Rick,
I have always admired the stuff that you build, your original NT III with the turbo Busa was probably one of the most impressive cars to ever run at the salt. Now your adaption of a turbo SBC into the NT III chassis is a marvel of packaging, engineering and fabrication. (OK here it comes) BUT what appears to be your design for a final drive really looks like it could be marginal at best. Using a 25 inch tire diameter (not considering tire growth at 400 mph, which could be considerable) I get a tire-ring gear speed of approx 5400 rpm and a pinion speed of 9600 rpm and you are going to put probably as much as 1500+ hp through a straight bevel pinion gear with 9 teeth and a ring gear with 16 teeth. I cannot say that I am optimistic about this working. Have you had anyone look at the tooth loads and cooling requirements for this drive?
Rex
Hi Rex Thanks
Jack and I and my team definitely have had good luck with NT II. NT III has been a little struggle but will get there.
The straight bevel gears have been in use on NT III for many years with up to 800hp and other than wear they are still alive.
in the past we used ATF in the diff and that was a bad idea, i'm guessing most the wear came from using the wrong lubricant.
I don't think we will dial in more than 8 or 900hp this year as we will be taking baby steps with our program, we can't afford to break anything so we need to race smart. In the future I can see the need of a stronger design but we will try, the car is light and we have a torque converter both those things should help the drive line live, then we can also play with torque management. To answer your question no I never had anyone look at the requirements for the drive.