Thanks for all your input's.
Still pondering with all the options.
How do you overcome the speedo error when using tyres larger than standard to decrease the engine rpm.
Also anyone ventured to use a BMW M or N57 2.5/3.0 engine and if mpg was any better also if any reliability issues. .
 
For what it's worth, I've owned Landys for over thirty years and although we have other cars, a Landy has always been my main ride, although for sanity and cost I rarely use it for daily commuting :eek:
But I used to drive from Sussex to North Wales and Yorkshire several times a year; used the A roads where possible but when I got my first V8 M-way driving became more practical. Trundling along at 60-65 at less than 3000rpm is sweet (1.4 T-box and on 235.85R16). I'm 6ft and only 11 st and don't find it uncomfortable at all. Admittedly noise levels especially in diesels can be tiring but the V8 allows conversation and a radio.
How do you overcome the speedo error when using tyres larger than standard to decrease the engine rpm.
Yo can change the speedo drive gear in the transfer gearbox.......see here https://www.land-rover-blog.co.uk/how-to-replace-the-speedo-drive-gear-on-a-land-rover/
Also anyone ventured to use a BMW M or N57 2.5/3.0 engine and if mpg was any better also if any reliability issues. .
Not me :cool: happy with my 3.5 efi auto; sod the mpg :D
If you want good NVH ratings and handling you may want to steer clear of a 'Defender esp for long distance M-way cruising. I grew up and learnt to drive in the days when most cars had the NVH, road manners and safety of a Landy; I find modern cars too out of touch with the feel of driving, too cocooned if you understand my drift.
 
P.S. @landymon

Land Rover 90/110 speedo drive gears
  • Colour: blue/20 teeth - Part number: FRC3310 - Tyres: 7.50/16 or 235/85/16
  • Colour: green/21 teeth - Part number: FRC3311
  • Colour: yellow/22 teeth - Part number: FRC3312 - Tyres: 205/16 tyres
  • Colour: red/24 teeth - Part number: FRC3313
 
I am slowly swinging back to a D2 Td5

So if the Td5 was uprated @180/200bhp or more, would this be a problem with reliability besides the exhaust manifold issue.
Using a 5speed R380 gearbox, LT230 transfer with Ashcroft 1.1 ratio, 3.54:1 diffs and 29/30" wheels.

Any issues with this
 
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OK Finally decided over the weekend, its going to be....
A Defender 90/110, because I think its has more stance from its looks and it will continue for many years where as the Disco has changed in how may times over the years.

But besides, will the Ashcroft 1:1 too low as my aim to cruise between 2000rpm and 2500rpm at 70mph
 
OK Finally decided over the weekend, its going to be....
A Defender 90/110, because I think its has more stance from its looks and it will continue for many years where as the Disco has changed in how may times over the years.

But besides, will the Ashcroft 1:1 too low as my aim to cruise between 2000rpm and 2500rpm at 70mph

fit an overdrive
 
You keep the flexibility of the lower ratios in the Transfer Box with an Overdrive, only using overdrive in 5th when you are up to speed. Probably easier to fit than swapping a transfer box and you can take it off and put it on a new vehicle if you sell.
 
Unless you are running a V8, or 205x16 tyres, I wouldn't bother with a 1:1 transfer box.
I have a 300tdi (110) with a 1.2:1 transfer box and 750x16 tyres, I definitely wouldn't go 1:1 with my set-up.
 
Over drive will reduce fool costs when it's being used as it will allow yer to reduce the revs and still do the same speed.
 
Ideally you want ~2700rpm@70mph in top gear.
That is basically what a 1.2 disco box with 31" diameter tyres (750's or 235/85 or 265/75) will do. Don't see the point is changing to a non-standard 1.1 or 1.3 ratio. or going through all of the expense of changing to a 1.1 or fitting an overdrive.

@landymon I would seriously consider either fitting a standard disco box or finding one which already has one fitted, and then driving it for a while before embarking on expensive modification like a 1.1 or an overdirve. You will possibly be surprised at the speed it will achieve and will possibly also be surprised by how "unsafe" they feel going faster. They are fundamentally not designed to go quickly and if in standard form do not feel as secure as certainly I would like once you get over about 80.
 
Over drive will reduce fool costs when it's being used as it will allow yer to reduce the revs and still do the same speed.

yes BUT.. the engine will be working harder like trying to pedal in a high gear on a push bike, you can gear up too much, 45 years driving artics has taught me that, there is a point where the gearing is too high for the output of the engine
 
From Ashcroft's site...
  • ZF 4 speed auto, 31' tyres, 1.4 (standard) box: Speed/Gear - Fourth = 70 MPH @ 2759
  • ZF 4 speed auto, 31' tyres, 1.2 (Disco) box: Speed/Gear - Fourth: 70 MPH @ 2370
  • ZF 4 speed auto, 31' tyres, 1.19(V8) box: Speed/Gear - Fourth: 70 MPH @ 2333
Ideally, for my use (3.5 hotwire efi auto on 235.85r16 converted from a 2.5P LT77) I might benefit from changing from the 1.4 to 1.19 or 1.2. I don't tow so first shouldn't be an issue....any comments?
 
I cruise my TD5 90 up and down the motorways of Britain with considerable enjoyment. The main thing that slows you down is other traffic. In standard trim the TD5 will more than exceed the national speed limit so it doesn't really need remapping. I put an overdrive on mine at the beginning of 2016 which made it a lot quieter for motorway cruising. I can get to Lands End and back in a day from my home in Leicester on 120 bhp. More would be nice but it is not essential. You might be able to accelerate faster with a remap, or hold a higher gear at lower speeds, but it is perfectly happy as standard.
 
What would be the advantage of OD in comparison to 1.1 transfer box ?

You keep all the normal ratios, except the overdrive gives you a 28% increase in ratio - you can also use it in any gear, high and low range.

Means on the motorway you can cruise more easily (lower revs) but, if you decide to tow with it, or off road you can still use the factory gear ratios as designed.

So win win.

I think a 1:1 would suck ass on acceleration and hills etc personally

Also top speed on a landrover is limited not by engine and gearing but handling and design. They don’t go fast like a saloon car, and those that are driven like that will eventually roll.....
 
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An overdrive may be a fine piece of kit, but they cost a hell of a lot more than a second-hand 1.2:1 transfer box.
The low-ratio box is the same in all LT230 transfer boxes, so off road capability isn't affected if you swap high ratios.
 

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