I came across something yesterday that I had seen before, but not paid much attention to. That is factory appearing stock tire drag racing. What that means is that you take a classic muscle car, keep it looking factory, use period correct bias ply tires and see how fast you can go in the quarter mile.
Since these cars were traction limited in the first place, one would think that racing like this wouldn’t be very exciting. But one would be wrong in thinking that.
Take a look at this:
What you have there is a 429 SCJ Mustang that runs 9.84 @ 139.82 in the quarter mile, on bias ply tires. It is amazing to me that they are able to get that much power to the ground with those tires.
And if you like small blocks:
How about a Duster that runs 11.27 @ 120.
While these cars are factory appearing, they are definitely not stock. They need to have an engine that was available in that year car from the factory, although you can upgrade the engine to a higher performance one than what was available. You also need to be running factory heads, intake and exhaust manifolds etc.
You also need to have a cam that sounds stock at idle. That means a really radical cam shaft is out. There is a way around that. A radical camshaft in a small engine is radical, but put the same camshaft in a larger engine, and suddenly it is mild. Stroker kits are allowed, up to a limit of 560 CI, 604 CI for the Ford 385 engine series. So you can have a ton of torque and horsepower, still look stock, and still sound stock.
The plus to using factory cylinder heads, is that they have been around so long, a lot of people know how to port them for maximum output.
But what still amazed me, is that they can get all that power to the ground with bias ply tires. Suspension mods are pretty limited, you can run different bars on a 4 link like a Chevelle, and a pinion snubber and clamps with leaf springs.
That means no slapper bars. The reason that those help, is that when the tires are turned, the differential tries to turn in the opposite direction. That whole basic physics rearing its ugly head again. The slapper bars stop that movement, and use that force to push the tires into the ground.
Different bars for the 4 links, and the basic leaf spring mods do the same kind of thing, just not as effectively.
I don’t think that I would build a car to compete in factory appearing stock tire drag racing, since I also want to go around corners fast. But I like the idea of a factory appearing engine that has a lot more power than factory. Even if I improve the suspension, brakes and tires.
But if/when I build a car to go fast in a straight line, then I would definitely look at the factory appearing stock tire way of doing things.
If you want more information, you can go to http://www.fastraces.org/ and look through the information there.
And just because I like watching youtube videos of cool old cars: