3.46 diff gears into a VX/VY SS A4

[cev]

Hey guys,

Im curious to see whether its worth it, or will make much of a difference to put 3.46 diff gears into a VX SS A4. Standard im sure most will know its 3.07.

Ive done a search on this but didnt find too many actual post-opinions. I read a post on the torque gains by percentage and saw that its a decent gain.

So I guess if i can get some 3.46 gears off someone selling them who has a manual SS, will it be worth it? What is the point in getting a new/different diff centre too? Also does the speedo go out by much? If so, where abouts do u get it recalibrated, anyone know a good place in Sydney?

Any opinions from ppl who have actually in the past upgraded on a VT/VX/VY SS A4 done this new setup? I was thinking 3.73 but considering my driving is 60/40 highway/city thought against it and plus other family members occasionally drive this car and I dont want to get them in a spot of bother, especially in the wet. If it makes any difference to what I should consider, I have a cat back exhaust, MCAI and 2nd hole, HSV headers and mafless tune.

Cheers.

[Oztrack Tuning]

Go the 3.73s or 3.45. The 3.45s will set you back less BUT it wont be near as punchy in 2nd gear. 2nd becomes a very common gear to accelerate with even from low speeds.

Economy might drop a little with 3.73 if crusing at 110 or above. But at 100kph it would be next to no difference.

You would be happy with 3.73s for sure. 3.45s might have you wishing you went further.

To fix the speedo is quite a simple alteration in the tune file - which i am sure Sonny will sort out for you.

[Ron]

Have a talk to Sonny about my car cev ,its a VX Berlina and I was in the same postion late last year and I did what you are thinking of doing re:3.46 and I`m very happy with it , dont regret not doing the 3.73 at all ,I was fortunate enough to pick up a rebuilt complete 3.46 LSD for $400 off my mechanic ,so I now have the 3.07 diff in my garage as a spare.

[cev]

Thanks guys,

oztrack you have always seemed to help me out with these noob questions and I appreciate it, I owe u a beer one day!

Ron I will definitely speak to Sonny about it, I just emailed him yesterday for something else but will ask now for this. My highway driving is actually going from Sydney down to your hood, the gong pretty much every weekend ;)

[nirvana]

correct me if im wrong but didn't the ss come out with 3.46?

[cev]

correct me if im wrong but didn't the ss come out with 3.46?

The manual 6 speeders did, auto 4 has the 3.07...

[tuff304]

I'm thinking about doing the same conversion down the line, however I dont think the 3.46 will have a big enough fun factor compared with the 3.73.
I will probably go for the 3.73 as I don't do much highway driving

[Vulture]

3.73 would be a great all rounder. 3.46 is good for the turbos :yahoo:

[Y55-7UT]

hi, my dads WH has 3.46/tune (224rw) and lights the rears when put foot down half way so thats gotta be worth something, so lucky you got traction ctrl in the autos, also he does alot of highway so it suits him as it sits on 2100 @100km

[NickS]

hi, my dads WH has 3.46/tune (224rw) and lights the rears when put foot down half way so thats gotta be worth something, so lucky you got traction ctrl in the autos, also he does alot of highway so it suits him as it sits on 2100 @100km

A 2 tonne car with 224rwkw that "lights the rears" on half throttle ... :bs:

[mido2k]

A 2 tonne car with 224rwkw that "lights the rears" on half throttle ... :bs:

Nick's in fine form this morning... I see you have a new quote too!!!


Back on topic, im looking at the 3.46's or even the 3.07's i got stooged when i bought my SS as it only has a single spinner in it :(

[macca33]

The 3.46:1 ratio will give you more snap off the line and will still see very sweet highway cruising. For an A4 they will be nice, if fair economy and subtle highway cruising is what you are after.

I remember when the 'other' brand first put 3.46s into their V8 models and they did feel more lively than the comparable Commodore.

If you plan on doing a little bit of 1/4 mile work, then 3.73s, but if only on the odd occasion you see a track, 3.46s will be a good choice.

Cheers,

Macca

[JBonDSS]

I got 3.46 fitted to my VX Berlina, nicer off the line in traffic, 2nd & 3rd are lots of fun with a bit of throttle. HWY barely notice they're there.

[cev]

I got 3.46 fitted to my VX Berlina, nicer off the line in traffic, 2nd & 3rd are lots of fun with a bit of throttle. HWY barely notice they're there.

Cheers for that, I think im set on the 3.46 for sure now because it will at least have some noticeable change off the line. My car has been very responsive in acceleration after the tune, more than others with similar cars I was told so hopefully it can make it even better!

Question to those that have gone to 3.46 or even 3.7s, how much does the fuel economy change? Does highway improve/not improve more over city, vice versa or both change?

[nirvana]

if your worried about fuel economy go the 3.46, i found with my 3.7's i use less fuel in city driving because its more responsive and i don't have to give it as much. but on the highway it uses a bit more.
for all out fun you can't go past the 3.7's a worthwhile mod.

[Vulture]

Question to those that have gone to 3.46 or even 3.7s, how much does the fuel economy change? Does highway improve/not improve more over city, vice versa or both change?

You will be hard pressed to calculate much of a difference in fuel economy between 3.46 and 3.73 on the highway. Counter-intuitive but that seems to be the experience of most.

[Kris78]

I have put the 3.46's in my VX SS A4 and now wish I went bigger....
I mean its good on the street.. But if you are into the drag side of things.. bigger is better! :)

[Peter B - CV8]

Cheers for that, I think im set on the 3.46 for sure now because it will at least have some noticeable change off the line. My car has been very responsive in acceleration after the tune, more than others with similar cars I was told so hopefully it can make it even better!

Question to those that have gone to 3.46 or even 3.7s, how much does the fuel economy change? Does highway improve/not improve more over city, vice versa or both change?

I've got 3.46's in my Monaro (auto).
Around town I get around 15.5 litres per 100 k's ( with an av speed of approx 40 kph - fair bit of stop/start). Previously with the 3.07 (stock) gears & untuned, I used to get mid 17's. I usually drive around town in 3rd gear as well)
On the open road/cruising at 110kph (in D)I get 9.5 - 10 litres per 100k's. Previously with the stock gears it was 8.5 - 9.5.
At cruising speeds with the 3.46 ratio your engine will be just a smidgen over 2,000rpm.
It is imperative to have you transmission shift points & speedo recalibrated when doing your gears. I also got a mafless tune a:driving: t the same time.

[Ron]

I have put the 3.46's in my VX SS A4 and now wish I went bigger....
I mean its good on the street.. But if you are into the drag side of things.. bigger is better! :)

I agree with Kris 100% ,if you do a few drag days then yes 3.73 ,but for me my car sees the 1/4 every blue moon so I`m happy with what I have for what I do with it ;)

[SandmanUte]

Thanks for the interesting reading. I have been thinking about doing the same, going from 3.08 to 3.46. My car is about the same tunes as cevs. CAI, mafless tune extractors.
Most of my driving(aprox 80%) is hwy driving 110kph or so. Usual trip away is 1000k plus. So fuel economy is a major importance. But I figure the extra 300 revs or so shouldn't make hardly any difference and may even help when car is fully loaded. (5 people + gear).
I'd like to hear anyone elses change and affects on fuel economy.
Mine rarely gets raced, and then it's just for a bit of fun.

[chris__85]

Ron picked up his gears for $400 s/hand off his mechanic, what are you looking at for a new set for either 3.46 or 3.7's?

im looking at FINALLY buying an eight and tossing up whether vy ss man, or vy calais.. calais auto only so would def be doing gears.. just gathering info. thanks - not to hijack the thread..

[GROUPA]

Hi I personally think Value for Buck 3.46 gears are alot easier to come across..
3.7 are great gears for racing...

SO its really up to you.
HOW much you got to spend. and how many times you going to race it..

For an every day ride. 3.46 Excellent. it will really wake up the AUTO ALOT..
:)

hope it helps

[TommyVTss]

are 3.9's to drastic for the street in a a4? would they be bad 100kmh fuel economy? would sit on nearly 2400 rpm?

[vyssls1]

3.7's will leave u wanting more, so go 3.9's in a a4 is quite frankly the best combo u can do.

fuel economy well, the amount u save around town due to less load placed on the engine when taking of, yes of coarse u wont get as good on the highway, due to the rpm's at eg 100km/h but u should be in the 9's ltr/100km with the 3.9's on the highway.(with a decent tune of coarse)

[vx350int]

I just installed 3.7s in the VX Calais A4 (was 3.07)....since the tune by Oztrack we have taken it out to the drags a netted a best time of 13.4 @ 104 (I am still getting used to it) in a full weight calais - fuel usage sits on around 9-10.5l to the 100 on the highway @ 110kmph....watch the 4 sale thread on this site and you will pick up a bargain...2nd gear is awesome..IMO go with a 3.7 or 3.9 diff

cheers