New to the bb and had some questions regarding Alfa Giulia GTAs (stepnose) that were later converted to GTAm, with GTAm mechanicals. There are three cars I know of where this happened:
1. The GTA of Mavros who raced for Motor Hellas in Greece who later died in a crash in this car.
2. The GTA of Olivier Chambon. Originally GTA, converted to GTA SA, and then converted again to GTAm in 1970.
3. The GTA of van Rooyen/Chatz. GTA 1900 as raced under van Rooyen and converted to GTAm under Chatz’s ownership with help from Autodelta
First of all, I would like to know what class they would have been able to race in? I am sure Angola and South Africa were different in regards to rules and regulations, so the Chatz GTAm might have had an easier time. I know these cars had to be much lighter in terms of FIA homologation standards, especially the GTA Chambon owned since it was full peraluman. Was there weight added to the cars of Mavros and Chambon (or Chatz for that matter) so they could race as GTAm’s in the correct classification? Were there other GTAs that were converted to GTAm and raced in this period? Also, I once read on here that in Germany they were using GT 1300 Juniors to convert to GTAm ecause they were lighter. If anyone can confirm this, is there photographs of any of these cars and were they done in period or more recently? Lots of questions, but I am hoping some of you on here can help to answer them. I have included pictures of each of the three GTAs that I mentioned for reference.
The GTA full alloy body homologated as GTA Junior, limited in displacement and weight by prescriptions from Art. 253, could be prepared claiming Art. 253 comma Q, and Art 256 / Rule for changing from one group to another and authorized amalgamation of groups/ in allowed but declared changes that suits regulations that follows:
FIA Art.282 /N.B./
NB: AMALGAMATION OF GROUPS 5 AND 6
Groups 5 and 6 will be amalgamated as from 1st January 1972, into a single
group called: Sport Cars—Group 5 (without minimum production).
Definition: Competition cars especially manufactured for speed or long-
distance races on closed circuits. Their use on open roads may however be foreseen
and, in that case, the cars must include all elements normally provided and
legally required for vehicles using public roads.
General specifications: These cars should comply with the general prescriptions
concerning cars of categories A and B (see Art. 253), except as regards the
a) the luggage trunk is optional (Art. 253 h),
b) the spare-wheel is optional (Art. 253 k),
c) the hood is optional (Art. 253 e),
d) In the case of an open car, the windshield and the transparent parts of the
door are optional; however, if they are provided for, their dimensions are
free (if no windshield is provided for, windshield-wipers are not compulsory)
e) in the case of an open car, the opening delimiting the passengers' compartment
must be symmetrical about the lengthwise center-line of the car.
Besides, it is specified that the Appendix J distinguishes only an entirely open
car, with the passenger’s and the driver’s seats uncovered, and entirely closed car.
Safety Rules: See Art. 253, 272 and 273.
In base of prescribed regulation, GTA lightweight body with 2000 cc prepared engine was allowed to start and compete in all FIA or FIA covered events with Group 5 or ‘open inscription’ foreseen. It is clear that GTA cars listed in this tread were used as group 5 and raced in events where the group 5 was allowed, without any weight compensation or ballast onboard, or any other handicap expected.
P.S. One of the GTA cars mentioned, 613015 was ex VDS GTA transformed in GTA SA in ’67, from 1972 owned by Oliver Chambon and converted in 2000 cc engine version. The car was sold to Mr. Ulrich Baumgarten, fine and true expert in all GTAs, sometimes present in this forum. Nobody better than him could explain the story of that car