Teaser the BPS Motorsports Adjustable Rear Shock Tower Brace for E46 M3

Bob @ BPS · #1 (**permalink**) 06-11-2008, 02:43 AM

Hi Guys,

Last year I contacted John Mason of Mason Engineering about making a 3-pc rear shock tower brace for the E46 M3. Those of you that are not familiar with John. He was a chassis fabricator for the Newmann-Haas Indy car team in the late 80s and early 90s, so he really knows his stuff.

Personally, I occasionally use my trunk and wanted it to be easy to remove and install. The first version was done back in December. I received 6 units and shipped one to Gixxer. His mechanic was able to make it fit, but mine was way off, so we never released the product. Well, months have passed and we finally have an updated verision. This one has an adjustable center section that ensures fitment AND allows for the ability to pre-load the rear shock towers, if desired.

These are expensive to make and would just like some opinions about the design. In aluminum it is likely to be over $400. We're considering doing them in black powder coated steel. Steel is stronger and cheaper, but would add about 3 pounds to the bar, and might come in around $300

Thanks for looking. I appreciate constructive criticism and positive comments. Please be specific about what you like or dislike. PLEASE no useless comments like "it sucks, dude". Please read the description and features below CAREFULLY before posting comments and opinions

Below is the full description from our website and some pics.

TIA,

Bob

BPS Motorsports Adjustable Rear Shock Tower Brace for E46 M3

This is the best designed rear shock tower brace ever available for the E46 M3. We commissioned John Mason, previously a chassis fabricator with the Newmann-Haas Indy car team, to help us bring to market a product that would stiffen the rear and add protection against mushrooming for the rear shock towers. I wanted something that would be strong, functional and easy to install and remove for those of use who occasionally need full access to our trunk. We feel we have added a host of great features and eliminated the design flaws found in other rear bars

Why are there 4 mounting points?

The other bars previously available have mounted using only 2 points. This creates a hinge. The other bars might prevent the shock towers from flexing closer together or spreading apart, but don't prevent the towers from flexing the same direction. This concept is known as racking. The other bars are not nearly as stiff or strong as the BPS Motorsports Rear Shock Tower Brace AND they are not adjustable.

High-Quality Hardware:
My original idea was to use seat-post binder bolts for the easiest installation and removal but, to my dismay, I found the largest of those bolts is on 6mm. We felt that 6mm isn't strong enough to provide the rigidity we were looking for from this brace.

Tell me about the end brackets...
The end brackets on our rear shock tower brace wrap around and bolt to the inside of the rear shock tower in two places. Each of these bolts can handle 1200 pounds in shear. This distributes the load over more of the rear shock tower. Rear shock mounts are helpful, but that can't compare to the protection provided by a set of RSMs AND our rear shock tower brace.

So, what else is different about this brace?
We made it adjustable. Why? Because we found our original design sometimes had fitment issues. Some of the cars we tested on were out of spec, so we went back to the drawing board. Also, based on talking with customers, we found that some guys wanted the ability to pre-load the rear suspension. The answer...make it adjustable. This killed two birds with one stone. NOW, the brace is guaranteed to fit perfectly AND hardcore track guys can adjust till their heart's content.

Features:

Installs easily in minutes with a 8mm hex bit or driver, and a 14 mm wrench.
Unique design is easily adjustable with a 14mm wrench
High-grade 10mm cap bolts for securely mounting the center bar to end brackets.
4 mounting points ensure maximum stiffness and prevents racking
Adjustability ensures perfect fitment in every car and allows for pre-loading, if desired
Steel end brackets provide unparalleled support and protection of your rear shock towers against mushrooming
Allows for bolted connections to chassis floor and shock mounts.
Design allows for removal of center cross bar for when extra trunk space is needed
Easily reinstalled for performance driving.

This is the right shock tower with a Rogue RSM in place

This shows the right side end bracket in place and ready to install. 2 holes are drilled in the fender well where the 2 panels are joined to give the strongest connection point with the insides of the shock tower.