4.10 gears

[Obioban]

Looking into running either 4.10 or 3.91... my first E46M had a Dinan 3.91 and even that was a decent upgrade from the stock 3.62. Car is mostly for weekend track use, but even so I'm somewhat skeptical about the useability of the 4.10 on certain tracks and on the freeway...

4.10s are just annoying, imo-- on the street or on the track. Back when we had the e36 M3 track car, it came with 4.10s... and I swapped it back to stock ASAP.

Maaaaybe would be fun on track if you have SMG. Or a stock power/weight vert.

[old///MFanatic]

The question is.. Is the 3.91 or the 4.10 faster on a straight line or it just feels faster?

In most senarios the 4.10 will be faster.
And in a rolling start it is quicker.

*this obviously isn't very scientific but has been around a while showing the 3.62 Left/ 4.10 Center/ 3.91 Right

https://youtu.be/JGatkOG9XVI

[Obioban]

In most senarios the 4.10 will be faster.
And in a rolling start it is quicker.

*this obviously isn't very scientific but has been around a while showing the 3.62 Left/ 4.10 Center/ 3.91 Right
https://youtu.be/JGatkOG9XVI

At some speeds it’s slower.

e.g. 90-100mph you have to be in 4th with 4.10s but can be in 3rd with stock gears, making the stock setup faster. Or, if you're doing a 50mph rolling race, you'd want to start the stock car in 2nd but a 4.10 car in 3rd-- so the stock car would be faster.

The race in that video is kind of designed to make the stock gears look slower. As in, they all started in the same gear at the same speed. If they all started in the optimal gear at the same speed the results would have been very different. What gear is optimal at a given speed for the 4.10s is not necessarily optimal for the stock gears.

[old///MFanatic]

Back when i had a dedicated track car, it came with 4.10s. It was non stop shifting all the time... I swapped it back to stock and had no regrets.

4.10s are just annoying, imo-- on the street or on the track. Back when we had the e36 M3 track car, it came with 4.10s... and I swapped it back to stock ASAP.

Well to be fair comparing the 4.10 diff ratio in an E36 M3 to the E46 M3 isn't exactly apples to apples.
E36 has the S52 engine that max's out at like 6,000 rpm with a redline of 7,000. With only a Five speed transmission and 3.15 diff ratio (stock) going to a 4.10 would be a gear change of 30%. That's almost 3x the jump of going from a 3.62 to 4.10 in the E46 M3. Which is just 13%. An M3 3.62 to the 4.44 diff change in comparison is 22%.
As we know the E46 M3 makes max power all the way up to 7,900rpm. The S52 ends at like 6,000rpm. Having it up there in rpms has it's benefits on E46 M3.

[Obioban]

Well to be fair comparing the 4.10 diff ratio in an E36 M3 to the E46 M3 isn't exactly apples to apples.
E36 has the S52 engine that max's out at like 6,000 rpm with a redline of 7,000. With only a Five speed transmission and 3.15 diff ratio (stock) going to a 4.10 would be a gear change of 30%. That's almost 3x the jump of going from a 3.62 to 4.10 in the E46 M3. Which is just 13%. An M3 3.62 to the 4.44 diff change in comparison is 22%.
As we know the E46 M3 makes max power all the way up to 7,900rpm. The S52 ends at like 6,000rpm. Having it up there in rpms has it's benefits on E46 M3.

My e36 had a (cammed) s50b32– very similar characteristics to the s54.

[zaharias]

Obioban are you running stock diff in your E46 M3?

[Obioban]

Obioban are you running stock diff in your E46 M3?

I am.

[old///MFanatic]

The question is.. Is the 3.91 or the 4.10 faster on a straight line or it just feels faster?
Probably on a stock car the 3.62 will be better.
I think the 3.91/4.10 needs a tune and rev limiter increase for best results but is it faster than an M3 with a tune and 3.62? 6MT road use only.

Maybe this video of the gear changes on a km/h speedo and tach on a manual (6MT) can help answer some questions for you. You can see how quickly you get up in speed and not having as large a dip in rpm after a gear change.

https://www.youtube.com/watch?v=we3GTgwPPxk

Here is a video review by an M3 enthusiast. This is on an smg though. It's somewhat long vid but last 1/3 is the review. Know that unless you're buying one already installed in diff unit, your gear set will need to be installed by a competent gear shop.
No tune needed on a manual. To answer your question any of 3 ratios could benefit from a tune.
*Once again the decision of what's right for you varies by each individual*

https://www.youtube.com/watch?v=4aIeTJqj29o

[maupineda]

Thanks for sharing the first video, I had not seen it. I don't think 1st is useless as some may have suggested, to me it is perfectly usable and launches the car nicely. I think 4.1 is a good balance!!! You still reach 60+ in second!

In my case, I want to go with 3.91 but I also plan to lower my tire size one notch in my Z4M

[Rudbari]

Had 4.10 for years but before one years I swap back to stock and it feel better now

[Tbonem3]

Had 4.10 for years but before one years I swap back to stock and it feel better now

Yep

[old///MFanatic]

Had 4.10 for years but before one years I swap back to stock and it feel better now

Something is mixed up in translation. 🤔
But it’s sounds like you’re offering your review that you switched it back after many years.

Perhaps you could help the future readers of this thread with some details for “your” reason why you switched. They may have similar reservations or completely dissimilar wants/desires for their car.

[Rudbari]

Something is mixed up in translation. 🤔
But it’s sounds like you’re offering your review that you switched it back after many years.

Perhaps you could help the future readers of this thread with some details for “your” reason why you switched. They may have similar reservations or completely dissimilar wants/desires for their car.

in city is annoying specially in traffic, your RPM is always high if your doing highway plus while deceleration it whine . Believe stock ratio is better .