b16a95eg

iTrader: (12)

thats what i was thinking too, if you up the boost, why would you tune everything before that, then raise it, then have to retune anyways? i guess the way i look at it is its a safer way to do it. but if you were only going up like 2psi peak why would you want to do it that way, is it that far off with that little of an up in boost?

Mr. Evo IX

iTrader: (5)

If your just optimizing an existing map (stock map, tuning for bolt-ons for example), you should set a boost level and then tune fuel, then optimize ignition timing. If your new you should probably optimize fuel and timing on the stock boost level so you dont blow anything up. However... in the old days of ECU Flash, we didnt have map tracer, and calculated load isn't very accurate, so we would log ignition timing and rpm to pinpoint where the car was running on the igniton map, which would correspond to the same location on the fuel map. Does that make sense? I still use this method when I'm reviewing text logs to know where on the map I am.


If your tuning a car from scrach with a standalone obviously you'd start with getting the management setup, sensors calibrated, etc. Get the engine to start, idle tuning, then you'd move to low load tuning, high load tuning, low boost tuning, and then high boost tuning. In most cases you'll lean on prior knowledge of what kind of ignition timing that engine type would use. This is just to get in the ballpark. I really havent tuned anything where we didnt have some sort of a basemap to start with. Sometimes it's just a NA map and were building a map for a turbo application. In that case you'd break out the pencil and make some educated guesses off of the stock map to rough in some conservative boost timing which will be optimized later. In other words, you can't just start with a timing map full of 0's and expect to tune the fuel and boost.

Mr. Evo IX

iTrader: (5)

Because your tuning the full map, so systematically starting with an area that already runs and is close is better than jumping into an unknown area that may not even be in the ballpark. Not only that, tuning a map is a building process, much of what goes in the next column is determined by the trend of your previously tuned cells.

raasfaas

iTrader: (30)

For the stock turbo it there a known optimal AFR range for it or is every car different. What I mean is, do you shoot for a little leaner AFR on spoolup vs peak, then during peak torque you richen up a bit, and for the rest of the range till redline you lean out again.
I know this is all dependent on the setup, meth, E85 etc. But is the concept the same?

Mr. Evo IX

iTrader: (5)

Every engine is different and once fueling is changed timing has to be made optimal for that AFR. Right around 12.2-12.3 is best power for gasoline. I try to spool around 12.0-12.2 and then richen to 11.5, sometimes going a little richer above 7K but no richer than 11.1. Maximum flame speed happens at 11.1, both richer and leaner slows the flame front.

raasfaas

iTrader: (30)

Thanks Mr. Evo just wanted to know if I was in the right range...we have really bad gas here in Jamaica, 90 octane, but I am spraying 50/50 meth. Looks like I can go a little leaner on my maps, I'm spooling at around 11.6-.7, peak tq I'm at 11.1 and from 5000rpm to redline I'm 11.5-.6. I chose to run a little more timing vs running a little leaner but I'm going to play around with it a bit and see what the car likes more.

leecavturbo

i don't know how you can tune for boost!
you are either tuning fuel or ignition end of! ??
at different boost levels maybe but you don't actually tune boost. you just set it.
is how i would look at it.

Mr. Evo IX

iTrader: (5)

You probably use a MBC. The phrase "you just set it" arguably doesnt apply to ECU boost control.

raasfaas

iTrader: (30)

^+1
Going through ecu based boost control there is a whole slew of tuning that needs to be done. Also, my AEM EBC does require some minor degree of tuning, you can tune it to have the turbo spike real hard and early but taper off a lot up top, or not spike so much and hold a little more boost by redline.