Run it until it quits working. I thought the car age thing was BS, but this season I felt the change in mine. I also had it repaired by someone different, which I think was a large part of the issue. If I can feel it, and my crew chief is complaining that he has to make bigger adjustments, well, it's time for a new one. My first car was 8 years old and had no issues aside from weight. I ran that one until I bent it, and I would have had it repaired if there were any good sprint car frame guys in Rhode Island.

Jim is the man I'm referring to lol! Bob Nichols always told us as long as all 4 wheels were on the ground the car didn't know it was bent etc. and could be made to work, it might just like something different.

Best I can remember this life expectancy theory does not hold true as we move up in class. I think the life expectancy of a WOL chassis is somewhere around a dozen shows if they don't wad it up first. Something about the chassis loosing some of its torsional rigidity and not responding as well as some of those drivers would like.

Most of those guys own very sensitive butts, that the average racer does not have access to and it shows in their pay checks. They are more critical in what they are expecting out of a chassis.

Honest Dad himself

Hey thanks for all the input!

I know its not dirt but don't tell Myers and Gerster that age matters. That 50 car is not new.

I built that chassis in 3 days back in 1991. It won its debut race at Salem with Steve Butler at the wheel.

I have had brand new cars from a reputable chassis manufacturer that would not work no matter what I tried while other identical chassis from the same manufacturer were winning.

The chassis Larson won 3 Oskaloosa races with was 4 years old and had major repairs (pulled straight and significant tubing replaced 3 times.

I don't believe the age or straightness matters as much as some other unknown quality in making a chassis work.

We won DuQuoin this year with a car that is at least 10 years old and a motor that is also 5-7 years old. You can make an older car work.

Once the loads on a chassis exceed a certain point it starts to take a permanent "set". That means bent in layman's terms. Most people are surprised to learn a mild steel chassis [1020] will be just as stiff as a chrome moly chassis [4130] since the modulus of elasticity is the same [30,000,000 psi]. What is different is the load at which they take a permanent "set."
The big tires and high horsepower of today's national midgets and all 360/410 sprint cars are capable of twisting even the best chassis. Our sportsman midgets and most other "lower classes" aren't able to produce the loads needed to create a permanent "set".
Think of all those Kurtis midgets that won races for 20 or 30 years; unless crashed they didn't get loaded enough to bent.
I was once told a midget really starts to handle after it has been upside down. Maybe it serves as a vibratory stress relief. Variation from chassis to chassis could be welding sequence or stress relief related. Theoretically 4130 requires a stress relief, 1020 doesn't. It has to do with carbon content.

When I was building chassis, I used a kind of free standing jig, square, plumb and level, all the stuff needed, then on each end, I started with the torsion bar tubes, mounted at the height I wanted, then bent the lower rails, and tacked them on, then the top rails, and tacked them on, then the motorplate tubes, and so on, using a digital square, and tube spacers I had made, to keep the tubes the same distance apart, I had stops on the jig to locate the tubing, but not clamp it tight, that allowed it to expand, then return to it's normal state as it cooled, then I had developed a welding sequence, that didn't concentrate a lot of heat in one area, then moved to the other side, and back and forth till it was all done. That more or less took most of the stress out of the chassis, then a good flip relieved the rest, which seems to happen unexpectedly. My car was built in 1998, and can still be set with as little as a 1/4 turn on any corner. I also used tubing that had the same heat treat numbers, especially on the main chassis members. Bob

Informative thread.... I am picking up a car tomorrow that's a bit older but is fresh and has new components. This was a good read. I am planning on stripping it and taking it to someone just to have it checked and re powder coated. That way I can go through it and I am confident in what I have.