as many have reading I am just starting out to tune my AFR on the street using the LM-1 AFR logger and my Predator.
here is the "before tune" graph:
I am always below 12to1. Then I made a -2.5 percent change in the Predator "Enrichment Mode" and here is an almost identical run with almost identical weather:
it never dips below 12 and moved the line up (leaned-out) about a .75 AFR on average.
could I feel it??? Let me say this; I did 3 runs "before" and 4 runs "after" tuning. The 1 to 2 shift gave much more tire chirp after tuning... more than the car has ever done before. I also noticed the engine running a little smoother during WOT after the tune. I pulled in the driveway with a BIG on my face.
I think I'll leave the AFR tune there for now and see if it helps on my track times.
here was my best ever 1/4 run from last year; and I'm aiming for the 12's the next time:
I again want to thank Phil (Phil97SVT) for making me aware of the Innovate LM-1 AFR logger and sharing his knowledge of it.
Re: AFR tuning - First attempt; Predator and LM-1 (Mike Mercury)
BTW, I've gotten emails asking about my installation of thr LM-1. I'm not finished yet with final installation; but here is a pic of where I have the O2 bung installed (passenger side) just in front of the pup-cap. Plenty of room there - obviously the O2 sensor is not in this pic, and the bung has the screw-on cover installed:
Re: AFR tuning - First attempt; Predator and LM-1 (gojo)
gojo;
good point - except I only install the WB O2 sensor for tuning runs, and then take it back out. The holes in this particular sensor are at the end of the thimble - which is situated near the center of the exhaust pipe when the sensor is installed. No matter what the orientation - the sensor element won't ingest water that's running along the interior surface of the exhaust pipe.
I don't have the RPM input installed yet. But as I mentioned earlier - my version of the Predator does not give RPM specific tuning. Instead it has a fixed curve over the entire RPM range which was finalized by data collected during their initial beta testing of quite a few C5's. So; I don't really require RPM dtat - though I will eventually connect that up to the LM-1; mainly out of curiosity.
Re: AFR tuning - First attempt; Predator and LM-1 (Mike Mercury)
I leave mine in. It's pain to remove it. Here's a writeup from Techedge.
"Sensor Positioning
The sensor requires an 18 mm (1.5 mm/thread) bung. This should be placed before the catalytic converter
and far enough from the exhaust port so that the exhaust gasses will not be hotter than the sensor. An extra
bung just before the cat is considered the best position. Tailpipe sensing is not recommended as the sensor can
be cooled and the cat will affect the unit’s measurements. Turbo installations should never place the sensor on
the high-pressure side of the turbo as the sensor’s measurements are made relative to an atmospheric
reference (and it’s generally way to hot for the sensor here too).
The sensor should be mounted between a 10 o’clock and 2 o’clock orientation, never upside down or
horizontal. This prevents condensation (mostly during starting from cold) from dripping on to the sensor’s hot
ceramic internals and causing immediate failure. Never point the sensor into the gas flow, as this will rapidly
clog the internal diffusion chamber."
Re: AFR tuning - First attempt; Predator and LM-1 (Mike Mercury)
Quote:
But as I mentioned earlier - the Predator does not give RPM specific tuning. Instead it has a fixed curve over the entire RPM range which was finalized by data collected during their initial beta testing of quite a few C5's.
Really ??
My Predator (model U7193, for 2004 models only) has two enrichment adjustments -- one for 2K to 4K, and one for 4K to 7K rpm. Ditto for the WOT spark advance/retard.
I'll have to see if my older version can be upgraded. I've edited my post so as to not confuse others.
Thanks for the info - too many lurkers here that will not add to the discussion.
Mike-
Word is they supposed to be upgradable but we are waiting for the elusive 1.4 upgrade. I have an E-mail somewhere about this and I'll post it later when I find it, maybe tomorrow tho. Jeff
__________________
My baby, gone, but never forgotten
99 Nassau Blue Coupe A4...JMX CLB, Optima Red Top, Z06 Ti's, HP Tuners, VaraRam, Hypertech 160, HomeLink, Window Valet, Borla X-pipe, A&A Rocker Rails, C6 Chromies!, Pro Torque 2800, 3.42 gears!!
Best ET 12.581/Best Trap 108.97 1.72 60 ft.
Mustang Dyno 7/10/04 311.5RWHP/319.2RWTQ
Mustang Dyno PFE 6/04/05 3 329RWHP/336RWTQ!!!!!
Mike, why not just bite the bullet and buy up in tuning software? Do you have many more mods planned? I would maybe start saving up for HpTuners, edit, or see what efilive comes out with. I also hear Tunercat is supposed to release a tuner in the near future. If you have many mods planned you'll hit predators limits pretty fast.
If your car is N/A then u should shoot for 13.0 AF which will give u more power. I would lean it a little bit. My car ran the strongest with a 13.2 AF in a cammed LS1. If u had a SC or Turbo then 12.0-11.8 would be ideal. Good luck.
Mike, why not just bite the bullet and buy up in tuning software? Do you have many more mods planned? ... If you have many mods planned you'll hit predators limits pretty fast.
I agree; but I'm more a technology geek than I am a racer. I am content with the single-fixed curve with my older Predator. And if they offer an ungrade to the dual RPM range AFR tuning - that would be awesome. But more than I would ever need.
Edit would more than cure your thurst for geeky technological type stuff. There's so many tables and so many adjustments you'd be busy for months. I've seen alot of your replies and you're very accurate and I can tell you've done some reading. I'd say consider the upgrade in the future.
Optimum AFR really varies depending on the car. Some N/A cars make more power at 12:8 and some cars like 13:2 and all points in between. The only way to know for sure what your car likes is to get it on a dyno and do some pulls.
Corvette Store
AFR tuning - First attempt; Predator and LM-1
on my face.
