From: "mark (m.d.) roberts"
markdr@nortel.ca
Date: Thu, 7 Nov 1996 13:33:00 -0500
Subject: Gear Ratios made easy in E-types
I'm not sure if this answer got around yet for the query on what the gear ratio was for a
particular E-type. The easiest way to find out what your rear-end ratio is, assuming no one has
been playing with the speedo gears, is the little number on the face of the speedometer
itself.
The key to the numbers is:
Series 1 3.8l E-type 6.40x15 RS5 tires/tyres
SN 6322/00 3.31 miles
SN 6322/01 3.31 kilometers not for Germany/Italy
SN 6322/02 3.31 kilometers for Germany/Italy
SN 6322/03 3.54 miles
SN 6322/04 3.54 kilometers not for Germany/Italy
SN 6322/05 3.54 kilometers for Germany/Italy
SN 6322/06 2.93 miles
SN 6322/07 2.93 kilometers not for Germany/Italy
SN 6322/08 2.93 kilometers for Germany/Italy
SN 6322/09 3.07 miles
SN 6322/10 3.07 kilometers not for Germany/Italy
SN 6322/11 3.07 kilometers for Germany/Italy
Series 1 4.2l E-type tires/tyres
SN 6322/00A 3.31 miles 6.40x15 RS5
SN 6322/02A 3.31 kilometers 6.40x15 RS5
SN 6322/03A 3.31 miles 6.40x15 SP41
SN 6322/05A 3.54 kilometers 6.40x15 SP41HR
SN 6322/09A 3.07 miles 6.40x15 RS5
SN 6322/11A 3.07 kilometers 6.40x15 RS5
SN 6322/13 3.31 kilometers 6.40x15 SP41
SN 6322/14 3.54 miles 6.40x15 SP41HR
SN 6322/27 3.31 miles 6.40x15
SN 6322/28 3.31 kilometers 6.40x15
SN 6322/29 3.54 miles 6.40x15
SN 6322/30 3.54 kilometers 6.40x15
SN 6322/31 2.88 miles 6.40x15
SN 6322/32 2.88 kilometers 6.40x15
SN 6322/33 3.07 miles 6.40x15
SN 6322/34 3.07 kilometers 6.40x15
SN 6322/35 3.31 miles 185x15 SP41
SN 6322/36 3.31 kilometers 185x15 SP41
SN 6322/37 3.54 miles 185x15 SP41
SN 6322/38 3.54 kilometers 185x15 SP41
SN 6322/39 2.88 miles 185x15 SP41HR
SN 6322/40 2.88 kilometers 185x15 SP41HR
SN 6322/41 3.07 miles 185x15 SP41
SN 6322/42 3.07 kilometers 185x15 SP41
I don't have any numbers for series 2 and series 3 E-types....sorry.
Regards, Mark Roberts Phone: (613) 763-2924
Ottawa, Ontario, CANADA Fax: (613) 763-3970
1988 VDP - SIII V12 e-mail: markdr@nortel.ca
1963 3.8L E-Type Coupe - 16 years into a 3 year project
-------------------------------------------------------------------------
Date: Fri, 17 Oct 1997
From: Michael Frank mfrank@acm.org
Subject: [E-Type] Differential swap Vs 5-speed
If you have a Jaguar 4 speed, then you have the following overall gear ratios:
Rear axle 3.07 3.31 3.54
1 9 9.70 10.39
2 5.85 6.31 6.74
3 4.26 4.59 4.92
4 3.07 3.31 3.54
Assuming that you pick 3500 rpm as your shift point, you will shift at roughly the following
speeds:
Rear axle 3.07 3.31 3.54
1-2 29 27 25
2-3 45 42 39
3-4 61 57 53
So at 3.07 will lead to quieter cruising at normal highway speeds. If you drive to excess, you
will be 'reaching for fifth' at the following speeds:
4-5 85 79 74
The 3.54 will give powerful acceleration, and is optimized for the ol' double nickels at the top
end.
The 3.07 gives you more 'headroom', but will add maybe a second to your 0-60.
Now let's suppose you replace the Jag 4 with a JT 5, but keep the 3.54.
Overall ratios will be:
10.443
6.8676
4.7436
3.54
2.832
And shift points will be:
25
38
55
73
Which is similar to the Jag 4, but when you reach for fifth, it will be there, and will carry
you quietly to 92 :->. So you have all the original punch, plus quiet cruising beyond the
limit.
Now let's look at the same thing, but with a Moss 4-speed. Your overall ratios will
be:
Rear axle 3.07 3.31 3.54
1 10.3459 11.1547 11.9298
2 5.7102 6.1566 6.5844
3 3.9603 4.2699 4.5666
4 3.07 3.31 3.54
And the shift points would be:
Rear axle 3.07 3.31 3.54
1-2 25 23 22
2-3 46 43 40
3-4 66 61 57
"Reach" 85 79 74
At least on paper, the Moss box with the 3.07 looks like a great combo...fast off the line, and
quiet at speed. I've always felt this box had an undeserved poor reputation.
Any thoughts?
Mike Frank
1969 E-Type 2+2