Thread: 4BD1 performance

Originally Posted by Killa

That torque curve is incredibly impressive...I see why everyone has been saying this Isuzu is unbeatable off-road...I want one!!!

Now take that graph and stretch the torque curve up to the 500Nm line.

Originally Posted by wovenrovings

never explored to top end that much myself as it isn't the best part of the isuzu power curve.

Petty right, mine gets ringed 1. to get the next gearchange, 2. cause it was half glazed and blue smokey, with blowby, seems to have improved a fair bit after 14,oookays of towing and flogging

Originally Posted by isuzurover

LT95 or LT85 (5 speed)? LT85 means it had the LT230 T-case, for which 0.996 isn't an available ratio.

Justin - yep I need to give mine a birthday too

Read the owners handbook. 0.996:1 is what it says for the Aust. production 3.9 Izuzu with LT85 five speed.

Mine does 100kmh @ 2000rpm in high fifth, 110 @ 2200, 120 @ 2400, and tops out at 130kmh in high fifth.

Originally Posted by Brian Hjelm

Read the owners handbook. 0.996:1 is what it says for the Aust. production 3.9 Izuzu with LT85 five speed.

Maybe you should.

Don't know which handbook you have, but mine (PN TP1107 B ) says:
On Page 26:

LT95 0.996:1 LR230T 1.003:1

Afaik there was no ratio taller than 1.003:1 available for the LT230 anywhere (or LR230 for that matter )

Originally Posted by isuzurover

Maybe you should.

Don't know which handbook you have, but mine (PN TP1107 says:
On Page 26:

LT95 0.996:1 LR230T 1.003:1

Afaik there was no ratio taller than 1.003:1 available for the LT230 anywhere (or LR230 for that matter )

Thats funny my handbook(PN TP1107)says on page 26 RUNNING REQUIREMENTS

Ben what gearbox and ratio does your county have? My listings suggest 1.222:1 Mine ('86) had LT85/230T with 0.996:1 which I changed.
Jim.

Originally Posted by yt110

Thats funny my handbook(PN TP1107)says on page 26 RUNNING REQUIREMENTS

Ben what gearbox and ratio does your county have? My listings suggest 1.222:1 Mine ('86) had LT85/230T with 0.996:1 which I changed.
Jim.

The PN of my handbook is actually TP1107 B - the B didn't show before because I had a ")" next to it.

My county is an '87 model with LT85/LT230T and 1.003:1 high range. Did you count the teeth on your gear, or are you just going from what is in the handbook. This is the first time I have heard of a 0.996:1 ratio for the LT230, so I strongly suspect it is a misprint (just as they have LR230T instead of LT).

The LT95 has the high range ratios:
0.996:1
1.113:1
1.174:1
1.336:1

The LT230 has:
1.003:1
1.192:1
1.222:1
1.410:1
1.667:1

The interesting thing to note is that NONE of these ratios correspond - so therefore I cannot see how the LT230 could also have a 0.996:1 ratio - but am happy to be proven wrong.

EDIT - on the subject of misprints in the handbook - on page 27 of mine it says TR230T !!! (everywhere else LR230T)

Originally Posted by isuzurover

EDIT - on the subject of misprints in the handbook - on page 27 of mine it says TR230T !!! (everywhere else LR230T)

Shouldn't that be LT230R?

I have the LT230R in my rangie (taken from a rangie with the TF727 3sp auto). It's the 1.003:1

It should be LT230. The 'LT' is derived from Leyland Transmission.