So I guess my evo has been black smoking for a long time but just started recently thinking about it. Buddies behind me say when I accelerate my car looks like a semi with the thick black exhaust. It leaves my whole back trunk, license plate black and etc. I'm on cobb stage 2 tune with a hfc and ultimate racing exhaust. I don't want all that black smoke. Could it be the hfc exhaust combo?

 

Do you have a wideband? Black smoke under boost? Or always? Sounds like a rich tune, you also get black smoke from a boost leak.

 

Buddies say it's when I first start accelerating from a stop, like at a stop light. Idk about when I'm moving on the higher rpm. I've recently done logs and watch boost on the cobb and I'm getting the right boost for my tune. Hit in the 26s or so peak.

 

I used to have a cobb ap stage 2 tune and it was quite rich. To be conservative I imagine. Your next mod should be an afr gauge.

 

Could that have to do with my below 200 miles I get a tank? I don't drive that crazy. I barely ever use sport mode on my mr. I guess I'll pm cobb. I might play with the maps, maybe I should try stage 1 or stock and see if it's the same?

 

try the stage 1 tune, im running stage 2 as well, but barely get any smoke at wot 0.o

 

< 200 miles per tank is very rich, I think I get around 260 and then the refuel light comes on.

 

cobb OTS maps are very rich...for insurance reasons i would assume. If they were tuned aggressively people would try running different stages than for what they are modded for and their engine would go BOOM! and they would blame cobb.

so to answer your question it is a very rich tune. you will probably see low 10's on the AFR if you had one.

 

well i'm waiting for the cobb guy to pm back, hopefully tomorrow since it'll be monday. Yesterday I installed the LWG stage 2 and had my brother help me with driving my car while I watched and saw a good amount of smoke, I can't believe how dirty my back is full of black crap. Maybe tomorrow I'll flash to stage 1 and do the same test with my bro and see. I've never gotten above 200 miles till refuel light comes on.

And a side note, I discovered how loud my evo is lol. a hfc and ur dual catback = loud lol. I might have to change exhausts too, seems too loud for my liking.

 

Its completely normal all X's do this. No tune will fix this.

I'm tuned for 11.5 while not very lean it is not very rich either, still blows carbon under WOT.

I believe I read somewhere its the way the exhaust valves are and leaves some unburnt fuel.

Every single X I've seen dose this unless they're on the corn.



There should not be clouds of smoke, but defintely a noticeable amount deposited when you get on it.

 

+1

I'm 11.8 at WOT. Still get black smoke.

R~

 

I could try to take a quick vid up close to get the amount of smoke to see if its what everyone else has. I used a fuel cleaner stuff a few weeks ago that helped my tank go a little longer, I use to only get 160ish, now i'm close to 200

 

I think the Cobb OTS maps suck. Just pay up for a tune its well worth it.

The car is night and day between the OTS map and a dyno tune.