diff gears?

[Fun_Bucket]

Ok, firstly i did a search, but it didn't return me with much useful info.(that i could find anyway)

I have a VP V6 auto, series 2. Completely standard.
I'm considering changing the diff gears in it, for improved performance. From what I've been told, and from what i've read, the 4.11 gears from a Nissan Pintara, will proved the most improvement in accelaration. But what are they like for day to day use. I live in Cairns, and to and from most places i drive to, the highest speed limit is 80Km/h. Has anyone fitted these 4.11 to their car before, and if so, can you tell me what it was like to drive. If 4.11's are a bit over the top, what would be a good compromise?And finally, because i don't know really anything about them, what would be a good price to pay for them, without the wreckers seeing me and coming, and trying to rip me off..

Thanks to anyone who can help

[sweefu]

hey mate, i'm in a similar boat looking to do diff gears but need more info, so will be interesting to see answers here

[georgeonboost]

4.11's are good gears for the strip(drag racing) although there are many people using 4.11's on the street aswell. the car have much more acceleration and will rev higher in top gear. for a daily driver, i would be going for 3.7's or 3.9's. that's my personal opinion though. are you going to put an LSD in aswell? doing so at the time of changing diff gears would be a good idea.

George

[Fun_Bucket]

i was going to keep the single pegger. I'm not really fused about having an LSD, i mean would be nice, but for now i'd be happy with just a good improvement in accelaration. Am i going to notice a huge difference with the 4.11's and a stock motor? Like say a rough difference between 0-100, and normal in gear acceleration?

[nickkurtz]

hi holden commodore vp
i got 4.11 in my burnout vn and thats ok for burnouts
i would go 3.45 or 3.73 but you will have to get speedo corrector to get speedo right again
vl,s had 3.45 in most cars
nick



ps i drove mine a while back on the road on trade plate to test after fitting diff gears and speedo was on 90kph and gps told me i was doing 65kph
took it up to 200 kph on speedo and gps said i was doing 120kph at 5500 rpm in over drive
it gets there real quick and burns rubber in drive but vibrates like s@&t at high speed
go 3.73 if you can get them

[<RaBBiT>]

ur best getting a lsd while ur at it as will help getting power to the ground otherwise u will be sitting there pegging away. and 3.7- 3.9 are gd for street use 4.11 are a bit over the top unless u want a traffice light warrior lol

[padrickz88]

dude i wouldnt even think about going to anything higher then stock with the single pegger.... Anything higher would just mke it hard to get off the line in the dry, the wet would be suicide lol....

Get an lsd or spool and put in some 3.7-3.9's... preferably 3.7's but they are hard to find so some 3.9's would be perfect...... BUT if you dont go over 80 then your fuel economy would be pretty sweet with some 4.11's :P

[Niggadore]

go 3.9's
not to high, but high enough for some fun with a spool


Also, as said above, don't bother changing diff gears without putting in and LSD or spool..
since this is your daily, i wouldn't bother with 4.11's, just to un practical..

[Fun_Bucket]

Thanks for the replies guys. What are the 3.9's out of? Were they factory fitted to the R31skylines?
I'd love an LSD, but i'd really just be happy at the moment with the extra accelaration the gears would provide. Even if i had to feather it a little on take off, that's a fair compromise to have to make, compared to the way it performs now. Also, if i'm sitting still, and jump on the gas all the way, i don't get any wheel spin whatsoever.If that normal for a auto V6 VP? (apparenty a memcal tune changes that completely..) This may be a pretty broad question, but does anyone know roughly what sort of time difference one could expect during 0-100 runs after installling different gears?My cars never likely to see a 1/4, so basically 0-100, or 80, is going to about the most it will see...

[padrickz88]

3.9's are found in r31 skylines.... (some have 3.7's but not very common)

My guess is that you will go slower with a single spinner with 3.7-4.11's because of the wheel spin, and you will be paying top $$ to get the gears put in so you might aswell put in an lsd or spool while your there....

Mine spins off the line sometimes in the dry with 3.9's and i have more weight over the rear end then most vn-vp's (heavy sub, gas aswell) so them gears in a single will just have you smoking the tyre.. So realistically you NEED an lsd or spool otherwise its a waste of money.

[levymetal]

i'm going to be a real pain and ask if anyone has the calculation to find out what RPM you'd be doing at a given speed if you changed diff gears. i cannot be bothered searching right now

[rickybobby]

this windows download program seems ok for free and it works.
i got the link from somewhere else on this site or a similar site.
whatever - seems ok.

google "gear calc peter ogden"

links

racingdownloads.com/racing_software-22.html

or

locost7.info/gearcalc.php

[padrickz88]

I just done

(current rpm / 3.08) * new ratio = new rpm....

[flanker]

your looking at around 600 - 700bucks for BRAND NEW 3.7's and thats if u find them, as the track/club boys are buying them all up. Some business's are catching on and you'll find by next year a lot of 3.7s around at a decent price. I paid 700 TRADE price for new 3.7s which I think is just way steep

In an auto, 3.7 would be sweet, but get a cheap spool for it so u can put it to the ground.

[Fun_Bucket]

Hey guy's, thanks again for all the replies. I've taken on board everyone's reccomendations about fitting either a spool, or LSD, to get the most out of swapping the gears. To be honest, i've always overlooked fitting a mini spool, because i thought they were a fairly expensive modification. But after looking around, i've found a few places that sell the spools new for around the $85 mark.Does this sound right? For that type of money, i'd definately look at getting it done.

[padrickz88]

thats about right usually between 80-100 ish.... give or take a little

[Fun_Bucket]

Spool ordered and on it's way, very excited