Help with diff ratios.

[etrocket]

Hey guys,

Have blown my diff and now looking for a complete replacement. First option will be to find a second hand one but if that doesn't happen will get a new unit. Had 3.7 before and I'm thinking to go back to stock gearing or 3.27. Would this be going bardwards? I think lower gears will let the converter work better and have less wheel spin but I'm not expert.

Wouldn't mind peoples opinion that have done this before?

[dogsballs]

whats the rest of the combo?

if you want decent times at strip, generally backwards step. hard to say though without details. hardly going to change fuel economy a great deal.

[whitels1ss]

whats the rest of the combo?

if you want decent times at strip, generally backwards step. hard to say though without details. hardly going to change fuel economy a great deal.

Exactly agreed.
Years ago I had another modded car with decent diff gears, I blew the diff and put stock gears back in while I found another decent setup,
I hated it to drive after decent gears and could not wait untill I got my decent gears again.

[etrocket]

Usual exhaust tune, 3500 stall and Otr. Did have 3.7 which are great off the mark but say I add more power (cam) will definiately have traction issues.

[mechatron]

It all depends on the type of cam you get. A bigger cam will generally give more total horsepower, but the torque is generally shifted further up in the rpm range, & you'll have less torque & be rather lifeless down low compared to the standard cam, hence the need for a diff ratio 3.7 or greater (i.e. 3.9, 4.11 etc) with a big cam.

Generally cars with boost will go back to diff ratios like 3.07 & 3.46

[etrocket]

Nothing's in concrete but I remember dcvinu (member) using a comp cam 231/239@113 with good results. Wouldn't go any smaller than that when the time comes

[OMR346]

Nothing's in concrete but I remember dcvinu (member) using a comp cam 231/239@113 with good results. Wouldn't go any smaller than that when the time comes

I have that exact cam in my SSZ. I had 3.73 diff and blew it at Powercruise. I went back to 3.07 while I got my new diff built. I hated it. It was sluggish down low. I then fitted up 4.11 gearing and it is now great to drive (better then it was with the 3.73).

The shorter gearing also makes it drive a lot better with the high stall converter.

[ittwgn]

et rocket is,nt your car a ve with an a6 not the a4 that most here including myself are more familiar with????

[etrocket]

Yeah mate, I mentioned above its for a ve so obviously a6

[OMR346]

Yeah mate, I mentioned above its for a ve so obviously a6

You did?

Being an A6, i would definitely stick with the shorter gearing then. I would go straight for 4.11

[Wonky]

You did?

Being an A6, i would definitely stick with the shorter gearing then. I would go straight for 4.11

Have you driven an A6? That would make first gear absolutely useless and wheelspin city!! There is a thread on here from a guy who drags and who tried all ratios from stock A6 2.92 through to 3.7 which etrocket originally had and found the best times were achieved with the HSV A6 ratio of 3.27.

[macca_779]

4.11's in a VE is like a côck pump looks good off the line but useless once you get going. If you think you need 3.9's plus in a VE you must be way down on power to not be able to turn tyres

[etrocket]

3.7 work really well with the stall, doesnt drag through the gears but traction is shit specially when the converter flashes from a dig. I think 3.45 will be better for traction but might feel sluggish with the converter. I got no idea.

[Roonstain]

With my stall, 2.92s are fine and still turns the 275/40/17 ET streets easily in the staging lanes

[OMR346]

Have you driven an A6? That would make first gear absolutely useless and wheelspin city!!

Yes I have. And you are right about wheel spin city off the line. I was thinking more for revs while cruising, highway, etc.