Tag Archives: compromise

If it sticks out, it sticks out

I have made the decision. The engine will stick up, out, and sideways and I will look around or over as required because I put the bottom of the bucket body even with the bottom of the car. This will get the C of G as low as possible for best handling, and since handling is the #1 priority for this car inside the superset of [Win Goodguys Autocross], compromise will be made that prioritizes handling over things like seeing out of the car and gas mileage. The main reason the Sprint-T even exists as a concept is participating in autocross and solo racing and winning Goodguys. I’m not happy about not being able to see around or over the Pentastar leaving a big blind spot to the driver’s right front, which means the Sprint-T is not going to be a daily driver. And using it for trips between races is going to require some method of seeing what’s behind the engine. Maybe having two different seat inserts, one for racing and the other for just driving around? That would mean the shoulder belts wouldn’t work for the “just driving around” insert because they would put my shoulders too high to be safe. And the SCCA rules about roll bar heights above the driver’s helmet would mean that when my eyes were high enough to see over the engine just driving around the halo of the roll cage would be right next to my head. Not good, so the simple expedient of raising the driver’s seat is out. But the alternative is raising the body and everything above the body by roughly 7″ which in turn raises the Center of Gravity, which reduces speed at ultimate grip. And that runs counter to #1 priority in the superset of reasons to build the car. So, more thinking is required on this.

In other news my Sweatcoin app is completely screwed up and stuck at 100 Sweatcoins, not even counting the bonus coins for clicking on ads in the app. And I can’t buy anything in the shopping section of the app with 100 coins, except discounts for things I don’t want. This makes the app pretty much useless for me until I can start collecting more Sweatcoins.

On a tangent, I keep hearing a violin instrumental cover of the Twisted Sister song “I Wanna Rock” in a TV commercial, but I can’t see to find it to listen to minus the smarmy commercial voice-over. I really want to find it as a stand-alone. The concept sounds as crazy as AC-DC played on cellos and we all know how that turned out. So far all I can find is this duet with guitar which is good but not the music played during the commercial. Which I was able to find. Not as good as finding the music separately, but at least I know the name of the violinist. Damien Escobar. Now I need to find a clean track of the whole song minus the smarmy announcer and more than 60 seconds long.


Designing gas tanks instead of sleeping

Just because I can’t get words out because brain not working right doesn’t mean I stop thinking. The exact opposite happens.

I was trying to come up with a frame that would put me on the driver’s side of the car and still be stiff and that I could fit inside the body without chopping the body into little pieces and hanging a couple of hundred dzus fittings on the frame to attach the body. Physically can’t be done. So I’m back to sitting in the center of the car and the gas tank is now sitting on either side of the frame instead of the passenger side of the interior. The fun part is now I have to design a pair of fuel tanks that literally have no parallel sides and figure out how much gas (E85) I can carry between them.

First things first I measured the body to find out what space I had to work with. The major design constraint is the sides of the tank are going to be flat pieces of steel for ease of construction, so where the curves in the body make that impossible defines the volume of the tank. First constraint is where the back of the body starts to curve up from the floor, which defines the length, 41 inches from the inside of the firewall. Second constraint is being able to slide the tanks in from the top without removing anything, so the tanks have to clear the dash and the top flanges of the body and the bottom of the dash is 10.5″ from the inside of the firewall, leaving 30.5″ as the length of the tanks. Measuring the inside of the body at the floor gave me a width of 33″ at the front and 34″ at the back. Measuring the same locations at the body top flange gave me 37″ at the front and 44″ at the back, and a depth of 19″ inside the body flanges. Now not all of this volume will be available for fuel storage, I’m going to occupy a large chunk of it, 27″ down the center front to back.

This leaves us with two methods to determine the available volume, find the total volume and subtract the volume taken up by the frame around the driver, or remove the space taken up by the frame around the driver from the measurements and calculate the space left over. The easy part is the volume occupied by the frame around the driver 27″ wide by 30.5″ long by 19″ deep, or 15646.5 in3. The volume around that is a bit trickier to calculate because the space is a trapezoidal polyhedron, and the volume is the average area of the top and bottom times the depth. The quick way to calculate the average area of the top and bottom was to average the top and bottom widths on both ends, by adding them up and dividing by the number of measurements (4) and multiplying by the length (30.5) and then the depth (19) to determine the total volume. Subtracting the volume occupied by the driver and frame leaves 25.4 gallons for fuel. Which is not enough to get across the E85 barrens of west Texas and NM at the projected fuel economy for the vehicle. That means I need to make the tanks bigger or find room for another tank. Now one way I can make the tanks bigger is taking less space for the frame (and me) but it is late and I’m getting tired and unmedicated brain is not thinking good and wants to sleep.

Random thoughts on Wreck-Free Sunday

Well this has been a busy day. Morning service came way too early for me as my ride got here while I was still in the shower, then I was not quite done with e-mail and comics before I had to leave again for the Church Board meeting. While I was waiting for the board meeting to get started I got a text that some of the D&D group were breaking up and would not be coming back to play. So lots of drama today but not much work getting done. I still need to get the slot done for the extended stem and then braze the assembly together do make it solid, and I haven’t had a chance to touch it since I posted the pictures two or three weeks ago. I really need to get that done.

I’m still thinking about the Sprint-T. Thinking as in figuring out what I’m going to do with it to get it together and drivable. The biggest obstacle is Mrs. the Poet’s ban on donor vehicles unless I build it someplace away from the house. Since there is no way I’m going to have that kind of budget I have to do the crate engine and transmission route that costs a lot more than buying a low-mileage wreck and robbing it of all the drivetrain and brakes and incidentals… So I have found some really cheap crate engines but there is a reason they are cheap. Horsepower costs money, how fast do you want to spend? The range I’m looking at runs from 180 HP at about $1.5k, to 430 HP at $4k. The $1.5K engine will cost about $2200 to complete and weigh 50 pounds more than the $4k engine which will cost about the same to complete. So looking at $3700 for 180 HP compared to $6200 for 430 HP. And neither of those includes the transmission or support equipment that doesn’t mount to the engine. Well nobody ever said building cars was cheap, just cheaper than buying new. And more fun than signing a bighuge check and driving away in something you just bought, signing a few big checks, or a bunch of little checks, and driving away a few months later in something you just built.

Seriously though this is the big question to solve on this build. If I can’t get this one solved, I don’t get a Sprint-T, as simple as that. I want to buy a late model wreck and strip it but Mrs. the Poet won’t let me. I can buy a totalled wreck for about $7500-12k, and that’s cheaper because I get a complete engine and transmission with all the electronics and brakes and engine accessories and everything, plus I get to sell the shell for body parts or as scrap.

Seriously, I need to get a bigger budget for this thing.

PSA, Opus the Poet