Thread: Various R380 gearboxes

any units for the measurements! what are they actually measuring there?

I dont think they make a lot of sense tbh!

With the R380's, in relation to 200/300tdi's;

Are the 200 & 300 the same pattern (engine side)?
Are these the same as a V8 pattern?

I have 2 boxes, one known from a D1 (but unsure engine) and another unknown (prob RR) will the suffix tell me anything about the source (apart from possibly rough year)? Since the J seems from reading the better box, given 200 or 300tdi & 3.54 diffs and up to 33" tyres what would be the preferable tfr ratio?

Originally Posted by clubagreenie

With the R380's, in relation to 200/300tdi's;

Are the 200 & 300 the same pattern (engine side)?
Are these the same as a V8 pattern?

I have 2 boxes, one known from a D1 (but unsure engine) and another unknown (prob RR) will the suffix tell me anything about the source (apart from possibly rough year)? Since the J seems from reading the better box, given 200 or 300tdi & 3.54 diffs and up to 33" tyres what would be the preferable tfr ratio?

V8 and diesel boxes have a different bellhousing and spigot shaft diameter. V8 boxes are higher geared (taller ratios) in 1,2,3,5, R(?). The suffix does not tell you that.

Anything pre 94/5 (e.g. 200Tdi) will have come with an LT77 originally.

Originally Posted by Psimpson7

This is what i did to mine at about 115k km: (probably due to abuse of reverse in large rocks)



98% of the work that had done was running std power figures. The last 2% was probably 170bhp/400NM.

I really dont think the torque of the isuzu is sufficient to break a decent late suffix r380. I also think the chiped TD5s have a more agressive power/torque delivery, and also higher peak figures than almost all of the isuzus. (and I am not refering to twin turbod state side things..) just LR applications.

Not many people actually seem to offer proof of the 4bd1t outputs...

TD5 outputs are easy enough to find. (from the je engineering website)

stage 2 - 400nm at just over 1850rpm and 420 peak roughly


The only 4bd1t one I have seen was 332nm at 1750rpm with a VNT, although he did say it had been improved and he thought peak torque may be as low as 1400 now.


Anyone got one to offer up?

Rgds
Pete

Dyno sheets, torque graphs. power point presentations are sometimes just that, bits of paper.

We had a former member running the following
TD5 chipped D2
R380 g/box
LT230 with 30% reduction
4:11 diffs
33" tyres

We were running
4BD1T fueled and i/cooled RRC (running TD5 turbo)
R380 g/box
LT230 with 30% reduction
4:11 diffs
35" tyres

The difference in torque was so noticable even with our bigger diameter tyres. The 4BD1T would climb hills and rock ledges in 1-2 gears higher. It could recover from low rev situations without stalling, the TD5 could not??, it would respond and boost quicker.????

On road towing campers the 4BD1T would eat the above D2 on hills, although it was not faster by any means.

No paper, no charts, just happened
I would think our 4BD1T would be max 80-90kw if your lucky. Its just Torque pure & simple.

Justin

End of hijack sorry again

Psimpson7,

Something wrong with the labels on the curves, the stage 1 and 2 power curves appear to be incorrectly labeled going by the torque curves.

clubagreenie,

I thought that the K and L suffix boxes are meant to be better than the J.

Originally Posted by Psimpson7

any units for the measurements! what are they actually measuring there?

I dont think they make a lot of sense tbh!

Power in Kw and torque in Nm.

Originally Posted by isuzurover

If you are converting a defender like CHT did or you are planning then it is probably a good/low cost option.

IRC CHT's engine is a genuine T with OEM turbo, no intercooler and OEM settings (???).

Pete - US Isuzu owners are tight arses and won't pay for dyno runs Plus the figures are usually very rubbery
Seriously though, didn't sam Dyno his isuzu recently???

My engine is indeed a genuine factory turbo engine. Fuel sttings are factory standard - I had the injection pump fully rebuilt nearly two years ago. The Turbo is the factory housings (watercooled Garrett) with upgraded compressor and turbine wheels - same spec as Justin Cooper's 466409-2a. (incidently the turbo fitted to the 4BD2T. No intercooler.

The R380/1.2:1 ratios were the best available of the viable LR gearbox options.

From what I unbderstand the TD5s that have lunched gearboxes have been agressively chipped and probably driven to the utmost of the available power. I know of at least one case where the chipped TD5 was towing a very heavy trailer with attendant consequences.

FWIW

C H T

Originally Posted by clubagreenie

With the R380's, in relation to 200/300tdi's;

Are the 200 & 300 the same pattern (engine side)?
Are these the same as a V8 pattern?

I have 2 boxes, one known from a D1 (but unsure engine) and another unknown (prob RR) will the suffix tell me anything about the source (apart from possibly rough year)? Since the J seems from reading the better box, given 200 or 300tdi & 3.54 diffs and up to 33" tyres what would be the preferable tfr ratio?

Originally Posted by slug_burner

Psimpson7,

Something wrong with the labels on the curves, the stage 1 and 2 power curves appear to be incorrectly labeled going by the torque curves.

clubagreenie,

I thought that the K and L suffix boxes are meant to be better than the J.

Yep, as often mentioned earlier the K and L 'boxes are heaps stronger than the J 'boxes