VS-VY Stock L67 PSI

[ben315vz]

I do a lot of highway driving, at the moment, driving from Ballarat to Melbourne, sits on 2000RPM at 110km/h. So I guess I should stick with a 3:08.1 LSD. There is one on eBay at the moment for $655 fully reconditioned, but I'll see how much it would cost to get mine rebuilt.

 

[GenFree]

A lsd out of a manual(3.46)is a good compramise

 

[SweetWagon]

I've just gone twin 2.5" exhaust, merged to single 3" before the diff. Nice and quiet at cruise (even at 2600rpm with the 3.9's), but sounds good under throttle.

Just for comparison, mine with 87mm pulley ("10psi") sits at about 8, but i haven't had a boost gauge on for ages, so would be lower now I'd assume.

Similar to me - I have twin 2 1/4", merged into single 3" before diff, but have to remember being auto his will drone more than the manuals

Out of curiosity how is 1st gear with the 3.9 gears?

Delete the boost solenoid,the mod is written up on l67 torque

This will stop any electronical interearance with boost if its not operationg correctly.

its nothing to do with electronic interference, the problem is the solenoid tends to leak, but if his getting that much pressure in the manifold it would be working correctly (if it hasn't been bypassed already)

 

[SweetWagon]

A lsd out of a manual(3.46)is a good compramise

a manual what? theyre all 3.08.

3.45 is a good compromise, but IMO if your replacing the gears they're not worthwhile especially in a auto you will barely notice improvement

3.45 is only a 12% gear reduction
3.7 is a 20% gear reduction
3.9 is a 26% gear reduction

but as the OP mentioned doing highway driving, you will be best leaving 3.08 and just getting the LSD centre, that way speedo and shiftpoints wont be affected either.

 

[wamboin23]

Similar to me - I have twin 2 1/4", merged into single 3" before diff, but have to remember being auto his will drone more than the manuals

Out of curiosity how is 1st gear with the 3.9 gears?

quick. it is usable, but you can start off in 2nd with no real problems.

 

[DevilDRake]

a manual what? theyre all 3.08.

3.45 is a good compromise, but IMO if your replacing the gears they're not worthwhile especially in a auto you will barely notice improvement

3.45 is only a 12% gear reduction
3.7 is a 20% gear reduction
3.9 is a 26% gear reduction

but as the OP mentioned doing highway driving, you will be best leaving 3.08 and just getting the LSD centre, that way speedo and shiftpoints wont be affected either.

VY manual utes most have 3.45's


I got a full reconditioned one, with lsd gears + 3.7's genuine gears for $800. Tight and works great.. Rev at like 2200RPM though, but if you got 3.45's you could get 1900rpm possibly.. which isn't too bad. I mean normally is like 1400 or something?

 

[pjdm1980]

Normal S/C six sit on about 1750RPM@100KPH

 

[ben315vz]

Similar to me - I have twin 2 1/4", merged into single 3" before diff, but have to remember being auto his will drone more than the manuals

Out of curiosity how is 1st gear with the 3.9 gears?



its nothing to do with electronic interference, the problem is the solenoid tends to leak, but if his getting that much pressure in the manifold it would be working correctly (if it hasn't been bypassed already)

The boost solenoid is all connected up and seems to be working fine, there was a plug for it on the wiring loom so I thought that I may as well use it.

I am taking the VS to the exhaust shop to get 2 high flow cats and a new Y-piece made up, just that is going to cost $550. So would you recommend 3 inch exhaust before the diff, twin system, or keep the 2.5 inch single system with the one sports muffler?

 

[wamboin23]

i got mine done as twin 2.5", into 3" before the diff, because later down the track it's not a big job to flange it before the merge and have a full twin system.

but i'd say single 2.5" will be too small once the mods begin.

 

[wana s' charge stock vt]

twin sounds better than 3' imo....

twin 2.25' works well and is pretty popular for mild motors... twin 2.5inch gets pretty loud n drony..


and from my reading 3.46 diff gears seems to be the most practical and popular...


ya may aswell delete the bypass 'solenoid' too. its free and they're pretty common to play up n make ya loose boost and do random shiit.... .