3.73 Diff Now In

[sly]

I have 800m of dirt road to negotiate leaving home before I get to the tarred public road. The first 200m is uphill and ATM is soaking wet and slippery, with the gravel washed away almost to the clay and grass jumping out of the ground alongside and along the crown. The LSD is a no-brainer for me when it gets like this, especially with increased power later this year.

[Mechan1k]

Hee hee ... that sounds exactly like my driveway ... I have a long uphill dirt (now sloppy mud) driveway up to my gate ... and then another shared dirt/gravel driveway to my street front.

[sly]

Yep. Uphill 200m to the gate and the rest is shared. Uncanny LOL.

[LOWAU]

I have 3.73 in my auto au and its a little suttle, if I was to redo it again I would go 3.9s for sure.

[Stav]

I have had the 3.73 and of course the 4:11's. My lsd went single spinner probably due to poor parts..With the dev 4 tuned by croydons I can assure you that trying to overtake from a standstill resulted in extreme burnout and no traction. I remember a lady looking at me like what the? ...while I was trying to get out of the left ending lane. Now with the 4:11 and proper LSD I rarely spin the wheels but they do sometimes chirp when I give it heavy throttle and changes gears. I must admit.I dont give it hell off the mark.Its this treatment which breaks diffs,suspension,gearboxeswears out tyres and generally puts shock into the whole car.

[ClassicAU]

Originally Posted by Stav

Its this treatment which breaks diffs,suspension,gearboxeswears out tyres and generally puts shock into the whole car.

Yeah, everything about dumping the clutch in 1st and chirping 2nd is extremely bad, but it's so much fun!!

[GK]

Originally Posted by stockoau

Thats rubbish, you don't get an LSD to bag it up off the line, you get one to get the power to the ground. Last year I was having troubles with wheel spin, even half throttle off the lights and I would loose traction, so I was planning on getting an LSD, but with the new wheels and tyres seems I don't have this issue. But anyway, this is what an LSD is for, to improve traction not break it.

You are right but perhaps I didn't make my point clear enough.

The LSD is for traction off the line. It's also for towing and pulling boats out of the water, and for some off bitumen applications.

What I meant was that if you're not towing, or racing off the line etc, then non LSD is fine. I also meant that doing burnouts will wreck the LSD, so going nuts with it off the line eventually means it won't give you the traction you want it for, off the line.

I hope that's clearer! LOL!

GK

[GK]

Got the car back, it's very different. First is short, so the quick shift into second is required. As with Evan's car, the shift needs to be precise to avoid the clunks the AU manuals are known for.

Second as Evan said is really nice, a good feel of power and at the moment I'm shortshifting into third and fourth until the diff is run in after another 300 kays or so.

So far so good though.

The diff itself makes a very slight whine, no probs though, at least the diff noises I had before (read heaps) are gone and the car feels so much smoother and solid.

I'll dump the oil in both the box and diff after the diff's done 1,000 kays to get the initial metal out of them both. Should be in another 2 weeks or so.

Speedo is soooooo far out though. I followed a friend in her Escape last night to get an idea of what was going on, 110=140, 100=130, 90=115, 80=90 etc, etc. Feels really weird with the speedo showing 140 when you are just cruising with the rest of the traffic! LOL!

As for revs, about 2,220-2,3000 at 110, but I wasn't watching that closely.

I'm pretty sure I'm going to be using more gas now! At least it's LPG. LOL!

I'm glad I went the 3:7, although I concur with Evan, stop start traffic is a bit of a pain, but if I keep it smooth it's okay. I pretty much had to go the 3:9 as 3:45s wouldn't have given me the kick I'd wanted because of the weight and power drop of LPG.

My car is no fire breather, but soooo much more fun to drive now.

GK

[AU2PWR]

so 3:7 is the go .. whats the cost of such a thing ?

[rob_liss_lms10]

I saw on E-bay the other night some place selling 3.4 3.7 3.9 and 4.11 for about $350.00. I assume then it's just a case of fitting them or getting someone else to do it. I'm thinking of doing the swap as well, but can't make up my mind on 3.7 or 3.9.

[AU2PWR]

4.11s .. nah ill think about the 3.9s

[StealthAu]

Originally Posted by AU2PWR

4.11s .. nah ill think about the 3.9s

Diff gears aren't just about picking the numbers that you like the sounds of, what are your over all plans for the car and what are you looking to get from it?

[AU2PWR]

Originally Posted by stockoau

Diff gears aren't just about picking the numbers that you like the sounds of, what are your over all plans for the car and what are you looking to get from it?

i Know dude .. i was replying to the previous post

[GK]

Car's revving at 2,300 @ 100kmph. Well, that's my best estimate before I get the speedo corrected!

The car picks up really well in top gear from 100. It's great for overtaking.

GK

[mik]

is there much difference at 100 kph in cabin noise exhaust etc.

[GK]

Originally Posted by mik

is there much difference at 100 kph in cabin noise exhaust etc.

There's a little more, but not enough to be annoying.

GK

[sly]

Originally Posted by GK

There's a little more, but not enough to be annoying.

GK

I'd second that, the engine note is a bit "busier" from about 90 up. It's noticeable, but only in the sense that the engine noise at any given speed is burnt into the subconcious after 330,000km. Before going ahead with the transplant I drove around for a couple of days in 3rd instead of Drive to see if any increased noise annoyed me... it didn't.

[sly]

Originally Posted by GK

I'm pretty sure I'm going to be using more gas now! At least it's LPG. LOL!

I'm glad I went the 3:7, although I concur with Evan, stop start traffic is a bit of a pain, but if I keep it smooth it's okay. I pretty much had to go the 3:9 as 3:45s wouldn't have given me the kick I'd wanted because of the weight and power drop of LPG.

My car is no fire breather, but soooo much more fun to drive now.

GK

I've just done the first fill after a few days of typical "town" running. Over the last few months my mileage in such conditions has been between 15.5 and 16 l/100km on LPG. After correcting the odometer distance (now reading 15% low), I got 15.8 for the first tank with the new diff. As I suspected, I'm not using as much throttle or holding 1st and 2nd gear to keep with the flow of traffic. The quicker initial response means I can let the autobox change up at 2000-2200 and get some use out of 3rd, saving enough fuel to offset any extra used once up to speed.

I find I have to ease on & off the throttle more carefully now at a steady cruise with the torque converter locked, it's now responsive enough to feel the change in throttle pressure... not harsh or clunky, just... responsive.

So yes, my car is much more fun now too, so much more responsive than before.

[teabags2]

Just found this thread.
I towed the caravan over easter and realised just how low the revs are on an auto sedan. Gas ring LPG does not help.
The manual states 3.08:1 everything else 3.3 ish to 3.55 i think to 1.
If anyone knows the expressway south of Adelaide well 80k's in 3rd is not very good.
If I went to 3.55 maybe up to high 3's (thats 12 to 15% lower) how much difference do you guys think I will see?

Bob

[sly]

Wagons are 3.23, XR's 3.45. Going from 3.08 to 3.45 is a little under 15% - about the same as my 3.23 to 3.73. According to my trusty spreadsheet, with a 3.08 diff and the standard AU2/3 215/60*16 tyres, at 80km/h in 3rd you'd be doing 1967rpm. With a 3.45 diff this would be 2204rpm, or with 3.73, 2383rpm.

[teabags2]

Yeah less than 2000 RPM is not exactly the power band. If I went 12 to 15% lower ratio would I see 12 to 15% more power for the same RPM? I mean with towing before and after a diff change of these sort of percentages would the power difference be enough to be worth the money spent?
Bob.