Is this soot normal?
 

after about 1 day of the car being clean the rear bumper is covered in this black dust that I assume is from the exhaust. Is this normal?

http://i890.photobucket.com/albums/a...4/IMG_0609.jpg

http://i890.photobucket.com/albums/a...4/IMG_0610.jpg

I doubt it's from the exhaust. You'd see it collect more as you get closer to the tailpipe. It looks too even across the bumper and likely from the road. Wash & clay bar should get that all removed. Just make sure you re-apply wax. Adding a quality sealant may also help repel it from sticking so much in the future.

It may also be iron deposits. You could try aquartz iron cut.

Every spoilered car I have ever owned collected dust and dirt like a magnet on the rear bumper. My NSX was especially terrible. I always thought it was mostly rubber, tire wear from the road.

Looks normal to me. I get that **** all over the side of my car. I hate it, like a weaker tar almost. Sucks to sit there and scrub with a micro fiber to get it off.

op- after you dry your car after a wash or wax, run the bumper with california duster. it removes the static build up.

and no, that is not normal. you are running too rich or just attracting carbon dust from another car.

Particle size is a bit large for tailpipe soot. And, as Cmike2780 pointed out, it would be more concentrated around the pipes. It looks like road dirt (tiny bits of tire, primarily) to me.

50/50

OP, do you have TPs or HFCs???



I HAD TPs, not back to stock and holy crap it's a world of difference...

I have test pipes, but I've had this problem since I bought the car new

A lot of it is brake dust. It is really bad after a track day. There isn't much you can do except switch to a lower dust pad.

do you guys think it has anything to do with the little vents in the rear bumper? Like brake dust getting through there? I also removed the little square paper filter looking things that are underneath the trunk lining near the fender wells...I had no idea what those were for.

Yes, the vents help but the dust comes from the front of the car too. Every time you hit the brakes you are wearing off a layer of the material. It ends up all over the back of the car because of the way air flows over it.

I wouldnt know.. I have a black car! :P

I have the same issue with mine with no change before and after TPs. I too thought it was exhaust soot but perhaps it is brake dust or just general road/ tire gunk. I haven't tried licking it yet. That may be next.

I have Art pipes, it wasn't bad until I lower the car and added spacers. Now it always there! Oh well, it give me another reason to spend time with her!

the rear bumper vents are fake!

i had the same stuff accumulate on my rear too after i put on res tp's. once they broke and i went back to the factory cats the problem lessened. the black stuff i see now is tire that comes off during heavy driving.

i would put those paper filter things back. they are for airflow of somesort and the paper part keeps crap out of the cabin. (if these are the same items im thinking about)


i made a thread about this awhile back. basically make sure your rear tires are aligned and yes the TP's are making it more dirty.