I actually have some tangible progress to report in this update. Parts have started to arrive! I ordered a seat and a used transmission last week and I spent this week measuring and modeling them so I could insert them into the TT1 CAD model. My wife wasn’t thrilled with this part of the process:
The seat is a Cobra Imola Pro-Fit (GT width).
I was a bit disappointed to find it weighs just about 20 lbs since it is advertised at 17 lbs but I’m still on track to be at (or under) my goal of 1350 lbs. I spent a few nights setting the seat at different angles and seeing how it felt and how high the top of my head was. I settled on a seat back angle of 45 degrees and I have started adjusting the frame to fit and moving the steering wheel, pedals, and shifter into appropriate locations for the seating position.
The transmission is a 6-speed from a 2001 Porsche 911. I will be installing it upside down compared to how it mounts in the 911 because the 911 is a rear engine configuration (with the transmission in front of the engine) and the TT1 will be a mid engine (with transmission behind the engine). If I didn’t invert it I would end up with 6 reverse gears and 1 forward gear. Inverting 911 transmissions for mid engine use is pretty common with kit cars and appears to be a fairly straight-forward modification. Basically, add a drain plug to the bottom (which used to be the top) and add a breather to the top (which was the bottom). I was pleasantly surprised that it only weighs around 140 lbs (dry, I assume) compared to the only weight figure I could find online which was 175 lbs. That definitely helps with the weight budget!
In the pictures above the transmission is right-side-up as it would be installed in the 911 (because it sits much more stable on that side). Here is how it will mount in the TT1
I also bought the wheels a few months back so I might as well include a picture of them, too:
The 15 x 11 rear wheels look ridiculously wide!
From here I should be able to finalize the design for the front half of the frame and start building it (although I’ll need to clear a spot in the garage and build some kind of table for it first). I can’t finish the rear frame design until I get an engine and measure / model it to make sure it’s going to fit (which should be fairly soon, hopefully).
Thanks for reading. It’s nice to be able to show some actual pictures instead of CAD screenshots. Exciting!
- Mickey Oswald