Grumpy

Finally caught up enough to expound on something.

Let me state right now, I think all hig perforance tuning should include IAT/MAT, Baro (full time), and a compenstation for Humidity. I've been ridiculed as being just too **** about things, by a number of people. So I just grin when folks start to agree with me.
Continuing:

On Speedvision, they had a Pro Comp Tuner talking about tuning. He was going on how even at some tracks now they include baro (height above sea level), and temp. on the timing slips.
Then went on to say even MORE IMPORTANT was compensating for HUMIDITY.
I rest my case.

One NEAT THING about hot wire MAFs is that in part they do compensate for that!!!!.
Any bets on way GM went back to adding them?.

Grim Reaper

Adding a "correction" table for humidity would be interesting. Having the ECM automatically compensate would be even more interesting.

There is a bar correction table in the SD 7730 and I've been contemplating trying some "tests" to see what happens. Might be some possibilities there.

Another couple of corrections I think would be interesting would be for "gear selection" and "vehicle speed". I've noticed on my SD car that the lower gears tends to run leaner (higher BLMs) at a given RPM/Load than in 4th. It strikes me that a little extra fuel correction if in one is in 1st or 2nd may be useful.

Also, for higher speeds, I have found that on a high speed passing situation on 3rd, I can use a slightly higher spark advance than at slower speeds in lower gears. The dynamics of an operating engine in a moving car in real world driving conditions adds additional complexities (and opportunities) from a stationary engine on a dyno. I think there lots of little "tweaks" that can be made to Source Code to aid in tuning.

Grumpy

Well,
if you want to get into load compensations, it's more about timing then fuel.
In the lower gears there is greater gear multiplications so the engine is actually seeing a lower load. Also, the conbustion chambers are cooler, so less chance of detonation as you first acclerate.
On some calibratons they use a Burst Knock Retard to min the effects of this.

I'm beginning to wonder about fuel off of MAF, and Timing off of MAP.
Then MAT Fuel / Timing corrections
BARO timing.

then depending on the Water Injection placement the IAT could max it's effects

Gads this sounds good.
Hmm come to think of it I better sleep on it <G>..

Sarkee

From my younger days, when I used to jump out of perfectly good airplanes, I recall that cold clear dry Winter days were best for skydiving, as the air was densest...

...As opposed to hot, humid Summer days, when the air is thinnest...

More or less the opposite of what you might expect...

hectorsn

Let me start off by saying I have no idea of what is involved in what you guys are talking about. I can't even pronounce dissasssssemble? That said, starting at $8988 there is nothing to $3000 on a $8D. Is that enough room to add a table and code for spark vs MAT? I know there is all kinds of stuff that has to be done and I assume it's very difficult as I hear of everyone talking about it but no one actually accomplishing it. I understand that a basic editor for a given mask won't cover this sort of addition so is this the reason it's unpopular? Another thing, the source code you speak of, is that in the prom or in the rom? Does a 730 even have a rom and if so what for? As far as humidity goes, what is used to determine it? I don't know but it seems to me that a baro and an IAT sensor isn't going to be enough but since I don't know how humidity is calculated..... I do know that where I live we always have humidity with the lowest humidity during the bright day, unless fo course it's raining. Things like these weather variables won't affect my tune too much as weather is the same for about 95% of the year: hot and humid. But it would be nice to further my edumacation with this stuff in search of the perfect tune.

Grumpy

Reading code takes time.
Understanding it takes more time.
Modifying it, well, that all's together another issue.
There are folks that can do all this, and it just seems most would rather not share the info.. Some thou will help with answers, but now that seems to be fading. While it's gotten to editors being low priced, the drive for other info., seems to have slowed as in almost come to a stand still.