Wide ratio vs. Close 4 sp in 70 Mach1
#1
I was wondering if you could explain the difference, in layman's terms, the difference between a 4 speed type 5 ( Wide ratio ) and that of a type 6 ( Close ratio ) tranny?  I happen to have a type 5 and have often wondered what is the difference. Confused

Many Thanks as everyone always offers great advice or information on all subjects.
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#2
The wide ratio transmissions have a shorter first gear, better for daily driving and faster launches.  The close ratio transmissions have a taller first gear better road racing conditions and getting the engine into the power band quicker.  Most people prefer the wide ratio transmissions over the close ratio.  I have a close ratio transmission in my car and have no complaints about it.

There is a ton of information on the internet about this topic if you want to hear peoples opinions and experiences.  There are other factors that go into the entire driving experience such as gear ratio and tire size.  It is best to match the tire size and gear ratio with your transmission to get optimal driving performance.

.
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#3
If I recall regarding gear ratios, high numeric numbers are known as low gear ratios.  And low numeric numbers are known as high (or tall) gear ratios.

Close Ratio Toploader 4 sp trans:

1st gear:  2.32:1 ratio
2nd gear: 1.69:1 ratio
3rd gear: 1.29:1 ratio
4th gear: 1:1 ratio

Wide Ratio Toploader 4sp trans:

1st gear:  2.78:1 ratio
2nd gear: 1.93:1 ratio
3rd gear: 1.36:1 ratio
4th gear: 1:1 ratio

As you can see the ratio changes between gears are smaller in a close ratio trans than with a wide ratio transmission.

Benefits of the close ratio trans:  For spirited driving, road racing and drag racing applications a close trans is the better choice.  The small gear to gear ratio changes keeps the motor in its peak RPM power range.

Drawback of a close ratio trans:  Because the ratio of 1st gear is not very low, a low (high numeric number) rear axle ratio should be used.  Such as an original 3.90: 1 or aftermarket 3.89:1 or numerically higher rear axle ratios are suggested.  From the factory the majority of cars with a close ratio trans came with 3.90: 1 or 4.30:1 rear axle ratios.  Numerically lower (higher gear) rear axle ratios such as 3.50:1 or 3.25:1 make the car more difficult to get rolling from a stop.

Benefits of a wide ratio trans:  The wide ratio trans is a better choice for average street driving and a lot of highway driving.  The lower (higher number) first gear ratio permits the use of numerically lower (high gear) rear axle ratios such as 3.25:1 or 3.00:1.  This will result in better highway gas mileage.

Drawbacks of a wide ratio trans:  Due to the larger gear to gear ratio changes they are not desirable for spirited driving, road racing, and drag racing.  More difficult to keep the motor in its peak RPM power range.

I use a close ratio trans and a 3.89:1 rear axle ratio in my 69 Mach 1.  It's fun to drive around town but not good for highway cruising.
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#4
Many Thanks to you both for the quick reply.  Not having ever driven a Closed ratio transmission I couldn't realize the differences that you both explained so well.

Appreciate the information.  Hope you have a good day,
Bill Thumbup
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#5
Bill,

Here is a chart I found that gives some comparisons of RPM's and MPH between close and wide ratio transmissions.  I thought it was interesting because it gives examples with different differential set-ups. 

http://www.mustangtek.com/toploader/Rati...lator.html

Mike
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