So is it true that Verts DO NOT suffer SUBFRAME damage?

Touring · Thu, Sep-02-2010, 01:51:17 AM

Quote:

Originally Posted by Mr. Wolfe

Where are you getting this information from?

NA M3 coupe (LHD): 26,202 examples produced from 02/01 through 05/06
NA M3 convertible (LHD): 17,577 examples produced from 03/01 through 08/06

Mr. Wolfe

Besides the words"I THINK". From my assumtion.

casper3t · Thu, Sep-02-2010, 02:31:03 AM

I read that people that never been to the track, doesn't race the car still get subframe failures. I think a big contribtion to the subframe failure is the road conditions.

Wengy · Thu, Sep-02-2010, 03:06:11 AM

Certainly it's not just people who track their cars that are getting subframe mount cracks, everyone is susceptible. The cracks are a result of torsional loads generated by the engine, the torque causes a twisting motion and the subframe mounts receive the brunt of it. I think it's less about road conditions, and more about hard and sudden accelerations, and doing such things repeatedly. This isn't my own opinion, as I actually know jack, but this is what I've read from the Turner Motorsport site.

"The E46 rear driveline and suspension are very similar to that of the E36. An unfortunate side effect of this is that the E46 also shares some of the same problems as the E36. One of these problems is the rear mounting points for the subframe, which can rip out from their spots in the sheet metal. This happens because the rear differential transmits the torsional load from the engine through the subframe, then into the chassis. This constant loading and unloading weakens the sheet metal and causes it to fatigue and separate from the chassis. BMW tried to fix this problem in the E46 by placing a cross member on the front two mounting points of the subframe. This cross member keeps the front mounting points from having problems by placing the bushing and the stud in double-sheer, thus reducing the twisting action on the sheet metal. The unfortunate side effect of this is that the load from the front of the subframe now gets transmitted to the left rear of the subframe. This is where we have seen many failures of the chassis on low mileage street cars and race cars."

MPOWERD · Thu, Sep-02-2010, 07:42:09 AM

Verts have a thicker belt of reinforcing metal along the same area where coupes see subframe cracking. This is for added stiffness for the body to offset the vert not have the hardtop of the coupe. This isnt saying it couldnt happen to a vert, but the odds are that it wont, since 99% of verts can never see the track AND the reinforcement in the body of the vert helps to offset hard street driving by verts...

henry333 · Thu, Sep-02-2010, 07:56:45 AM

tracking the car don't means subframe damage. If so all m3 at the track are cracking?
These no proof that vet owner drives less hard then coupes. It all depends on the owner. If i have a vert and i know it wont tear the subframe ill drive harder instead of thinking it will tear.

Touring · Thu, Sep-02-2010, 12:09:49 PM

Quote:

Originally Posted by M3_Modness

Verts have a thicker belt of reinforcing metal along the same area where coupes see subframe cracking. This is for added stiffness for the body to offset the vert not have the hardtop of the coupe. This isnt saying it couldnt happen to a vert, but the odds are that it wont, since 99% of verts can never see the track AND the reinforcement in the body of the vert helps to offset hard street driving by verts...

Thank goodness

**Obioban** · Thu, Sep-02-2010, 12:27:35 PM

These two are correct:

Quote:

Originally Posted by Wengy

Certainly it's not just people who track their cars that are getting subframe mount cracks, everyone is susceptible. The cracks are a result of torsional loads generated by the engine, the torque causes a twisting motion and the subframe mounts receive the brunt of it. I think it's less about road conditions, and more about hard and sudden accelerations, and doing such things repeatedly. This isn't my own opinion, as I actually know jack, but this is what I've read from the Turner Motorsport site.

"The E46 rear driveline and suspension are very similar to that of the E36. An unfortunate side effect of this is that the E46 also shares some of the same problems as the E36. One of these problems is the rear mounting points for the subframe, which can rip out from their spots in the sheet metal. This happens because the rear differential transmits the torsional load from the engine through the subframe, then into the chassis. This constant loading and unloading weakens the sheet metal and causes it to fatigue and separate from the chassis. BMW tried to fix this problem in the E46 by placing a cross member on the front two mounting points of the subframe. This cross member keeps the front mounting points from having problems by placing the bushing and the stud in double-sheer, thus reducing the twisting action on the sheet metal. The unfortunate side effect of this is that the load from the front of the subframe now gets transmitted to the left rear of the subframe. This is where we have seen many failures of the chassis on low mileage street cars and race cars."

Quote:

Originally Posted by M3_Modness

Verts have a thicker belt of reinforcing metal along the same area where coupes see subframe cracking. This is for added stiffness for the body to offset the vert not have the hardtop of the coupe. This isnt saying it couldnt happen to a vert, but the odds are that it wont, since 99% of verts can never see the track AND the reinforcement in the body of the vert helps to offset hard street driving by verts...

m3whiteknight · Thu, Sep-02-2010, 02:34:49 PM

Quote:

Originally Posted by M3_Modness

Verts have a thicker belt of reinforcing metal along the same area where coupes see subframe cracking. This is for added stiffness for the body to offset the vert not have the hardtop of the coupe. This isnt saying it couldnt happen to a vert, but the odds are that it wont, since 99% of verts can never see the track AND the reinforcement in the body of the vert helps to offset hard street driving by verts...

Nice, I do not know that . That is a good piece of info

Jako1 · Thu, Sep-02-2010, 03:36:52 PM

Yes. This can explain why the verts are more than 300lbs heavier than the coupes

MY02M3DINAN · Fri, Sep-03-2010, 03:24:18 PM

I drive my vert pretty hard.

Thanks to some friends at the track, I'm able to get on without the need for a roll-cage for some events. (not recommended)

I also autocross now on a regular basis.

My car does not have any sub-frame cracks.
I'm dropping the diff this weekend and will take another look.

I believe the vert frame is tough enough.

Thu, Sep-02-2010, 02:31:03 AM	#22
casper3t Registered User Join Date: Feb 2008 Posts: 1,719 In the garage: '02 BMW M3 Reputation: 0 Location: Anaheim	I read that people that never been to the track, doesn't race the car still get subframe failures. I think a big contribtion to the subframe failure is the road conditions. __________________ '02 Euro Tuned///M3 6spd Carbon Black cover with a layer of dust and Grey Int. Suspension: Koni Adj with Vogtland Springs, UUC FCAB, RE RTABS and GC Street Camber Plates

Thu, Sep-02-2010, 07:42:09 AM	#24
MPOWERD Mod Hound! Join Date: Aug 2008 Posts: 10,724 In the garage: '03 BMW M3 Convertible Reputation: 0 Location: Texas	Verts have a thicker belt of reinforcing metal along the same area where coupes see subframe cracking. This is for added stiffness for the body to offset the vert not have the hardtop of the coupe. This isnt saying it couldnt happen to a vert, but the odds are that it wont, since 99% of verts can never see the track AND the reinforcement in the body of the vert helps to offset hard street driving by verts... __________________ 2003.5 e46 ///M 3 TiAg Cabriolet SMG II... <> CSL Carbon Fiber Intake w/MAF, Brembo Gran Turismo, Euro Headers & Cats, K&N 69, Radenergie Carbon Fiber Strutbar <> EAS Carbon Fiber Kidney Grills, Carbon Fiber Fender Grills, SMG Carbon Fiber Paddles, Vorsteiner 2 Sided CF VCSL Boot <> EAS Slvr Carbon Fiber Interior Trim, Blk Carbon Fiber SMG Dome, Carbon Fiber Console, & Blk/Slvr Steering Wheel Trim <> EAS Carbon Fiber Engine Bay, Vorsteiner Carbon Fiber Valve Cover, RPI Intake Scoops, CarPC w/Nav/MP3/HD Radio/TV <> Eisenmann Race Exhaust, Supersprint X-Pipe with Resonator, Ekarbon 1/2 Carbon Fiber Diffuser, DEPO Smoked Corners <> 19x8.5 19x9.5 VMR V710s in HyperSilver, Painted Corner Reflectors, EAS Carbon Fiber Emblems, Carbon Fiber Hood Vent <> Slvr CF Pedals, OEM 2-Tone Hardtop, Windscreen, & Alarm, 6K Headlights & HID Fogs, Blk Carbon Fiber Headlight Trim

Fri, Sep-03-2010, 03:24:18 PM	#30
MY02M3DINAN Registered User Join Date: Apr 2009 Posts: 187 Reputation: 0	I drive my vert pretty hard. Thanks to some friends at the track, I'm able to get on without the need for a roll-cage for some events. (not recommended) I also autocross now on a regular basis. My car does not have any sub-frame cracks. I'm dropping the diff this weekend and will take another look. I believe the vert frame is tough enough. __________________ 2002 TiAg M3 Cabriolet Dinan S-M3 Kit {Throttle Bodies/CAI/MAF/Stage 4 software} Dinan Strut tower brace & Front sway bar Auto Solutions SSK UUC Motorwerks "Rasp-X" mid-pipe Urethane RTAB's/FCAB's/RSM's Hawk HPS Brake Pads CDV delete V1 Hardwired THIS CAR IS NOW FOR SALE!

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Thu, Sep-02-2010, 03:06:11 AM	#23
Wengy Registered User Join Date: Oct 2009 Posts: 697 In the garage: '01 BMW M3 Reputation: 0	Certainly it's not just people who track their cars that are getting subframe mount cracks, everyone is susceptible. The cracks are a result of torsional loads generated by the engine, the torque causes a twisting motion and the subframe mounts receive the brunt of it. I think it's less about road conditions, and more about hard and sudden accelerations, and doing such things repeatedly. This isn't my own opinion, as I actually know jack, but this is what I've read from the Turner Motorsport site. "The E46 rear driveline and suspension are very similar to that of the E36. An unfortunate side effect of this is that the E46 also shares some of the same problems as the E36. One of these problems is the rear mounting points for the subframe, which can rip out from their spots in the sheet metal. This happens because the rear differential transmits the torsional load from the engine through the subframe, then into the chassis. This constant loading and unloading weakens the sheet metal and causes it to fatigue and separate from the chassis. BMW tried to fix this problem in the E46 by placing a cross member on the front two mounting points of the subframe. This cross member keeps the front mounting points from having problems by placing the bushing and the stud in double-sheer, thus reducing the twisting action on the sheet metal. The unfortunate side effect of this is that the load from the front of the subframe now gets transmitted to the left rear of the subframe. This is where we have seen many failures of the chassis on low mileage street cars and race cars."

Thu, Sep-02-2010, 07:56:45 AM	#25
henry333 Registered User Join Date: Feb 2009 Posts: 87 Reputation: 0	tracking the car don't means subframe damage. If so all m3 at the track are cracking? These no proof that vet owner drives less hard then coupes. It all depends on the owner. If i have a vert and i know it wont tear the subframe ill drive harder instead of thinking it will tear.

Thu, Sep-02-2010, 03:36:52 PM	#29
Jako1 Registered User Join Date: Jul 2006 Posts: 993 Reputation: 0 Location: North Vancouver	Yes. This can explain why the verts are more than 300lbs heavier than the coupes