Black smoke on acceleration and declaration
 

93 Rx7 pte 6262 single turbo divided manifold dual waste gate,vmount micro tech ecu 16bls boost. Now that my setup is out there here is my thing. A few of my 3rd gen buddies say that when I am on boost and when I down shift a large puff of black smoke exits the muffler. There cars under the same conditions throw fire. Am I running just to rich or is there something else going on?

Probably too rich. Could be too much fuel or the timing isn't where it should be.

Dale

Could be worn apex seals. How many miles on the engine? Has the compression been checked?

Engine rebuilt two years ago by a reptuable builder. It makes good power aend still holds 18 of vacuum. I figured it was to rich for my afr is less than 10 afr under boost. I just figured if it we're rich it would blow flames but no fireworks. Bought some plugs and the car goes for tunning tomorrow. I hope this fixes the problem.

If you're THAT rich you're probably not going to get flames. There's such thing as too much fuel.

Dale

I was thinking the same thing but I know there much more experienced and knowledgale persons them me on this board. Thanks brother I hope to get this resolved today. This rich mixture has clogged my plugs and 02 sensor. I replaced them yesterday and hope to get tuned up today

How did it go ?

Got stuck at work I'll 8pm so it was a no go. I resceduled my tunning for tomorrow at 930 am. I am concertned that it will not go as i plan. It appears that this dual wastegate setup may be harder to fine tune correctly. Going to try to convince my tuner to also tune the egt also. Don't know if tunning dual wastegate are more complicated. Hopefully someone with more knowledge can chime in

Bump
 

Bump

Update
 

Got the car street tuned. It is way better but still on the rich side under boost. I am thinking of having egt tuned

Well
 

At one point I was 10.5 under boost while he was tunning but when I got on the boost after I left the shop it was different. My wide band starts to read at 10 afr but I am below that on boost. He fixed partial throttle and the transition from primary to secondary. When I am off the boost the car is at 13.5 to 14.5 under acceleration. No boost. I always thought my car should be at 10.5 to 11.0 afr under boost. Is this too lean or is this safe. I always thought it was safe. Also egt tunning was recomended by my tunner since I run two separate westegates. He can't stand that setup do to possible lean condition on one rotor and not the other