Georgia Fiero Club Forum
All Things Fiero => Tech Tips, Tech Questions => Topic started by: f85gtron on May 27, 2015, 07:34:10 pm
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Anybody try tuning? I'm contemplating it and am looking for word off wisdom!
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I've done a little. What are you trying to do?
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I would like to tweak the tune I got from Ryan. My idle blm is around 99-113 and the part throttle knock. There is some other messing around I'd like to do, like adjust the shift light to work correctly. Ryan said it's too much for him to bother with because he's got other customers, and he's got a point. I'm just one guy that gives a flip about these things, so I was thinking that this might be a perfect opportunity to buy a moates burn2, a couple chips, and have at it. I'm just nervous about jumping into this all the way.
Honestly, I thought I'd just buy my Fiero, put it back together, and be happy..........well, I'm happy, but now I'm obsessed too......
What kind of undertaking is tuning?
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Well, no turning back now.....just ordered the moates burn2 and a couple chips. Gonna learn the hard way.
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There's some good stuff here, if you don't mind weeding through all the "noise".
http://www.thirdgen.org/forums/diy-prom/
I remember reading something more concise. I'll see if I can find it.
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I've received my burner in the mail. I hooked it up, first to aldldroid......no data, then to tuner pro, no data. I changed the buffet and chip address and managed to get data of the chip, but it's not lining up with the adx's I'm using (I've tried several, just to make sure the adx wasn't faulty). The .bin I pulled off the chip can't be right. The graphs are all spiky and the parameters and tables don't seem right.
What I think is I've pulled data from the wrong starting point in the chip, or it's stored in a different area than standard. It's supposed to be an $88 mask on a 27sf512 chip.
What am I doing wrong?
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I don't think the 7730 uses a 27SF512. Think it's a something...128 or 256. I forget what I ordered (and subsequently buried - somewhere) for mine. Still has the same number of pins, though.
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The 27SF512 is what was in it from the p.o. the chip that Ryan with sinister programmed for me also was on a 27SF512. I've got a couple blanks sitting here of the same persuasion, so it better accept a 27SF512 If it knows what's good for it!
In an act of desperation, I setup the addressing and buffer ends for a different kind of chip, and voila! It appears I've got data lining up probably with the xdf I'm using and now I'm getting better looking graphs and tables.
I looked at the chip through a hex editor and the data was set weird. There was some kind of filler dataset (F's and y's), then actual data, break, data, break, data, then nothing to the end. According to moates, data is supposed to be at the end, not the beginning and middle. I'm confused.
I don't understand enough to know what I'm looking at.
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Fyi. On the chip from sinister, I found one of the bin stacks at 000000 -> 007FFF , which is the default for the 29C256 chip, even though it's a 27SF512. I'm looking at good data parses now, so all that's left is to mess up some stuff! :)
Ron
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What they may have done is programmed the data into the chip twice. Kind of front to back, if that makes sense. Once as a filler, and once at the memory location where it's supposed to start. I've heard of people doing that with replacements for the stock 2732. (I forget what they were using, but the reason for doing that was so that they could use EEPROMS instead of the UV erasable EPROMS. No need to erase them first. I may be wrong on the details, though. It's been a while.)
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Gotcha. That must be "stacking". According to Moates and some forum info (which I always trust, lol), the data was supposed to be on a different part of the chip. But hey, it works!
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Update:
Got my first changes onto the chip. For my first tune, i smoothed out the advance graph and played with idle. Also experimented with highway mode. Ran with the new chip to work and it felt much smoother and much more predictable. I took too much advance out and fuel, so it also had less power. I think I've inadvertently found the tune I'll be installing when my daughter wants to drive it ;)
I'm having no problems tuning with tunerpro rt, but aldldroid is giving me problems.
Aldldroid is superior for data logging, though.
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Got the shift light fixed. A member on another forum posted an $88 fdx that had a complete set of items, so i was able to program my gear ratios by programming gears 1-3 skipping 4th and programming 5th. The program in the ecm works sooo much better now! There must be dependent variables being calculated or something. Much peppier than before.
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I really wish I had gotten into this before I dropped $$$ for a tune! Tuning is crazy easy.....just takes understanding data points. The tune sinister sent me was pig rich at idle and slightly lean during acceleration. I downloaded the factory .bin for our cars and the fueling and spark advance maps look TOTALLY different from what is on the chip they sent me. So I'm doing another tune, using the factory maps and then I'll find tune them, since I assume that gm knew what was best for our little motors.....stay tuned......(ha ha)
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I ha ha'd too early. With the factory tune, it idled perfectly, but fell flat on it's face trying to accelerate. Not enough fuel. I must have done more mods that I realized! Back to the drawing board.......
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May I suggest that you run a fuel pressure meter to the inside so that you can see what it is doing under hard acceleration?
The Manifold Air Temperature and O2 sensors also affect air/fuel ratios.
Oops! I forgot about the Manifold Air Pressure sensor.
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I'll do that. I threw my old chip back in while I figure this out. It runs fine on the sinister tune, just a little off..... i know the factory ve tables are MUCH lower than what is on the sinister chip.
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I'll do that. I threw my old chip back in while I figure this out. It runs fine on the sinister tune, just a little off..... i know the factory ve tables are MUCH lower than what is on the sinister chip.
Check the Base Pulse Constant (I think it's called.) It's in one of the first menus. It's a two-dimensional slider, based upon displacement and injector size, among other things. (Been a long time. I don't remember the formula.)
It affects all of the fueling. If it's the same in both chips, the lower VE tables will truly indicate less fuel. If it's significantly larger, then the lower VE tables will tend to cancel it out. (Not really correctly, I don't think, but it kind of works out that way.) Just more to add to the confusion.
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Sooooooo, what you're saying is, bigger is better? ;)
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Sooooooo, what you're saying is, bigger is better? ;)
That's "The First Rule..." "If 'more' is enough, then 'too much' is just right"
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Raydar,
I found two problems that held back fueling.
Maximum asynch bpw was set to 5ish. It needed 9ish to spray enough fuel.
Second, as suspected,.the fueling tables where 10% too low at600-800rpm, then 20%+ at 4000 rpm.
Its still lean at the higher rpms and I'm still tinkering with it.
Otherwise, the factory fueling curve seems to feel better than the one sinister, based off a Firebird 3.1, had provided.
......to be continued......
Ron
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Cool. Thanks for sharing. I never messed much with async settings, I don't think.
I'm learning something...