Downshifting

[E92Gok]

So this may be a noob question but I was hoping somebody would have a answer for me. I own a 2008 e92 m3 6mt. My problem with my car is when driving and downshifting from 3rd to 2nd gear and rev match the car it doesn't let me pop it into 2nd and makes this almost odd "grinding" noise. I personally think I am rev matching and downshifting properly but I may be wrong. I was just hoping somebody would know what it may be from. The way I downshift just to clarify is clutch in, blip throttle, select gear, catch with clutch. From what I've read I may just have bad synchro's.

Thanks in advanced!!

[///M Power-Belgium]

Originally Posted by E92Gok

So this may be a noob question but I was hoping somebody would have a answer for me. I own a 2008 e92 m3 6mt. My problem with my car is when driving and downshifting from 3rd to 2nd gear and rev match the car it doesn't let me pop it into 2nd and makes this almost odd "grinding" noise. I personally think I am rev matching and downshifting properly but I may be wrong. I was just hoping somebody would know what it may be from. The way I downshift just to clarify is clutch in, blip throttle, select gear, catch with clutch. From what I've read I may just have bad synchro's.

Thanks in advanced!!

All you need is a DCT .

[radiognome]

Just blip to higher RPMs

[squartus]

Just takes practice to get just right, 1st and 2nd in this car are not exactly smooth compared to most transmissions.

[E92Gok]

Originally Posted by ///M Power-Belgium

All you need is a DCT .

Haha, I actually test drove the DCT before I test drove my car and to be honest didn't like it that much

[E92Gok]

Originally Posted by radiognome

Just blip to higher RPMs

Thanks I'll give that a try!

[E92Gok]

Originally Posted by squartus

Just takes practice to get just right, 1st and 2nd in this car are not exactly smooth compared to most transmissions.

After doing a bit of research I came to that conclusion as well seems like that's what everyone says and some people actually recommend to change the transmission fluid to royal purple. It's not my first manual car but I guess every car is different. Thanks for the response tho!

[loveskiing]

Originally Posted by ///M Power-Belgium

All you need is a DCT .

You can lead a horse to water...

[pbonsalb]

BMW puts lifetime fluid in the trans, but does not define lifetime. Changing it could help. No guarantees, but worth a try. There is debate as to what you should use. I used BMW fluid but it is expensive and there are a bunch of alternatives that should work -- a few from Redline like MTL, D4ATF, MT90, and LTW ShockProof, RP Synchromesh, and probably some from other brands. I have run all of those over the past 10 years in my 99M3 that is supposed to take a BMW fluid and they all work fine.

[Gooner5643]

Have the same issue with mine. It's only 3rd to 2nd. I rev match every gear every time I downshift but 3rd to 2nd just won't budge. I tried changing trans fluid to redline d4 atf and hasn't helped at all. Guess 2nd gear synchro is on its way out. (It is tough going from 1st to 2nd as well but doesn't grind like it does going from 3rd to 2nd quickly.)

Anyone know if it's possible to just replace the synchro and not the whole trans?

[E92Gok]

Originally Posted by pbonsalb

BMW puts lifetime fluid in the trans, but does not define lifetime. Changing it could help. No guarantees, but worth a try. There is debate as to what you should use. I used BMW fluid but it is expensive and there are a bunch of alternatives that should work -- a few from Redline like MTL, D4ATF, MT90, and LTW ShockProof, RP Synchromesh, and probably some from other brands. I have run all of those over the past 10 years in my 99M3 that is supposed to take a BMW fluid and they all work fine.

Thanks for the advice! I'll definitely try it out and see how it goes.

[Locksmythe]

Originally Posted by loveskiing

You can lead a horse to water...

But you can't make him paddle shift?

[GSTE34]

BMW likes to make crunchy trans

[dparm]

Originally Posted by GSTE34

BMW likes to make crunchy trans

BMW doesn't even make the transmission.

[dparm]

Originally Posted by E92Gok

So this may be a noob question but I was hoping somebody would have a answer for me. I own a 2008 e92 m3 6mt. My problem with my car is when driving and downshifting from 3rd to 2nd gear and rev match the car it doesn't let me pop it into 2nd and makes this almost odd "grinding" noise. I personally think I am rev matching and downshifting properly but I may be wrong. I was just hoping somebody would know what it may be from. The way I downshift just to clarify is clutch in, blip throttle, select gear, catch with clutch. From what I've read I may just have bad synchro's.

Thanks in advanced!!

Don't take this the wrong way, but I think it's more of a skill issue than a mechanical one. If you are grinding, that means you probably didn't time things correctly or you under/over-revved.

Find an empty stretch of road an experiment a bit more. YouTube also has a lot of videos, but ultimately professional instruction will show you the best method for your car.

As an example, if you are cruising on the highway in 6th gear and want to drop to 5th, does it grind at all? The reason I ask is that the RPM change here would be minimal so bad synchros would still be obvious. If you see a grind for more extreme RPM changes, like 6th to 3rd, that is likely a skill problem. You might also want to try and narrow it down to a specific gear (e.g. it only grinds from 3-2, or 6-5), as that would indicate more of a mechanical problem.

[E92Gok]

Originally Posted by dparm

Don't take this the wrong way, but I think it's more of a skill issue than a mechanical one. If you are grinding, that means you probably didn't time things correctly or you under/over-revved.

Find an empty stretch of road an experiment a bit more. YouTube also has a lot of videos, but ultimately professional instruction will show you the best method for your car.

As an example, if you are cruising on the highway in 6th gear and want to drop to 5th, does it grind at all? The reason I ask is that the RPM change here would be minimal so bad synchros would still be obvious. If you see a grind for more extreme RPM changes, like 6th to 3rd, that is likely a skill problem. You might also want to try and narrow it down to a specific gear (e.g. it only grinds from 3-2, or 6-5), as that would indicate more of a mechanical problem.

It's all a learning experience and no I don't take things personally. This is my second manual car I first had a e92 335i that was automatic then I went to a VW GTI that was manual and I personally don't consider that car manual driving it was so easy it took little to no effort at all. And I recently purchased my m3 about 3 weeks ago, so this car is still sort of new to me and I don't even daily it. I guess it may be a driver error and I need to practice it. But to be honest the only times that "problem" has occurred was going down from 3rd-2nd. And it only happens on certain downshifts it's not something that happens every single time. I've noticed it happens whenever it's around 3k rpm and going about 32-40MPH. What I'm guessing is I just need to blip the throttle a little more and enter the shifter into second a little harder. Thanks for the response I appreciate any kind of feedback!

[dparm]

Originally Posted by E92Gok

It's all a learning experience and no I don't take things personally. This is my second manual car I first had a e92 335i that was automatic then I went to a VW GTI that was manual and I personally don't consider that car manual driving it was so easy it took little to no effort at all. And I recently purchased my m3 about 3 weeks ago, so this car is still sort of new to me and I don't even daily it. I guess it may be a driver error and I need to practice it. But to be honest the only times that "problem" has occurred was going down from 3rd-2nd. And it only happens on certain downshifts it's not something that happens every single time. I've noticed it happens whenever it's around 3k rpm and going about 32-40MPH. What I'm guessing is I just need to blip the throttle a little more and enter the shifter into second a little harder. Thanks for the response I appreciate any kind of feedback!

The motor in the M3 revs pretty fast, so it might take some getting used to. If you have the POWER button pressed, the throttle sensitivity goes up even further and that might make it even more difficult -- or maybe it will help you if you're too slow?

Rev-matching is a tough skill and it will take time to get it right, especially on a new car.

[E92Gok]

Originally Posted by dparm

The motor in the M3 revs pretty fast, so it might take some getting used to. If you have the POWER button pressed, the throttle sensitivity goes up even further and that might make it even more difficult -- or maybe it will help you if you're too slow?

Rev-matching is a tough skill and it will take time to get it right, especially on a new car.

Hmmm okay, I'm gonna give that a try when I get a chance, I'll try both M mode on and off and see if that changes things in any way. Thanks for the advice I appreciate it.

[dparm]

Originally Posted by E92Gok

Hmmm okay, I'm gonna give that a try when I get a chance, I'll try both M mode on and off and see if that changes things in any way. Thanks for the advice I appreciate it.

I'm talking about the POWER button by itself. M mode can be configured to whatever you want (which can include combinations of the throttle setting, steering, EDC, etc).

[McSwine]

If you drove your manual equipped GTI without issue you'll get there. I came from a Fiesta ST that was easy to drive and I have to admit there was a bit of a learning curve with the M3. The shorter gear ratios, the distinct "mechanical" feel of the transmission and the relative stiffness of the shifter take some getting used to, but now that I've driven it for a while I love it (that's not to say I don't FU a shift every now and then). You have to DRIVE this car and at the end of the day I guess that's why we all bought one. I don't know if practice makes perfect, but it certainly helps.

[L4ces]

Ive had mine for 7 years and just perfected the 3-2 and the 2-1 rev matches at 166K miles!
I used to grind when going from 1-2 near red line and I can now do that without grinding.

Two major changes.

1. A basic tune (in my case it is the Dinan).
Ill those that know more of what goes into the tune elaborate. I thinking the mapping of pedal position to throttle position has been fine tuned (in short some change in throttle mapping). Somehow I just have time to when near redline to shift. I just couldn't locking the timing of both pedals and stick shift. After the tune, shit just felt different.

As you know the amount throttle blip from 3-2 is different from the higher gears (the rpm range is wider between 2-3 than it is between 3-4 and the up. So what I notice now is that a quick stomp of the accelerator to the floor and super quick shift is the perfect amount of blip for 3-2. In other words, I don't have to worry about over revving the engine on a 3-2 anymore.

2. My new arm position has increased my confidence and speed.
I've tried many positions and grips of the knob. I;ve swapped to weighted shift knob which I want to say has made it better but not like it is now with this new position. Previously my elbow was always position somewhere above the center arm rest. Now my elbow is tucked between my hip and the arm rest. This position restricted forces forward and backwards. My forearm segment is now at 90 degrees instead of it being greater than 90 degrees. Two guarantee I shift into the correct gear, I bend my wrist and the way should will have to bend when positioned this way clearly conveys what gear you will push up to or pull down into. No guess worked, no second guess, no fear! My enjoyment has start all over again.

What I can now do is fast downshifts and skipping gears. More importantly I can get a sharp near perfect blip just like a DCT in any gear.

When at 5000rpm or above and in 3rd I can accurately rev match to 2nd and hear the signature triplet (3) pops from the exhaust (3-2 pop pop pop). Also the pop when shifting up gear really fast sounds better which I loved about the DCT.

[Denk]

You probably just need to get used to it...or tolerate it.