Racing AMX Information

[oldtransamdriver]

Mike, I don't believe Bob Tucker is the same guy.  Gary from the Garage Blog should have any pics of Bud running his Sprite or AMX.

The early AMX was a 2 seater so did not qualify as a sedan per SCCA specs  Not sure how SCCA classified A,B,C etc production classes but it also had something to do
with performance specs as classes were bumped up and down thru the years.

Robert Barg

[klvn8r]

I have a 68 AMX, last ran vintage as A/P since I had a 390 'plus'.  Current configuration will be a 343, and be B/P.  Pretty minimal differences, otherwise. Four wheel discs, 7.5" wheels, single four barrel, etc.  390 cars were classed against BB Cobras and Vettes, 343 cars ran against SB Vettes, and Shelbys etc. 

klvn8r

[Shadow Ahead]

I'm curious where the displacement "line" is between AP and BP. The other curiosity is whether
 to leave some form of drum brake rear or go with discs.

S A

[klvn8r]

The "line" is decided by the SCCA rulebook.  Sadly, if you have a 70 AMX, you only qualify for AP....even with the little 360.  My guess would be the 'line' is somewhere after 350 CID, as some of the 350 Vettes are BP.  I've come to the conclusion that I can build a 343 to run as good as any 289/302 Shelby, and similar to a legit 350 SBC.....but I'm not going flares and huge tires, like a Vette.  As for brakes, I'll keep my rear drums for starters, and decide later if I need the discs.

klvn8r

[Shadow Ahead]

Hence a 390 for a '70. A 360 would be giving up too many inches. The drums sound like a good start. Anything trick like segmented shoes or simply metallic linings and braided hose?

 S A

[klvn8r]

For whatever reason, the AMX is homologated with the regular drums or discs up to the exact same size as a Corvette,  11 3/4" x 1 1/4".  I'm thinking of stuff like Matador wagon drums out back...   In 1997, I ran my AMX at Road America with a Corvette front discs.  I built my own caliper bracket, but decided that maybe it was too thin/weak.  I had problems with the Vette Brakes Products calipers leaking, and decided that it was due to flex in my bracket.   Yes, on the braided lines and custom shoes...probably something from Porterfield.

klvn8r

[Shadow Ahead]

If you can go that large, why not. Which begs the question since the Corvette factors into what is allowed. Were any of the calipers alloy?

S A

[klvn8r]

No, the Vette pieces are cast iron...and heavy....but they work good on Vettes!  "Production" stuff keeps you pretty limited, but it would also depend on what 'vintage' club you're running with, and how strict they are. 

klvn8r

[Shadow Ahead]

That's where I'm more inclined to find the right AMX for me and the ideas I have and then find an organization that generally fits. I was almost talked into the Vintage Trans AM group but a) it's very expensive to enter events outside the travel expenses, b) what I want/ expect from an AMX would severely narrow my latitude of choices in order to meet the historical requirement. i like the concept, and the look, of vintage "iron" but want the flexibility of finding a suitable candidate that doesn't have to have the "pedigree".
 I'm sure, when they aren't leaking, that those calipers stop.

T S

[Jon Mello]

I know the Trans-Am cars were allowed to use the lighter, aftermarket calipers like Girlings and Hurst/Airhearts beginning in the
1970 season. However, the AMX was an A or B/Production car and not eligible for the Trans-Am series. I would have to go looking
through the rule book but I suspect the production cars were not allowed to use the aftermarket calipers back in that era.

[Shadow Ahead]

I'd be interested in finding out, Jon. I understand the desire to keep the historical "architecture" in place. I also understand that what works is important in a sport such as this. There are many period alternatives to choose from that are capable, if allowed. On the other hand, having said that, the Lincoln calipers are legal, like the Corvette ones, they are heavy. Another way of looking at it is it forces the creative side of the brain to work overtime to overcome the rules limitations.

T S

[klvn8r]

The 68 Kaplan cars had the big Lincoln fronts and I believe standard Mustang fronts on the back of the Javelins.  Girlings were on the 70 Penske cars, and I believe Roy Woods went to the Airhearts in 71 or 72.
Klvn8r

[Shadow Ahead]

I read about the Girlings which they derived from the 917. One of the cars, if my buddy still has it, that I'm considering is set-up similar to the '69 and later Baby Grand National Javelin front suspension-wise I do not wish to saddle it with heavy calipers were I to get it.

T S

[Jon Mello]

You probably need to figure out what racing group you would like to run with and what they allow as far as brakes and other details are concerned. The one decision will take care of the other.

[Shadow Ahead]

Perhaps. perhaps not. The way my personality works the car has to arrest me. The body or sanction "authority will follow from there. My question would be  is that if it's a road race concern, as opposed to gymkhana, you mentioned that there were some regs you could look up. Give me a nod in the right direction and I can do the rest of the legwork.

T S