Which Diff - 3.9 or 3.45 or money better spent elsewhere?

Mangi · 18-04-2006, 11:00 PM

Hey All
I have a AU XR6 Series III and I am getting my diff done tommorow as my car is a single spinner. Getting it changed to LSD. I was thinking is it worth the extra cash to change from 3.45 to 3.9 or would the money be better spent on other mods. I Currently have Herrod Extractors, 2.5" Hi flow Exhaust, Unichip, 3" mandrel bend Air intake with K&N filter. I am looking at Doing further mods like Cam etc but is there also any advice on my setup currently and how it can be improved or what to add? Also I have been Quote $770 for the conversion with new parts fitted. Is this good? I dont know how much extra it would cost to get the Ratio changed to 3.9 but also roughly how much would this cost? Whats a good price cause i will ask tommorow and i dont want to get riped off. Oh by the way i am getting it done at
"Automotive Differential & Transmission Centre @ 114 Gaffney St Coburg VIC 3058"
Are they good?

Any one who has done diff changes might like to post: what? where? how much? about their diffs and what they think of them!

XR6-VCT-2000 · 18-04-2006, 11:05 PM

Quote:

Originally Posted by Mangi

Hey All
I have a AU XR6 Series III and I am getting my diff done tommorow as my car is a single spinner. Getting it changed to LSD. I was thinking is it worth the extra cash to change from 3.45 to 3.9 or would the money be better spent on other mods. I Currently have Herrod Extractors, 2.5" Hi flow Exhaust, Unichip, 3" mandrel bend Air intake with K&N filter. I am looking at Doing further mods like Cam etc but is there also any advice on my setup currently and how it can be improved or what to add? Also I have been Quote $770 for the conversion with new parts fitted. Is this good? I dont know how much extra it would cost to get the Ratio changed to 3.9 but also roughly how much would this cost? Whats a good price cause i will ask tommorow and i dont want to get riped off. Oh by the way i am getting it done at
"Automotive Differential & Transmission Centre @ 114 Gaffney St Coburg VIC 3058"
Are they good?

Any one who has done diff changes might like to post: what? where? how much? about their diffs and what they think of them!

Neither - i would go 4.11's - i swear by them , had them in my XE with a 4 speed auto , kicked arsss on takeoff , ill be adding 4.11's to mine soon as i can afford it. But if your gonna go either 1 go the 3.9 imo.

TCK-098 · 19-04-2006, 09:25 AM

Ive got 3.45 and i was going to 3.7 but it would make no differance so the 3.9 are going in but price wise everywhere charges differnat even though they proberlly use the same components.

**Stav** · 19-04-2006, 09:29 AM

I did the conversion to 3.73 diff lsd.I can say that I noticed no difference. For 1400 dollars I wish I bought a streetfighter head.

EvilChief · 19-04-2006, 01:30 PM

i chnaged from 3.08 to 3.71 and put a manual into it at the same time and it made a huge diff

AWD Chaser · 19-04-2006, 01:36 PM

Have ya got a hi-stall converter? Might be worth trialling that before a diff upgrade...

Mangi · 19-04-2006, 02:54 PM

well i took the car in this morning and i have decided to go the 3.9! I pick it up at 4pm so i will write back later tonite after i have had some fun with it and let you know if it was money well spent! oh by the way do you have to run in the diff for a certain amount of k's before you can torture it a bit or are they generally good to go from start?

Mangi · 19-04-2006, 02:55 PM

Oh by the way its costing me $1300 for the lsd conversion and the 3.9

AWD Chaser · 19-04-2006, 03:17 PM

To bad if you do. I picked mine up from having the diff done... 100M down the road, U turn and a MASSIVE burnout.... right infront of a speed camera van....hmmm....

:

AU:PROJECT:UTE · 19-04-2006, 03:39 PM

Sounds very good Mangi, I'll be keen to hear your results as I'm thinking the next thing for my ute should be 3.9 gears + LSD.
Oh I'm assuming yours has IRS?
All the best and hope it rewards you!

Tim

AWD Chaser · 19-04-2006, 03:47 PM

Is it possible to get 3.45 w/ LSD or 3.23 w/ LSD?

I've got LSD on mine but im not too sure of the ratio.

AU:PROJECT:UTE · 19-04-2006, 04:33 PM

Yep it sure is possible havepersonally seen 3.08;3.23;3.45 and 3.73 all of which were factory LSD. There was an AUII XLS usedy here at work and I noticed it had an LSD in 3.45, I kick myself now for not taking the couple hours to swap the diff's over into my ute and vice versa before they went and whole saled it...

BI6TIM · 19-04-2006, 04:57 PM

EbII and ED also had an option for 3.27 LSD. 3.23 gears were from EA's and EBI's, they went back to them with the AU for some reason. The 3.27 gears only got a short run.
Also the 3.45 were available from EBI Sxr6 all through the XR range and some Fairmont Ghia's, right up till now. All were available with factory LSD.
Just a bit of trivial info, could be helpfull to someone maybe.

TheSneakiness · 19-04-2006, 05:03 PM

Quote:

Originally Posted by au3 chaser

Is it possible to get 3.45 w/ LSD or 3.23 w/ LSD?

I've got LSD on mine but im not too sure of the ratio.

I've got a 3.45 LSD in my ute, which came off an AU XR sedan.

LOWAU · 19-04-2006, 05:14 PM

Quote:

Originally Posted by Mangi

well i took the car in this morning and i have decided to go the 3.9! I pick it up at 4pm so i will write back later tonite after i have had some fun with it and let you know if it was money well spent! oh by the way do you have to run in the diff for a certain amount of k's before you can torture it a bit or are they generally good to go from start?

I got told to run it in for 1000 km before giving it stick. Also i paid $1200 for my new LSD and good 2nd 3.7 gears, by good i mean no whine while driving.

BTW- is you car manual or auto?

XITED_6 · 20-04-2006, 02:15 PM

i have a good 2nd hand lsd centre with my 3:45 gears cost me $550 from Preston Automatics. Best mod ive done the LSD

I was told to take it easy for approx 2 tanks of fuel approx 1000km

i believe u can get yourself some 2nd hand good condition 3:9 gear ratios from the wreckers on the 89 model nissan skyline/pintara pretty cheap

JC · 20-04-2006, 02:18 PM

Quote:

Originally Posted by au3 chaser

Is it possible to get 3.45 w/ LSD or 3.23 w/ LSD?

I've got LSD on mine but im not too sure of the ratio.

If it is LSD, it will be 3.45.

Futura01 · 20-04-2006, 09:41 PM

Sorry guys quick question ? from the information gathered if i was to buy a xr6 lsd 3.45 ratio center would this bold straight into my standard non lsd diff in my au2 futura ????
thanks

Mangi · 21-04-2006, 12:49 AM

sorry for the late reply but the 3.9 is great!!!!!! I got told 500km to run in but i have already been accelerateing hard at around 200km (couldnt resist)!!! I love the lsd as well so much difference!!!! By the way the $1300 included brand new bearings, center, diff oil etc, new everything but a second hand gear ratio which i was told was in excellent condition and so far no whine so fingers crossed!!! I seriously reccomend getting 3.9 lsd, well worth it! By the way my car is non irs as well! I will be there on sunday so i hope to speak to most of you all then. Thanks for the help. will keep you posted on how it continues to go.
Cant wait to launch of the line and really see what it can do!

FPVWEPN · 21-04-2006, 02:29 AM

Quote:

Originally Posted by JC

If it is LSD, it will be 3.45.

Actually this is not true 3.23 lsd's are also common amongst ba's, ef's and el's.

Casper · 21-04-2006, 08:35 AM

Quote:

Originally Posted by FPVWEPN

Actually this is not true 3.23 lsd's are also common amongst ba's, ef's and el's.

ok, I'll make JC's post a little clearer.

If it is an AU LSD, it will be 3.45.

This is the auflacon.com forums afterall.

StAndArdAU · 21-04-2006, 01:11 PM

Good Morning Mr Fordforums...

"Sir Sir Sir (standardAU sits impatiently with his hand in the air). What is a diffs purpose and does changing it create better response?"

now everyone knows how far my car knowledge really extends...

Casper · 21-04-2006, 01:15 PM

Quote:

Originally Posted by StAndArdAU

Good Morning Mr Fordforums...

"Sir Sir Sir (standardAU sits impatiently with his hand in the air). What is a diffs purpose and does changing it create better response?"

now everyone knows how far my car knowledge really extends...

all explained here:
http://auto.howstuffworks.com/differential.htm

StAndArdAU · 21-04-2006, 02:00 PM

Casper you is like that old black lady on the matrix...just without the female body and annoying monotonous protoge'.

Mangi · 21-04-2006, 03:10 PM

Dont worry StAndArdAU. 1 year ago i knew half if not less than what i do now. These forums will teach you heaps as well as just general experience. Just learn as you go and ask if in doubt is the best way!!!!!