My TT is running Rich, looking at the exhaust, anything I can do about that, should I try lower octane fuel for a while ??

 

Have you put it on a Durametric and measured the air:fuel ratio? Does it run rich all the time, or just when it's cold? How can you tell it's running rich from looking at the exhaust - soot on the exhaust tips? If I were you, I wouldn't change anything until I collected some data.

Jon

 

+1
I also have to ask , what makes you thing its running rich.
Any other symptoms
AS above advice , get it checked out first for codes and have some logs taken.

 

simply by looking at the end of the exhausts

 

They all run rich when the engine is cold, so soot deposits on the ends of the exhaust. Doesn't mean anything.

If you hook up a Durametric, you can read the air:fuel ratio in real time, record it during boost run, etc. It's reported as lambda value, which is the ratio of the actual ratio to stoichiometric, which is 14.7. You should see lambda=1 most of the time, and it will fall to somewhere between 0.72 - 0.85 under boost, depending on your tune.

Hope that helps.

Jon

 

seemed to go well on slightly lower octane today, still pulls 1.2 bar and the exhaust is a tad cleaner

 

Pulling 1.2 bar on lower octane fuel increases the risk of detonation. If you're not looking at AFR data from your O2 sensors, you really have no idea what the exhaust is doing. Please buy a Durametric and take some data.

Jon

 

Don't do this. You are almost always better off with higher octane.

 

Exactly. Just run the recommended fuel and clean your tips regularly. You're risking pre-detonation /advanced timing by running lower octane.

P.S. It always bothers me a little when people talk about "detonation" rather than correctly specifying that it's detonating too soon. If fuel didn't detonate, a car wouldn't run.

 

I stand corrected!

 

Why in the world would you think lower octane would make you run leaner? Blowing up your engine is not a good way to guess...

 

There is difference between detonation and normal combustion (burning). You don't want your fuel to "detonate" under any circumstance. Detonation causes a huge rapid increase in pressure and temperature resulting in bent rods.

 

If I recall correctly hes running the ams K16s with OEM injectors...
running richer is always better then leaner... unless you like to experience the 4th of july all over again in September...
Get a duramtric and log your car....

 

I don't mean to be an English teacher here but "detonation" means something igniting under compression resulting in a force that's felt external to the ignition point. By definition, detonation is a natural part of car functions, and highly desired if you want to go anywhere.

But that's probably too much Labor Day partying and my foreign mother who was an English nut speaking...

In the real world, you're correct, people always talk about "detonation" to mean "pre-detonation" so I have no problem admitting I'm colloquially incorrect...

 

There is detonation and then there is pre-ignition. I've not heard of pre-detonation. It's no big deal. Technically when speaking of internal combustion engines, detonation has a specific meaning, i.e. detonation = knock.

http://en.wikipedia.org/wiki/Engine_...d_pre-ignition