LT230

[tony]

Hi all, does a Disco II use the same LT230 as the Disco I's? Can I use it with my LT77? and will the 1.2 ratio work well in a 90 with a 2.25 petrol engine with more HP than standard? With the present 1.6 ratio t-case the engine RPM's are at 3300 at 100KMH with the 1.2 it should bring it down to 2200 RPM at 100 KMH.

[HeadDamage]

Some DII LT230 t-cases do not have center diff lock. Also the front input flange is different but I think you can swap it for the DI flange. There may also be a different tail/output housing that may or may not have provision for a speedo output. Not sure if there are other differences.

[red90]

1.2 would be a bit much for a 2.25. I'm running a 1.2 on my 90, but have a souped up TDI and the military LT77 with the extra low 1st gear. If it had the normal 1st gear or a stock TDI, it would not work.

[tony]

So would a 1.4 ratio work better? with 2700 rpm at 100 km h?

[red90]

A 1.4 should work. Do you know which specific LT77 you have? That can affect the answer. I'm assuming a "50A".

[HeadDamage]

GEAR RATIO = RPM * Tire Diameter / MPH * 336



RPM = MPH * Gear Ratio * 336 / Tire Diameter



MPH = RPM * Tire Diameter / Gear Ratio * 336



TIRE DIAMETER = MPH * Gear Ratio * 336 / RPM

[HeadDamage]

I have a 1.2 LT230 in my RRC 200TDI with the stock LT77 (higher gearing than the military LT77). I run 225/75/16 tires and the gearing is perfect. When I tried running 235/85/16 tires it was clearly over geared and was more of an effort to drive. I think that my RRC 200tdi would benefit from a 1.4 LT230 if I want to run 235/85/16 tires.

[tony]

Yes 50A red 90.

[Rob]

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