pgmfi.org

1) GhD *really* should be more clear on the way it expresses the MAP values. Yes, you did mention that atmospheric pressure is about 26 in Hg, but the ignition table is not at all clear about the difference between pressure and vacuum in an intake. The higher the manifold pressure, the faster the burn, and the less advance you need to maximize power. Right? Okay. And from that, it seems fairly clear, from looking at the values of the stock bin, that the farther to the right you move on the table, the higher the *absolute* pressure. The problem is, the pressure readings in "in Hg" appear to be expressed in *vacuum*. The reason this is confusing, is that the table claims the headings are in *MAP* value, "manifold absolute pressure". A measure of vacuum in an intake is really a "gauge" pressure reading, not an "absolute" pressure reading. If the heading really lists manifold absolute pressure, the numbers would start at the left at 1 in Hg, and increase to 26 as you move to the right. And another confusion is, if the table headings are in vacuum, they really should have the negative sign in front of them, to signify that they are in inches of vacuum Hg. This is one of those small problems that could really have *horrible* consequences to someone who makes the wrong assumptions about what they are reading. Well, I don't want to make any assumptions until this is clearer. What, exactly, is the pressure value convention used in the table headings in GhettoDyne?

2) How the heck do I make a "backup copy" of the stock bin? Other than copy the numbers onto a piece of graph paper, I don't know any way to keep a record of the bins as I tweak, and that really is a necessary function of a tuning program.

3) Here is a tiny, frustrating problem. I don't know how to get my Window arrows to expand the GhD window open farther than a certain point on the right, and beyond that is the message about the Checksum being zeroed out. Without being able to see this part, I have no way of knowing before chip installation whether the checksum has been zeroed.

4) Last question. Does GhD include pretty standard "closed loop" function? On the fuel tables in GhD, it appears to have a pulsewidth for every part of the operating regime. I have heard that under a certain rpm, or a certain TPS value, or a certain MAP value, the stock ECU automatically assigns fuel pulses via a feedback loop, i.e., is in "closed loop". And therefore, in these regions, no "open loop" fuel table would be needed. But the GhD fuel table has no such blank areas. Just wondering what exactly the deal is here.

Thanx, Eric

Uh, lemme comment on #2; You have a couple options, some more advance than others:

1) At the Dos prompt type "copy <originalbinfilename> <newbinfilename>
2) In windows explorer, drag and drop the original file with the right mouse button and use "copy here"

That really is a stupid question.

On your #3, I have no idea what the hell a "Window arrows" is. Are you talking about the mouse cursor?


???????

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1) I advocate the use of mBar absolute. That being said... I didn't write Ghettodyne, and I'm too stupid to write a competitor, so I'll use whatever it pleases Mike to use and not bitch about it. I never once misunderstood what the values meant, and you need to research a bit more before you touch an ECU if you can't figure it out yourself.

2) Yes, that feature needs attended to.

3) I have no such problem, does this happen to anyone else? You might need to figure out what you have in common. Desktop resolution?

4) Ghettodyne uses the OEM Honda closed loop function, it is perfect in every way. The Ghettodyne .bin is, at least for now, very very close to the stock one.

Your understanding of open/closed loop is inaccurate. The ECU is guided by the 'open loop' fuel tables in closed loop, and *then* tries to correct for stoichiometric. Tweak a .bin to run pig rich, chip your ECU, and cruise it around while monitoring O2 volts. The O2 sensor dwells on the rich side even with closed loop switching action.

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Hrm. Go to the chart at the very bottom of this page:

http://xtronics.com/reference/convert.htm

It seems that 26 In/Hg implies a deviation toward vacuum from atmospheric. A (-) sign is not needed, and would confuse people who knew better.

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Ok, I have to respond to this for obvious reasons:

1) Inches of Mercury *IS* how you measure pressure. There is no negative and positive values. If you need a negative sign then you should not be messing with the tune at all since you don't have a good understanding of how pressure is measured.

2) Read the readme file, or the help section, or both. It states GhD doesn't make a backup. Both help files state to make a backup copy before you ever begin. If that is something you need to ask how to to do, then we have bigger problems.

3) I made GhD non-resizable for a reason. If the whole program doesn't fit on your screen then you are running a resolution under 800x600 which I didn' think anyone did anymore! I will take this into consideration for V2.0

4) The revision if GhD you have does not mess with the open loop/closed loop routine at all. It basically takes a COMPLETELY stock 91 Si Bin and lets you modify the fuel and ignition tables, and the rev-limit. That is all it does. Again, the bin it comes with is completely 100% stock, dumped streight out of my 91 Si ECU. Not changed at all, not even commented. Did I mention it was un-touched? All that you are doing is changing the fuel and ignition settings for closed loop operation when the throttle positioning sensor is pasted ~20%. The next release supports a ton of other options, but still has bugs that need to be weeded out.

Joseph: I'd love for you to beta test V2.0 My domain is all jacked up so I haven't been able to reply to your email yet I'll e-mail you when it's back to normal (few days).

Lastly, I'm always up for suggestions on how to make GhD better.

Mike

Wooohoo!

Scaling injector size down by hand has thus far sucked lots. Thanks!

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"Inches of Mercury *IS* how you measure pressure."
I think that's how _you_ measure pressure. Most of the rest of the world no longer uses a
measurement system based on an imperialist nations former kings appendages

??? Former Kings appendages? I don't get it...Mercury is still used to measure pressure as well as temperature, barometric pressure, satellite communications, terrorist bomb triggers, when to tell my furnace to turn on...

Mike

xtensive: the US/English/Imperial/Whatever you want to call it anymore measurement system was originally founded on say.. a foot = the kings left foot length. ... so thats what he was reffering too if that isnt enough obscure history for ya

ever heard of a ROYALE WITH CHEESE motherfucker? the METRIC system? Pulp Fiction maybe? :-p

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You're gettin' ready to blow? I'm a mushroom-cloud-layin' motherfucker! Every time my fingers touch brain I'm "SUPERFLY T.N.T.," I'm the "GUNS OF NAVARONE." I'm what Jimmie Walker usta talk about. In fact, what the fuck am I doin' in the back? You're the motherfucker should be on brain detail.

word

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it's still a valid method of measurement, no matter how archaic... and even if you don't like it.

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Yah, plus Foot Long sounds better than Decameter long or whatever.

Metric system is bad for porno.

anyone who think the metric system is lame is very closed minded. it makes much more sense and u couldnt do simple physics without it.

someday the USA will switch over, they are living in the past.