Why so much black carbon on exhaust tips and cutout ?

[mytta49]

I have been running the TTA with the electric cutout open now for about a month. When put up on the lift, I found that the butterfly had somewhat of a thick dry black carbon. I drove the car for a few days with the cutout closed and the top of the rear bumper had a very fine layer of black carbon.
What is causing this ?

Here are the mods
Alky kit
TT chip for alky
30 lb injectors
Scanmaster
RJC boost controller
RJC power plate
160 thermostat

Running 20 psi boost with cutout open and 18 with it closed.
Using Denatured Alcohol and have been adding 100 no lead gas at a rate of 50/50 meaning for every gallon of 93 I add a gallon of 100 as a precaution.


42 FP with line off
Alky dial setting between 4 and 5
BLM 127 at hot idle
O2 change at idle and generally when I do a recall on the scanmaster after WOT through the gears, I get 0 knock and O2 readings generally around 850 to 870
AF 05

 

[Quiky One]

Black soot could be unburned fuel. You rich? You also shouldnt need 100 octane gas with 18 psi and alky..

Jason

 

[87geeinn]

With those 02s and BLMs, I'd say you are running fairly rich.

 

[mytta49]

Thanks, but any idea how to get it to run leaner ? I think I will post this on the TTA forum to see if anyone there has had the same problem.

 

[mytta49]

moved

 

[Razor]

Your too rich.

Your BL's at idle are fine, problem is your chip is designed for 23-24 PSI boost worth of fuel with alky. You run 18 PSI.. its gonna be pig fat.

Once your MAF hits 255.. the computer doesnt know or care what boost your at.. at that point it will open the injectors "X" amount. You need to adjust boost based on fueling.. if you want to run less boost.. have a chip with less fueling made.

This extra fueling will show up as soot on your rear.. and with a stock computer... you dont have perfect control of your fueling. O2's in the 850's is also evidence..

HTH

 

[mytta49]

Razor
So if I increase the boost to 22, should that take care of the rich problem ?
I did have it up to 22 not long ago with no knock if I set the Alky knob to 6, but turned down the boost as a precaution only.

 

[Razor]

Should be better at WOT.. getting to WOT is another story.. but you'll be on the gas longer at WOT than getting there.

At least the car will pull way harder .. 22 PSI is nothing