Custom Bumper

General Composites Discussions Composites Talk
#1

I will be starting, well may be starting depending on the clients needs, a new custom rear bumper.

He has the car and bumper all there. We want to make a rear diffuser into the bumper and exhaust holes in it plus it will hang lower to the ground than the stock bumper does. The diffuser is integrated into the part.

What is a good way to modify a stock bumper into this sort of plug? How in the world do you get carbon cloth to lay down into a diffuser mold that is one piece mold. The diffuser winglets don’t fasten on afterwards. The wing portions are like 7" tall as seen from the back and stick off the tray about 4 or 5 inches. How do you stuff the carbon into the mold and have it stay in those areas?

Also what materials could be best used to make the plug using the stock bumper as the base? I can come up with ideas, but i’m looking for other’s ideas.

#2

about the diffuser: you don’t. you make the big part in one shot, (the Π shaped thing) and the winglets are made separately and bolted or bonded on. unless you are talking about a structure that is more pleasing to the eye, than the air coursing through it.

about the bumper, you can take a big piece of mdf or melamine, and place it underneath the bumper at the desired height, that will be your bottom of the bumper.you will use that to build the extension of the bumper, by either using floral foam that you will sand down then add fiberglass mat and polyester on it, maybe use some paper board profiles to make both sides identical and use the hotwire method to cut foam into shape, or even polyurethane foam and then hack it and shape it with big grit sandpapers and blocks. i would suggest you look into http://www.fiberglassforums.com/index.php ,they make a lot of stuff like that. dirty methods, and most of them dont even know what carbon is, but you can always learn something new…

#3

Oh no… that site is Ghetto… decibal ghetto lol.

I’ll have a read sometime.

It always cracks me up that people will add 200lbs of car audio crap to a car. oh well… i guess they like it.

#4

if you suck the winglets in first, cure, demould and trim, you may be able to basically sit them back in afterwards and secondary bond the flat section of carbon to them in the mould. its a long winded way if doing things and to be honest id just make a flat panel and bond winglets to it afterwards. im on fiberglassforums too. not everyone uses truckloads of bog and has big stereos,but yes, there is a lot of ballbags on there that rate their crooked expanding foam bumpers and stereos. no offence taken. unfortunately, sometimes the clients budget dictates a bit of ghetto, or a penchant for multiple subs.:slight_smile: