2A diff ratios

[Lost Landy]

G,day all just a quick question. Iam looking at putting a higher diff ratio in my 2A LWB to help it have a better crusieing speed.
Will the 2.25 Diesel be able deal with the higher ratio? I cant fit an over-drive as I have a PTO winch that uses the pto all ready.

[djam1]

If you drive on the flat or down hill in an 88 inch it would probably be ok.
Beyond that it would probably be ambitious.

[Blknight.aus]

you might just about push a 4.1:1 if you had no load and nothing fighting the vehicle (hills wind) but there wouldnt be much in it.

[stage1slave]

If you drive on the flat or down hill in an 88 inch it would probably be ok.
Beyond that it would probably be ambitious.


For sure! After putting 3.54 diffs in a 109" ally trayback, we had to go down in tyre size to 9R 15/235R75 15. Else you had to take off in low range! Oh an that's with a holden red motor, so I'd be forgetting about that, loose the whole idea with a 2.25 diesel.
cheers
Evelyn

[JDNSW]

I think you are asking a bit much of it to pull anything except the standard diff with the diesel, especially in a lwb. How much faster do you want to go? In most circumstances the speed is limited by engine power, which for this engine reaches a maximum at 4,000rpm governed rpm. This is over 100kph with 7.50x16 tyres.

About the only thing a higher gear ratio would achieve is making things a little quieter at high speed, but you won't get significantly faster. The basic situation is that the available power is only just enough to reach the speed limit on the level with no headwind, especially with a bit of load. Change the gearing to reduce engine rpm, and the available power is less since the engine rpm is lower. Unlike petrol engines, there is no appreciable fall off in power at high rpm, with this engine power continues to increase until it reaches the governed speed.

John

[Dougal]

For sure! After putting 3.54 diffs in a 109" ally trayback, we had to go down in tyre size to 9R 15/235R75 15. Else you had to take off in low range! Oh an that's with a holden red motor, so I'd be forgetting about that, loose the whole idea with a 2.25 diesel.
cheers
Evelyn

Excuse the ignorant question, but what size is a holden red motor?
A mate has a series 2 with a holden 6 in it. I'm trying to give him my 3.54 ratio ex-rangie diff heads and he's resisting.

[Wolfman_TWP]

Excuse the ignorant question, but what size is a holden red motor?
A mate has a series 2 with a holden 6 in it. I'm trying to give him my 3.54 ratio ex-rangie diff heads and he's resisting.

That will depend on whether it's a 186 or 202. The 186 is a 3litre and the 202 is a 3.3litre engine.. (I have a 202 in one of my Landy's)

Wolf

PS: Just remembered that my Landy with the 202 (3Litre) has 3.5 ratio diffs in it..

[BigJon]

That will depend on whether it's a 186 or 202. The 186 is a 3litre and the 202 is a 3.3litre engine.. (I have a 202 in one of my Landy's)

Wolf

Or a 161, 173, 179, etc...

[stage1slave]

Excuse the ignorant question, but what size is a holden red motor?
A mate has a series 2 with a holden 6 in it. I'm trying to give him my 3.54 ratio ex-rangie diff heads and he's resisting.


Started off with a 202, but now has a 186. The smaller tyres really make it very drivable now, at the expense of a bit of ground clearance.
cheers
Evelyn