LSD Diff Ratios in Autos, Which one?

[DevilDRake]

Hey everyone,


Well I was having a discussion with my brother and he says for a VX-VZ Diff you wouldn't go any higher than 3.7 ratio because it revs too hard at 100.

What i want to know is, is there anyone out there that have 3.7, 3.89 or 4.11 diff gears, tell me how they run and what they rev at @ 100kph. VX-VZ owners only, and I'm talkiing v6's.

I don't want a big table, because even though it may be right if the auto doesn't shift it'll hold the higher revs.

So is it bad to go higher than 3.7's?

Thanks

[HamaTime™]

Do a search, I know there was a pretty comprehensive thread posted about this not long ago...

However, I'm pretty sure a 4 Speed auto will rev at about 2500 with 3.9's @100kph - not so bad with a manual because of the extra gear!

I'm looking at new diff gears. I'll probably go 3.45's - good mix of both!

[DevilDRake]

I've had a manual with 3.46's for ages. I already know that with 3.89's in an auto would do 2,900rpm @ 100kph. I wanted to know from personal experience not Mathematics. I know in top gear it can do 2900 @ 100kph but the thing is WILL it change, WILL it actually do them revs. That's why i put the question out there for people who have it fitted.

3.45's in my manual is 2400 @ 100kph, so it's abit off.

Thanks for your input though

[HamaTime™]

I've had a manual with 3.46's for ages. I already know that with 3.89's in an auto would do 2,900rpm @ 100kph. I wanted to know from personal experience not Mathematics. I know in top gear it can do 2900 @ 100kph but the thing is WILL it change, WILL it actually do them revs. That's why i put the question out there for people who have it fitted.

3.45's in my manual is 2400 @ 100kph, so it's abit off.

Thanks for your input though

Well putting your mathematics aside, I've driven a mates VS SS, shift kitted T700 with a rebuilt LSD/3.9's and on our yearly cruising to NSW it would do just on/over 2500rpm at 100. So that's personal experience for you. Theory is not always gospel

however, it could depend on numerous factors to each car.

[DevilDRake]

Yeah.. Hmm.. Wouldn't a v8 have that extra gear in auto though O.o? Compared to the v6 that is.

[HamaTime™]

Yeah.. Hmm.. Wouldn't a v8 have that extra gear in auto though O.o? Compared to the v6 that is.

No, they use the same transmission. still a 4spd auto, and 4th gear is basically the weakest excuse of a gear, i.e. cruise gear.

[DevilDRake]

Yeah. Well i wanted to put 3.89's in my auto i'm getting soon i just didn't want it reving it's tits off @ 100kph.

[HamaTime™]

Choice is yours mate. Choice is yours....

Personally, I'd go with a mid range gear set of 3.45 or 3.46 - If that's too little, then 3.7's