Bonneville Landspeed Racing - Let's Try a Thing.

TT5.9mag said

It’s rpm, tire diameter, final drive in trans, and final drive gear. It’s just maths.
:lol:
My guess is you’ll want the 2.50 gear with a big block. But don’t overlook driveshaft critical speed. A 3” steel tube driveshaft probably isn’t going to cut it.

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Thanks Mike. I understand the maths, just don't want to reach 6000rpm at mile 1 for some reason, and carry that for another 2 miles (yes exaggerating). It would be best to reach 6000rpm at the 1/4 and carry it out the back door, yes? I know when Aaron first brought his roadster there, he was running (IIRC) 9200rpm from mile 4 to 5. A gear change and slight aero, he picked up 21mph! I just don't know how to guess the given distance and rpm. It will be CoD and HP related, but just trying to sort out the best practice.

I plan to run a 4 or 5" aluminum driveshaft for CS, but when going to max effort run, will likely change it to a 2 piece race shaft as it is 57" length.

What are your thoughts on a 2.50 ratio vs a 3.23 and OD? Calculators say 2.50 with 1:1 and 28" tire is 200mph at 6000 or 3.23 with 0.76OD and 28" tire to be 203mph at the same 6000rpm. The 3.23 combo would accelerate quicker but traction will be an issue.

If Viren ends up full on board, then 2.50 AND the OD with a 2 piece shaft.....