Diff Gears ???

[chrrr]

I put some 3.9s recently with a minispool in my stateo and i love it. big difference from the 3.08 ratio.

What did you rev at before/after at 100kph?

Im also looking at chucking out the 3.08's for some shorter gears. I generally drive at 50kph to work and back, but do hit 100 every week or so, petrol ecconomy isnt the biggest thing to me but id not like to be revving my ass off at 100k's

What would be the best gears for me? I'd like maximum acceleration, but dont want to suffer like crazy on the odd occasion i hit 100kph.

On a side note, if i do 1500rpm in 3rd @ 50kph now, if i get shorter gears will I be able to drive in 4th at 50kph?

 

[STEALTHY™]

I had 3.45s in my VP when it was auto, didn't really notice much increase from the standard 3.08.


I now have 3.7s, but thats with a 6 speed.




I'd say 3.9s at most. 4.11s and you'll just have no top end. 3.9s would still be revving quite high at 100, but you said you want max acceleration aswell.

 

[greenfoam]

Just remember the 3 fastest stock engined 5 litres have run

14.0 = 5 speed manual on 3.08s
14.06 = 5 speed manual on 3.45s
14.1ish = mine, Auto on 3.45s

No one has gone that quick on 3.9s on the standard manifold/cam so that's something to think about

 

[STEALTHY™]

The driver would depend alot. If it was you driving all 3 cars, it would be a good comparison, but otherwise, its not really helping haha

 

[chrrr]

Just remember the 3 fastest stock engined 5 litres have run

14.0 = 5 speed manual on 3.08s
14.06 = 5 speed manual on 3.45s
14.1ish = mine, Auto on 3.45s

No one has gone that quick on 3.9s on the standard manifold/cam so that's something to think about

Thanks (thanks stealthy also!!!) Id be more interested in 0-60mph times as im not going to take it down the strip, its mearly a daily street car that id like to get some more acceleration out of. As long as its not doing anymore than say 2600rpm at 100k's I wouldnt really mind.

Thanks again for the input guys.

 

[STEALTHY™]

Its been a while since my car was auto, so i can't help with what the revs would be. I just remember a mates VN SS with 4.11s was crazy at 100. thats basically all he could so with the top end.

 

[greenfoam]

I think the best ratio for you will probably be 3.7s unless you will perhaps do a cam and manifold change in the future then go for 3.9s. Gears do help heavier cars like yours alot more than they do a 14.0 second manual executive

 

[ScoHar]

does anyone do this themselves? or get a diff guy to do it? I've been told very hard to get backlash and stuff right, correct?

not the type of thing for a mechanically advanced person? as in is it best left to the specialists?

 

[greenfoam]

I made mine myself but I can see how you could stuff it up . The IRS centre is easy to adjust tho, you just turn the spinny things on the sides untill the teeth are line up right, I used bearing blue to see how they were sitting and adjusted it up till I was happy. And I had someone teach me how to do it :0 so it was pretty failsafe for me

 

[ScoHar]

done, diff coming out this weekend 3.45's going in.