First my WOT A/F ratio runs about 10.8 to 1 and 11.5 to 1......Is this too rich; car runs on 93 octane.

Now, here is the strange thing, when the car sits at idle it goes all the way to 15 to 1 and 16 to 1. I am thinking that this is way too lean. Car seems to also run really hot. Runs at 210 w/ a 160 stat in 80 degrees. Fans kick on at 160 as well.

My tuner says that it is ok, but I want him to look at it again. The car has Dart 205 heads, and a 242/244 on a 114 cam. The idle quality seems ok.

Just wandering if the A/F seems off to you guys?

 

AFR at idle can be deceiving with a large overlap cam. If it sounds like it's running right, it probably is.

For N/A, any AFR below 12.2~12.5 is probably too rich. You should be around 12.6~13.0.

As for the temps, the stock setup won't even turn the low fan on until temps hit 220's. If the car was tuned for it's operating condition, then it should be fine.

 

I don't know about the cam, but the temps seem high. I have a 160 stat and the settings appropriate in the PCM (which it sounds like yours is also) and I typically run 180-190 in 80 degree weather.
Your open loop AFR is certainly too rich and should be corrected.

 

Could you elaborate a bit more on that? Are you saying those numbers because of the cam he has? I thought the target would be about 14.7? I'm starting to tune my medium sized cam and am seeing around 12.8ish so I guess I'm alright. The cam is around 231/235 600/600 111lsa.

Thanks

 

14.7:1 is stoich and what is targetted during normal closed loop driving.... the 12.6-13.1:1 is the AFR to shoot for at WOT.

 

What AFR should you be at for idle though?

I was referring to Idle AFR on my last post by the way. Just trying to get all this stuff straightened out

Thanks!

 

Sorry bout that....

Typically, cam'd cars will find a decent AFR at idle somewhere around 14.7~15.7:1....depending on how much overlap is in the cam.

I like to set cruise (before PE kicks on) to 15.2~14.5....richening up a little as load increases. Low load doesn't need as much fuel.

WOT should target the numbers I mentioned above.