keithjh Posted July 16, 2016 Share Posted July 16, 2016 Hi All, I have rebuilt a 1988 90 now fitted with a 300Tdi (origonally from a disco, fully rebuilt). I have fitted auto box also from a disco (also fully recon). The tyres are 235x85x16. I am now needing a Transfer Box what ratio is the best?, the 90 will not be used offroad as its for my wife, so tarmac with a fair share of motorway driving. I will in the future funds allowing get a larger intercooler and tweak the pump but at the moment its all standard. Regards Keith Quote Link to comment Share on other sites More sharing options...
hangover Posted July 17, 2016 Share Posted July 17, 2016 I would use the disco transfer, i have the same setup , 300tdi auto, running 265/75/16's so about the same size. If it was being used offroad more i would use the Defender 1.4/1 transfer. Quote Link to comment Share on other sites More sharing options...
Disco-Ron Posted July 17, 2016 Share Posted July 17, 2016 The off road gearing doesn't change from one ratio to the next. So that's irrelevant. ... with the 1.2 you'll find that the box won't lock up until about 55mph .. which means on most ARe situations these days you'll be using more fuel and generating more heat.... I swapped mine (v8) from the 1.2 to the defender 1.4 and it made it so much better. .. acceleration from zero is better... personally there's only one option.... Quote Link to comment Share on other sites More sharing options...
PaulN Posted July 17, 2016 Share Posted July 17, 2016 The off road gearing doesn't change from one ratio to the next. So that's irrelevant. ... with the 1.2 you'll find that the box won't lock up until about 55mph .. which means on most ARe situations these days you'll be using more fuel and generating more heat.... I swapped mine (v8) from the 1.2 to the defender 1.4 and it made it so much better. .. acceleration from zero is better... personally there's only one option.... ....and what was the comparable difference to revs, noise and speed when either had achieved lock up on good road? Quote Link to comment Share on other sites More sharing options...
Disco-Ron Posted July 17, 2016 Share Posted July 17, 2016 Ultimate speed isn't any different. .. as power basically dictates that.... and even though once locked you're using more revs, because you Don t need to use as much throttle it's actually more economical and quieter..... Quote Link to comment Share on other sites More sharing options...
Dave W Posted July 17, 2016 Share Posted July 17, 2016 With that size tyres I'd go for 1.4 or 1.6. 1.6 will give you better acceleration and give the engine a more comfortable (albeit lower) cruise speed, 1.4 will give slower acceleration and a higher cruise speed but it will be harder for the engine to maintain the cruise speed. A standard 300TDi won't pull a 1.2 box with those tyres, you'll find driving it hard work as it will need to change gears on even the slightest incline when trying to stay locked up. Quote Link to comment Share on other sites More sharing options...
Gren_T Posted July 17, 2016 Share Posted July 17, 2016 Hi Keith, On my 90 I run 235x85x16MT's its a 1.22 trans box and have run it for the last 6yrs & 65k mostly motorway and "A" road miles, it pulls fine & top gear is at 52mph, she will cruise at 65-70 easily and only drops on long climbs. 65mph is around 3k rpm it will rev to 4k when kicked down but its more noise than go. The biggest bugbear Is that at 50mph its in the upper rpm band of 3rd - I've found thats the speed most of the "A" road traffic moves at, also on the motorway for my longer trips I cant tailgate the trucks to save fuel as the box swaps between 3rd&4th. However the above aside it's not bothered me enough to change the transfer box, I have a 1.4 to swap in but never got around to it. regards Gren Quote Link to comment Share on other sites More sharing options...
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