discomikey Posted June 17, 2012 Share Posted June 17, 2012 mine sits at 60-70mph quite happily at cruising revs. on the other hand, my old 2.25d never sat at anything above 50 max. thats on 600 tyres and foot to the floor Quote Link to comment Share on other sites More sharing options...
Snagger Posted June 17, 2012 Share Posted June 17, 2012 Remember that while an OD gives a 28% gearing increase, 3.54 diffs give roughly 35% - it's a much bigger increase. Ashcroft's high ratio transfer case uses standard low gears but taller high gears, about 30-32% if I recall correctly, and like the OD, the don't affect speedo callibration. That's still to tall for NADs, but worth considering for punchier engines where you want to leave low ratio unaffected and don't like the added complexity or weak link of an overdrive, and it's a fraction of the cost too. Quote Link to comment Share on other sites More sharing options...
Julian Posted June 17, 2012 Share Posted June 17, 2012 Remember that while an OD gives a 28% gearing increase, 3.54 diffs give roughly 35% - it's a much bigger increase. Ashcroft's high ratio transfer case uses standard low gears but taller high gears, about 30-32% if I recall correctly, and like the OD, the don't affect speedo callibration. That's still to tall for NADs, but worth considering for punchier engines where you want to leave low ratio unaffected and don't like the added complexity or weak link of an overdrive, and it's a fraction of the cost too. Yep. Sticking with what I've got - It's just that I can't help play around with things and experiment! I like my OD as I find 3rd+OD is very useful for hills out on the road when 3rd is too low and 4th causes it to start bogging. Julian. Quote Link to comment Share on other sites More sharing options...
Julian Posted June 17, 2012 Share Posted June 17, 2012 mine sits at 60-70mph quite happily at cruising revs. on the other hand, my old 2.25d never sat at anything above 50 max. thats on 600 tyres and foot to the floor What I find with mine is that on the motorway it will run along quite happily at about 55mph in OD 4th, ie exactly the speed of the lorries running up against their governors. So I can sit behind one at a sensible distance and relax ;-) Julian. Quote Link to comment Share on other sites More sharing options...
ejparrott Posted June 17, 2012 Share Posted June 17, 2012 I have to use 3rd+OD for 30 mph with my TDi and 3.54's, occasionally dropping to 3rd for a few of the bigger hills. Quote Link to comment Share on other sites More sharing options...
Snagger Posted June 18, 2012 Share Posted June 18, 2012 I have to use 3rd+OD for 30 mph with my TDi and 3.54's, occasionally dropping to 3rd for a few of the bigger hills. I'm keepingt he3.54s on my axle swap, but I had been seriously considering fitting the 4.71 diffs to those axles. I still might do that if I find the 3.54s too tall. I'd like to have gone for 3.9 diffs - Dana make the gears that would fit the Salisbury and KAM make 3.9 gears for Rover diffs, but it'd be damned expensive. I don't like the 4.71s - they're too low with a Tdi, even with the overdrive, so I'll see how I get on. If the 3.54s are worse, then I'll swap the gears for the lder ones and save up for 3.9s. At least that would also give me a standard SIII low ratio, having already fitted lower low range gears. Alternatively, I might see how much Global Roamer (the new name of Roverdrive) sell their over/underdrive for when it is launched (It was an idea Ray was kicking about when I last spoke to him) to replace my Roverdrive, which would give enormous flexibility with the 3.54s. Quote Link to comment Share on other sites More sharing options...
discomikey Posted June 18, 2012 Share Posted June 18, 2012 What I find with mine is that on the motorway it will run along quite happily at about 55mph in OD 4th, ie exactly the speed of the lorries running up against their governors. So I can sit behind one at a sensible distance and relax ;-) Julian. what i find is that i sit at exactly the speed of the porsche infront. although anything above 75 the wind noise starts to get a bit more noticable even with tight doortops. im going to make some windscreen frame mounted wind deflectors cos at the moment wind tries to get into the cab even with the new doortops at anything above 75 Quote Link to comment Share on other sites More sharing options...
Landy-Novice Posted June 18, 2012 Share Posted June 18, 2012 above 75?!? wtf? is brian rocket powered??? daft question to ask a landy owner, whats his top end speed? Quote Link to comment Share on other sites More sharing options...
ejparrott Posted June 19, 2012 Share Posted June 19, 2012 We've had the hybrid over the ton, and thats got the same engine and gearing as my 88........... Quote Link to comment Share on other sites More sharing options...
discomikey Posted June 19, 2012 Share Posted June 19, 2012 on an airfield near me (now used for microlights and stuff) i managed to get 103, ashcrofts says its geared for 110 but i doubt it really as its revving too high and a TDI has no power high up. if it had another gear it would pull to over 110 using the low down power though. although its not something you want to try that often to be honest. when at that speed i was constantly thinkin.. what if.... but remember that is with the engine pushing 20psi boost at the turbo and quite overfuelled too. Quote Link to comment Share on other sites More sharing options...
task Posted June 19, 2012 Share Posted June 19, 2012 I wouldn't like to try an emergency stop at that sort of speed! I know my 88" is a little twitch when pushing on and the brakes are applied. Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted June 19, 2012 Share Posted June 19, 2012 what i find is that i sit at exactly the speed of the porsche infront. although anything above 75 the wind noise starts to get a bit more noticable even with tight doortops. im going to make some windscreen frame mounted wind deflectors cos at the moment wind tries to get into the cab even with the new doortops at anything above 75 Standard Defender doors bow out by about 1" at the top when doing 120mph if that helps. Quote Link to comment Share on other sites More sharing options...
discomikey Posted June 19, 2012 Share Posted June 19, 2012 I wouldn't like to try an emergency stop at that sort of speed! I know my 88" is a little twitch when pushing on and the brakes are applied. i know how you feel, although mine does pull up very straight. wouldnt like to do that speed on the motorway. imagine if you have a blowout haha. major pile up Quote Link to comment Share on other sites More sharing options...
Phil Hancock Posted June 19, 2012 Share Posted June 19, 2012 Alternatively, I might see how much Global Roamer (the new name of Roverdrive) sell their over/underdrive for when it is launched £1380.80 Quote Link to comment Share on other sites More sharing options...
Snagger Posted June 20, 2012 Share Posted June 20, 2012 £1380.80 That's for the overdrive model I already have (SX) - I would imagine the combined over/underdrive will be more. But the cost of 3.9 crowns and pinions for a Rover and a Dana diff would probably not be much less, and would be a lot less flexible and would lose out on the very high cruising ratio. It looks like an eye watering price, but it's all relative... Quote Link to comment Share on other sites More sharing options...
Julian Posted June 24, 2012 Share Posted June 24, 2012 We've had the hybrid over the ton, and thats got the same engine and gearing as my 88........... Once I took mine for a run with the centre seat panel off so I could see the Xmission brake drum revolving @ over 4 times wheel speed. I was alarmed at how fast it was turning at 50mph! I wonder if you risk bursting it at a ton? Has it ever happened - the bits would probably go straight through the floor and take your bsollocks off :-( Julian. Quote Link to comment Share on other sites More sharing options...
ejparrott Posted June 24, 2012 Share Posted June 24, 2012 Haven't the foggiest, but a) I wasn't driving, and b) its not a regular thing anyway...seem to recall him saying something about some numpty being a plonka....I wonder what the burst speed of a LR handbrake drum is... Quote Link to comment Share on other sites More sharing options...
discomikey Posted July 9, 2012 Share Posted July 9, 2012 i bet its more than you think, its quite meaty as vehicle drums go Quote Link to comment Share on other sites More sharing options...
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