patsmx5

iTrader: (16)

So.... When I ran 12.5:1 AFR's it didn't smoke in boost, or at least not noticeably from driving and nobody ever told me it did. But with my car tuned to 11.5:1 in full boost, I can see a decent amount of black smoke coming out the back. I don't have a catalytic converter. Motor runs strong as hell, no knock, never uses oil ever at all whatsoever not even a spec or an infinitesimally small amount. But it black smokes in full boost. Like a diesel with a programmer, but not a sever obviously. Just wondering if I'm alone.

Do you have a catalytic converter?
What AFR do you tune for in full boost?
Any visible smoke at full boost?

cjernigan

iTrader: (13)

No cat.
12:1 & 11.8:1 above 14 psi
No visible black smoke at full boost but I do get some soot on my bumper so there must be some. The small black specks **** me off most.

m2cupcar

iTrader: (5)

Has cat. No visible, but the tail pipe is black. I think those specs come from a collection of particulate in the exhaust that breaks loose. I get it, though not bad.

y8s

iTrader: (8)

I haven't seen soot out of mine even running slightly richer than I was (high 11s at 9 psi).

I have no clue if my bumper is black. but that's more from rich idle since the flow velocity at speed is high enough to keep it off your car. note: i idle at 14.3:1.

cjernigan

iTrader: (13)

You are running a cat still though aren't you Y8s?

crashnscar

iTrader: (9)

Yep....

Braineack

iTrader: (62)

you saw some out of mine that one time right? but i have no cat...

Laur3ns

Could be accel enrich as well if the black smoke is only short. I'd be more worried about blue smoke...

patsmx5

iTrader: (16)

Nope, it's just the tune. Just curious if everybody has this to some extent. I never noticed till yesterday when I decided to look in the rear view mirror during full boost. Scary to take your eyes off the road when in full boost. I did a few 2nd and 3rd gear pulls and it's pretty repeatable.

Laur3ns

Rear mount cam... may try this tomorrow...

Savington

iTrader: (31)

11.0:1 at high RPM and no black smoke here. I have video of 4-5-6 pulls to redline in 6th and there's nothing from my tailpipe. This was with a cat, though.

therieldeal

iTrader: (2)

YouTube - Escort GTR Turbo - dyno's 241 hp / 244 tq

this was shortly after i upped the boost from 9psi to 18psi... REALLY conservative tune, like high 10's AFR. no visible smoke (exhaust exits next to passenger side tow hook)

i do have a cat.

johndoe

iTrader: (5)

I've noticed it on mine and I've noticed it on brand new modified cars as well. Black is okay as far as i can tell.

kotomile

iTrader: (24)

No visible black smoke, plenty of soot on the bumper between washes. 11.5:1 in boost, no cat.

karter74

iTrader: (4)

No black smoke here at 11.5:1 in boost. No cat either.

patsmx5

iTrader: (16)

I guess mine's special. Guess I could datalog it just to make sure it's running 11.5 and not richer. Need to hook up my AFR gauge one day.

y8s

iTrader: (8)

I am running a cat...

but you've all seen the AFR readings on the dyno... they exactly match the onboard wideband. even with the cat. over 3000 rpm, it's not doing much.