Just got my UTEC and I am not afraid to admit that I am a in a little over my head and I have a couple of questions:

1. In open loop boost control the UTEC defines boost parameters as % of boost contronl soleniod duty cycles. My question is how does this translate into different boost levels?

2. Open loop boost control vs. closed loop and MAP vs MAF which is better?

3. What is a good fuel formula to use to determine optimum AFR at varying load levels?

I'm sure I will have more stupid questions and I don't plan on doing any tuning until I am a lot more skilled, but, a guy has got to start somewhere. The guys in this forum seem to have an outstanding technical knowledge base so any help would be very appreciated.

 

Oh yeah except for my boost gauge and UTEC my evo is bone stock

 

The simple answer is "It depends" Generally with the ABC opened about 2 turns, 75% duty is about 19psi.. But it will vary with weather, mods, and a few other things, its trial and error, just like an MBC. The higher the duty% the higher the boost is. There's a limited range that the stock solenoid and lines are capable of, so the ABC component lets you alter the "Window" a little higher.

Closed loop boost control is better, requires the MAP sensor to work, but boost levels stay consistent regardless of weather

MAP vs MAF depends, remember MAP at this time doesn't mean Speed density conversion, its just a reference input.. BUT if you have an aftermarket intake which causes your MAF frequency to jump around alot, using MAP/TPS for load reference helps make things more consistent. For the most part most stick with MAF as a load reference until they have issues with consistency in the MAF reading

Again, this varies.. there isn't one "Good value" since conditions and fuel quality will vary, same thing with the type of plugs/ignition your running and timing values. I tune pretty aggressively with no knock, and my AFR's are what most would consider pretty lean.. BUT AFR's aren't really going to be a "smooth target" just smooth transitions between cells, under some load levels and load sites, the car will need to be richer with more timing, others can be leaner with less timing. Generally the more timing you run, the richer you run it, but there's MORE to it than that simple analogy. Generally if your really unfamiliar with tuning, learning and research is your best friend, even better, the first time or two, have the car tuned on a dyno professionally and learn (ask him questions) about what works best for your car, look at the instrumentation he uses (you'll need a Wideband at the least and some sort of audible knock detection headset, and I recommend getting a EGT sensor since it aids in tuning)


There's no such thing as stupid questions, the only stupid question is asking "Why did my engine blow" after not asking any questions in the first place.

The big problem is many tuners keep the "Big secret" with tuning, the truth is no matter what engine management system you use, the optimum tune for a particular car varies, but the techniques are pretty much the same. (this is changing though and many once secretive tuners are freely giving out tuning guidelines and advice)

 

Thanks for your response. I definitely have a pretty steep learning curve, my buddy recommended Modern Engine Tuning by Alexander Graham Bell as a good reference. I think I will pick that up do some reading and take your advice, get some good diagnostic tools and try to find a good pro to tune my car the first couple of times. The only thing is I live in rural MO and I am betting goog tuners are a little hard to come by out here...