Thanks to an awesome hookup from board member "tintboy" I fitted BMW Motorsport gears last night/today,
Sadly I didn't take photo's, Only of the actual differential and the gears, Nothing when installing to make a DIY thread,
But this really isn't what I'd call a bolt on anyway,
I did it alone with the car on jack stands, GOD do I wish I had a lift,
Lifting that diff was an absolute nightmare, I have some scrapes on my chest etc from being on my back lifting it,
And anyone who has ever done things like this (clutch jobs, transmission swaps) on their back you know what I'm talking about
But there you go proof it can be done without a lift
Its also very hard getting the diff in and out, there is NO room under there and it doesn't go straight up, Its sort of like a puzzle getting it back in,
Getting it out you have gravity helping you, Or trying to kill you whatever way you look at it,
Anyway you don't care about that, you guys want to know how it feels,
Well I'll tell you it feels good
Real good 
It does seem sport mode is on all the time, Then when you actually do turn sport mode on 1st gear pull away's get a little jumpy and bouncy sometimes, But not all the time, I guess its almost like having to re-learn launches,
However saying that 1st gear is still very usable :confused2, I was reading stories that 1st gear is useless and that just isn't so,
I think people put this mod of a pedestal and talk about it like its the best mod ever,
Id say its a definite improvement and it would be nice if this is what the car was like from the factory, but it doesn't transform your car suddenly into an F1 car like some people make it sound,
You can feel the car PULL hard, and it revs faster, Doing a highway entry (on an empty highway) and just flooring it and hit 8k in every gear you simply can't help but be impressed and notice a difference, and a big difference in lateral G force, The car is very fast through the gears and you hit a very high MPH quickly, Id say 0-60 is way down in the 4's, I heard it takes a nice chunk out of your 1/4 mile times too,
I'm sure I could slap a $100 bill to the dash and my passenger couldn't grab it
Around town its as I said before, Like sport mode is always on, much more responsive and much more "go", as soon as you hit 4K its simply and animal,
You obviously have to be in the right gear too, with the engine bogging around 1K rpm your not going to just suddenly slam the gas and be planted in the seat,
Overall its an awesome mod, Apart from the RPI scoop this is the only mod (so far) to my M and its thankfully a noticeable one,
Also to all the people on the fence of 3.91 and 4.10 gears, Might be a little bias it might seem but its 4.10 all the way,
Honestly for the amount of money your going to pay for 3.91 gears and labor putting it in (if you can't do it yourself) its just not worth it,
Even if you could put it in yourself the cost just isn't justified,
I don't think these 4.10's justify the cost either, Its a very pricey swap for something that costs $149 from Ford Racing for Mustangs and after physically seeing the gears you get the same thing from BMW at nearly 10 times the price,
People on the fence, Ive just pushed you over the fence to 4.10's,
Just get them!
I do have a few misc pics of the open diff and there might be tech heads like myself that would love a peek inside so I'll try to get them up today
(oh and be prepared to have your jaw drop when you see how much this SAF-XJ oil is from BMW)
Sadly I didn't take photo's, Only of the actual differential and the gears, Nothing when installing to make a DIY thread,
But this really isn't what I'd call a bolt on anyway,
I did it alone with the car on jack stands, GOD do I wish I had a lift,
Lifting that diff was an absolute nightmare, I have some scrapes on my chest etc from being on my back lifting it,
And anyone who has ever done things like this (clutch jobs, transmission swaps) on their back you know what I'm talking about
But there you go proof it can be done without a lift
Its also very hard getting the diff in and out, there is NO room under there and it doesn't go straight up, Its sort of like a puzzle getting it back in,
Getting it out you have gravity helping you, Or trying to kill you whatever way you look at it,
Anyway you don't care about that, you guys want to know how it feels,
Well I'll tell you it feels good
It does seem sport mode is on all the time, Then when you actually do turn sport mode on 1st gear pull away's get a little jumpy and bouncy sometimes, But not all the time, I guess its almost like having to re-learn launches,
However saying that 1st gear is still very usable :confused2, I was reading stories that 1st gear is useless and that just isn't so,
I think people put this mod of a pedestal and talk about it like its the best mod ever,
Id say its a definite improvement and it would be nice if this is what the car was like from the factory, but it doesn't transform your car suddenly into an F1 car like some people make it sound,
You can feel the car PULL hard, and it revs faster, Doing a highway entry (on an empty highway) and just flooring it and hit 8k in every gear you simply can't help but be impressed and notice a difference, and a big difference in lateral G force, The car is very fast through the gears and you hit a very high MPH quickly, Id say 0-60 is way down in the 4's, I heard it takes a nice chunk out of your 1/4 mile times too,
I'm sure I could slap a $100 bill to the dash and my passenger couldn't grab it
Around town its as I said before, Like sport mode is always on, much more responsive and much more "go", as soon as you hit 4K its simply and animal,
You obviously have to be in the right gear too, with the engine bogging around 1K rpm your not going to just suddenly slam the gas and be planted in the seat,
Overall its an awesome mod, Apart from the RPI scoop this is the only mod (so far) to my M and its thankfully a noticeable one,
Also to all the people on the fence of 3.91 and 4.10 gears, Might be a little bias it might seem but its 4.10 all the way,
Honestly for the amount of money your going to pay for 3.91 gears and labor putting it in (if you can't do it yourself) its just not worth it,
Even if you could put it in yourself the cost just isn't justified,
I don't think these 4.10's justify the cost either, Its a very pricey swap for something that costs $149 from Ford Racing for Mustangs and after physically seeing the gears you get the same thing from BMW at nearly 10 times the price,
People on the fence, Ive just pushed you over the fence to 4.10's,
Just get them!
I do have a few misc pics of the open diff and there might be tech heads like myself that would love a peek inside so I'll try to get them up today
(oh and be prepared to have your jaw drop when you see how much this SAF-XJ oil is from BMW)





