As the topic reads. I have been using a Japanese Tuner for the past few dyno pulls. He is very knowledgable, and can sense detonation before it happens. My concern is that he doesn't have an air/fuel meter. The last few times I have dynoed, he tells me if I am running rich or lean and where and makes the various corrections using my vafc, and each time I leave I end up extracting more power.

Should I be concerned that I am possible running too rich or lean?

 

wrong forume.

is it ITR realted at all ?

 

think about what your asking, then you will figure it out.

 

A really good experience tuner can actually tell the engine is running too rich or lean without a A/F meter. I think for NA engine, as long as the A/F ratio is within a safe range and you get more power after each dyno pull, then it should be all good.

 

Mafay-

Thanks for the help.

Soup ****- Sorry mabye the initial topic title was wrong. My main conern was that my tuner tunes my car without an A/F meter, and I was afraid I may not be making the most possible power because of this.

??--Although not necessarily ITR related it was a general question about dynoing and a/f ratios. I post in here because the majority of members in this forum are fairly knowledgeable. THis posts relates to all cars in general so I feel it is appropirate in this forum, regardless of what car I drive. How do you know I don't have a swap?

 

 

if you're running boost, too lean is gonna screw you.

 

yes running lean is worse than running rich, running too lean can cause you to detonate and damage internals. running a lil rich will actually keep internal operating temps cooler(but worse mileage, but who cares?).


[Modified by Razor, 2:14 PM 12/7/2002]

 

 

There is an A/F, for each particular setup, that will offer optimal performance.

Anything other than this ratio (whether it be more rich or more lean) will not offer the absolute best performance.

 

This was something I've been wondering for quite a while. As far as I know. I'm planning on I/H/E mods and VACF. I can tune the A/F ratio to each rpm range for better power output. The general rule is to never let it run lean.
-Correct my above comments above if I'm wrong-

Whats the optimal A/F ratio for a naturally aspirated engine?
Does the optimal A/F ratio varies in the rpm powerband?

 

When I setup the holley on my mustang, I was told to set it run just a little rich. The idea being that you'll always have enough fuel for all the air which means more power.

 

Fuel is cooling the engine, so you better run rich. But too rich can hurt performance...

Too lean can cause knock (detonation somewhere else in the cylinder at a location where it doesn`t belong at the wrong time). Knock kills your engine slowly.

Some tuners use to lean out the engine at high rpms to raise the curve (better peak numbers), so be careful.

Everytime I went to track, I offered my R some extra percent fuel in the upper rpm range to prevent damage....Better rich than lean, but best performance is somewhere between there.