Measuring our ASA stock car chassis: Square or not? And what can we do if it’s not? | ASA tube-frame racer

What’s the most important part of building a race car that’s also perhaps the least exciting? How about accurate measurements?

No, wait, keep reading.

We’re bringing a long-dormant tube chassis back to life–work should start in earnest by early 2023–but before we can order that first part, we have important things to do: research and lots and lots of measuring.

We started by reaching out to Howe Racing, whose staff was kind enough to send over the basic original instruction manual for the car from its debut in the early 2000s. The manual includes lots of helpful info about squaring the chassis for initial setup, along with basic layouts of suspension components.

Howe built all the original center sections for the ASA cars; ours is No. 404, one of the last assembled. Then, Howe and a few other chassis builders added their own front and rear subframes to complete the assembly of the chassis.

Our car was originally finished by Lefthander Chassis, but the design is very similar to the Howe car depicted in the manual.

Now, on to the measuring.

While the manual contains some factory measurements, we wanted to confirm those specs and get a better idea of how everything works together. So each evening, we broke out the tape measure and notepad with the goal of producing a blueprint drawing we can use to plan our suspension setup, component relocation and the like.

So far, there have been few surprises, which is good when you’re assessing a project.

The car has a 108-inch wheelbase, which it’s supposed to, and the chassis is indeed symmetrical–at least when it comes to the main tubes.

The setup, however, isn’t symmetrical, as the car was originally prepared for oval track racing. Front suspension points, for example, measure out symmetrically, but the driver-side spindle features a lot of built-in positive camber. We’ll need mirror-image spindles if we want to truly square up the chassis.

The front suspension itself appears symmetrical, as do the mounting points on the frame. As far as we can tell, most of the offset was achieved using spacers, and it’s certainly easier to remove or replace those than it is to relocate mounting points.

Even so, moving those mounting points on this car really isn’t that big of a deal. The tops of the front shocks are mounted between two tabs welded to the tubular frame.

Want to move them? That’s two cuts, two welds and some spray paint away from being a reality.

We’re also finding that a lot of the accessory mounts are heavily left-biased as well. The mounts for the dry sump oil tank and battery, for example, sit directly behind the driver on the left chassis rail. To optimize our side-to-side balance, we’ll move those items over to the right side of the chassis.

We’ve measured some asymmetry in the Sweet power steering rack, too: It’s offset slightly to the left, but we think there might be enough adjustment available via its slotted mounts to center it up. That will require switching to equal-length steering rods, which we want to do anyway.

Finally, all this measuring has given us a much better idea of the options we’ll have for skinning the car. Likely it will eventually wear some bodywork from Five Star or ARbodies, companies that supply most of the oval track racers in the U.S. as well as those taking these cars road racing.

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