VE manual SS 3.45 to 3.7 diff gears

[MclarenF1]

Hi guys, i know there is a discussion on diff gears at the moment but this is a question related to a manual SS. I'v just spoken to the Brock shop an they tell me i could increase the performance with a diff upgrade to 3.7's. As far as my knowledge doesn't the HSV R8 ansd GTS run 3.7's and does anyone know what they rev at travelling a 100kph. My 6 speed is at appox 1500rpm.
If i did this mod would it rev on the freeway at the same amount of revs as the HSV's do?, the reason i ask is because i'm worried about the economy of the engine decreasing:)

Thanks

[michaels1v8]

Hi guys, i know there is a discussion on diff gears at the moment but this is a question related to a manual SS. I'v just spoken to the Brock shop an they tell me i could increase the performance with a diff upgrade to 3.7's. As far as my knowledge doesn't the HSV R8 ansd GTS run 3.7's and does anyone know what they rev at travelling a 100kph. My 6 speed is at appox 1500rpm.
If i did this mod would it rev on the freeway at the same amount of revs as the HSV's do?, the reason i ask is because i'm worried about the economy of the engine decreasing:)

Thanks

Here you go mate check out this thread

http://www.ls1.com.au/forum/showthread.php?t=79032&highlight=gear+drives

have a look at the ratios for the MM12 box as I think this is what is fitted in the VE's.

Diff gear upgrades usually result in better economy around town as they get your car moving with less effort and on the highway because you can cruise in 6th and have enough pull in the gear to get up all hills and possibly do some overtaking in it...

[MclarenF1]

Here you go mate check out this thread

http://www.ls1.com.au/forum/showthread.php?t=79032&highlight=gear+drives

have a look at the ratios for the MM12 box as I think this is what is fitted in the VE's.

Diff gear upgrades usually result in better economy around town as they get your car moving with less effort and on the highway because you can cruise in 6th and have enough pull in the gear to get up all hills and possibly do some overtaking in it...

Thanks for the link and info, i never thought about it that way. I can see how higher diff gears would use less fuel around town in that it would take less engine power to move the car forward. Thanks for the insight:)

[Pacific77]

If your doing 1500RPM at 100kph with a 3.45 diff(standard SS) then a 3.7 will give you about 1610RPM at same speed. As far as I know the VE R8 runs a 3.37 diff but box ratios are totally dirrerent to that of VESS, ie 6th ratio is 0.69 (VESS is 0.57). What all that means is that a R8 is doing 1800 RPM at 100 KPH.

[Vulture]

Here you go mate check out this thread

http://www.ls1.com.au/forum/showthread.php?t=79032&highlight=gear+drives

have a look at the ratios for the MM12 box as I think this is what is fitted in the VE's.
.

That is a link for gear drives and timing chains. It has nothing to do with gearbox ratios.

[brentonsav]

If your doing 1500RPM at 100kph with a 3.45 diff(standard SS) then a 3.7 will give you about 1610RPM at same speed. As far as I know the VE R8 runs a 3.37 diff but box ratios are totally dirrerent to that of VESS, ie 6th ratio is 0.69 (VESS is 0.57). What all that means is that a R8 is doing 1800 RPM at 100 KPH.

i have a spreadsheet for vt-z which could be modded to suit ve's.

if someone posts the gear ratios of both boxes and the final drive options, ill do it for you, so you will have a direct comparison.

[mustanger]

HSV gear box ratios are as follows ; MANUAL GEARBOX
1st 3.07
2nd 2.07
3rd 1.43
4th 1.00
5th .84
6th .57

DIFF RATIO is 3.73


HSV AUTO TRANS are as follows ;
1st 4.03
2nd 2.36
3rd 1.53
4th 1.15
5th .85
6th .67

DIFF RATIO is 3.27

This is for HSV cars only.

Holden equipped cars are as follows:

SS manual run a 3.45 diff ratio and the autos run a 2.92 diff ratio


Hope this helps..........Cheers John

[brentonsav]

so the available diff ratios for ve models are 2.92, 3.27, 3.45 and 3.7?
they are the ones everyone wants compared?

[mustanger]

so the available diff ratios for ve models are 2.92, 3.27, 3.45 and 3.7?
they are the ones everyone wants compared?

Yes,that is correct. :thumbsup:

[brentonsav]

Yes,that is correct. :thumbsup:

righto

here we are kids,
see here (http://www.users.on.net/~bsavio/Diff%20Ratio%20VE.xls)

remember to change tyre sizes to suit car!!
only touch the width, profile and dia box, the spreadsheet does the rest :)