Daily Archives: August 11, 2019

I have other things to think about than the Sprint-T

I sometimes try to not think about the Sprint-T, and think about other things I want to make, like bicycles and furniture (I have a plan for a bed stand/storage thing to put a mattress on that has been rattling around my head for years ever since the last repair to the futon frame), but for some reason I always seem to keep coming back to race cars for SCCA Solo Racing A/MOD class. The rules are simple, minimum wheelbase of 72″, minimum tread of 42″ and minimum weight of 900 pounds with driver. A few safety rules to protect the driver in case of a rollover, and that about covers it. Oh and a maximum of 20 ft2 total wing surface and unlimited underbody downforce developers, bodywork covering tires optional, that kind of thing.

My design philosophy has been lots of tire and suspension built to keep it square to the road, lots of brakes and an engine that can motivate without adding too much weight. Usually I come up with motorcycle or go kart powered things that have all the weight in the center of the wheelbase and as close to the centerline of the car as possible, but the latest fantasy was an LS7 coupled to a shorty Powerglide mounted to the right of the chassis and the driver seat to the left just enough to balance left-to-right, and a chain coupled transfer case to get the power to the center of the chassis to line up to the input of the rear, and front, axles. That’s right AWD traction to get 505 HP to hook up on a sub 1000 pound car. Of course I’ll never have the funds or facility to build this mini-monster, but it’s fun to think about. Given that there is scant difference in weight between the various naturally-aspirated LS engines but huge differences in low-end torque it makes sense to go for the 7 liter big dog, and the shorty Powerglide is the lightest transmission capable of handling a standing start that will bolt to the LS family bellhousing pattern (which it shares with the venerable SBC first sold in 1955), and the possibility of 4 smoking tires when the loud pedal is used too enthusiastically were just too much for my fevered imagination to bypass, so I didn’t. Estimated weight is 900 pounds without driver making it weigh about 1100 with my lard ass in the driver’s seat, or about 2 pounds per HP on 93 octane pump gas. The number of cars with this power-to-weight that are intended to make right and left turns on the regular in competition can be enumerated on the fingers of one foot. I think there are a few sprint cars in the same ballpark, but they are literal grenades, and there were some F1 turbo cars back in the 3-liter formula days that might be in the same power range, but again those were literal bombs on wheels with 1499.9 cc turbocharged engines putting out about 900 HP in qualifying trim and good for maybe 3 laps at full chat and very little time at rated output before exposing the inner works to the world. And if you think I’m exaggerating look up some YouTube videos of late ’70s to mid ’80s F1 qualifying sessions especially the Renault powered cars. In comparison the LS7 is an anvil used as a paperweight

So anywho, you have insight on my fantasies of power and glory, enjoy!

Just in case you were feeling generous…

There’s something I need for the Sprint-T build, that might not still be there when I have access to that much money again. This was the oil pan I was thinking of making to get clearance for the bottom part of the front hoop under the engine. This looks like a 50 -60 hour fabrication job for me, vs $330 cost to buy and install. I would need to buy or make the oil pump pickup either way, so that’s a wash.

But seriously I need that oil pan for this build or I need to go dry sump, which is even more expensive because it requires external tanks and extra pumps, or a special crankshaft and front cover if the factory dry sump system is installed, which while better than the wet sump for hard cornering is inferior to the aftermarket, and almost impossible to find in junkyards (they only came on Corvettes and Corvette engines are bought before the vehicles even get to the junkyards).

Now I’m going to go watch the Michigan NASCAR Cup race. Y’all have a good one and remember that Hephaestus wants you to build something that improves somebody’s life. Even if it’s only one person, make that person’s life better.

NOTE I had to edit this after I hit post because I didn’t catch the typo of my deity’s name, now I need to beat on some iron or something in pennance.