[Nate@IND]

All of us at IND have loved the E90 M3 since the day the car was released to the public. It’s wide and aggressive rear fenders and it’s perfect mix of style, performance, and utility confirm what most BMW enthusiasts already know- after 40 years at the top, BMW still makes the best sports sedans in the world.

Unfortunately, fans of the E90 M3 got the short end of the stick in many ways, especially when it came to aftermarket support. Those who got into an E90 M3 early on will remember how difficult it was to source exterior parts- everything from trunks to hoods had to be custom made in the E90’s early days.

One area where we felt E90 enthusiasts were truly short handed was the lack of a carbon fiber roof. The E92 M3’s carbon roof represented a major step for BMW M as it was essentially the first use of structural composite components bonded into the car’s unibody specifically to save weight. BMW had not released an item like this on a mass scale before the E92 M3, and of course chose to highlight this feature by leaving the roof panels completely unpainted. Of course, fans of the E90 who wanted a carbon roof were out of luck.

IND addressed this problem several years ago when we worked to develop our own mold for a carbon fiber roof for the E90 M3 chassis. Since then we’ve been blessed to perform carbon fiber roof conversions on some of the most notable E90 M3s in the US, and this week are tackling our next job.

I wanted to share some photos of the conversion in progress with the M3community, to give some insight into the process:

www.IND-Style.com
http://ind-style.com/2011/05/10/ind-...on-fiber-roof/



Our first step is removing the roof molding, and then removing each spot weld on the factory metal roof panel.





The roof panel is lifted from the M3.



The OEM roof panel weighs about 24lbs…



Next, we install the factory roof liner.



We apply Valvoline brand adhesive to the roof frame…





First, here are some photos of the roof panel prior to installation. You can see that the panel is a complete carbon fiber piece, with no fiberglass reinforcement.

We grind through every spot weld in order to release the metal roof skin from the roof frame. We cover the entire interior in plastic, and then in very heavy welding blankets to prevent any sparks from striking the interior components.



After the spot welds have been removed, we can separate the roof skin from the roof frame.



…while the carbon roof weighs in at 9.8 lbs! That means the carbon roof provides a 60% savings over the original panel, even without the sunroof assembly. A sunroof equipped car could see a very substantial weight savings, right at one of the most important points on the car.



…and then lower the roof into it’s position.





The roof is retained with the factory fastners, and also clamped to the roof frame while the adhesive cures.

Stay tuned to see the finished product!

[Prit@EAWerx]

Very nice!

[AMPowerJ]

I want this ... wish you guys were local!

[1seriesMcpe]

What does a conversion like this cost for a M3 sedan with sunroof?
Beautiful conversion by the way.... Love it!

[Ibanez]

Originally Posted by 1seriesMcpe

What does a conversion like this cost for a M3 sedan with sunroof?
Beautiful conversion by the way.... Love it!

more than you can afford pal

[mach250]

dont understand the need for this...unless buyers remorse of the sunroof like the guy above kicks in...

[captbilly]

So the original roof panel weighs 24 lbs. (including some sound insulation). The Carbon fiber panel weighs 9.8 lbs (not including the sound insulation). Then you add in the adhesive and some sound insulation, and a bit of hardware. So my question is; if you include everything, roof panel, insulation, glue, hardware, etc. how much weight do you actually lose from this mod? My rough guess would be about 10 lbs. total loss of weight. Then we need to consider other ways one could lose weight on an M3, what it would cost, and how significant would that loss be. Certainly it seems as though 10 lbs off the roof of an M3 should be a good thing, but how good would it be to lose 20 lbs or rotating unsprung weight by going to lightweight wheels (perhaps $3500 - the selling price of your original wheels. Or how about losing 50 - 60 lbs of rotating unsprung weight by going to carbon fiber wheels. One could also lose 50 lbs of sprung weight by installing the complete akrapovic titanium exhaust (about $6,000). We could consider the weight savings of going to ceramic brake disks, about 10Lbs per corner, 40Lbs total of unsprung rotating mass. so for about $10,000 you could lose 100 lbs, 1/2 sprung and 1/2 unsprung and rotating. Another 100 lbs of unsprung rotating mass could be removed for maybe another $10,000 worth of ceramic rotors and carbon fiber wheels. So our average price for losing sprung weight is about $120/lb. THe cost for losingnrotating unsprung weight is perhaps $100 per pound. THat would make a cost effective price on the carbon fiber roof at about $1200. What does it actually cost?

[AMPowerJ]

This really isn't about saving weight. It is for looks guys.

[foolio]

I would rather have a carbon fiber wrap if I was into that look. I bet the cost of this mod is astronomical. Nevertheless, it is a pretty cool mod if this is where you choose to spend your money.

[m3j0n]

Originally Posted by Nate@IND

The E92 M3’s carbon roof represented a major step for BMW M as it was essentially the first use of structural composite components bonded into the car’s unibody specifically to save weight. BMW had not released an item like this on a mass scale before the E92 M3, and of course chose to highlight this feature by leaving the roof panels completely unpainted.

Nate, I have been a big fan of your work as well as appreciate documenting the process - keep up the good work... Two things though: A) how much does the CF roof cost? and B) not to nitpick, but there was an E46 M3 CSL with a carbon fiber roof... and lets not forget that little car called the M6 which was definitely a mass produced car since 2006.