Brakes

[AMMO]

As part of the Winter re-build at the end of November I'm thinking of uprating the brakes. I've ruled out running the standard calipers with better pad material as I don't want to pay the weight penalty of the standard cast iron calipers.

 

As far a I can see the options are:

 

Alcon 4 pot calipers with standard discs.

 

Wilwood vented discs and 4 pot calipers. Anyone tried these? They come in three disc sizes for the Seven (according to which wheels you have) and are very good value for money. About £400 + VAT I think. Worried about availability of pad material.

 

Go the whole hog and get the AP setup just on the front end. Does anyone know what the calipers and discs weigh?

 

Fit Brembo calipers from a open wheeler to the standard or slightly bigger solid discs. I have the capability to make up adaptors etc. Not sure if I really need vented discs. Race Minis used to run vented discs with KAD 4 pot calipers. They now run solid discs to save weight.

 

As I'm not interested in going over 120 mph and don't want to be over-braked. The car is in daily use with occasional track days.

 

Thanks for any advice.

 

AMMO

[R2D2]

I have been going around the same loop for some time and have not made any sensible decisions. Every system seems to have problems and although I want to spend money on the car I can't come to a conclusion.

 

The problems that I have are;

 

1. The idea of increasing the unsprung weight with large vented discs doesn't seem to be a great idea particularly as I don't seem to suffer from fade with my current

system. (Std. Spitfire calipers, Red Dot discs and Pagit pads) I can lock up the fronts at about 60mph on a dry road without too much trouble with 185 x 60 A021Rs.

 

I understand that most people who have fitted the AP big brake system are pleased but I think it may be overkill for my needs. I am also concerned about the effect it would have on the brake balance of my live axled car.

 

2. The Alcon set up is very tempting but the calipers don't have dust seals and I use my car on the road and I am concerned about damaging the seals/pistons. I realise that this is common practice on race cars but they are probab;y maintained more regularly than my road car.

 

3. The Willwood system seems tempting and is not a bad price but does mean that you have to run a vented set up. (Weight again) The Wilwood master cylinder has a flange which has a horizontal bolt position not the vertical mounting of the Caterham unit so if you bought the kit you would need an adapter or modify the cylinder mountings.

 

4. All of the Brembo calipers that I have seen need vented discs as they are too wide for the standard disc.

 

5. I have been looking at some of the four pot AP calipers and they have a relatively light caliper which would fit a 13" wheel and would run with a standard disc. It would also be possible to slightly increase the disc diameter to about 10".

This caliper has dust seals and there are quite a large range of pads available including some quite interesting Ferodo materials. Some adapters would be needed as the cetres are wrong.

I have a data sheet at home but this seems to be the optimum compromise, for me in terms of weight/performance.

 

I am trying to develop a modified rear Ital hub arrangement so that I can convert my axle to a fully floating design and fit rear discs and match up a set of rear calipers but progress is slow.

 

I have been dithering for months now but I think I will eventually fit the small AP set up with solid discs and fit an adjustable bias bar.

[Pierre Gillet]

Try HI SPEC BILLET 4 as advertised in CCC. The ad says : Fully dust sealed from £125 +VAT each.They are CNC machined 4 pot callipers light weight rigid ally body powerful 1.5 or 1.625 " pistons.

Kits are manufactured to fit Caterhams.

Phone: 01322 286850

www.highspecbigbrakes.co.uk

 

 

Pierre

[Swiss_Tony]

Do you need the Willwood master cylinder to go with the front calipers?

 

James

 

[R2D2]

If you fit 4 pot calipers it is quite likely that the cylinder area will increase and if the master cylinder isn't changed the pedal travel and effort will change.

 

I thnk that the Willwood "kit" may include a suitable cylinder.

 

The Caterham large diameter cylinder is about £157 + VAT and Willwood cylinders are less than £100.

 

I guess the need to change cylider depends on what size is fitted on the car and the relative increase in piston area you have with the new calipers.

 

With the small AP's i will probably fit a standard cylinder should be OK.

[Graham Sewell]

Pierre,

 

I cannot get through to the hispec web site, can you check the URL????

 

Cheers,

 

Graham

[Fast Westie]

Use the Wilwood Dynalite calipers on standard disks with Greenstuff pads. Note that the Wilwood calipers don't have outer dust seals and will need cleaning regularly.

 

You don't need vented disks on a Seven, but I think you can fit the thicker Triumph GT6 disks if you are worried. Talk to Rally Design. It would be worth having drilled disks.

 

The car in front is a Westfie1d wink.gif

[AMMO]

Thanks for your replies.

 

I will use the stock discs and mastercylinder and upgrade the caliper only for the time being. Would like to try Brembo calipers if possible.

 

Chris, regarding calipers with no dust seals, I've run KAD 4 pot calipers on my Cooper S for two winters with no problems. When sold to me I was told to maintain them regulary (I check the pistons when I check for pad wear) and "don't park the car in the sea". Still working fine. The pistons are hard anodised ali which as you know is better than stainless as stainless has a tendency to seize in aluminium. Some motorcycle calipers also have no dust seals on caliper pistons. Doesn't seem to be a problem.

 

AMMO