E46 Subframe solution (PIC inside!)

I have been looking for a way to reinforce the rear subframe without welding anything.

The way I see it, is that when you weld the reinforcement plates in, you burn the paint and any sealant off on the other side of the floor panel. Normally this wouldn't be such an issue however the floor in E46s is double layered which does not allow you to properly paint and seal the weld area on the inside. This will lead to rust and weakening of the subframe in the long run.

So...I set out on a search for a solution, here is what I found...

EDIT: more pics and instructions added on page 4



http://www.masonengineering.net/Subpages/E46.htm


Any thoughts???

I wonder how it attaches to the floor. Hope it's bolted up like the rest of it.

I would not trust that monstrosity unless they can proven to me that it solves the problem with Finite Element Analysis, Over Stress Testing and it was designed by a Mechanical Engineer. Many if these 'tuner' shops are run by technicians who are smart and practical individuals, but they are not engineers nor do they have the University training to back it up.

Originally Posted by Optio

I would not trust that monstrosity unless they can proven to me that it solves the problem with Finite Element Analysis, Over Stress Testing and it was designed by a Mechanical Engineer. Many if these 'tuner' shops are run by technicians who are smart and practical individuals, but they are not engineers nor do they have the University training to back it up.

IIRC,

The e46 sub frame was designed by engineers/Mechanical Engineers with University training and tons of experience.

The result? The shittiest subframe ever designed on a BMW that needs re enforcement for daily driving.

oh and upper strut towers as well.

I was looking though their website and it looks like they do "Structural deflection testing and calculations" as well as "Design & Engineering work"

http://www.masonengineering.net/Custom%20Shop.htm

Originally Posted by newe46fan

iirc,

the e46 sub frame was designed by engineers/mechanical engineers with university training and tons of experience.

The result? The shittiest subframe ever designed on a bmw that needs re enforcement for daily driving.

Oh and upper strut towers as well.

haha

I see that the company name is Mason Engineering which means that they are required by law to have a licensed professional engineer on staff. Checking the California Board for Professional Engineers, I see a couple of John Mason's that could be the person of interest.

http://www2.dca.ca.gov/pls/wllpub/WLLQRYNA$LCEV2.QueryView?P_LICENSE_NUMBER=20737&P_LTE_ID=751

http://www2.dca.ca.gov/pls/wllpub/WLLQRYNA$LCEV2.QueryView?P_LICENSE_NUMBER=28983&P_LTE_ID=751

Originally Posted by Optio

I see that the company name is Mason Engineering which means that they are required by law to have a licensed professional engineer on staff. Checking the California Board for Professional Engineers, I see a couple of John Mason's that could be the person of interest.

http://www2.dca.ca.gov/pls/wllpub/WLLQRYNA$LCEV2.QueryView?P_LICENSE_NUMBER=20737&P_LTE_ID=751

http://www2.dca.ca.gov/pls/wllpub/WLLQRYNA$LCEV2.QueryView?P_LICENSE_NUMBER=28983&P_LTE_ID=751

Interest for what? Have a beer with him?
I just want the reinforcement

Originally Posted by XXRUSIANXX

haha

Many of these structural issues on the E46 are a result of abusive driving and or modifications that change the engineering intent. Also, the road surfaces in the USA are in poor condition. BMW does offer a rough road package to prevent the strut tower issue. I have 100,000 miles on my E46 and my rear sub frame and strut towers are perfect. I have three other buddies with E46's with mega miles (120,000, 165,000 and 272,000) and no issues with the rear sub frame.

I have seen too many people who attempt to engineer a solution without the formal training, fack it up to high heaven. Just because I can put a band-aid on a wound....does not make me a doctor.

Originally Posted by XXRUSIANXX

Interest for what? Have a beer with him?
I just want the reinforcement

John Mason is a very common name: The board of engineering has two mechanical engineers with the same name. One of them might be the John Mason who owns Mason Engineering.

Originally Posted by Optio

Many of these structural issues on the E46 are a result of abusive driving and or modifications that change the engineering intent. Also, the road surfaces in the USA are in poor condition. BMW does offer a rough road package to prevent the strut tower issue. I have 100,000 miles on my E46 and my rear sub frame and strut towers are perfect. I have three other buddies with E46's with mega miles (120,000, 165,000 and 272,000) and no issues with the rear sub frame.

I have seen too many people who attempt to engineer a solution without the formal training, fack it up to high heaven. Just because I can put a band-aid on a wound....does not make me a doctor.

Well I have two BMW's and one had a ripped subframe.
My friend with an m3 has one now and trying to have BMW fix it.

I use my BMW mostly for racing and want to prevent any possible damage.

i used duct tape, works great

What brand duct tape?
Any links of where you got it?
Does color matter? (would like it to match my cars color)

i got my duct tape off ebay, it was some camo duct tape cuz i want to try and make my car blend in more so i can be stealthy u no? u can try carbon fiber to save some weight but ya id just go with camo or carbon fiber

Originally Posted by Optio

Many of these structural issues on the E46 are a result of abusive driving and or modifications that change the engineering intent. Also, the road surfaces in the USA are in poor condition. BMW does offer a rough road package to prevent the strut tower issue. I have 100,000 miles on my E46 and my rear sub frame and strut towers are perfect. I have three other buddies with E46's with mega miles (120,000, 165,000 and 272,000) and no issues with the rear sub frame.

I have seen too many people who attempt to engineer a solution without the formal training, fack it up to high heaven. Just because I can put a band-aid on a wound....does not make me a doctor.

Say that to the engineers who designed the Porsche 924 back in 1978. I've got one-- ALL of the subframe attachment points are INTACT and flat strut towers... The car has seen many different states and OVER 7 YRS of tracking and AUTOCROSSING by myself along with millions of clutch drops etc on solid upper strut mounts, solid rear subframe mounts and monoball bearings on 600 pound springs up front and 800 rear along with many winters, road salt, poop, you name it!!!! ( not anymore, running 400 pound springs up front and took the coils out. just running koni's and torsion bars in the rear now.

It could just be that Porsche/VW know how to cost cut their cars without catastrophic longetivity issues.

Let's face it the advent of CAD design and cost cutting to increase profits hurt car companies and car longetivity; It is not just the engineer's fault; They don't over engineer vehicles like the used to in the old days because they are forced to cost cut.

Originally Posted by Optio

Many of these structural issues on the E46 are a result of abusive driving and or modifications that change the engineering intent. Also, the road surfaces in the USA are in poor condition. BMW does offer a rough road package to prevent the strut tower issue. I have 100,000 miles on my E46 and my rear sub frame and strut towers are perfect. I have three other buddies with E46's with mega miles (120,000, 165,000 and 272,000) and no issues with the rear sub frame.

I have seen too many people who attempt to engineer a solution without the formal training, fack it up to high heaven. Just because I can put a band-aid on a wound....does not make me a doctor.

True, but have they taken responsibility and issued a recall or at least offer to fix bulging strut towers for free? NOPE. Almost a good 80% percent of OEM E46's I've seen have bulging strut towers.

anyways....
I don't know why we are talking about whether or not there is a problem to be addressed with our subframes. I don't think it is a secret that there is a problem.

Has anybody used this?

^^^ +1

Originally Posted by REKLESS ROB

^^^ +1

+1 I really do want to know.

this is interesting..