Diff ratio

[eb91xr6]

ok as some know im atempting to change the center on my falcon, i have the LSD center 731 just wondering what gears will fit on it and out of what. i know pintara gears will fit but there 4.11 but i think that is too high what are peoples thaughts on 4.11 lsd

[mcflux]

4.11 + manual? Probably a little short. 4.11 + auto? ...

What exactly is LSD centre 731? What ratio diff did it come out of? Basically 3.08 and above can house ratios up to around the 4.11 mark (inc. 4.11), while the 2.77s are somewhat limited with ratio changes.

[eb91xr6]

dont know but the current ratio on it is 3.23

[eb91xr6]

oh and i have a EA t5 in mine so short 1st gear

[trick_xd]

4.11s and fun with or without a lsd
I have 4.11s in my EL have had for over 2 years and its good .. I am doing 2,500rpm @100km with a auto..and wearing out rear tyres that is the only down side.. Good sides are heaps..
fast take offs no lag better overtakeing on the open road better throttle responce..

[eb91xr6]

yer i would hat to think what my top speed it on a manual with a 4.11 any one got one in and a EA t5

[gngtho]

4:11's you will loose alot of top speed yeh good take off but no good o highway, drag cars use them only for 1/4 mile.

for your long trips you need something like 3:23's or if you want some kind of take of get wat i want 3:77's

[Rollin]

probably about 140km/h lol.

to work out new cruising rpm take your current rpm@100km/h then divide by diff ratio then multiply by new diff ratio, ie:

2000/3.23 = 619.19 X 4.11 = cruise rpm of 2544rpm approx

to work out top speed with new diff gears divide 100 by your rpm@100km/h, then multiply by max engine rpm (5500) which will give you theoretical max vehicle speed, ie:

100/2544 X 5500 = 216km/h (if the motor can push the car that hard, and if the tailshaft doesn't punch a hole in the floorpan or the road...)

with an EA box I would go 3.7s, because i had 3.9s in my manual EB XR and the ratios were all pretty short...4.11s would be a PITA i reckon, esp with the shorter ratio EA box.

[eb91xr6]

will the 3.45 out of a VL calais fit as they use a bogwarner diff

[trick_xd]

Originally Posted by eb91xr6

will the 3.45 out of a VL calais fit as they use a bogwarner diff

Yes they sure do
even the lsd fits

[eb91xr6]

well i dont need another lsd but i think a 3.45 would be the best choice

[Mr_4.0]

go 4.11. u wont regret it. the revs are no where near as bad as you'd think.

[eb91xr6]

yours is auto mine is manual and a short ratio EA T5 box it revs alot higher then an auto

[mcflux]

A 3.45 ratio would suit your EA box quite well ;)

[eb91xr6]

just need to know if it will fit and i was told by a friend that all VL calais were fitted with 3.45 gearing is that true

[eb91xr6]

also what skyline had the 3.5 gearing

[mcflux]

OK, YES the 3.45 gearing from a VL will fit your current 3.23 diff housing.

Skylines came with 3.7 and 3.9 gears (3.7 from manuals, 3.9 from autos). Pintaras came with 4.11 gears. All these gearsets will fit in your 3.23 diff housing.

[OED666]

all vl's had 3.45's, not just calais.

used to have a manual skyline wagon (not me personally, little brother) and it had 3.9's. He got another diff with 4.11's from an auto pintara.

eb91xr6 - are you fitting your lsd centre you got last week. you may run into problems fitting shorter gears, as they will not be suited. you will need a spacer plate, and they suck. i know from experience

[eb91xr6]

well i was talking to mark (stockstandard) and he said that xr6 gears wont fit so i will need ether gear out of a pintara or skyline he has informed me that VL gears wont fit

[OED666]

if your intending to fit your lsd centre, then you wont be able to fit any short gears, without a spacer plate.

i think the highest you can go is 2.92:1

have you looked at your diff tag to see if you have 25 or 28 spline axles.

If your diff tag on the filler plug says "High Performace Diff" then you have 28 spline axles, and you wont be able to fit you LSD.

[eb91xr6]

got axels to suit got the whole internal of the diff that it came out of

[OED666]

do you have abs brakes???

[eb91xr6]

no i dont