Originally Posted by
chevota
The data has random delays so it's pretty hard to tell what is happening when, so you either let off first, or it cut power and you let off a fraction of a second later. By looking at it I'd say you simply let off.
I try to keep boost under ~22 but it can't control boost for shyt so it's all over the place. Apparently a "safe" boost for my car is 17-18.
My car details are in my signature.
Power I don't know because changing certain things to make more power will skew the torque reading to read low. The Normalizer is the main one, so they say, so if you reduce it 10% then the reading is 10% low. In my scanner I have two torque readings, one is what the ecu thinks it is, the other is that x 1.111 to bump the # back up. There are other things that screw up the reading too.
Someone said messing with the Spark MBT screws it up, and who knows what else does. I have no way of checking, unless I buy some dyno time, which is expensive and ultimately pointless imo.
On the other hand I've had the power reading go way up as well. Not sure what I did but for a while it said I was making 800ftlbs with a peak of 812. In reality it was probably making more like 500, based on the boost.
Ultimately I simply shoot for the boost I want, adjust spark to just shy of retarding with whatever fuel I have, and set lambda to lean-ish but seems safe?
What boost and lambda is safe is subjective, imo. People say boost for my eng should not exceed 18, and lambda should be .800, maybe even richer. Well, more boost is more power so that 18 is pretty difficult to comply with, and .800 costs me power.
A leaner fuel mix nets more power and better throttle response, but under heavy load you need extra fuel for cooling. Ironically, when I add more fuel, the exhaust temps go up. It doesn't necessarily mean my cly temps are hotter, but if there is no O2 then how does more fuel make a hotter exhaust? So all I can do is wing it and hope I'm adding enough fuel to cool, but not hurt power too much. The .800 hurts power a lot, so I try to keep it closer to .850, which is considered dangerous to most. Imo the direct injection allows a leaner mix, and combustion chamber design and material are a factor, so I believe .800 is an outdated #? Maybe I'm just ignorant but in an old school engine it will start to ping when it's not rich enough, mine actually pings when I add fuel. So it may ping just a hair, or none at all at .850, then ping more at .800. Very confusing, but to me ping is a result of to much heat, so no ping seems to say you're good to go?
This brings up another question I've always had but rec'd zero answers; the Lambda sensor cannot read fuel or fuel mix, but instead bases it's value entirely on O2 levels. So if Stoich of 14.7 uses ALL the O2, then how can it possibly read a richer mix?????? It likely needs more like 14.3 to 14.5 to really get all the O2, but the point is no O2 is no O2, so how does it read a richer mix?
I've been meaning to add Methanol injection to cool it better, but too lazy and haven't installed it yet. I actually have two, the thought was one for pure Meth and one for pure water. With water doing the cooling I expect it will drop the Ex temps and cool the cyl better, and no weird stuff, but we'll see.
I think the more boost you have the more you need something like that, and I mean you. Speaking of you, you named your tune xxxxx stage_3, what does that mean? Did you buy a stage 3 tune of some sort and now you're tinkering with it? If so, details about it, and post the oem tune, please.
I figured you were in Euro. I'm in the US. I don't have your engine so I won't be able to help much, just the basics.
Best too keep everything here on the forum so others can bennie from it, and share thoughts. As you can see the forum is all but dead, but there are a few here.