Convince me to put a TKX in my Dart

72bluNblu said
So, I've been doing some research into further improvements for my car and part of that was tracking down some of the out of print books from Steve Smith (thanks @autoxcuda for your contributions to that old "reading list" on Moparts) because they included pictures and explanations for some of the modifications on the old Petty Nascar builds and some of the kit cars.

One of the books I managed to get ahold of was "Building the Race Car Picture By Picture" by Steve Smith, S110, 978-0936834108. All the catalog numbers are here Amazon product ASIN 0936834102, I didn't pay anywhere near this price for mine FYI.

Anyway, one of the gems in that book are pictures of the Petty Enterprises torsion bar crossmember, which had a part number and everything I assume for purchase for the kit cars etc. Anyway, it weighed 125 lbs and was used because of how much it added to the torsional rigidity of the cars. Keep in mind, those were cars with full cages, and they STILL used a 125 lb reinforced torsion bar crossmember, in a race car where weight was crucial. Think about that.

Bottom line is, I wouldn't have done it before, but there is now absolutely, positively, not a snow ball's chance in hell I would run a torsion bar car without the upper hoop of the torsion bar crossmember. Makes me feel much better about going with the heavy duty T56 crossmember I used, and much less like that was "overkill".

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Glad those old reading list could help.

I used to have that list on my old website: 68 Cuda Autocrosser. And I had a scanned in version of the "Trans Am and Corvette Chassis" book on that old aol.com site decades ago.

The torsion bar cross member is in the 1974 Petty Circuit Car catalog (Cup cars, not Kit cars) It probably was available earlier than that. And could very well be derived from a Nichols Engineering part.

Nichols had the contract for building Mopar nascar parts and cars before 1970. That’s when Petty switched back to Mopar and got the parts and car building business. That was part of the deal.