I've seen something about this on here somewhere else before; has anyone else noticed the black soot the exhaust seems to be emitting from the speed 3's? Is it because the engine is running too rich a fuel mixture? I'm pretty sure it has been a common problem for speed 3's, mine has it, and the brand new one on the dealer's floor right now, with onlya couple of miles on it, has the same black soot. Could the CAI and exhaust sort of fix that, if it is running too rich, or would the computer just adjust according to the airflow? If it is running rich, can't that cause some fairly serious problems with the turbo? Sorry if there's already a thread for this, I didn't see one...

 

Mine has the black tail pipe, but the computer controls the air/fuel mixture so CAI won't help. In theory, more air allows more fuel which equals lower mpg. I don't know how it effects the turbo.

 

All cars are tuned to run rich to a certain extent. Running lean melts parts, you NEVER want to run lean.

As the A/F ratio varies due to various factors(it's not static), the fuel mapping is set up to be Rich to Ideal, but never toward the lean side. Black build-up isn't unusual, even for a non-speed (my 3i 2.0L also has build-up on the exhaust tip.)

Example, that wierd smell you get when someone in front of you accelerates real hard is a rich mixture - unburnt fuel getting spent out of the tailpipe. Although you Speed3 guys might not see too many people in front of you accelerating away....

 

My 3i 2.0 does the same thing but i have custom exhaust where the resonator was removed and now i smoke like an old-school CRX. Especially when i accelerate are spit out alot of water/gas/black soot. I really need to get a stand alone fuel mang. but with out turbo it seems kind of pointless but you speed3 guys might want to take a look at a stand alone especially if you are going to going up the turbo or get a boost controller or intake or full exhaust.

 

If I clean the pipe if the MS3 and just start it up, there will be some soot deposited in seconds. Maybe it was already in the pipe and gotblown out to the tip on startup, but it does return right away.

 

cars run rich on start up and this is where the carbon aka soot comes from. best thing you can do to keep it in check is make sure you get you car up to temp every time you drive it and put some hgwy miles on it

 

I agree with everything i've read here so far. I'll add that the fuel mixture is changed in the us for certain areas, low temps in winter. I'm not completly sure what the use of this winter mixture is but i have been assured it will cause more 'stuff' from the exhaust. Also the speed3's a rich running anyway, and turno cars usually are and have the same thing. Only thing i can say is keep it cleaned at least once a week. Over time it'll work at the chromw and you'll still be cursing after hours of poilishing. ^^