safe a/f ratios
 

i see anywhere from 11.1 to 14.8 on my a/g gauge is this safe?

it idles at 11.1 when i cruise its at like 13.6 and wen i get on it a lil bit it goes to 12.4.

how lean can it go before damaging the motor?

i ment a/f**

anyone?

11.1 at idle is pretty damn rich (same as my car), and 11.1 is about normal for WOT.

AFR'S
12.0-12.5 at idle
14.7:1 at 25"hg and climbing to ->13:1
13:1 at 0psi
12.5:1 at 1 - 7 psi
12:1-11.5:1 at 7-20 psi

thats weird im running 10.5 at 5-12 PSI

12:1 are you kidding!...thats way to lean for 10-15psi of boost on an rx7??

I run at 10.5-11.0 is this insanely rich then

I would think that 10-15 psi would merit a rich mixture. especially once you start considering the ramifications of detonation.


On another note, in the PFC forum, there is a gentleman that runs 16:1 when cruising down the freeway, but under any load it goes to richer than 14:1.

um.....i have an autometer gauge.
i have an option between lean, stoich (wtf?), and rich. can anyone put a number to this? lol
i idle right on the edge between stoich and rich but under any acceleration it goes halfway into rich.

Are you using a wide band O2 sensor and gauge or just the cheap gauge you splice into your stock O2 sensor? If you have the cheap one then you cannot tune by it accruately, you need a wide band for tuning.

on 9psi i get 11.5 and on 12psi i get 10.5 should i be worried? car is stock apart from apexi intakes and untuned powerfc.

10.5 is too excessive

excessively rich or lean? i thought 10.5 was ideal

10.5 is rich

So what is the ideal cruise stoich ratio for a non emissions FD?

is it possible to detonate by leaning out the LOW-Low Throttle cruise rpm ranges? i try to run a 14.5afr

Under boost I always maintain a 10.5 at any PSI....is this really too rich guys?

10.5 is supposed to be extremely rich for other turbo applications....11.5 -12 theoritical is very good and u are not afraid of high temps in the motor....but anything above that will cause high temps in the engine and we all know the results....
but this is theory when i was working on piston engines!
even the subaru impreza turbo BOXSTER engine was a bit strange...and dint like more than 11.5-11.7 , anythin more than that made the 3d cylinder get much damage (cuz the turbo was close to it....)

So what about wankels???

I figure under boost, you dont exactly have to worry about carbon build up, and sacrificing a little fuel economy and a little bit of power to be running that much further in the safe zone... with a rotary... is worth it imho

Let walk through the steps... I`ve learn this the hard way by blowing a couple engines in my earlier years.


AFR'S
12.0-12.5 at idle is VERY ACCEPTABLE ON ROTARIES...PORT SIZE VARIES THOUGH.

14.7:1 at 25"hg and climbing to ->13:1

13:1 at 0psi WHILE TRANSITIONING INTO LOAD/BOOST/HIGH RPM

12.5:1 at 1 - 7 psi VERY ACCEPTABLE WITH CONSERVATIVE TIMING

12:1-11.5:1 at 7-20 psi VERY ACCEPTABLE WITH CONSERVATIVE TIMING

11.2-10.8 AT 22-30 PSI (10.8 FOR SAFETY)

10.5 IS VERY RICH. PROBABILITY FOR CARBONIZATION AND STICKING SIDE SEALS.


To each`s own...Good Luck.

yes i have a wideband.

and thats for the steps *andre sinclair*

11.5 to 12.1....conservative....thats aggressive as hell for 15psi

HENCE THE WORD: "Conservative Timing" ... you can also separate timing split/gap.

Try looking in the PFC forum, or searching under Chuck Westbrook, aka CEWRX7R1 for AFR's.

Many people run 16-16.5 for cruising with no problems, better mpg. At 12psi I would run at or just above 11.5:1, if you have 93 octane.

Chuck Westbrook I've heard is very good. But, Steve kan I've met in person and he has confirm my thoughts and taught me thing or two.

Try a search for either tuners.