I FINALLY got myself an SAFC. Through a middleman (zjbarra) who originally bought it from pp13bnos and decided to go standalone, I now have the SAFC that tuned the 167 rwhp S5 NA that CJ had.

So I hooked it up. Thanx to the search I found some great info from Hailers and Wozoom about install and settings for street ported motors.

The darn thing is soooo easy to use. I caught onto it in about 20 seconds after first turning it on. I took a road trip and played with it and tried optimizing settings in each gear, which ended up being 2k, 3k, and roughly 4k rpm at 60 mph. I just punched it from those rpms and messed around with the settings until I found what felt the strongest.

My car is a streetported NA so I can get away with this kind of 'tuning' . . a lean condition felt like this: gas pedal goes in real easy and the power isn't quite as strong as before. If the setting is leaner than this the engine would start to surge and fall off, sort of oscillating in power. An optimum condition was usually just richer than the lean condition: gas pedal goes in not quite as easily but easier than a rich condition, and power is the strongest.

Anyhow, I didn't have my gtech with me so I couldn't do this scientifically, but will get around to it.

The car pulls a bit harder above 5k rpm now. The engine has mild primary and secondary ports with a big aux, and the upper end needed a tad more fuel while the lower end needed some taken out. Judging by how it pulls now, a proper tune could be worth a few tenths in the quarter mile.

So get an SAFC and tune it if ur like me and love optimizing everything.

 

congrats man! I wondered about the SAFC, but I'm going with a haltech in the near future...

 

Isn't that a bit unsafe to tune it that way? I would think you would want to know your a/f ratios exactly instead of just feeling for it.

 

My thoughts exactly.

 

It never knocked on me even when it was a little too lean.

This is how u tune model airplane carbs . . I know I know, piston two stroke is not a fuel injected rotary.

Humidity was high also so it was like getting some natural water injection, which reduced the chances of preignition or detonation.

The motor is pretty new and has had premix run through it over its 7k mile lifespan, so it's probably still squeaky clean on the inside. Preignition / detonation chances are reduced when the engine's combustion chamber is clean.

88IntegraLS can get away with it, hahahaha. When I get my hands on a lysholm type twin screw charger and run 7-10 psi through this thing, it will be tuned on a dyno, etc.

NA's are forgiving if they are in good condition. Like I said, I never felt / heard one ping let alone a knock, and my timing is advanced about 15 degrees over the factory setting, bwahahaha.

 

He's got a little more leeway being n/a and all. Is "leeway" a word I just always say it, but I have never typed nor written it before.

 

Come on NA guyz, don't be scared of going slightly lean. It is easy to tell when the engine was in stoich territory because the power falls off slightly right at tha point.

Airplanes have a mixture setting and pilots feel for a lean condition whenever they are setting the mixture for maximum range in cruise flight. They are instructed to lean out the engine until the power just drops off, and that is ~ 15:1 air/fuel ratio which gives maximum range (or fuel economy in our cases). P51 mustang pilots did this in WWII, and every piston powered plane shy of the lowly Cessna 152 has a mixture setting that u have to know how to set when cruising at medium to high altitude.

All these horror stories of blown motors are making u guys get scared of a little intelligent experimentation with air/fuel mixture. It takes high intake temps, high compression ratio or boost, and a hot spot inside the engine combustion chamber to cause a knock. My motor has none of that stuff, and neither should any other NA motor, but some of them are old and have carbon all over the rotors so I understand the concern.

 

im sure itll be just fine, i was just thinking usually you want the exact AFR's but i donno.

 

For the price of a PLX wideband, noone should go without one that actually tunes their cars..