LagondaNet

[david]

I put a 2.88:1 diff into 13380 and it has helped with cruising speed versus engine revs but disappointingly the off the line performance of the car has been affected, there is just not the torque in these engines in standard form to handle the diff ratio change on its' own.

Part of me wants to refit the 3.07:1 diff but I can't find the time!

Maybe re jetting the carbs for idle and progression would help but this is time consuming as well.

It may not be a problem with injected cars as the overall performance of the engine was much improved.

I think a Chrysler A518 or maybe 618 would be the simplest way to go as they are not microprocessor controlled.

A good four speed conversion is a ZF 4HP22 as this is cable controlled and no ECU's involved.

Ossi has one in his car (ex Landrover I think but the sump is not ideal, use the Jaguar/BMW box for a more suitable sump) and his goes very well.

Fitting a 4HP24 or GM 4L80E would be very complex if indeed impossible due to the entire box function being controlled by an ECU and said ECU requires and relies upon engine and road speed inputs in order to function.

Otherwise they just remain in 3rd gear and this somewhat defeats the object of the exercise.....

I doubt a 4L80E would physically fit, they are huge and also weigh an incredible amount, probably the heaviest modern aluminium cased gearbox we have ever dealt with.



David

[Hawke]