Daily Archives: January 24, 2022

Sorry for not posting

Because I don’t have anything to write about. Mostly what I have been doing is looking for an overdrive transmission that doesn’t weigh anything and has a torque capacity to handle large displacement LS engines and can be picked up for next to nothing at a junkyard. The difficulty is light weight and high torque capacity are pretty much mutually exclusive, or are hideously expensive. There is a T5 variant that weighs 80 pounds and has 550 ft-pounds capacity, but runs north from $4k when you can find it, which is slightly more often than “never”.

There’s a kit that makes a T5 handle 600 ft-pounds, but you have to have the T5 first, which I don’t. The good thing is the replacement gears in the kit are only a pound or so heavier than the stock gears so your finished transmission is 76 to 78 pounds plus a quart of ATF.

What I’m fighting against is the power to weight to cost champ is the LS-LT GM family of engines from the junkyard have more torque than the cheap transmissions can handle. The cheap champ OD transmission is the T5 at $500 and up for rebuildable cores locally, but only has a 300 ft-pound capacity and the 4.8 LS has 300-330 ft-pound output depending on tune which is the lowest of the engine families. If I wasn’t trying to build as light as possible because the classes I’m competing in have essentially no minimum weight, or a minimum weight so low that I will never get that low with the car I’m trying to build, I could go with the heavier transmissions. But I’m building light and cheap because F=m*a and reducing “m” increases “a” proportionally, and I’m a genetic tightwad. Or maybe a cultural tightwad because I don’t see any signs of it in my kids. But I’m building to a 900 pound with driver minimum weight for the class with a published minimum weight, or about 700 pounds empty, and the other classes have no minimum weight but do require equipment that kinda raise the weight the car has to be built to, like horn, headlights and fenders. And a pickup bed in one class. So we are looking at about 1500 pounds empty± in race trim (3 gallon gas tank).

And this is about where I’m putting this to bed, I’m running out of things to say.