Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) 4/4 back axle ratio

I remember someone posting about a better back axle ratio for the current 4/4 sport and wondered if anyone here had done it and if it improved perceived torgue?
All comments gratefully received....
Nick

Jays was certainly one...

ALSO...anybody have an opinion on whether the mazda gearbox is better/worse/same as the Ford ones.
Ta everso.

You won't find this forum short on opinions...

I'll open the batting on this one. I have two 4/4s - a 2010 and a 2012, both 1.6 Sigma engined, the 2010 on a Ford 'box and the 2012 one of the earliest with the Mazda 'box.

There is no comparison. The Mazda gearbox encourages you to fly up and down the gears and really wring the most out of this charismatic but low-torque little engine.

The Ford gearbox.... well, doesn't...

My Father, who uses the car, is waiting for the Ford gearbox to loosen up after a few thousand more miles. If it doesn't, I shall get him another with the newer gearbox.

The alternative ratio is the "competition" one 4.1:1 . I always thought that it was the best mod I ever did to my 4/4 Sport. It allowed me to use 5th gear without bogging down and I don't think the economy was affected either as you could make more use of 5th gear.

I can't comment on the gear ratios of the Mazda box ( and 5th might be better so taking away need for changing axle ratio) but I do know that the quality of the gear change is a lot better! I am told that the gearbox in my Roadster is the same Ford one...but it has a vastly improved gear change so clearly not all Ford boxes are bad!
Actually I'm not sure that it is the box at fault as the MT75 is quite well thought of in some circles, but the remote gear change in the 4/4 Sport is very Heath Robinson in design!

MORGAN 4/4 SPORT GEAR RATIOS AND RPM/MPH SPEED TABLES
with none stock tyres



Morgan FORD MT75 RWD GEARBOX:

RATIOS
1st Gear : 3.61
2nd Gear : 2.08
3rd Gear : 1.36
4th Gear : 1
5th Gear : 0.76


Optional Diff 4.10 with Tyre Size 175/75/15
Gears/RPM First Second Third Fourth Fifth
1000 RPM 5.1 mph 8.8 mph 13.5 mph 18.4 mph 24.2 mph
1500 RPM 7.6 mph 13.3 mph 20.3 mph 27.6 mph 36.3 mph
2000 RPM 10.2 mph 17.7 mph 27.0 mph 36.8 mph 48.4 mph
2500 RPM 12.7 mph 22.1 mph 33.8 mph 46.0 mph 60.5 mph
3000 RPM 15.3 mph 26.5 mph 40.6 mph 55.1 mph 72.6 mph
3500 RPM 17.8 mph 30.9 mph 47.3 mph 64.3 mph 84.7 mph
4000 RPM 20.4 mph 35.4 mph 54.1 mph 73.5 mph 96.8 mph
4500 RPM 22.9 mph 39.8 mph 60.8 mph 82.7 mph 108.8 mph
5000 RPM 25.5 mph 44.2 mph 67.6 mph 91.9 mph 120.9 mph
5500 RPM 28.0 mph 48.6 mph 74.3 mph 101.1 mph 133.0 mph
6000 RPM 30.6 mph 53.0 mph 81.1 mph 110.3 mph 145.1 mph
6500 RPM 33.1 mph 57.4 mph 87.9 mph 119.5 mph 157.2 mph
7000 RPM 35.6 mph 61.9 mph 94.6 mph 128.7 mph 169.3 mph
7500 RPM 38.2 mph 66.3 mph 101.4 mph 137.9 mph 181.4 mph


Stock Diff 3.73 with Tyre Size 175/75/15
Gears/RPM First Second Third Fourth Fifth
1000 RPM 5.6 mph 9.7 mph 14.9 mph 20.2 mph 26.6 mph
1500 RPM 8.4 mph 14.6 mph 22.3 mph 30.3 mph 39.9 mph
2000 RPM 11.2 mph 19.4 mph 29.7 mph 40.4 mph 53.2 mph
2500 RPM 14.0 mph 24.3 mph 37.1 mph 50.5 mph 66.5 mph
3000 RPM 16.8 mph 29.1 mph 44.6 mph 60.6 mph 79.8 mph
3500 RPM 19.6 mph 34.0 mph 52.0 mph 70.7 mph 93.1 mph
4000 RPM 22.4 mph 38.9 mph 59.4 mph 80.8 mph 106.4 mph
4500 RPM 25.2 mph 43.7 mph 66.9 mph 90.9 mph 119.6 mph
5000 RPM 28.0 mph 48.6 mph 74.3 mph 101.0 mph 132.9 mph
5500 RPM 30.8 mph 53.4 mph 81.7 mph 111.1 mph 146.2 mph
6000 RPM 33.6 mph 58.3 mph 89.1 mph 121.2 mph 159.5 mph
6500 RPM 36.4 mph 63.1 mph 96.6 mph 131.3 mph 172.8 mph
7000 RPM 39.2 mph 68.0 mph 104.0 mph 141.4 mph 186.1 mph
7500 RPM 42.0 mph 72.9 mph 111.4 mph 151.5 mph 199.4 mph

Blimey Cain....you've been working hard! Very useful set of figures there.

Hi Jays
Have one printed out and on the dash as I use them in the rallies, as my reference to instructions from Co-driver.

Cain

Funny this topic appeared as I picked up my 2011 4/4 ford G/Box, yesterday after having the rear axle changed to 4.1.1 (parts have been on order since feb from mmc)
Well what can I say it was like picking up a new car. 30mph in 4th 40 in 5th & somehow the engine seems "freeer" accelerating from 70 to 80 (um private rd:)) just happens in 5 th. in a nut shell now drives like you'd expect. Transforms the car.
But not sure how true this is but I was warned that the supplied gears can be noisy.
Not a cheap job but after only 2 days IMHO well worth it.
Bob:)

I can confirm that 1500 rpm in 4th equates to 30mph and 1500 in 5th is 40. I drive by rpm in towns as the info is directly in front of you. Speedo is in the wrong place in my opinion.

Ford gearbox btw.