Might as well get the ball rolling early on 2026.
My drive to and from the challenge is about 14 hours each way. That is a lot of time to spend alone in the car, and the mind wanders and comes up with some dumb challenge car ideas. There were many but as I drove I kept coming back to this one. This year I decided I want to build a “traditional” hot rod for the challenge. But since Nocones is building it it will be anything but “Traditional”.
With the LMP360 the car was built to replace the MG as my track car. Other than the EJ engine that is a mission it has filled expertly. But being built as a track car there were limitations imposed on the build that made it more involved and difficult of a build than a pure Challenge car would be. The build overall would have been easier had I just planned it to have no life beyond the challenge. I have decided that I want to build this as a dedicated challenge car. It won’t have much purpose beyond the challenge and I won’t worry about appropriateness for anything else. If it gets parted out after the challenge that is fine.
The idea is similar to the “917” challenger that ran years ago. Put a normal RWD drivetrain directly attached to a rear axle. I plan to use IRS which will enable the complete removal of the driveshaft shortening the required length some. I’ve done some measuring and feel a ~110-115” wheelbase will be reasonable to get the job done.
For the chassis I will fabricate a simple tube style chassis on top of a 1920s Model T chassis. The Model T chassis will be tapered at the front but otherwise will be fairly “original”.
The Engine/rear end will be a 1UZ plus 4 speed Auto from a Lexus LS400. I believe I will be able to attach the transmission output 3 bolt flange directly to the differential input Guibo so the “driveshaft” will simply be a single rubber Guibo. The suspension arms will be rebuilt and to save a few inches of drivetrain length the hubs/driveshafts will be swept forward 3-6”. This may be unnecessary though as my math says I need to keep <65” from Axle to pulleys to keep the WB in check and the 1UZ per GRM is ~27” and the Transmission appears to be 29”.
Front uprights will be Mazda Miata with custom A-arms. Steering will be?? Pedals and the column will be from the LS400. The suspension will probably basically borrow the geometry from the LMP360 scalled to work with the uprights. That suspension worked well in a rear heavy Mid engine car so why reinvent the wheel. Shocks will be rear motorcycle units at all 4 corners as they really work well for a <2000lb car. Bellcranks with Pullrods in the front and pushrods in the rear are likely.
The body will be a narrowed (probably fabricated) T-bucket and your feet will extend through the “firewall” into what aesthetically will be an engine cowl but it will actually be the footwell. The rollbar side tubes will run all the way to the front and the grille will contain an additional small rollhoop ensuring adequate safety for the driver cell.
The LS400 radiator will most likely be laid flat in one of the sidepods, and the other sidepod will contain the battery and a small fuel tank. But I may run the radiator above the trans/diff and leave the sidepods off and just make the entire back look like a stretched out Model T Truck/rumble seat piece.
Wheels are currently unknown but the goal will be to use Sprint car takeoff tires to have something reasonably sticky but chunky looking. Possibly 13's in the front and 15s in the rear.
IF the LS400 stuff does not work for length, I will pivot and use the drivetrain and subframes from the ManX-5 build. I’m $500 into that chassis and should be able to easily $0 it out on recoup. It would not be a V8 but then it would also likely weigh less and I would add a turbo. The Miata engine has proven it is capable of bringing home the Challenge W so I wouldn’t be concerned if the pivot had to be made.
This one seems extra dumb. I’m not expecting it to perform super well because it won’t be little. I estimate the weight will be around 1400lbs but the handling will be “Who knows”. I’m building this one just for fun so I won’t science it as hard as the LMP360 nor overthink every decision I have to make.
Expect me to get started in the next few weeks. This weekend the Panhard Leaves, and the Autobianchi is spoken for so I actually don't have any "on deck" projects right now. I’m on the hunt for a close to my house Model T frame. There are like 10 of them for ~$50-100 but all are 2.5+ hours away.