[Healeys] Overdrive ratios

[John Sims]

This excel spread sheet is now on the Miscellaneous section of the Technical
page of my site. Thanks, Scott.

 

John Sims, BN6

Aberdeen, NJ

 

http://www.healey6.com

 

 

From: J. Scott Morris [mailto:jstmorris at yahoo.com] 
Sent: Saturday, March 06, 2010 10:52 PM
To: Charlie Baldwin; Austin Healey
Cc: John Sims
Subject: Re: [Healeys] Overdrive ratios

 


Hello Charlie; Here is an excel spread sheet that will calculate your speed
given different transmission final ratios, tire diameters, rear axle gear
ratios, and engine rpm.  At the moment the inputs are for my MkII Tricarb.
Just change the red input items to suit your car.

--Scott Morris; Simcoe, Ontario, Canada

J. Scott Morris - Keep Smiling, Murphy Lives

PS: I have copied John Sims if he thinks it is suitable for his web site.

--- On Sat, 3/6/10, Charlie Baldwin <mgcharlie at comcast.net> wrote:

From: Charlie Baldwin <mgcharlie at comcast.net>
Subject: [Healeys] Overdrive ratios
To: "healey list" <healeys at autox.team.net>
Received: Saturday, March 6, 2010, 9:42 PM

The Austin-Healey overdrive ratios are 28% and 22% which are the first 
two numbers in the serial number shown on the plate on the overdrive 
unit.  How does that translate into figuring what the ratio coming out 
of the transmission is?  For example, 4th gear is 1.00 to 1.00.  An 
overdrive ratio would be 1.00 to (a number less than 1.00).  Obviously 
it is not 1.00 to 0.28 or 0.22.  Would it be 1.00 to (1-0.28) or 1.00 to 
0.72?
Thanks.
Charlie