Just wondering if anyone out there with the Apex N1 exhaust have observed 2
tone colors in their tailpipe. If you look at the pics below, you'll know
what I mean. The exhaust tip is black (running rich), the pipe inside the
muffler is chocolate brown/tan color (lean??), but the cat back piping is
also black, inside the midpipe is black as well.

My car has all the mods, running full open exhuast, intercooler, streetport,
Walbro fuel pump, fuel pressure regulator, ECU, apex SAFC, etc. It's making
good power, and wide lambda O2 testing on the dyno shows healthy air fuel
ratios. EGT temps at WOT around 700C.

I can't understand why my exhaust would have 2 tone colors, and not sure if
this is anything to be concerned about. I know some people read spark plug
colors, does the same apply to exhaust piping? Anybody have the same thing
on their exhaust, or know why the color is like this?

Pics of what I'm talking about:
http://www.geocities.com/rotapowered

 

anybody?

 

bump

 

Since you have open exhaust, what color is the exhaust. If it is dark (black), then you are running rich, nothing to worry about. If not, well, u know. The bownish color may just be oxidation at high temps. scrape some off and put a magnet near it to see if it contains iron, if so, it's oxidation.

 

That's basically how mine looks too.. and every time I see it, I say to myself "If I wasn't running SR's fat pfc maps, I might have thought that I was a tad lean."

Gotta get that wide band working now.