The Triumph Dolomite Club - Discussion Forum

Hi everyone

I am currently looking for some FIA group2 homologated vented disc for a dolly.

The car has been bought by my father in 1976. It was only a few month old. He modified it to race it first in group1, then group2.
Some time after that, he stopped racing and kept the car.

Today we are thinking about taking the car back to the roads of rallyes.

Unfortunately my father never changed the brakes and he raced it with standart disc !!!

Today, we are, as I said realier, looking for vented discs that can be FIA homologated in group2 as they are described in the homologation form.

Please give me informations about them, and where to find them.

Thank you.

Aurelien.

We had good results with a company called circuit surplies who had close connections with AP, as far I know AP still make the 4 pot historical calipers, disk wont be a problem.

Ap made special for us the frontbrakes, within the Fia RAC forms.
Just send a complete frontend in, including the 13" wheel, otherwise you could run into clearance problems, 13" is rather narow.

Hans

Thank you Hans.

I have send them a message, the things are moving.

I saw in your posts that you say your car has good braking power. You say you can "overbrake the escorts" , are you using rear discs or the front disc are enough to do the job?
Don't you have overheating problem with theese brakes?

Aurelien.

We started with the calipers from a TRIUMPH 2500 (the same connection to the hub) with slightly machined 2500 disks, including the 4 grooves per side as AP use to keep the pads cleen, you can do this also on any road car.
Actually our injection road sprint has this setup already over 10 years, including a Rover main pump. this is quit an improvement, and if you run on a trac day car the relatively small tires from a F3 it could be ok but not enough for a 1/2 hour race.


So we went off to AP and seeping the RAC Fia rules in mind.
These brakes where expensive but fabulous, currently we run these special Goodyear slick tires who overrule by there construction legal the rules about the rims. we are allowed to use up to 9" but these tires put almost 10" on the track.
At a tire temp of about 90 till 100'c I can tell you the do grip, but it is still no big deal to lockup the front at 100 miles+, but by far the most important the braking point is also after 15 laps exact at the same point, no fading at all. brake temp about 550' C (AP temp paint).

Although great braking capacity, In the beginning we had problems because there was a significant temp difference between the inner and the outer part of the disk, coursed by insignificant cooling.
Just directing a cooling hose including duct to the disk is with a salooncar not enough, specially because the wheels we did run at that time (Weller Formula Ford did give the max disk clearance in 13") blocked off the cooling air from the outside to much so the temp difference was over 100' C , so the disk start to crack.

To clear this problem we build our own cooling solution, and had wheels made at Compomotive with big cooling openings.
Next to that, now we made our own disks out of new disk for a small van.
The max braking capacity is the same, but I must sea the "feel" is different , the AP disks have a wonderful feel, they have a temp treatment befor shipping, and a for racing made casting material.
But around 200 pound per disk, using 2 sets per season, running 2 cars had some impact on our budget. not talking about the AP, and Ferodo pads, they are stiff to.

A side problem is the weakness of the stub axles and vertical links, in total they bend in every corner to much, so the pads are pushed away, and before the next corner you will find a long travel of the brake pedal.
A good caliper though have springs behind the pistons what push them back, and keep the pads in contact with the disk.
This is very important, you will find out, and know after a while that the brake is always there what give great confidence, no pumping up of the brake before every corner.

Aurelien, if you send me a mail I will you send some picture.