As I am often asked for advice about the obtaining of FIA HTPapers for historic Sebring Sprites, I recently consulted John Hopwood who is one of the MSA-appointed registrars. I was aware that when John Sprinzel applied for homologation of the Sebring Sprite he inadvertently quoted the track dimensions of a standard car, rather those of a Sebring equipped with disc brakes and wire wheels.
John Hopwood tells me: "There is a dispensation for an increase in track of 1" (in Appendix K) for cars running Dunlop CR65s, as it would be impossible to make the homologated track without the tyres fouling the rear springs. Even so, to make the original track plus 1" means narrowing the rear axle. Bodywork must be the same material as used in period, so alloy top and steel or alloy rear for a Williams and Pritchard style body".
I also asked him whether one could build a car replicating the fibreglass bodywork of the 1961 Sebring 'works' cars or the 4-wheel disc brakes of the 1959 cars, to which he has replied: "Various cars were prepared with quite creative specifications but were 'prototypes'. You could replicate any one of them exactly but should beware that now many races do not accept prototypes! Brakes were one of the items that had to be homologated so cars with 4-wheel discs would have been entered as prototypes".
"Up to 1961 cars would be to Homologation 47, while later cars may have been on different papers, depending on spec. Only bodywork was free, everything else had to be as per homologation. The Mk 2 Homologation (62) is pretty much the same as the Mk 1 mechanically.
All period E cars (1947 - 1961 inclusive) must be to 47".
With the original Girling Type 10 brake calipers being almost impossible to find, an alternative has been approved under Appendix K:
Sprite Mark I
A tolerance of 1 inch is accepted on tracks for Mark I cars of Periods Eor F. Brake callipers of the GM/ATE type (standard equipment on the rear brakes of the Vauxhall/Opel Carlton 2.0 litre Estate of the late 1980’s,utilising 38 mm pistons) are the only substitution acceptable for the existing front disc brakes.
Sprite Mk2 and Turner Climax
Brake callipers of the GM/ATE type (standard equipment on the rear brakes of the Vauxhall/Opel Carlton 2.0 litre Estate of the late 1980’s, utilising 38 mm pistons) are the only substitution acceptable for the existing front disc brakes.
For more information see below:
HTP Guidelines - All you need to apply for HTPapers for your historic car (Tim Spencer)
1958 on Austin-Healey Sprite Supercharged - FIA Recognition No.87(?)
1960 Speedwell GT - FIA Recognition No.26 (thanks to Mike Wylie)
1958 on Sebring Sprite - FIA Recognition No.47 ( thanks to Mike Wylie)
1962 Austin-Healey Sprite Sebring Mark II - FIA Recognition No.62 (thanks to Mike Wylie)
1962 Speedwell GT model 2A - FIA Recognition No.92 (thanks to Mike Wylie)
1962 Speedwell GT model 2B - FIA Recognition No.93 (thanks to Mike Wylie)