Daily Archives: March 3, 2022

Another case of nothing to write but a compulsion to write something

The tl;dr version of this post is I feel the need to write, but I don’t have a topic springing to mind at the moment. I think I wanna write about the Sprint-T, but I don’t have anything to say about it, except for how frustrating it is to not have a budget for building this thing.

I have been thinking about also the dedicated A-Mod racer with the aluminum block LS engine sitting next to the driver for the lowest possible polar moment of inertia, because if you can’t do anything with the main project distract yourself with a different project that has even less likelihood of completion than your main project. The idea driving the LS A-Mod is offsetting the engine and transmission to one side and putting the driver next to it but offset the other direction so that the two moments balance out. The exhaust will run over the driver’s legs, and the driver’s butt will be right about even with the rear face of the block. This will mean the engine will be offset about 10″ away from the driver because of having to clear the physical parts of the engine specifically that bellhousing, but the driver could be offset more than the engine. Like I already know how far to move the engine when the driver sits completely behind the engine and there is some left-to-right overlap, it’s just basic algebra to use when they’re side by side. Basically the engine has a moment relative to the driver, the driver has a moment relative to the engine, and the two moments have to add up to 0 when the car is built. This kind of stuff is what I do for fun and relaxation, and I’ll say it first: NEERRRRRD! I’m literally doing a word problem, for fun. Sioux Geonz teaches remedial math to college freshmen and I’m told sometimes links to my blog posts as examples of real-world applications for what she teaches. If it helps, I’m happy with it.

Anyway part of the reason the engine is beside the driver is another moment problem. If the driver is in front of the engine like most formula race cars, it stretches the car out and results in a larger moment than if they are side by side, and for this particular style of racing this makes the car with the larger moment slower than the car with the smaller moment because the smaller moment lets the car change directions quicker. And if your car can change direction quicker then you can cover the distance the direction change has to take place in faster. And as in everything about cars this results in a tradeoff, the driver is exposed to more heat sitting beside the engine than if they are in front of the engine and not under the exhaust. There’s also the location of the cooling system to consider in the heat loading situation, in that there is a greater likelihood of the radiator blowing on the driver with the side-by-side driver-engine configuration because the cooling system is literally hung off the front of the engine and is easier to plumb if the radiator is in front.

And I’m writing right now because I’m trying to not think about the Ukraine, and dinner is ready, so I’m going to put this post to bed now.