dinan 4.10 diff installed and broken in

[duk]

Hmm this sounds kinda nice but what I really want is a taller 6th gear for better gas when cruising lol

[isugoo]

Originally Posted by duk

Hmm this sounds kinda nice but what I really want is a taller 6th gear for better gas when cruising lol

Actually I was thinking same thing. I want to drive 80 mph under 3k rpm in 6th gear.

[M&M]

Originally Posted by e46e92love

What you gain in acceleration, you lose when you have to shift early and the stock car keeps going; trust SWAMP when he says many of us have been over this MANY times. The 3.62 may make it feel faster, but I can assure you its not.

The answer, my friend, is to raise the rev-limiter 300rpm. You enjoy the torque multiplication in-gear, and you shift around the same time as the stocker. So every gear you put distance on him. Have been doing this since 2005 with my E46 M3, and have all the data to prove it. And no, there is no issue with the valvetrain when revving higher. Over a sample of 3 cars we have tested over 130 000km of revving 8500-8600 every day for 3 years with no ill-effects. Schrick state the stock valve springs are good for 8800rpm on the S54.

[mixja]

Originally Posted by M&M

The answer, my friend, is to raise the rev-limiter 300rpm. You enjoy the torque multiplication in-gear, and you shift around the same time as the stocker. So every gear you put distance on him. Have been doing this since 2005 with my E46 M3, and have all the data to prove it. And no, there is no issue with the valvetrain when revving higher. Over a sample of 3 cars we have tested over 130 000km of revving 8500-8600 every day for 3 years with no ill-effects. Schrick state the stock valve springs are good for 8800rpm on the S54.

This is apples vs oranges - apples vs apples is if I raise the rev-limiter with the stock FD ratio as well - then the same arguments still apply.

I can definitely see the need for a higher FD ratio in the MT transmission - the gearing honestly was too tall for me coming from the shorter geared RS4 transmission. The problem I have is paying for it as an aftermarket modification for the street - I know in reality it doesn't actually make the car faster in many scenarios (like actually adding power to the engine does in ALL scenarios) and I certainly feel it is the ratio that BMW should have offered on the car from the factory.

I guess it's like paying for coach vs business class - I won't actually get to where I'm going faster, but the experience no doubt will be better.

[mixja]

Originally Posted by H Bomb

all you are basing it off of is stuff you read no real life experience correct?? if you have real life experience btw a car with a diff and one without then i take it back

he actually has real life exp with the two to compare. i don't care what you post or graphs you show nothing beats real life experience

i haven't even broken mine in yet and i can already tell the car pulls harder and is faster through the gears. def one of the best band for the bucks mods

Assuming you have 3.62 vs 3.15:

- The car is pulling 15% harder in gear (3.62/3.15)
- The car is taking 25% less time to reach redline
- The car is travelling 35% less distance in gear

Can you see why it feels like you are going faster but in reality you are not?

You think your butt dyno is telling you the car is faster, but in reality the car is pulling you harder for a shorter period of time over an even shorter distance (relatively speaking). The net effect overall being the car is not necessarily faster from point A to point B (depending on starting speed and gear), and if it is faster, the difference is far less than what your butt dyno experienced.

[J08M3]

^-- this is true, but this is a lot of theory.

the FD change will change the RPM range you are in, in a given situation. sometimes you need that quicker acceleration for a shorter distance, depends on what's in front of you (i.e. sharp turn). so the 35% decrease in distance isn't always an issue.

This is why race cars run different FD ratios depending on the track they are at.

[DaFish]

Originally Posted by mixja

Assuming you have 3.62 vs 3.15:

- The car is pulling 15% harder in gear (3.62/3.15)
- The car is taking 25% less time to reach redline
- The car is travelling 35% less distance in gear

Can you see why it feels like you are going faster but in reality you are not?

You think your butt dyno is telling you the car is faster, but in reality the car is pulling you harder for a shorter period of time over an even shorter distance (relatively speaking). The net effect overall being the car is not necessarily faster from point A to point B (depending on starting speed and gear), and if it is faster, the difference is far less than what your butt dyno experienced.

I think "quicker" or more responsive. When I put my foot into it, I want the car to move NOW. If the 4.10 does that, and makes me "feel" quicker - that is all I want.

I would actually love to see a 1/4 run video of stock 6MT vs 4.10 6MT.

I am less concerned with whether the 0-60 or 1/4 mile time is faster. When I drive, I want to be in the open space in the next lane on the highway RIGHT NOW and I don't want to wait for the torque to build to accellerate to get there.

- if the car pulls harder - that feels better to me
- If the revs build 25% faster to that sweet 5k+ RPM range - perfect, it means I don't have to wait as long to feel that OMG power....
- if I shift more, well that is ok too - the gears are pretty long in the 6MT.

End of Second is over the speed limit, end of 3rd is jail time.... I am not going to use the top end, I will use the 3-5k range for regular driving 90% of the time.

I think the 4.10 is what I would like to do. The only issue I see is how short 1st is... I love how fast that is... I hope the 4.10 doesn't wreck first....

The additional gas.... well, I will have to live with that.

[Fen335i]

this is a good thread...very informative. I've toyed with the FD mod as well. This sheds a lot of light on it. Thanks

[DaFish]

Originally Posted by Studntloan

2. ive lost about 5-10 miles in each gear after 3rd, i haven't really redlined it since i would have to be going pretty quick to be in those gears to get there and weather hasn't permitted it currently.
but the car accelerates so much quicker then stock, it feels like an entirely new car.

Have you had a chance to go full power now on each gear - can you comment on differences in traction please?

1st - does it just light up the tires after 6k -can you red line it still?
2nd- again - does it break loose ? If not, I would love to feel that....
3rd - this must be the real joy of this mod.... that would pull like crazy and be totally addictive....

[mixja]

Originally Posted by J08M3

^-- this is true, but this is a lot of theory.

the FD change will change the RPM range you are in, in a given situation. sometimes you need that quicker acceleration for a shorter distance, depends on what's in front of you (i.e. sharp turn). so the 35% decrease in distance isn't always an issue.

This is why race cars run different FD ratios depending on the track they are at.

Granted it all depends on the situation and it that situation is well defined (e.g. a track) the decision is much easier - a street car is a different scenario where the owner has to consider a wide range of scenarios. Where the higher FD ratio does show improvement, my point is that the gains are MUCH less than what the driver feels he/her is experiencing (unless you are looking at just a single in-gear run).

[mixja]

Originally Posted by DaFish

I think "quicker" or more responsive. When I put my foot into it, I want the car to move NOW. If the 4.10 does that, and makes me "feel" quicker - that is all I want.

I would actually love to see a 1/4 run video of stock 6MT vs 4.10 6MT.

I am less concerned with whether the 0-60 or 1/4 mile time is faster. When I drive, I want to be in the open space in the next lane on the highway RIGHT NOW and I don't want to wait for the torque to build to accellerate to get there.

- if the car pulls harder - that feels better to me
- If the revs build 25% faster to that sweet 5k+ RPM range - perfect, it means I don't have to wait as long to feel that OMG power....
- if I shift more, well that is ok too - the gears are pretty long in the 6MT.

End of Second is over the speed limit, end of 3rd is jail time.... I am not going to use the top end, I will use the 3-5k range for regular driving 90% of the time.

I think the 4.10 is what I would like to do. The only issue I see is how short 1st is... I love how fast that is... I hope the 4.10 doesn't wreck first....

The additional gas.... well, I will have to live with that.

I hear you - DCT owners like myself are lucky in this context given we have an extra cog and our gearing therefore in the higher gears is much more daily driver friendly.

If I had an MT car I probably would buy the 4.10 FD ratio to be honest - because the MT M3 just didn't inspire me enough as a daily driver coming out of an RS4 (a short shifter kit would also definitely be required as well)

[swamp2]

Originally Posted by H Bomb

all you are basing it off of is stuff you read no real life experience correct?? if you have real life experience btw a car with a diff and one without then i take it back

he actually has real life exp with the two to compare. i don't care what you post or graphs you show nothing beats real life experience

i haven't even broken mine in yet and i can already tell the car pulls harder and is faster through the gears. def one of the best band for the bucks mods

I think others have stated a response to this already. You do realize that every major system in all modern cars are designed with simulation correct? Saying you don't trust simulation and do trust your butt dyno is like turning back the progress clock of modern science and engineering back to the dark ages.

Similarly goes the debate that someone can't understand car X or mod Y unless they have personal wheel time with it. That is utter rubbish. Science, math and engineering allow one to understand and even feel in their minds eye (in additon to providing very accurate actual numbers) various aspects of automobile performance.

Like DaFish appropriately stated above in post #29 - if it feels good and all you want is feel - that is perfect. That makes it a great mod - FOR YOU. Just don't call it the best bang for the buck mod because when you want overall performance a FD mod just does not deliver on many modern sports cars, M3 included.

Last but not least how about having some Vbox runs instead of a butt dyno. Sorry science and simulation >>>> butt dyno any day.

Cheers.

[H Bomb]

i honestly don't care what proof you have or graphs you have etc etc to show there is no difference. i know i am not even passed 5k yet and i already like it alot more then bf with the stock diff. plus i have the Dinan software so i have an added rev limiter so i will be able to enjoy it even more

what is on paper and is on paper and it very well may be true but all i know is i have liked the diff in all my M cars and you can add this one to the list. what i like is all that matters. to me real life experience in the car is a better judge then some graphs any day of the week. i am glad i didn't let any of that steer me away from the diff bc i really like it and i am sure once my break in is over i am gonna love it

to each there own but i notice that 99% of the people talking down on the diff mod or saying it is not worth it are people that don't have it. just sayin

[H Bomb]

its all good, i never said you are wrong or anything but i really could care less to hook up ant vbox to my car etc

other then my midpipe i think this is one of the best bangs for your buck, doesn't mean i am right just my opinion

you can keep your graphs and your science etc and i will keep my diff and be 100% happy and that is all that matters to me

since you know alot about these cars, what would you consider the best bang for the buck mod then??

thank you

Originally Posted by swamp2

I think others have stated a response to this already. You do realize that every major system in all modern cars are designed with simulation correct? Saying you don't trust simulation and do trust your butt dyno is like turning back the progress clock of modern science and engineering back to the dark ages.

Similarly goes the debate that someone can't understand car X or mod Y unless they have personal wheel time with it. That is utter rubbish. Science, math and engineering allow one to understand and even feel in their minds eye (in additon to providing very accurate actual numbers) various aspects of automobile performance.

Like DaFish appropriately stated above in post #29 - if it feels good and all you want is feel - that is perfect. That makes it a great mod - FOR YOU. Just don't call it the best bang for the buck mod because when you want overall performance a FD mod just does not deliver on many modern sports cars, M3 included.

Last but not least how about having some Vbox runs instead of a butt dyno. Sorry science and simulation >>>> butt dyno any day.

Cheers.

[swamp2]

^

The best bang for the buck mods are (roughly in order):

-X pipe with secondary cat delete
-High octane fuel
-ECU software (perhaps matched for the above mods)
-Pulleys
-Titanium cat back exhaust (weight drop and small power bump)
-Increase redline

Some might argue for a high flow air filter but I'm not convinced these actually add power.

With these mods you can count on 30-35 hp gain for about $6k. This car will leave any FD ratio modded stock M3 in the dust.

[swamp2]

Originally Posted by H Bomb

to each there own but i notice that 99% of the people talking down on the diff mod or saying it is not worth it are people that don't have it. just sayin

You realize, of course, this is because many of them (us) have done our homework and we realize that we prefer measureable, multi-gear, real world gains in many performance metrics. And guess what the FD mod just does not deliver. Feeling fast is fine, being fast is much better.

[Meff]

Originally Posted by swamp2

You realize, of course, this is because many of them (us) have done our homework and we realize that we prefer measureable, multi-gear, real world gains in many performance metrics. And guess what the FD mod just does not deliver. Feeling fast is fine, being fast is much better.

Why is speed (being fast) the only criteria you are using to measure an improvement in the car?

If the car "feels" better for whatever reason, is that not the ultimate goal of any modification? We drive these cars because of the way they make us feel - enhancing this is what any modification strives for.

There are any number of mods that do nothing for speed, yet enhance the enjoyment for the driver - it's often these intangible things that "science" can't capture in a graph or simulation.

my $ 0.02 worth anyway.

[jeff@autocouture]

Originally Posted by DaFish

Have you had a chance to go full power now on each gear - can you comment on differences in traction please?

1st - does it just light up the tires after 6k -can you red line it still?
2nd- again - does it break loose ? If not, I would love to feel that....
3rd - this must be the real joy of this mod.... that would pull like crazy and be totally addictive....

i can honestly say i havent really noticed any traction issues, and i can still redline line it in all the gears, ill pay attention when the weather is a little nicer and go through the gears for. but the car still holds traction just like before

[Alekshop]

Originally Posted by isugoo

Actually I was thinking same thing. I want to drive 80 mph under 3k rpm in 6th gear.

you guys need to buy camry great gas mileage !

[Alekshop]

BMW uses 4.10 on their GT4. It sounds like a good choice for 6MT

[swamp2]

Originally Posted by Meff

Why is speed (being fast) the only criteria you are using to measure an improvement in the car?

If the car "feels" better for whatever reason, is that not the ultimate goal of any modification? We drive these cars because of the way they make us feel - enhancing this is what any modification strives for.

There are any number of mods that do nothing for speed, yet enhance the enjoyment for the driver - it's often these intangible things that "science" can't capture in a graph or simulation.

my $ 0.02 worth anyway.

Your point is absolutely a good one. There is nothing wrong with striving for a feel.

However do note, simulations capture such an effect perfectly well. In this case you can see it by higher in gear accelerations, improved in gear times for speed x to speed y, but a mix of improvement and losses in most multi-gear metrics.

[H Bomb]

i would rank the midpipe first as well. when i put my Dinan midpipe on it was a new car with all the added power. the diff would be second in my op. the other stuff is ok but nothing special. i have them except for the fuel and the only things that impressed me was the midpipe and the diff.

but again the diff is not for everyone as you noted. although i have yet to read anyone with the diff that does not like it

Originally Posted by swamp2

^

The best bang for the buck mods are (roughly in order):

-X pipe with secondary cat delete
-High octane fuel
-ECU software (perhaps matched for the above mods)
-Pulleys
-Titanium cat back exhaust (weight drop and small power bump)
-Increase redline

Some might argue for a high flow air filter but I'm not convinced these actually add power.

With these mods you can count on 30-35 hp gain for about $6k. This car will leave any FD ratio modded stock M3 in the dust.