Keep hearing about frame twist with 440s

Uncle Tony answered a question about frame connectors on his live stream last night (4/12/20) and he gave a new explanation that had some rational thought behind it.

He acknowledged that a stiffer car with connectors will perform better but the extra flex in a non-reinforced car makes them much easier to control/drive. He says that once you start to “lose it” in a stiff car, it’s harder to regain control.

Assuming that’s the actual difference comparing a stock chassis to a stiffened one, I guess I can see that. If we’re being honest about our reaction times, especially as many of us are well past middle age at this point, a car that flexes and soaks up a percentage of the variables that could upset the car could make some sense.

I fly model planes and on really fast/responsive models, it’s a common practice to set up an exponential curve to the control inputs which essentially allows you to more easily make small inputs and keep the plane from feeling too “twitchy.” You could fly the same plane with linear inputs if you are precise enough with your inputs but most people recognize how much harder it is to do that and that it’s just more fun to soften the controls and not have to change your pants after you land. It seems like a parallel consideration...maybe?

Anyway, I aspire to be able to take advantage of a precise, responsive setup and when I do drive actual sports cars, I feel like I’m still able to calibrate my inputs and enjoy a sporty, snappy driving/handling car without putting it into a telephone pole..:but my Dart Sport is a relatively lazy 300hp small block car on no-season 15” radials. Chassis reinforcement, stiff torsion bars, heavy springs, performance shocks, big sway bars or not, it’s not exactly a Formula 1 platform. Maybe it would be harder to drive like a hooligan if it wasn’t still a bit “compliant.”

While Uncle Tony definitely has some knowledge on other aspects of these cars, he’s just proving further that he’s making it up as he’s going along on chassis reinforcement and handling. He’s out of his depth if he’s not talking about driving in a straight line.

Handling control is about precision and predictability. If your chassis sucks up all of your inputs and reactions with flex, you can’t be precise. If you can’t predict exactly how the chassis will react to a given input, you can’t control the car as well.

Yes, there’s a balance. If the chassis is rock hard and transmits every bit of chatter and noise to the driver then it will be more difficult to control. But here’s the thing, that’s not all chassis. A lot of that is how your suspension is set up, how your alignment is set, whether or not you’re in oversteer or understeer, etc. And the chassis isn’t even the biggest component of some of that set up.

And let’s face it, adding subframe connectors doesn’t make these cars all that stiff. I have a bunch of chassis stiffening on my car- torque boxes, subframe connectors, j-bars (forward chassis reinforcement), a tubular radiator support brace, etc. Yes, my car is much stiffer than it was from the factory. But it’s not anywhere near as stiff as a car with a full cage. Or even a high end modern performance car.

Yeah, the average driver would think an F1 car is insanely hard to control. But subframe connectors don’t make these cars anywhere near that stiff. Even the level of chassis reinforcement that my car has, which is more than a lot of these cars have, doesn’t make it overly stiff. If anything it still has more flex than would be ideal, even for a street car. Plus it’s a moving target- if you have 15” rims with crappy compound tires you don’t need as much chassis reinforcement, you’re not putting as much force to the chassis. If you’re running soft compound 275’s on all 4 corners even with a significant amount of reinforcement you’ll still get flex because you’re transmitting a lot more force.