston at the top.

Geoff at Hi Spec also suggested a higher temp pad than the Ferodo DS3000 - a pad from Performance Friction which I think is an American outfit. I may try these later in the season if the DS3000 struggles to cope. All this to come.

Charlie

 

Exactly my point , well done Charlie .PFC pads will "eat "your disc mate , i'd be very surprised if a DS 3000 or Mintex F2 wont be enough for you .
If you have to run a 15"rim can you find a std version with a more "open spoke" design , this will aid airflow before you start buying Donkey Dick for it ??

 

Donkey Dick?

Thanks for your input Tony

I won't change anything for a while. Was speculating about the pads and ducting for future use.

I have considered lighter more open wheels. Next race is in June so I'll see how I get on there with what I have.


Charlie

 

ducting

 

Gotcha.