Outer Limits 4x4 Board

Hey all,

I'm waiting on the new engineering laws to come in b4 I decide what tyre size I can run on the road, and then I need to work out what rpm the chev gen 111 ls1 engine works best at 100- 110km/h, for economy.

I'm not sure that what the common dores run at will suit a lifted and slightly heavier dual cab Hilux, but would be cool to know anyhow.

I always thought the idea was to cruise at peak torque. This doesn't work too well with a peaky engine with peak torque at 3600 rpm, but with something like a Gen 111 I would expect it to work OK. What's peak torque?

Scott

NJ SWB wrote:I always thought the idea was to cruise at peak torque. This doesn't work too well with a peaky engine with peak torque at 3600 rpm, but with something like a Gen 111 I would expect it to work OK. What's peak torque?

Scott

That sounds sensible. After searching the web, came up with some figures of 250kW at 5600rpm, 473Nm at 4000rpm.

I haven't seen torque curve so don't know how much is available at around 2000- 2500rpm (assuming this would be cruising rpm), however I did read the later LS2 has much improved torque in the lower rpm, with 473Nm being available at 2600rpm.

What gearbox are you using??? Auto, or 5sp/6sp manual??

I think the 6 speeds LS1 cruises at about 1800rpm.. nice and low

most holdens with g3 ls1 run 100k at 1800 rpm.

I set mine to run 100 k at 2050 rpm. (355CI stroked 308)

Michael.

I agree 1800 to 2000 RPM.

Eric

Will probably run t700 auto. The toss up is between Rover Lt230 t case with it's 1.2: 1 high range or 1: 1 high of anything else.

So with Rover t case 1.2 : 1
top gear 0.75: 1
diff 4.1 : 1

final drive will be 3.69: 1 so if I run 35's at 100km/ h the engine will run at 2236 rpm.

With a 1:1 t case, final drive will be 3.075: 1; the same tyres at 100km/ h will make engine run at 1864 rpm.

slosh wrote:Will probably run t700 auto. The toss up is between Rover Lt230 t case with it's 1.2: 1 high range or 1: 1 high of anything else.

So with Rover t case 1.2 : 1
top gear 0.75: 1
diff 4.1 : 1

final drive will be 3.69: 1 so if I run 35's at 100km/ h the engine will run at 2236 rpm.

With a 1:1 t case, final drive will be 3.075: 1; the same tyres at 100km/ h will make engine run at 1864 rpm.

I was looking at running the LT230 in my Scout they are stong enough and you can replace the hi and low range gears.
But i thought they are full time 4x4 with a center diff lock.???

Eric

scout392 wrote:

slosh wrote:Will probably run t700 auto. The toss up is between Rover Lt230 t case with it's 1.2: 1 high range or 1: 1 high of anything else.

So with Rover t case 1.2 : 1
top gear 0.75: 1
diff 4.1 : 1

final drive will be 3.69: 1 so if I run 35's at 100km/ h the engine will run at 2236 rpm.

With a 1:1 t case, final drive will be 3.075: 1; the same tyres at 100km/ h will make engine run at 1864 rpm.

I was looking at running the LT230 in my Scout they are stong enough and you can replace the hi and low range gears.
But i thought they are full time 4x4 with a center diff lock.???

Eric

Yes full time tho part time kits are available. This loses the ability to "front dig" by holding the handbrake on tho.
They do come with 1:1 high range I may start looking for one of these.

HotFourOk wrote:What gearbox are you using??? Auto, or 5sp/6sp manual??

I think the 6 speeds LS1 cruises at about 1800rpm.. nice and low

My wife's VX ser II 6 speed runs at about 1600 rpm @100km/h. Tacho may be out, because it definitely doesn't read as high as 1800rpm @ 100km/h.

There a very revvy V8, not a whole heap down low like earlier V8's particularly say, 351C's, but a very interesting engine when above 4000RPM!!!


Regards

dosn't the ecu go into lean burn + self tune when cruising? if so, when in a different car the ecu wont realise that you are cruising, due to the different revs and throttle posistion? it'll assume you are going up a really, really long hill and dump in excess fuel. You wont get optimum economy unless you get the chip remapped.

i could be wrong though ...


Simon

Around 1800rpm @110km/h for both LS1 & LS2 in a 6speed Dunnydoor.
This varies slightly as SS/execs run 3.5 diffs, Clubbies 3.7 and Utes 3.9.
New LS2 Clubbie runs 3.5 diffs and has WAY more torque than LS2. Will accelerate crisply in 6th from 110km/h, unlike a (stock) LS1.

popeye wrote:dosn't the ecu go into lean burn + self tune when cruising? if so, when in a different car the ecu wont realise that you are cruising, due to the different revs and throttle posistion? it'll assume you are going up a really, really long hill and dump in excess fuel. You wont get optimum economy unless you get the chip remapped.

i could be wrong though ...


Simon

sort of true. The computer is more sophisticated then that and really responds well to programming, they are very very tunable, so many parameters. It cost me $1100 for an exchange unit (alone$300) (they have to be dskw (on the white sticker under the black holder) for optimum tunability as the older ones have less adjustment.)and a full custom mafless tune with every "wire" removed from the fault code list as they are not hooked up in my application - vss, thermo fans etc. I had mine done for regular fuel too, which i will change after the obc. diff ratios, gear ratios etc can be programmed in as well, also thermofan on/off temp settings, fuel pressure at any part of the rev range, etc

auto or manual computer is no different in another application (4x4etc)just sort turned on/ off etc

i got powertorque in brendale to do it.

I looked at it like this
theft unlock $300
exchange comp $300
Full mafless tune inc above $1100 - should be cheaper now. 300kw + at flywheel should be 285 on reg.

cheers bru

[/quote]

Yes full time tho part time kits are available. This loses the ability to "front dig" by holding the handbrake on tho.
They do come with 1:1 high range I may start looking for one of these.[/quote]

From where and how much.

Maybe a LT230 is back on the drawing board

Eric

scout392 wrote:
Yes full time tho part time kits are available. This loses the ability to "front dig" by holding the handbrake on tho.
They do come with 1:1 high range I may start looking for one of these

From where and how much.

Maybe a LT230 is back on the drawing board

Eric

I've asked this question on here b4, with the reply that ashcroft transmissions (from UK) sell them. Haven't looked into it any further however I did notice that 4wdsystems.com.au (South Australia) advertise a pert time kit for Landrover Discovery for $695.

Gear
Ratio
Tooth Count
in/int/int/out
Models Used and Comments
Box S/N

Low Range
3.320
26/41/19/40
LT77, LT77S, LT85
13D, 22D, 28D


4.340
26/41/20/55
Maxi-Drive Engineering Low range gear set. Exact ratio depends on input and intermediate gears that are used which vary slightly by model.


High Range
1.003
RR 3 speed auto (TF727)

1.222
26/41/40/31
LT77/LT77S
28D

1.1923
90 V8s with LT85 gearboxes
29D


1.211

1.206

1.410
26/41/?/?
All 90s except V8
All 110s except 2.5/2.25l petrol and N/A diesel
13D, 22D


1.667
26/41/35/37
110s with 2.5/2.25l petrol and N/A diesel

Heaps of ratios

eric