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-   -   BMW M3 with SMG... is it worth it? (http://www.maxbimmer.com/forums/showthread.php?t=144815)

Syn 08-05-2011 10:23 PM

BMW M3 with SMG... is it worth it?
 
Looking to upgrade from my 330i to 03 BMW M3 [smg gearbox]

Tried to look up online for any feedback but it was mixed up, what do you guys think, is it worth it. is SMG a big expensive headache?

Car just hit 125,xxx km


Thanks for all the feedback

bmwm5lover 08-06-2011 11:28 AM

I would personally steer clear of SMG, especially some of the early ones. They are known to have their issues.
There is a thread about a M6 SMG, search for it, lots of good SMG info.

SamE30e 08-06-2011 11:58 AM

It's very.... rough...

If you're driving fast, it's fine. Driving slow and in traffic..Terrible.

golf_hero 08-07-2011 11:14 AM

I had a 2005 M3 with SMG and switched to a 2009 M6 also with 7 speed SMG - night and day difference. I would stay away from early SMG. Super rough and worrisome out of warranty. The SMG on my M6 took some getting used to but as long as you drive it like a manual (auto mode is still rough) it is awesome.

JayR_84 08-09-2011 09:32 AM

Haven't had any issues with any of our SMG cars. I also have manual cars and almost always prefer taking out the M5 instead of the manual M3, especially for highway or track use.

Auto is still king in stop & go.

The early SMG (330i, z4, 5/6 series non-M) and SMG II (m3/m5) cars were all designed using regular manual gearbox. The bellhousing slightly redesigned to house the hydraulic pump, but otherwise exact same internals including gear ratios and flywheel. The gearbox is designed for a human to control it. (the clutch delay valve is removed on SMG cars though). But humans and robots work differently and at different speeds. The issue with M3 (and Z4 / 330i Magnetti-Marelli gearboxes) is that the gear ratios are too far apart and it takes too long for the engine to spin down when changing gears leading to clunky shifts.

The 7-speed M6 SMG III gearbox is a completely different box than what is used in the Manual 6-speed M6. BMW didn't cheap out this time. They made it much smoother by making the gear ratios closer together (by adding a 7th gear) so the engine doesn't need to spin down as much when changing gears leading to smoother shifts, and by adding a lighter weight flywheel which helps with rev-matching, especially when skipping gears.

If you purchase an M3 or Z4/330i there will be delay when changing from 1st to 2nd gear because of the gearing and the computer has to 'wait' for the engine to reach the proper speed before re-engaging the clutch, unless you use a more aggressive shift program then you'll get a 'clunk' from the drivetrain when the engine hooks back up early.

The single most effective upgrade for these SMG's is a lightweight flywheel. It will allow the engine to rev-match much quicker which eliminates the 'clunk' in most cases. Don't go too light otherwise the SMG computer will need reprogramming. Dinan makes some effective lightweight flywheels for both cars and for the M3 has a SMG reprogram map as well. Ensuring the SMG fluid is filled up is important too.

This is also why these cars shift better at higher engine RPM (or faster speeds), the engine load makes it rev down quicker for smoother shifts at higher RPM. The engine revs down slower at slower speeds with less load.

FYI:

M5/M6 ratios

Gear ratios for the seven-speed SMG transmission are
3.99:1 (first)
2.65:1 (second)
1.81:1 (third)
1.39:1 (fourth)
1.16:1 (fifth)
1:1 (sixth)
83:1 (seventh)
3.99:1 (reverse).

The six-speed manual gear ratios are
4.05:1 (first)
2.40:1 (second)
1.58:1 (third)
1.19 (fourth)
1:1 (fifth)
.87:1 (sixth)
3.68:1 (reverse).

The final drive ratio for each transmission is 3.62:1.

3x Beemer 08-09-2011 10:15 AM

No regrets. I was sceptical of SMG when looking for my M3 but now that I am used to it it's fine. Big learning curve as it is definitely different. Sure nice in stop and go traffic.
As for expense so is an automatic trany when it bites the dust. If you can afford an M3 it should not be a concern. IMHO

golf_hero 08-09-2011 11:53 PM

Great info - Thanks JayR

Quote:

Originally Posted by JayR_84 (Post 1517103)
Haven't had any issues with any of our SMG cars. I also have manual cars and almost always prefer taking out the M5 instead of the manual M3, especially for highway or track use.

Auto is still king in stop & go.

The early SMG (330i, z4, 5/6 series non-M) and SMG II (m3/m5) cars were all designed using regular manual gearbox. The bellhousing slightly redesigned to house the hydraulic pump, but otherwise exact same internals including gear ratios and flywheel. The gearbox is designed for a human to control it. (the clutch delay valve is removed on SMG cars though). But humans and robots work differently and at different speeds. The issue with M3 (and Z4 / 330i Magnetti-Marelli gearboxes) is that the gear ratios are too far apart and it takes too long for the engine to spin down when changing gears leading to clunky shifts.

The 7-speed M6 SMG III gearbox is a completely different box than what is used in the Manual 6-speed M6. BMW didn't cheap out this time. They made it much smoother by making the gear ratios closer together (by adding a 7th gear) so the engine doesn't need to spin down as much when changing gears leading to smoother shifts, and by adding a lighter weight flywheel which helps with rev-matching, especially when skipping gears.

If you purchase an M3 or Z4/330i there will be delay when changing from 1st to 2nd gear because of the gearing and the computer has to 'wait' for the engine to reach the proper speed before re-engaging the clutch, unless you use a more aggressive shift program then you'll get a 'clunk' from the drivetrain when the engine hooks back up early.

The single most effective upgrade for these SMG's is a lightweight flywheel. It will allow the engine to rev-match much quicker which eliminates the 'clunk' in most cases. Don't go too light otherwise the SMG computer will need reprogramming. Dinan makes some effective lightweight flywheels for both cars and for the M3 has a SMG reprogram map as well. Ensuring the SMG fluid is filled up is important too.

This is also why these cars shift better at higher engine RPM (or faster speeds), the engine load makes it rev down quicker for smoother shifts at higher RPM. The engine revs down slower at slower speeds with less load.

FYI:

M5/M6 ratios

Gear ratios for the seven-speed SMG transmission are
3.99:1 (first)
2.65:1 (second)
1.81:1 (third)
1.39:1 (fourth)
1.16:1 (fifth)
1:1 (sixth)
83:1 (seventh)
3.99:1 (reverse).

The six-speed manual gear ratios are
4.05:1 (first)
2.40:1 (second)
1.58:1 (third)
1.19 (fourth)
1:1 (fifth)
.87:1 (sixth)
3.68:1 (reverse).

The final drive ratio for each transmission is 3.62:1.


rendered 08-10-2011 04:26 AM

Took me a good month to get used to it, but I loved my E46 M3 SMG transmission... no problems, and shifted so crisply and quickly in my car... others I drove weren't as good.. but every car is different... drive this car in particular, and see if you like it... keeping in mind it will take you a little while to really appreciate it...

use the highest mode, and maybe even turn traction off, and have some FUN... tell us you don't like it then... :D

I notice a lot less chatter from the clutch and flywheel with SMG compared to my 6spd Manual E46, and other 6spd M3's.

chromius 08-10-2011 10:06 AM

When I was searching for my M3, I was in the same boat, wasn't sure if I should even bother looking at SMG M3's or not, then I stumbled across this review of the M3's SMG transmission and was sold.
http://www.bimmerfest.com/forums/showthread.php?t=10057

Basically after reading this review I didn't have any problems looking at either SMG or 6sp Manual. In the end I ended up going with a manual, but if the right SMG had come up, I would have done it.

From what I've read when I was looking, the most expensive problem with the SMG's is if the SMG pump goes out, which does happen, but seems to be hit or miss, and cheaper alternatives to the dealer do exist. Seems like a lot of times the problems are relays or actuators though which tend to be cheaper. The way I looked at it, was that just like anything with a used car, you could end up with an expensive repair regardless of what it is, it's always a risk even if you do your research. So if you're willing to do it, who knows, you could have 200,000k of problem free SMG.

Personally, if the right one comes up with SMG, I wouldn't let that sway you to not get it. It's a used, high strung car, there are going to be repairs. Fix them when they happen, and move on. If the problems start to happen more often than you are able to enjoy the car, sell it and start fresh.

NOTORIOUS VR 08-10-2011 10:28 AM

I drove my buddies E46 M3 SMG and it was great! You learn to drive it smooth in any setting just like you do when you get used to any of your cars... There is a way around everything.

SiR 08-10-2011 03:39 PM

manual box pls..even in the worst traffic

propr'one 08-11-2011 12:59 PM

Before i bought the roadie i was thinking about e46 m3 vert, and i had decided against SMG when i found out the pump failure was somewhat common, and cost 4-5K to fix.

ac_2007 08-13-2011 05:23 PM

No SMG and miles are kind of high.

twboy1999 08-13-2011 07:14 PM

will be hard to e46 m3 under 100k
125km is alrite

ac_2007 08-13-2011 11:07 PM

Ok, I forgot Im coming from a US website where they use Miles lol. Yes 125k is perfectly fine. I would still opt for the 6 speed manual gearbox though.


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