It's normal under WOT acceleration on a stock Evo. These cars are so rich in stock tune that the A/F ratio falls off the charts. It's an added layer of safety for those with poor quality gas. At enginge RPMs above 5K you can gain another 20-30 HP by tuning the A/F and timing. Need to get your ECU reflashed, install a piggy-back controller, or get a stand alone EMS to do this. Reflash is the easiest and cheapest way to do it. Other options offer more flexibility but cost more.

 

its normal bro...

 

Yeah he didn't say on the bumper, my bad. Soot leaves residue, so I figured that is what he meant. If he said smoke I would have posted differently.

 

Quite normal

 

Now what if there's soot shooting out the exhaust? The other day I noticed a trail of black residue (soot?) on the pavement where I was parked. Is it just me running super rich? I do have the S-AFR idle mixture set @ +15%-20% to compensate the loopy cam idle.

 

that sounds gross.

 

LOL

 

thats normal. If you park there everyday - everytime u start ur car up - it will shoot it out - but then when warm, ur ok

 

Thanks! I feel kinda bad for the black Accord behind me though...

 

No offense intended to you at all man.. but if you beat a 5k modded STI by over a car length with your stock evolution... Then there's something seriously wrong with that guys STI

 

so this is normal?

 

Yes, it's an Evo, try being catless, then it's even worse without a tune... Richness up the waazoo

 

Think before you type.

Evos run around 10/1 air fuel ratio from the factory. So black soot coming out is normal.

 

I thought it was ~9/1 A/F...

 

Like everyone said its normal evos run on the rich side. If the stock black soot bothers u dont go full catless and expect to keep her clean