Legitimately? I say because I've run a few cars in the stock class at local derbies over the years, and have a few rule sheets handy. Here's the rule sheet from the 2013 Greene county derby, for the stock class, just because it's got the shortest list. Minimum wheelbase of 100 inches, No trucks, jeeps, limousines, hearses, Lincoln Continentals or Chrysler Imperials will be allowed. All glass, plastic, lights, and trim must be removed from the car, this includes interior panels. All doors must be secured. Doors must be either welded, chained, wired or bolted, but must be secured in an acceptable manner, do not weld station wagon tailgates. Frames may be notched, but you cannot re-weld, or plate them You must run a stock, OEM, passenger car bumper, front and rear, no homemade bumpers! Hood and trunk must be secured with either 4 pieces of #9 wire, or light chain, in addition to being bolted shut with two pieces of 3/4 inch all thread. Hood must have a 10x10 hole above the carburetor. Absolutely no frame stiffening, this includes plating, tension-ed wire, concrete, or doubling. No welded or solid suspension, heavier springs are allowed, however the car must still have some give or bounce at inspection. Fuel cell and battery must be relocated to the inside of the car. A rollbar is required, at minimum, you must have an overhead bar going from the floor behind the driver up and over the roof, as well as door braces on either side. Only engines originally available to the car will be allowed, with no major modification. (I.E. No big block Chevy's in 80's Impalas) Exhaust must be directed upward, at no point may the exhaust pipes be under the car. Transmission coolers are not allowed. Only OEM rear axles may be used, no 3/4 or one ton full floating axles will be allowed. Differentials may be welded Forklift and V-tread tires are permitted, so long as they are no larger than 30x9.50. No welding or reinforcing or wheels is allowed.
No problem, let me know if there are other classes you want to know about. --- Post updated --- Here are some pictures of some cars that a buddy of mine has run in the past.
The rad was toast, and the front end was still steer-able, the A-arms were bent, but still attached. And as for classes, it depends on where you're running. Usually around here we usually run 4. Compact, Pretty self explanatory, compact cars only, less than 99 inch wheelbase. Basically same rules as the stock class, albeit with stock I-4's and V6's in FWD cars. Stock, Explained in a previous post. Old Iron, Essentially the same rules as the stock class, with the stipulation that no car can be newer that 1970. Outlaw, Only safety rules apply, Run kickers, doubled bumpers, braced frames, etc. open to any make or model car. (No trucks / vans / jeeps etc.) Then there is also what is known as a 5 ft class, I've never seen a 5 ft car in person, but from what I've heard is that it's like an extreme outlaw class, where anything is allowed so long as it looks like a car from 5 ft away. (Think full tube frames behind the body)
The purpose of the hood pipes? Several reasons, so the exhaust can't get smashed shut from an impact, So you ca see the exhaust and tell if the engine is starting to go, so it's never anywhere near the fuel tank, and not so much of a purpose, but some added convenience, is that you haven't got to remove the headers when pulling the engine.
There's a persistent back-and-forth on whether or not straight piping an engine leads to a power bump because the exhaust doesn't have to be forced through the muffler, and a long, twisting pipe. I've never looked too closely into it, but from what I know, it seems that straight pipes were more effective at increasing power to older engines strangled by emission controls. Now that cars have gotten better at making power in spite of them, straight pipes have become much less effective. Check the torque curves of the straight-piped I6 and regular I6 for the Barstow to see where the developer team lands in the effectiveness debate.
