3.46 Diff

[cp993]

hi im looking at purchasing a 3.46 ratio diff for my VZ SV6 Alloytec 190 but wouldnt know where to look ive looked on ebay and im not sure which one to buy any help would be awesome also any info on anyone who's done this already and how they found the difference in acceleration off the line..cheers

 

[morphix]

m78 type diff with 3 bolt flange iirc.

 

[acarmody]

Or an M80. .

 

[morphix]

Or an M80. .

Isn't the flange on the m80's slightly larger than the m78 so it won't bolt straight up?

 

[jwaye2]

Correct me if im wrong but I think the M78 is VT-VX and M80 is VY-VZ. The diff itself is pretty much the same but the flange is different just a 30mm(ish) nut and can swap the flange over without taking the diff apart.

And to answer your question I went from 3.08 to 3.46 last week and I personally didnt feel much difference tho ive been driving nicely to run it in and havent really tested it out yet. What I did notice is that the same acceleration I used to use to cruise at 100km/h now cruises at about 120-130km/h lol. Got a speeding fine cause I wasnt paying attention :/

 

[morphix]

I was certain the VZ V6's still use the m78 and m80 for v8.

The VZ SV6 Auto is 2.87 ratio, so going from that to 3.46 ratio from what i've heard is a decent upgrade. (depends if auto or manual)

 

[WazzaVN]

vz were all m80 i found out the other day. even the v6's. but vy v6 still get the 78.

must be because of those super powerhouse alloytec motors

 

[acarmody]

Isn't the flange on the m80's slightly larger than the m78 so it won't bolt straight up?

Don't think so. I had a diff from a VY SS bolted up to my VX V6 and it was a direct fit. Assuming both have rubber coupling and not the uni-joints.

 

[cp993]

Don't think so. I had a diff from a VY SS bolted up to my VX V6 and it was a direct fit. Assuming both have rubber coupling and not the uni-joints.

can someone link me to an example of what im looking for? sorry im not real familar with upgrading the diff thats all

 

[Surfwagon]

The larger flange is only used on the HSV VZ LS2 6.0L and later VZ's fitted with the L76/98 6.0L.
The earlier VT2-VZ1 5.7L use the same size flange as all VT2-VZ V6's regardless whether M78 or M80.

The difference shown below with smaller flange on top.