After getting my car tuned i expected a bit of carbon build up on the back but this seems a little much. is this normal and what are the long term effects to this. im worried about getting that yellowness you see on some cars. cleaning it every second day is becoming not so fun. opinions.

after one week ~ 180kms / 111 miles








after 1 day ~ 30kms / 18 miles (washed everything but half bumper)

 

I have to say, I know mine gets soot/black fast(maybe no as fast as yours)... all I can suggest is keeping it clean, and having a good layer of wax on it too.

 

You got a tune and it is still that rich? Holy crap..

Either you are flooring it everyday for 100 miles straight, or your AFRs are like 8s.

My car gets black, but it takes Atleast two or three weeks and lots of hard driving to even come close to your one week pic. And yes, I have a testpipe.

 

So if the tune is real rich it will develop that soot on the back? How come everyone says the OEM tune is very rich but it doesnt develop all that carbon or soot?

 

I get some carbon build up on the back after a night of beating on it, however it is not even close to that bad.

I have noticed after a few months it actually changes the color of the paint, and you need to use a heavy duty cleaner or clay bar to remove it.

 

Personally if that were happening to my car I would get a second opinion on my tune.

 

My VIII was like that. When I get on it my X lets out a big black puff but no real build up on the car.

 

+1. That's what I was saying. Either the OP is driving like a maniac from point A to point B all day, or his tune is CRAZY rich.

Well, I'm guessing since you have a new Evo, but you are prolly running the stock cat. Switch that bad boy out to a testpipe and watch the back of your car turn colors.


EDIT: Just noticed this guy is from Australia. I know it shouldn't make this big of a difference between different countries fuel, but could that also play in to it? What kind of fuel are you running? 93 oct? E85?

 

thanks guys, i give it a bit of punch out of roundabouts but its really just driving to and and from work nothing spastic. still have the cat in, no test pipe.

when the car was stock i used to get a small puff of black smoke but it never built up like this ever. Im not really sure how the physics of the smoke even works. if im on the move the whole time never get stuck in traffic maybe a bout 5 red lights a day how does it even stick on there. should it just blow off into the distance.

i put the go pro on the back to see how much black smoke was coming out, as i see a fair bit in my rear view under acceleration. but i pointed its at the exhaust which wasn't ideal (apart from the awesome noise and the pops and bangs). so ill point it out back next time.

running BP Ultimate 98 Octane

unfortunately the tuner is about 6 days drive away otherwise id just take it back.

what are the downsides to running so rich ?

 

I had the same thing with my Force-Fed tune, and it's been barely noticeable once I got tuned by someone else

 

I have the stock tune and I don't get anything like that on my back bumper. Just road dust.

 

Mine did this on stock tune when I changed the catback. Crazy amounts, even more than in the OP. It's still doing it after a tune but not nearly as bad, though the guy who tuned it said it is probably because I have a 120* aftermarket thermostat and that's way too cold for the X.

 

Basically, being really rich makes you just burn through more gas and makes the back of your car dirty. The stock tune is rich to be safe.. If you start going on the opposite side of the spectrum (running lean) that's dangerous. But running rich isnt too bad..

 

6 day drive for a tune? And I thought I had it bad.

 

What mods do you have done besides the tune? This is pretty normal with an open exhaust...especially on an Evo. Here is a picture of my driveway. Only about 7 months worth of build up in this picture.

My old 05 STi had it and my old 09 370Z had it...though neither 1 near as much as the Evo. Other than going through spark plugs more often, and if you still have a catalytic converter, going through that more often, it's no big deal.