Rear Disc Brake Setup
Posted By : Nigel Gibbins, 08-Jan-2004, 03:56pm
Hi Robert,
The simple answer here is no-one does it in our championship (the regulations specifically forbid it) and you will also find that any Historic Series's Regualtions will also forbid this modification. But that being said it isn't really needed, you may want to consider fitting Vitesse/GT6 drums, as they are bigger - in class C this is the thing to do, but then again some drivers are still using standard drum with standard shoes.
If you want to improve your braking then you need to look at the front disc - the two popular options hear are 4pot (princess or willwood) calipers or GT6/Vitesse - both on capri 2.8i discs. There is debate as to whether you need to use vented disc for either of these options - again some drivers do and some don't - they all seem to stop quickly enough.
I'm assuming you're asking because you have a 'racecar' project as all this fussing and modification will only gain you inches once the basic changes are made and for a road going car that's an awful lot of work. But in racing where every inch can count.... well that's a different storey
NiG
TSSC Competition Secretary
The simple answer here is no-one does it in our championship (the regulations specifically forbid it) and you will also find that any Historic Series's Regualtions will also forbid this modification. But that being said it isn't really needed, you may want to consider fitting Vitesse/GT6 drums, as they are bigger - in class C this is the thing to do, but then again some drivers are still using standard drum with standard shoes.
If you want to improve your braking then you need to look at the front disc - the two popular options hear are 4pot (princess or willwood) calipers or GT6/Vitesse - both on capri 2.8i discs. There is debate as to whether you need to use vented disc for either of these options - again some drivers do and some don't - they all seem to stop quickly enough.
I'm assuming you're asking because you have a 'racecar' project as all this fussing and modification will only gain you inches once the basic changes are made and for a road going car that's an awful lot of work. But in racing where every inch can count.... well that's a different storey
NiG
TSSC Competition Secretary
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Rear Disc Brake Setup
Posted By : Andy Vowell, 08-Jan-2004, 05:21pm
Hello Robert
The theory of using disc brakes on the back of a spit would be an interesting project. However with most of the weight of a Spit being at the front especially under braking ,I (IMHO) do not think it would give you much gain in performance. Plus if you are building a Race/Trackday type car, then you can take so much weight out of the back end that efficient rear brakes may end up locking up a lot.
A little story to explain another problem. I used to "spanner" for a friend who raced (and subsequently won) the 750 Motor Club Kitcar championship. His car was a Silva Striker that was fitted with a Ford escort drum braked axle at the rear. It the never ending development that racing drives us too, he fitted a rear disc setup to the axle. This lasted a single race as he found that under the lateral loads the rear of the (tail happy) car the pads were constantly getting "knocked off" the discs. Therefore the first press of the brake pedal just moved the pads upto the discs, and it took a second press before any braking effect started. Having to press the pedal twice before braking was no improvement.
I believe that with the realtivley "sloppy" rear suspension of spitfires built with genorous tolerances then the same problems will arise.
Personally I use standard spit drums with road shoes and they seem to do the job. Effort is better spent on the front brakes where as well as NiGs suggestions you can go for aluminium calipers from Wilwood and AP (among others)
Cheers
Andy V-
Rear Disc Brake Setup
Posted By : Robert Westgarth, 09-Jan-2004, 09:22am
Thanks for that NiG and Andy. I will pass the info on to my son who is an affiliate member and hope he will see the light and leave well alone untill he has tried the standard set up.
Cheers,
Bob
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