Steel or aluminun SMFW?

Quebequer · 04-23-2013, 11:59 PM

What do you guys run?
What, other than a little bit more inertia, are the downsides of a steel vs aluminum flywheel?
What are the downsides of an aluminum vs steel one? More chatter?

I'll be getting a Spec stage 2+ clutch + SMFW, just don't know if it will be aluminum or steel.

Thanks

Dmacc · 04-24-2013, 01:27 AM

If you want to avoid chatter, get the steel flywheel, it chatters just slightly when in neutral clutch out, and around 700 rpms, but it will be a lot quieter than the aluminum one.

3000GT MR · 04-24-2013, 02:37 AM

aluminum will have a little more harsh engagement, chatter, a little more "bogging" during a launch. all other normal driving conditions are a little better do to less rotating mass.

steel will yeld better launching, smoother idle in some cases, less noise, torque power band a little sooner.

really depends on your driving style. The weight between the two isn't really that much.
I prefer the steel because of the little added weight helps with boosting on the line, more inertia for launching, and drivability. It would be nice for someone who has driven with the same clutch on both flywheels to chime in. Possibly Jeff has.

turb0mik3 · 04-24-2013, 04:08 AM

I will say that the Aluminum isn't as chattery as I expected. When you have a cold start it will rumble the car a little and then in neutral idle it will have a little chatter. I actually love how the torque comes in a little later so you don't just spin your wheels stupidly. I also love the bite it has when you shift gears; It feels extremely solid & strong but sooooo smooth. It takes a slight getting used to but I absolutely love it!

P.S. Going from the spec stage 3+ clutch to my OEM 87 Merc clutch is

It feels like I am pressing air.

Quebequer · 04-24-2013, 10:22 AM

Thanks!
As my car is DD, I would like to avoid as much chatter as I can, so it seems like the steel SMFW is the way to go in my case..

Joshboody · 04-24-2013, 11:34 AM

chatter depends on many factors: injectors, dirty valves, AC, idle rpm, gearbox oil, tranny tolerances... its not the same for everyone. In my case steel chatters pretty good with AC... I would say DM is only sure way to eliminate it on the n54.

What we are talking about is gearbox chatter. Clutch chatter is during engagement. My 2+ has pucked surface on 1 side and you have to rev a little to limit chatter.

Quebequer · 04-24-2013, 12:45 PM

Quote:

Originally Posted by Joshboody

chatter depends on many factors: injectors, dirty valves, AC, idle rpm, gearbox oil, tranny tolerances... its not the same for everyone. In my case steel chatters pretty good with AC... I would say DM is only sure way to eliminate it on the n54.

What we are talking about is gearbox chatter. Clutch chatter is during engagement. My 2+ has pucked surface on 1 side and you have to rev a little to limit chatter.

Thanks sir.

04-23-2013, 11:59 PM	#1
Quebequer Private First Class 10 Rep 140 Posts Drives: BMW Join Date: Apr 2012 Location: Quebec, Canada iTrader: (0)	Steel or aluminun SMFW? What do you guys run? What, other than a little bit more inertia, are the downsides of a steel vs aluminum flywheel? What are the downsides of an aluminum vs steel one? More chatter? I'll be getting a Spec stage 2+ clutch + SMFW, just don't know if it will be aluminum or steel. Thanks __________________ 2008 BMW 335xi MT e90 JB4 G5, WW meth kit, turbonetics intercooler, DCI, UR catted dp's, UR catback, koni yellow + H&R springs, Rieger front bumper, Avant Garde 19" wheels
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04-24-2013, 01:27 AM	#2
Dmacc Colonel 208 Rep 2,799 Posts Drives: 2011 BMW 1M Join Date: Mar 2010 Location: So Cal iTrader: (1)	If you want to avoid chatter, get the steel flywheel, it chatters just slightly when in neutral clutch out, and around 700 rpms, but it will be a lot quieter than the aluminum one. __________________ thanks to MGallop
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04-24-2013, 02:37 AM	#3
3000GT MR Major 267 Rep 1,392 Posts Drives: 09 335i/3000gt vr4 Join Date: Jun 2012 Location: Sav GA iTrader: (6)	aluminum will have a little more harsh engagement, chatter, a little more "bogging" during a launch. all other normal driving conditions are a little better do to less rotating mass. steel will yeld better launching, smoother idle in some cases, less noise, torque power band a little sooner. really depends on your driving style. The weight between the two isn't really that much. I prefer the steel because of the little added weight helps with boosting on the line, more inertia for launching, and drivability. It would be nice for someone who has driven with the same clutch on both flywheels to chime in. Possibly Jeff has. __________________ Have a single turbo and/or tired of burning up O2 sensors? Ask me about the new ADV O2 sensor retro kits! 335i 2010 e92 M-sport Mods: VM Top mount 6466, Aquamist HSF4 w/custom direct port. VRSF IC + Exhaust 335i 2009 e90 665RWHP VFF900 ST RIP .
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04-24-2013, 04:08 AM	#4
turb0mik3 247 Rep 2,781 Posts Drives: E90 335i Racecar Join Date: Jan 2010 Location: San Diego, CA iTrader: (1) Garage List 2010 BMW 335i [8.90]	I will say that the Aluminum isn't as chattery as I expected. When you have a cold start it will rumble the car a little and then in neutral idle it will have a little chatter. I actually love how the torque comes in a little later so you don't just spin your wheels stupidly. I also love the bite it has when you shift gears; It feels extremely solid & strong but sooooo smooth. It takes a slight getting used to but I absolutely love it! P.S. Going from the spec stage 3+ clutch to my OEM 87 Merc clutch is It feels like I am pressing air. __________________ HG Motorsports \| Motiv Motorsport \| Sparta Evolution \| BBS Motorsports \| Sabelt \| JRZ \| NASA ST1 SoCal --- 554whp/487wtrq --- 3200lbs <<YouTube Channel w/ Race Videos>>
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04-24-2013, 10:22 AM	#5
Quebequer Private First Class 10 Rep 140 Posts Drives: BMW Join Date: Apr 2012 Location: Quebec, Canada iTrader: (0)	Thanks! As my car is DD, I would like to avoid as much chatter as I can, so it seems like the steel SMFW is the way to go in my case.. __________________ 2008 BMW 335xi MT e90 JB4 G5, WW meth kit, turbonetics intercooler, DCI, UR catted dp's, UR catback, koni yellow + H&R springs, Rieger front bumper, Avant Garde 19" wheels
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04-24-2013, 11:34 AM	#6
Joshboody Lieutenant Colonel 66 Rep 1,708 Posts Drives: pickemuptruck Join Date: Jul 2009 Location: Phoenix, AZ iTrader: (7)	chatter depends on many factors: injectors, dirty valves, AC, idle rpm, gearbox oil, tranny tolerances... its not the same for everyone. In my case steel chatters pretty good with AC... I would say DM is only sure way to eliminate it on the n54. What we are talking about is gearbox chatter. Clutch chatter is during engagement. My 2+ has pucked surface on 1 side and you have to rev a little to limit chatter.
	Appreciate 0 Quote