Gear Ratio Selection & Comparison

Post any technical questions or queries here.
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mk1
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Gear Ratio Selection & Comparison

Post by mk1 »

Just a quick heads up to say that I have just uploaded a new tool from Ian Hamilton, the authour of the superb SU needle comparison tool in the MK1 site.

This latest tool allows you to compare a wide range of gear sets, drop gears & final drive ratios to enable you to choose optimum gear ratios for any given project.

Like Ian's SU tool, it's easy to use, very useful & informative.

Thanks to Ian for some more excellent work!

Ratio Tool: http://mk1-performance-conversions.co.u ... anical.htm

SU Needle Tool: http://mk1-performance-conversions.co.u ... l_carb.htm
ianh1968
1275 Cooper S
Posts: 1012
Joined: Sat Nov 03, 2012 6:00 pm
Location: West Sussex

Re: Gear Ratio Selection & Comparison

Post by ianh1968 »

Mark,

Thank you for your very kind words...

Nothing stands still at "Spreadsheet Central" and I am still
improving the "Ratios" spreadsheet.

The latest enhancement is the addition of a chart to graphically
display the results. This is in the testing phase at the moment
and will be issued as "Release 004.Mk1" very soon...

Watch this space!

Ian
ianh1968
1275 Cooper S
Posts: 1012
Joined: Sat Nov 03, 2012 6:00 pm
Location: West Sussex

Re: Gear Ratio Selection & Comparison

Post by ianh1968 »

The "Ratios" spreadsheet has evolved further and has morphed
into "Release 005.Mk1"... (Dated 31/10/2014).

Hopefully the latest version will appear here:
http://mk1-performance-conversions.co.u ... anical.htm
... before too long. That's if Mark F. recovers from today's little "event"!
:shock:

Many improvements have been made, as described in the "Updates" log...

2014/10/31
Release 005.Mk1
On “Data”, added laygear part numbers to many of the comments and added a
“Search By” feature to help identify the various gearsets.
Moved the comments and gearbox ratios to the top of the grid.
Added pulldown menus for the numbers of teeth in “TTEST”.
Improved “TTEST” to allow for 5th being direct and 4th being geared.
Added two more Leyland gearsets: “3HCR”, Helical Close Ratio (22G210 Laygear)
and “3SCC”, Straight Cut Standard Cooper 'S' (22G335 Laygear).
Added two Ford Type 9 helical boxes, “T9F20” 1.6-2.0L and “T9F28” 2.8-2.9L.
Added two Colotti-Francis dog boxes, “5CFRD” Road Set and “5CFRC” Race Set.
Many thanks to mk1-forum.net member JohnA for providing 1960's document scans
detailing "5CFRC" and "5CFRD".
Thanks also to mk1-forum.net member m1cH1 (Mike) for providing the actual
tooth count for "5CFRC".
Search mk1-forum.net or Google “Colotti-Francis Gearbox” (With the quotes).
or Click Here!
viewtopic.php?f=3&t=10726

Why the Ford boxes? ...
Well, these are for the benefit of our fellow 'A' Series cousins with
Morris Minors and Spridgets. Many of the gearsets listed also fit
into the inline boxes and the "Ford T9" is a popular replacement.

There are a few boxes that I would like to track down and any help
with this would be greatly appreciated:

1) Jack Knight boxes from the 1960's
2) The elusive Colotti-Francis box with a 2.96 first gear.
3) The 5 speed box as used in the "John Cooper" cars from the 1990's.
(Was this a Jack Knight as well? Used 2 reverse gears???)
4) Any other box which has been "generally available" at some point.
( 4 or 5 speed only... Please check the latest release of "Ratios" to
see what I have already... 27 different gearsets!)

Ideally, I'd like a tooth count for any box suggested, but if one is not
available, some kind of documentation to demonstrate its existence and
the ratios would be appreciated.

Again, the any gearset must be or have been "Generally Available".

If anyone is desperate to get the latest version and cannot wait for it
to appear on the main Mk1 website, please feel free to send me a PM.

Ian
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