|Discovery II - Driveline|
Engine is a factory Land Rover TD5, 2.5 litre, turbo intercooled diesel engine with direct injection controlled by an Engine management computer. The ECU has been replaced with an upgraded unit designed by Davis Performance Landy's in Annangrove Sydney which has produced a significant gain in power production. The next day a Roverworks high capacity intercooler was also fitted and the engine settings altered to suit. This setup produces around 160-170kw of power and 520Nm of torque, which is a significant gain over the standard Discovery TD5 specifications of 101kw and 315Nm. The engine performs significantly better through the entire rev range, does produce a small amount of extra soot, though the fuel economy has not altered.All installations and setup has been done by Davis Performance Landys and the performance is sensational.
Exhaust has had the centre muffler removed. This was done by Parramatta exhausts, and my hopes were for reduced exhuast temps and faster turbo spooling. If the performance has changed at all, the gains are very minor. The noise level has increased and is still legal. The tone being deeper with a more pronounced turbo whistle.
Snorkel has been produced by Safari, which is the same as the original factory unit. Actually Safari manufacture the Land Rover Discovery snorkels! This part I cut the panels for and completed the installation. The reason for installing the snorkel wasn't only to keep water out of the engine during water crossings, but also to keep a lot of the dust out during remote touring. Unfortunatly the construction of the airbox in these 4WD's are not the best. When the air filter clogs, a lot of dust seems to slip around the filters, which I have found via telltale dust traces. With the snorkel moving the air intake from the dusty wheel arch guards to up high at roof level where there is minimal dust.
Automatic Transmission unit is a ZF HP22EH automatic as supplied with the vehicle from new. The transmission is essentially standard, although it has an additional high capacity oil cooler to help cope with the increased engine outputs and heavy terrain such as sand driving.
Transfer case is the LT230Q from LandRover. This came from the factory without the ability to lock the centre diff lock. This action has been reinstated by the inclusion of the John E Davis Motorwors CDL actuating link.
CDL is now by the JDMW centre diff lock actuator, that automatically locks the centre diff when low range is selected. This modification has done wonder for the Discovery. It has minimised an enormous amount of wheel spin from the 4WD system. Wheelspin destroys tyres, causing chipping, cracking and chunking.
ETC over-ride switching has been wired in by myself to give the ability to select or deselect the use of ETC. I have found no terrain where the vehicle performs worse with ETC, including sand.
Propshaft Front has been replaced with a new heavier stronger shaft from Tom Woods shafts in the USA. This shaft is in the same configuration as a factory shaft, though built with stronger 1310 universal joints in the uni joint and the double cardin joint. It also has a Tom Wood's adaptor to mate the 1310DC joint to the transfer case output flange.
Propshaft Rear was supplied by Davis Performance Landys, and is now a full Uni-uni tailshaft. The original rotoflex (rubber coupled) tailshaft was flicked as the rotoflex was not capable of maintaining integrity with the riguers of 35" bog style tyres and a high output diesel engine. The shaft has been replaced with a heavier stronger shaft from Tom Wood's shafts in the US, and has been changed from the regular Uni-Rotoflex configuration to a 1310 double cardin to uni joint setup. This is significantly stronger and removes any vibrations generated from the suspension lift. This larger 1310 joint also requires the use of an adaptor.
Locking Diffs are manufactured by ARB in the front and rear. These are air atuated by the onboard air compressor and manually switched from a roof console inside the cabin. The have significantly inceased the offroad ability and the low impact crawl ability of the truck.
Onboard air compressor has been made by ARB as a lockers ready unit. I have installed this under the bonnet, and wired the loom into the cabins roof console. The compressor is also used to reinflate tyres after 4WDing.
CW/P gears are manufactured by Dana in the US to suit the Rover diff, and cut as a HD 4.11 ratio. This is lower than the factory 3.54 ratio and chosen to suit the larger 33" and 35" diameter tyres that are now being used. This gear ratio allows the use of 33" tyres with standard performing gearing.
Axles are manufactured by Maxi-Drive from Hytuf, and aircraft grade alloy. These axles are infinately stronger than the original units and will cope with the stresses from 4.11 diff gears, lockers, 35" bog tyres, increased engine output and driver abuse.
CV's are Maxi-Drive supplied. These are a larger replacement heavy duty CV, that have a laminating ring pressed onto the CV bell. Maxi-Drive predict the CV to be strong enough to break the alloy axles, though at full lock the CV may still break first. The CV also uses a replacable outer axle, so in the event of a failure, the axle only needs replacing, not the entire CV assembly which is typical.