PorscheDoc

Since my car is off the road for the winter while I am doing the paint, a freind of mine and I decided we really didn't like the rear bumperettes on the cars. So, we decided to get rid of them. Not only are we getting rid of the rear bumperettes, but we are also sucking the bumper itself in about 1.5-2". The end result will be a rear end that will drop pretty much straight now from the spoiler. We figure we are shaving about 3" off the rear. The process involves removing the bumper and bumperettes, and Tig welding the 6 holes in the bumper shut. A little grinding, a little sanding, a little filler, and some primer and paint, and it should look pretty good. Because we are sucking the rear bumper in further than the eccentrics allow, we also will be modifying the bumper end caps, and shortening them about 1.5-2". You can see in the last picture how much we will shorten the caps. It will take some work to modify the caps, as the mounting bolts attach to the front of the cap, which we will be cutting off. Since the shocks will be collapsed, we do increase the risk of increased damage if involved in a rear end collision, but if that happens, I will gladly take the money and run. Thankfully, Chris has a degree in metal working, so for him, this work is pretty easy. I do a lot of watching, and saying, yup that looks good, we should cut there.....if you think so, lol. Anyways, here are some pictures of how it will look.

The first bumper that Chris sealed up. The skim coat of bondo is on there to fill any imperfections, the holes have been Tig welded and ground smooth.


And on my car, we modified the bumper shocks and held the bumper in place to give us an idea of where to trim the bumper caps and how the depth will look:


Once we sucked it in, I was afraid the rear valence would stick out too far, but it is still not as far back as the rear of the bumper.

testarossa_td

Keep up the good documentation !

Cross thread.
https://rennlist.com/forums/showthre...t=front+bumper

https://rennlist.com/forums/showpost...08&postcount=5

jgporsche

I have taken the bumper pads off and love the look, but lately i have been thinking about trimming some of the bumper off to make it so it sticks out less, great project. I am very interested to see how it comes out....... BTW here's a pic of my rear.....

PorscheDoc

The front end from the other post is ready to paint, i have primed and wet sanded, just waiting for a nice enough day that I can shoot it outside the shop, then move it inside. The conditions have to be near perfect when shooting the Metallic paint. Today is 68 degrees, but there is a 20mph wind, so that shot my plans for spraying today. Which is ok, as I can then finish the bumper, get it sanded and primed, and wet sanded and ready to do all at once. I should be able to bang out the modifications to the bumper this week. Spring is coming, so once the weather starts being a little more consistent, things should start rolling as I had planned.

My other small mod, since I am not painting the rear quarters right now, I am going to remove the rear side markers, sand them smooth, prime them, and paint them to match the car. Since I filled the front markers, I figure probably will look just as good like that for now, as if I left the red markers there anyways. We will see how it comes out, if it doesn't work, then I will just pop in another set of side markers for the time being. Curiosity killed the cat I guess you could say.

testarossa_td

smooth....

RK951

I love the look. Would it have been easier to install the rear euro bumper?

PorscheDoc

Probably, but what is the fun in that This doesn't cost anything but time and a little primer and paint, which would be needed with a euro bumper anyways.

User 41221

This mod also has the advantage of not shattering like the euro bumpers do if they get tapped. The downside, as noted by Karl, is that more significant damage might occurs, and I would be worried about the insurance company finding out... lol Damned if you do, damned if ya don't!

Regards,

Burma Shave

How do you intend to reshape the end caps while keeping the taper/proportions smooth.

SamGrant951

hmmm, I never thought of doing this. I have a euro front bumper on mine and like you was not painting my rear quarters so didnt have them filled. Interesting idea - I may follow suit and prep the sidemarkers to have painted when they shoot my 968 mirrors/handles next month. Is there any kind of special adherent to use when painting plastic...ie like a primer? Easy to go back to how it is if it looks horrible.

I also appreciate the work going into the rear bumper - I think it will look great but leave a little safety net vs. a euro fiberglass bumper. I have a fiberglass rear and its thin with no shocks/bracing. Goodbye rear end if Im ever hit.



rear/side view: http://members.rennlist.com/sngrant/951rearside1.JPG

PorscheDoc

The end caps will stay exactly the same, only they will be shortened a few inches. There is enough material that it shouldn't be a problem with lining up with the rest of the rear quarter panel from what we can figure. If there will be any issue, it will be at the very bottom front corner, which is completely covered by the rear valence.

PorscheDoc

Damit Sam, I love your car, lol. I was wondering the same thing on what to use to adhere to plastic, I will ask the paint shop what they recommend doing with it, and will let you know what I find out. Granted it is a different plastic, but I can't imagine it being any bigger of a process than painting the front bumper cover.

jgporsche

Sam, GREAT looking car!!!

SamGrant951

Yeah, Im guessing a flex additive would normally be used, but I can't see the sidemarkers "flexing" like a normal plastic or urethane part - just wondering if there is something added to promote better adhesion to plastic Do let me know what you hear...and thanks for the kind words.

btw - keep us updated with pics, cool project.

Matt Sheppard

The adhesion facilitator your talking about is called tie coat, at least at the paint shop I frequent. You can add some into the paint after shooting it 100% on the urethane part to give it some elasticity. I shot my side skirts and batwing with it when I painted them body color and it's held up nicely for well over a year of abuse.