# DIY: Another new front bumper, version 4.0 **URL:** \ **Category:** Builds\ **Created:** [July 1, 2006, 7:24pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061 "2006-07-01T19:24:46Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![LAFENGAS](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/lafengas/32/7573_2.png) [@LAFENGAS](https://forums.speedlife.net/u/LAFENGAS)\ **Post date:** [July 1, 2006, 7:24pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/1 "2006-07-01T19:24:46Z")
Okay…so my last bumper was an ///M3 bumper that I hacked up to fit my car and molded a lip to it, ect. Anyway…after a year and half of abuse the lip cracked pretty badly and other flaws that bother me. Bottom line, it was time for a change. This is infact my 4th bumper change. I liked the CSL bumper, but didn’t care for the single duct on the driver side, so i decided to modify the CSL bumper to my liking. . 1st. The Splitters were very weak looking. Holding them up to the light i could see right through them! Worried that I would crack them if i hit anything, now was as good a time as any to reinforce them: ![http://photos.e46fanatics.com/data/500/7558CSL_01.JPG](http://photos.e46fanatics.com/data/500/7558CSL_01.JPG) So…i dipped into my ballistics kevlar supply (this isn’t the aesthetic stuff) ![http://photos.e46fanatics.com/data/500/7558CSL_02.JPG](http://photos.e46fanatics.com/data/500/7558CSL_02.JPG) Reinforced the backside of the splitters. The ‘pointed’ frontmost section has 7 layers of kevlar which is thicker than standard issued army helmets. It’s not pretty stuff, but it works! ![http://photos.e46fanatics.com/data/500/7558CSL_03.JPG](http://photos.e46fanatics.com/data/500/7558CSL_03.JPG) Next I started taking measurements for the duct so i could make an accurate mold and posistion it correctly. It’s not simply just cutting a hole out. To do it correctly, the duct is angled slightly and has a taper to it. ![http://photos.e46fanatics.com/data/500/7558CSL_04.JPG](http://photos.e46fanatics.com/data/500/7558CSL_04.JPG) I found a large yogurt container had a near pefect size. Taking my depth measurements i transfered them to the yogurt container to get the proper sizing and angle. ![http://photos.e46fanatics.com/data/500/7558CSL_05.JPG](http://photos.e46fanatics.com/data/500/7558CSL_05.JPG) I then took an uncut yogurt container and poured plaster in to allow it to solidify an make a good sturdy mold. I used my vacuum bagging system to force the Carbon Fiber tightly around the yogurt container. If i didn’t reinforce it, it would just colapse under the pressure. (this obviously wouldn’t make a great mold) This pic is fresh from the vacuum bag. There are several layers ontop of the carbon fiber. This process removes a lot of excess epoxy so you have a higher CF to Epoxy ratio which gives you a stronger lighter (not that it matters much for this) part. But i had to make sure the CF was pressed firmly against the mold to get a nice smooth shape on the inside of the new duct ![http://photos.e46fanatics.com/data/500/7558CSL_06.JPG](http://photos.e46fanatics.com/data/500/7558CSL_06.JPG) Once all the garbage has been removed and the yogurt container pulled from the CF this is what it looks like: ![http://photos.e46fanatics.com/data/500/7558CSL_07.JPG](http://photos.e46fanatics.com/data/500/7558CSL_07.JPG) Now I cut the CF to shape using the template i made earlier out of the other yogurt container. Putting the CF duct in the appoximate place on the bumper, i used more CF to build a flange around the duct. Doing this gives a more rigid part, more as well as surface area to bond the part to the bumper. ![http://photos.e46fanatics.com/data/500/7558CSL_08.JPG](http://photos.e46fanatics.com/data/500/7558CSL_08.JPG) Now to cut the hole. I put a piece of paper over the OEM duct and traced it. Flipping the paper over gave me the mirror image i needed to be able to a hole in the proper shape and location on the opposite side. ![http://photos.e46fanatics.com/data/500/7558CSL_09.JPG](http://photos.e46fanatics.com/data/500/7558CSL_09.JPG) Using a high strength 2-part epoxy to bond it in place. I left the hole slightly undersized so i would have material to play with once the duct was in a permanent location: ![http://photos.e46fanatics.com/data/500/7558CSL_10.JPG](http://photos.e46fanatics.com/data/500/7558CSL_10.JPG) ---
**Author:** ![LAFENGAS](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/lafengas/32/7573_2.png) [@LAFENGAS](https://forums.speedlife.net/u/LAFENGAS)\ **Post date:** [July 1, 2006, 7:25pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/2 "2006-07-01T19:25:28Z")
After some sanding and rounding the edges to match the otherside. notice the hole isn’t a circle, but oblong. Not an easy hole to match and place correctly: ![http://photos.e46fanatics.com/data/500/7558CSL_11.JPG](http://photos.e46fanatics.com/data/500/7558CSL_11.JPG) And the duct complete: ![http://photos.e46fanatics.com/data/500/7558CSL_12.JPG](http://photos.e46fanatics.com/data/500/7558CSL_12.JPG) Still have more fabricating to do on other areas of the bumper, but I was happy that I got the process down well enough to complete in a short time. Started it Friday early evening and the duct was completed as shown on saturday, the next day. The bumper comes with license plate bracket mounts, which not only look hideous, but i have no inention to use. So i removed them by plastic welding and puddle filling the holes ![http://photos.e46fanatics.com/data/500/7558CSL_13.JPG](http://photos.e46fanatics.com/data/500/7558CSL_13.JPG) this picture is from the backside, i embedded some metal screen as reinforcement so the work won’t ever crack in the future: ![http://photos.e46fanatics.com/data/500/7558CSL_14.JPG](http://photos.e46fanatics.com/data/500/7558CSL_14.JPG) here you can see the screen/reinforcement at the bottom of the hole: ![http://photos.e46fanatics.com/data/500/7558CSL_15.JPG](http://photos.e46fanatics.com/data/500/7558CSL_15.JPG) Completely filled and awaiting to be sanded and smooted out:(will do that tonight) ![http://photos.e46fanatics.com/data/500/7558CSL_16.JPG](http://photos.e46fanatics.com/data/500/7558CSL_16.JPG) I also decided it would be a good idea to further reinforce the backside of the splitters. I’m molding the splitters and doing whatever i can do to distribute the forces to improve my chances of avoiding any cracking of my bodywork. I place a few layers of CF on the backside of the splitter, increasing the bond strenth to the plastic: ![http://photos.e46fanatics.com/data/500/7558CSL_17.JPG](http://photos.e46fanatics.com/data/500/7558CSL_17.JPG) I finished up the fabrication portion. In summary, the following changes have been made from original shipment. -added the air duct to passenger side -molded the splitters to eliminate a seam -reinforced the splitters with kevlar and CF -shaved the license plate mounting holes ![http://photos.e46fanatics.com/data/500/7558CSL_18.JPG](http://photos.e46fanatics.com/data/500/7558CSL_18.JPG) ![http://photos.e46fanatics.com/data/500/7558CSL_19.JPG](http://photos.e46fanatics.com/data/500/7558CSL_19.JPG) ---
**Author:** ![LAFENGAS](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/lafengas/32/7573_2.png) [@LAFENGAS](https://forums.speedlife.net/u/LAFENGAS)\ **Post date:** [July 1, 2006, 7:27pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/3 "2006-07-01T19:27:31Z")
Painted. FYI, the other small hole is for my tow hook and has a cover which isn’t pictured. ![http://photos.e46fanatics.com/data/500/7558CSL_20.JPG](http://photos.e46fanatics.com/data/500/7558CSL_20.JPG) ![http://photos.e46fanatics.com/data/500/7558CSL_21.JPG](http://photos.e46fanatics.com/data/500/7558CSL_21.JPG) ![http://photos.e46fanatics.com/data/500/7558CSL_22.JPG](http://photos.e46fanatics.com/data/500/7558CSL_22.JPG) what the bumper woulda looked like had it only been painted: ![http://www.rsportscars.com/foto/05/bmwm3csl03_02.JPG](http://www.rsportscars.com/foto/05/bmwm3csl03_02.JPG) I painted the splitters for a couple reasons (rather than leaving them stock). 1.) I wanted my car to look like it was sitting lower 2.) I wanted to mold the splitters into the bumper 3.) I wanted something slightly ‘different’ from just bolt-on-stock 4.) because i can. ---
**Author:** ![articzap](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/articzap/32/7361_2.png) [@articzap](https://forums.speedlife.net/u/articzap)\ **Post date:** [July 1, 2006, 7:44pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/4 "2006-07-01T19:44:59Z")
pics on car? ---
**Author:** ![LAFENGAS](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/lafengas/32/7573_2.png) [@LAFENGAS](https://forums.speedlife.net/u/LAFENGAS)\ **Post date:** [July 1, 2006, 7:59pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/5 "2006-07-01T19:59:50Z")
> [@articzap](#): > > pics on car? nope, not on yet. Still need to wet sand, buff, polish, wax, and maybe 3M clear bra. ---
**Author:** ![RuBiCaNT](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/rubicant/32/7622_2.png) [@RuBiCaNT](https://forums.speedlife.net/u/RuBiCaNT)\ **Post date:** [July 1, 2006, 8:18pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/6 "2006-07-01T20:18:27Z")
Nice work as always, Josh!! :tup: You never fail to impress… ---
**Author:** ![Shrives](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/shrives/32/7250_2.png) [@Shrives](https://forums.speedlife.net/u/Shrives)\ **Post date:** [July 1, 2006, 10:21pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/7 "2006-07-01T22:21:54Z")
i love reading your DIY’s ---
**Author:** ![MikeRi24](https://avatars.discourse-cdn.com/v4/letter/m/57b2e6/32.png) [@MikeRi24](https://forums.speedlife.net/u/MikeRi24)\ **Post date:** [July 1, 2006, 10:33pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/8 "2006-07-01T22:33:10Z")
you’re crazy man! nice work as always. ---
**Author:** ![Anonymity](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/anonymity/32/7215_2.png) [@Anonymity](https://forums.speedlife.net/u/Anonymity)\ **Post date:** [July 2, 2006, 4:01am UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/9 "2006-07-02T04:01:58Z")
looks great. are you going to run the duct work to the brakes? or andt where else ---
**Author:** ![Zer0DazE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/zer0daze/32/7624_2.png) [@Zer0DazE](https://forums.speedlife.net/u/Zer0DazE)\ **Post date:** [July 2, 2006, 5:21am UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/10 "2006-07-02T05:21:42Z")
> [@fastandcheap](#): > > looks great. are you going to run the duct work to the brakes? or andt where else i was thinking the same thing turned out really nice. its nice to know that if by some 1 and 10000000000000000000000000000000 chance we’re hanging out, and get into a gun fight, we can hide behind your splitters. 🙂 ---
**Author:** ![BIGHANDS](https://avatars.discourse-cdn.com/v4/letter/b/f9ae1b/32.png) [@BIGHANDS](https://forums.speedlife.net/u/BIGHANDS)\ **Post date:** [July 2, 2006, 7:02am UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/11 "2006-07-02T07:02:09Z")
thats cool good work ---
**Author:** ![Onyx\_Z32](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/onyx_z32/32/7581_2.png) [@Onyx\_Z32](https://forums.speedlife.net/u/Onyx_Z32)\ **Post date:** [July 2, 2006, 7:02am UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/12 "2006-07-02T07:02:16Z")
I like it :tup: ---
**Author:** ![Jeller](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@Jeller](https://forums.speedlife.net/u/Jeller)\ **Post date:** [July 2, 2006, 8:48am UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/13 "2006-07-02T08:48:07Z")
:tup: again at your amazing work and detail :tup: Edit: Now that you have 2 ducts on the bumper, are you going to make them both functional? such as brake air ducts or something? what was the OE purpose of the one duct? intake? Jeller ---
**Author:** ![rj-92](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/rj-92/32/7310_2.png) [@rj-92](https://forums.speedlife.net/u/rj-92)\ **Post date:** [July 2, 2006, 9:40am UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/14 "2006-07-02T09:40:42Z")
Wow man. That’s sweet big ass :tup: ---
**Author:** ![LAFENGAS](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/lafengas/32/7573_2.png) [@LAFENGAS](https://forums.speedlife.net/u/LAFENGAS)\ **Post date:** [July 2, 2006, 12:52pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/15 "2006-07-02T12:52:13Z")
> [@Jeller](#): > > :tup: again at your amazing work and detail :tup: > > Edit: Now that you have 2 ducts on the bumper, are you going to make them both functional? such as brake air ducts or something? what was the OE purpose of the one duct? intake? > > Jeller the brake ducts are stock on my car. The only difference now is I have to convert them from square to round. My plan is to make a flange that will be bonded to the inner fender well and mold a piece of ductowork that will slide over the bumper duct (from the backside obviously) and connect to the flange. The Driver side will do the same, except the duct will split off to feed the Supercharger as well. will update. ---
**Author:** ![SilverGT](https://avatars.discourse-cdn.com/v4/letter/s/8dc957/32.png) [@SilverGT](https://forums.speedlife.net/u/SilverGT)\ **Post date:** [July 2, 2006, 7:01pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/16 "2006-07-02T19:01:20Z")
> [@LAFENGAS](#): > > The Driver side will do the same, except the duct will split off to feed the Supercharger as well. > > will update. Supercharger is that on the car presently or in the works? ---
**Author:** ![psphinx81](https://avatars.discourse-cdn.com/v4/letter/p/e9a140/32.png) [@psphinx81](https://forums.speedlife.net/u/psphinx81)\ **Post date:** [July 2, 2006, 7:51pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/17 "2006-07-02T19:51:40Z")
god thats freaking awesome :tup: ---
**Author:** ![bladez](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/bladez/32/7237_2.png) [@bladez](https://forums.speedlife.net/u/bladez)\ **Post date:** [July 2, 2006, 8:47pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/18 "2006-07-02T20:47:30Z")
amazing work! I love to read your DIYs. Can’t wait to see the car with this bumper on it 🙂 ---
**Author:** ![ly555is](https://avatars.discourse-cdn.com/v4/letter/l/3bc359/32.png) [@ly555is](https://forums.speedlife.net/u/ly555is)\ **Post date:** [July 2, 2006, 8:48pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/19 "2006-07-02T20:48:26Z")
i’m still with my motion to sticky all your DIYs EDIT: shit man i mean i’m even all sticky from that ---
**Author:** ![JaysGreenLX](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jaysgreenlx/32/7321_2.png) [@JaysGreenLX](https://forums.speedlife.net/u/JaysGreenLX)\ **Post date:** [July 2, 2006, 10:00pm UTC](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061/20 "2006-07-02T22:00:00Z")
Geez, great work again. Where do you learn this shit? [Next page](https://forums.speedlife.net/t/diy-another-new-front-bumper-version-4-0/14061.md?page=2)