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AUS 4.10 over US 3.91 worth the price?

2K views 25 replies 19 participants last post by  dyno junkie 
#1 ·
Backstory: differential whines bad, need to replace diff. bearings. Figure while I'm paying someone to work on it might as well upgrade my gears at the same time.

On gforce's site, there is a $230 difference between the US and AUS version of the same gears. There are no US 4.10 gears available (AUS only) leaving the $679 version of 4.10's the only choice available.

Don't want to settle for a cheaper option and regret it later, however car is basically weekend fun car that doesn't see the track (at least until I can learn to not wheel hop like crazy) so getting an extra tenth out of the 1/4 mile doesn't really matter to me. The question that matters is 'how much of a difference will I actually notice?'

Therefore my questions to the pros: you think $230 is worth going from 3.91 to 4.10's for a non-track car? Is there a US version of these gears through another company? Thanks.
 
#2 ·
i'm in the same dilema. curiously awaiting replies.
 
#3 ·
If i was in the market for gears I would go with the US 3.91s because I couldn't rationalize going to the 4.10s. My friend has 4.10s in his camaro which stock are like 3.23? and he noticed a huge difference. With us we already have 3.46 so it's not going to be as big but for the price I would stick with 3.91s. If they were the same price I would go with 4.10s hands down. I'm holding off on buying gears in hopes they make a 4.10 set from motive(US).
 
#4 ·
I am no pro, but have 4.10 gears in my DD m6 and love them. I have no regrets.

Since I don't care about mileage, if I got 3.91 gears knowing 4.10 was an option I would have regretted it.
 
#13 ·
#6 ·
Since it's just a weekend car and you're not chasing down ET's, I don't think it's worth it to buy the 4.10s. From what I've heard, you'll be quite happy going to the 3.91s. You could use the saved money towards some anti-wheel hop axles.
 
#7 ·
It isnt that the Aussi 4.10 gears are better because they are more expensive, they are a great gear but the high price is due to the shipping costs of getting them shipped over here from Australia.
If they were here in the US then the price would be very close to the US gears.

Thanks
Chris
 
#8 ·
I have the "Aussie" 4.10 gears

Good questions to ask; Are they really made in Australia? If so by who? Is the ring gear cut of the design as the OE gears? Can I see a picture of an OE, Motive, and "Aussie" ring gear next to each other?

It can feel a little "shifty" at times but if you're planning on doing a gear swap once then get what you want and don't let a day of pay separate you from what you really want.
 
#9 ·
I went from the US 3.91s to the Ausie 4.10s. No difference in terms of noise. Small but noticeable difference on the street, in every gear. To me, the 4.10s are perfect for a mildly modified street car with an M6. I am glad I made the switch.
 
#10 ·
how does it drive at highway speeds?? what RPM are you at cruising in 6th doing 75? im afraid 4.10s may be too much gearing for me.
 
#11 ·
I had more fun with my 3.91s than I did with my pecker during the same period of time. Just saying
 
#14 ·
whats 4th gear rap out at with a 4.10 and a 3.91... if your tracking that it may be a deal breaker, when you talk tryin to shift at the 1000+ ft mark.

i have not tracked my car with the 3.91s but with the 3.46s i was in 4th through the traps/at the line.
 
#16 ·
i found this thread not helpful at all!!!!!! i still dont know... :(
 
#17 ·
If you ever plan to trap above 120ish then go for the 3.91's. If you ever plan to trap above 135ish then go for 3.73's.
(results may vary based on tire size and rev limiter)
 
#18 ·
I just found my answer... (for M6 -- sorry A4 guys, you can plugNchug the #s yo'self)
I haven't done the calculations for quite some time so I wanted to recheck my maths before dropping coin:

http://www.5speedtransmissions.com/gear_calculator.html

For 4th gear
4.10s @ 6500 = 123mph
3.91s @ 6500 = 129mph

After last week's passes I'm pretty sure the car already has 122-123mph in it with the stock gears, so 3.91s it is.
 
#23 ·
We had the Motive gear reps stop in for a visit this week and thy told us it may be very likley that one of it's companies makes the Australian gears.
Motive gear is owned by Midwest truck and they are a very big outfit owning lots of companies.
They also bought Richmond gear recently and will be moving all of it's production to the Motive facility.


Thanks
Chris
 
#24 ·
Hopefully Motive makes the 4.10 gear soon, would be a nice option to have. Any word on that Gforce?
 
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