rear disc conversions
Discussion
As far as I know, a couple of people have converted the M-series rear drums to discs, but I'm not one of them (yet 
).
I've run a 3000M and a 3000S with 7x15 wheels with 205/60 tyres. They rubbed slightly on the M on bumpy roads but are fine on the S, as TVR made the wheelarches larger. The M did have slighty shorter springs which probably was a contributing factor so I guess it wouldn't have been too much of a problem to solve.
Another 3000M that passed through my hands was a special-build car that had 7x15 wheels with 225/55 tyres. These never rubbed at all but the gap in the wheelarches was visually too large. I suppose it's another classic case of 'you pays your money...'
). I've run a 3000M and a 3000S with 7x15 wheels with 205/60 tyres. They rubbed slightly on the M on bumpy roads but are fine on the S, as TVR made the wheelarches larger. The M did have slighty shorter springs which probably was a contributing factor so I guess it wouldn't have been too much of a problem to solve.
Another 3000M that passed through my hands was a special-build car that had 7x15 wheels with 225/55 tyres. These never rubbed at all but the gap in the wheelarches was visually too large. I suppose it's another classic case of 'you pays your money...'
I had a modified Taimar which ran 15x7 (205/55 SO2s) on the front and 15x9 (225/50 SO2s) on the rear. Part of the rear arch was taken away on the inside to improve clearance, but they would still touch under extreme provacation (undulating bumps in the road taken too fast), never touched on a circuit or sprint. The car was running uprated springs with Ledas all round.
The wheels were Revolution RFXs (still available), the rear wheel was standard and the front wheels had 19mm spacers.
With the tyre combinations above the overall circumference was reduced by about 5% (from a 195/70 on a 14" wheel). Email me offline and I'll send you some pictures if you want.
When I sold the car it went via Steve Reid (Gamekeeper) and it is now a couple of owners on and I know from the current owner its back on the Wolfraces so someone out there must still have the wheels/tyres, contact Steve and he may be able to help.
Regarding rear disc brakes, as Terminator says a few of Germans/Swiss have modified their cars and there is someone in Switxerland who cast some new uprights for rear discs. It has been done in the UK by Dave Smith on his much modified 3000S. BUT unless you have significantly modified the front brakes, the car will be overbraked at the rear and liable to prematurerear lock up unless a brake bias valve is introduced, then you'll probably end up with the same braking power as the drums!! I had uprated front brakes and my car would outbrake all (unmodified) modern TVRs on the track and was stable so I left the rears alone.
Hope this helps
davidy
The wheels were Revolution RFXs (still available), the rear wheel was standard and the front wheels had 19mm spacers.
With the tyre combinations above the overall circumference was reduced by about 5% (from a 195/70 on a 14" wheel). Email me offline and I'll send you some pictures if you want.
When I sold the car it went via Steve Reid (Gamekeeper) and it is now a couple of owners on and I know from the current owner its back on the Wolfraces so someone out there must still have the wheels/tyres, contact Steve and he may be able to help.
Regarding rear disc brakes, as Terminator says a few of Germans/Swiss have modified their cars and there is someone in Switxerland who cast some new uprights for rear discs. It has been done in the UK by Dave Smith on his much modified 3000S. BUT unless you have significantly modified the front brakes, the car will be overbraked at the rear and liable to prematurerear lock up unless a brake bias valve is introduced, then you'll probably end up with the same braking power as the drums!! I had uprated front brakes and my car would outbrake all (unmodified) modern TVRs on the track and was stable so I left the rears alone.
Hope this helps
davidy
Different car but I had a rear disk conversion on a Talbot Sunbeam rally car once. It was a total nightmare, the fabricated brackets weren't quite true so the calipers were always working themselves loose no matter how many lock nuts were put on them.
And if you fit rear disks you will have to look into the whole hydraulic system because the balance front to rear will go all to pot - you'll really need a bias valve to re-adjust things.
To cut a long story short I wouldn't bother. My current Golf Group One race car (brakes are free in regs) has rear drums.
>> Edited by spnracing on Thursday 2nd January 11:30
And if you fit rear disks you will have to look into the whole hydraulic system because the balance front to rear will go all to pot - you'll really need a bias valve to re-adjust things.
To cut a long story short I wouldn't bother. My current Golf Group One race car (brakes are free in regs) has rear drums.
>> Edited by spnracing on Thursday 2nd January 11:30
Many thanks for the quick and interesting replies. I ask about the rear disc conversion as an alternative to the standard as some years back i lost a wheel going around a roundabout! Namely the "stub" shaft between the rear hub bearings sheared. It was not a pleasent experience i can tell you! Yes i could replace these every so often on an exchange basis, but also wondered if this incident is a common problem with the "M" series? I am producing considerable power thru the back wheels (LSD probably helps share the load). As for disc's on the front - Willwood on 285mm disc's but am prepared to up the disc diameter (and obviously caliper carriers) if the wheels increase to 15". What about the Revington TR CV set up on the shafts any experience (tho the same bearing set up).
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