INTRODUCTION

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Some of you might not recognize me. I've been a regular contributor to most of the dragracing forums until a few months ago. I offered some free information through a website (which was also free to me). I got the impression that very few racers wanted my help, so I stopped visiting the forums. I figured those who wanted my advice could simply visit the website. Then, I started to receive phone calls. The website was no longer available. I don't know why the website went away (I was never the owner), but I suddenly realized how many racers were using the spreadsheets and other information I had placed there.

I'm a retired automotive engineer and I could never figure out why there wasn't more universal usage of the site. After all, it was simply basic knowledge used by those who design the cars we all drive. Then, it finally dawned on me! Dragracing is a hobby. Yes, it's a very expensive hobby, but it's still a hobby. For five days out of the week, you take orders from the boss. You do everything his way. But, on the weekend, you're the boss! (Except for the "honey-do" list, of course.) You look down your collective nose at those who buy headers off the shelf. You make your own. You don't buy things out of a catalog. You make your own. Why would you ever listen to someone else...even an automotive engineer...when you know what's best for YOUR hobby? Okay, I understand that and I was never bitter, even before I understood. The vitriol with which some responded to "catalog" answers did, however, suprise me. I'm also surprised that racers are quite satisfied with tearing up their expensive cars with repeated trips to the strip over most of a season to simply adjust the rear suspension when the adjustment could have been done in one day in the shop without starting the engine. I don't know if I'll ever understand that one! Considering the cost, in both money and time, I would think a racer would jump at the opportunity to use that which I call a "tractiion dyno." And, why don't the chassis shops place a centrally located, CG height, loop in their work for the chain? Another puzzler!

I've been asked what I would use for a rear suspension. There's quite a choice, isn't there? There's ladders and 4links, of course, and I cover a few others in the following pages. But, if I'm restricted to a beam axle, I'd fall back on the old K.I.S.S. principle. What was the basic rear suspension in the early cars? It was called a "torque tube" suspension. A tube, rigidly attached to the rear axle housing, extended forward, enclosing the driveshaft. The single driveshaft U-joint was at the front, immediately behind the transmission. The suspension loads were not carried by the U-joint, of course, but by a "ball" which enclosed it. The axle was located laterally by either parallel leafs (GM) or by a Panhard (Ford). When we count the links in a rear suspension using a Panhard, we usually don't count the Panhard, so this would be a "zero" link suspension. Now, suppose we go to an open driveshaft and no longer attempt to cover it, but, instead, go to two torque tubes...one on each side of the open driveshaft. Recognize what we've got? Why, it's a ladder bar arrangement. But, wait a minute! Why did we go to two torque tubes (ladders)? Simply uncovering the driveshaft doesn't cause any axle location problems. And, there's a particular benefit to having a single ladder offset to the right: It provides for cancellation of the effect on tire loading caused by the driveshaft torque. So, that's what I would use. It's definitely simple, and, with a vertically adjustable bracket at the front, provides some adjustment without affecting pinion angle. Problem is, you won't be able to buy the parts out of a catalog.

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