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[Field Marshal Dr. Opti]

Is there a simple equation for this?

Can the answer be found with a final drive ratio (2.56) and gear ratio (0.667) or is further information required?

.......and yes I know you can get a rough idea from speedo and rev counter readings.

 

[Lincs Robert]

Two questions ...

1) Why do you need to know this?
2) Does your inbox have any space- still trying to PM you!

Ta

[Viral_Jim]

I suspect wheel diameter (and therefore circumference) will be needed.

Also it will doubtless only work for manuals and autos when in full lock-up.

[STEMO]

I'll start: my astra is showing 3500 at 70.

[Field Marshal Dr. Opti]

Two questions ...

1) Why do you need to know this?
2) Does your inbox have any space- still trying to PM you!

Ta

In answer to your questions, Robert.

1. Just interested.
2. I'll look into this. I thought I'd sorted it.

[Field Marshal Dr. Opti]

I'll start: my astra is showing 3500 at 70.

Try changing into top gear.

That sounds like gearing from a 1966 Cortina.

[Field Marshal Dr. Opti]

I suspect wheel diameter (and therefore circumference) will be needed.

Also it will doubtless only work for manuals and autos when in full lock-up.

I did suspect this, Jimmy. And then what would I do with the additional information?

[STEMO]

I suspect wheel diameter (and therefore circumference) will be needed.

Also it will doubtless only work for manuals and autos when in full lock-up.

I did suspect this, Jimmy. And then what would I do with the additional information?

Multiply it by the diameter of the tyre minus the diameter of the wheel X Pi - the outside temperature.

[Field Marshal Dr. Opti]

I suspect wheel diameter (and therefore circumference) will be needed.

Also it will doubtless only work for manuals and autos when in full lock-up.

I did suspect this, Jimmy. And then what would I do with the additional information?

Multiply it by the diameter of the tyre minus the diameter of the wheel X Pi - the outside temperature.

Are you taking the piss?

[Doctor Gollum]

Multiply it

Distance travelled per revolution... smaller diameter tyres require more rpm for a given speed as they travel a shorter distance per rotation

Diameter referring to rolling radius rather than wheel diameter 

[STEMO]

I suspect wheel diameter (and therefore circumference) will be needed.

Also it will doubtless only work for manuals and autos when in full lock-up.

I did suspect this, Jimmy. And then what would I do with the additional information?

Multiply it by the diameter of the tyre minus the diameter of the wheel X Pi - the outside temperature.

Are you taking the piss?

Moi? 

[Bigron]

Isn't it in the manual? From memory, for a 2.6 FL auto saloon in locked top it's 28 mph per 1000 rpm.

Ron.

[Field Marshal Dr. Opti]

Multiply it

Distance travelled per revolution... smaller diameter tyres require more rpm for a given speed as they travel a shorter distance per rotation

ameter referring Dito rolling radius rather than wheel diameter 

Lets say wheel and tyre have a diameter of 28 inches. So circumference 28 x 3.14(ish) equals 88 inches(ish) Car travels seven feet four inches with each revolution of the wheel.

Yes?

No?

No idea?

[Viral_Jim]

This is a bit American-acised, however should work

http://www.crawlpedia.com/rpm_gear_calculator.htm

[Field Marshal Dr. Opti]

...or is it 3.14 times the radius (14 inches) rather than diameter?

My brain is starting to hurt.