Rear Axle: Bonneville Hawks 1963 rear axle gear ratios

[(S)]

Does anyone know if the Bonneville Hawks used the ' standard' 3.73 Differential that 'came with' an R 2 engine to go 140 MPH, or did they drop a ratio or two, to get that higher top speed of 140 MPH ...? Thanks in advance...

[DEEPNHOCK]

While not an exact answer.... Somehwere in between here: Gear ratios range from 2.72:1 to 5.89:1

[Bud]

I have a 3.73 gear in my Avanti and I don't think the the engine could push the car to 140MPH before the engine runs out of RPM. I would think that a 3.07 gear was used to get that speed. Bud

[BobWaitz]

You can go here and do the calculating for yourself:
http://www.csgnetwork.com/rearendgearcalc.html

With a 1-1 ratio in top gear and 27 inch tall tires, you'd need a 2.73 rear end @ 5000 RPM to exceed 140.

You'd need to go 6500 with a 3.73 rear end to hit 140 with 27 inch tires.

[BobPalma]

I have a 3.73 gear in my Avanti and I don't think the the engine could push the car to 140MPH before the engine runs out of RPM. I would think that a 3.07 gear was used to get that speed. Bud

Right, Bud; IIRC, that's what they had. BP

[52-fan]

What did Ron Hall use in his car?

[jpepper]

We set the record using a 3.0 gear. The initial run in 93 used a 2.75 ratio and the engine would not pull it. Power met resistance at about 188 MPH. At 200 the engine was turning about 7100 RPM. The car has a Ford 9" from a Lincoln Versailles.

[(S)]

The 3.07 ish range is what were we thinking . I have yet to DRIVE mine, so i was not sure what speeds it would do vs RPM's .Thanks

[t walgamuth]

Those rear tires look very tall in the Bonneville pic from the sixties. Seems like maybe they were indy car tires....18" rims?