Ok, I read the article on burning your own chips. Very helpful. I am just confused about simple things. For example, when you bring you take your stock prom and put it in your computer....what exactly are you viewing on the computer screen?

Numbers? Formulas? A graph that shows fuel mapping or something similar?
That is waht I'm confused about. Or how do you adjust for a different cam? Is all that you're controlling : air and fuel ratio and ignition timing?

How long will it take me to get the hang of it. Im well versed with computers. I suck in math.

Also, can a chip be set to run a 160* stat?
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91 Formula
305 TPI 5speed
1LE/G92/WS6
Custom cold air intake w/K&N, SLP airfoil, ported plenum, TB coolant bypass,Crane AFPR (47psi),94 octane,Crane Extruded Alum. 1.6 full roller rockers, Timing set from 4*BTDC to 10*BTDC,MSD6AL, Holley 9mm Annihilator Laser shot 50 wires, Ac Delco cap,rotor and plugs, Bosch O2sensor, SLP 1 5/8 headers,SLP catback,3:73s,JET 195* fan switch, Macewen white face gauges, Intellitronix Digital Gauges

Stock throttle body, runners,intake manifold,cam, and heads.

[This message has been edited by theformula (edited December 13, 2000).]

 

What are you viewing on your screen?

Well, various tables and such that relate to fueling vs a variety of inputs.

you need to check out programming 101 and Tuning tips on the GMECM page
www.diy-efi.org then click on gmecm, then on papers

or download winbin or tunercat and start playing with it to see what its like for yourself

Im pretty sure trax put links to all this in the article. What you need to do now is to look at all those, read them up and down, and then look for more info on just tuning in general. I suspect what you need isnt even EFI specific. I know, because I was once where you were and id say 90% of it is just learning about tuning in general, this can apply to efi or carbs or whatever, what does what, and why


You can set up a chip to run any engine operating temp you like, doesnt mean that lower is better, 160 is actually too cold for an SBC anyways and a much larger task to tune for chip wise (not that youd want to, 180 is better)

 

Pablo in on the money

Tim

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TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's after installing Hooker LT Headers and reducing weight.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

 

We'll just take a make beleive gm program here.
Way we're working on a ecm that uses a 16K long bin file. 0000-0800 is going to be all the tables switches and settings. The rest can be disassembled and read using a Motorola Pink Book (ie 6811 or 6801).
The tables and such as all expressed in hex (h) values, and the language is best discribed as GMESE for some of the stuff, all the common formulas are found in Programming 101 over at DIY_EFI. However an editor like GMEPro or Tunercat saves you needing to know any of that.
Nowadays it's about as much actually understanding tuning, as it is the software, IMO. Not to many years ago all you could tune were the fuel and spark tables, and the rest you had to find mechanical solutions. A sharp guy in just a couple months now will have just enough info., to realise how little he does know. It's really a Zen thing. If you think you know it all, you probably don't, and the closer and longer your at it the more you'll understand this if you don't let your ego get into it. There are some sharp guys selling chips that really haven't a clue about making an engine run it's best.
As a min you'll have 256 tables switches setting to tinker with on a hac'd ecm. You can compensate for the most picky of items.
That is often the problem now with folks getting too abstract.
HTH

 

Thanks Grumpy and Pablo for the replies.
Thats what I wanted to hear.

 

2 more quick questions

I dont understand how you tune a chip. When your tuning it for SD how do you tune for WOT ?

How do you compensate for a gear ratio change?
thanks

------------------
91 Formula
305 TPI 5speed
1LE/G92/WS6
Custom cold air intake w/K&N, SLP airfoil, ported plenum, TB coolant bypass,Crane AFPR (47psi),94 octane,Crane Extruded Alum. 1.6 full roller rockers, Timing set from 4*BTDC to 10*BTDC,MSD6AL, Holley 9mm Annihilator Laser shot 50 wires, Ac Delco cap,rotor and plugs, Bosch O2sensor, SLP 1 5/8 headers,SLP catback,3:73s,JET 195* fan switch, Macewen white face gauges, Intellitronix Digital Gauges

Stock throttle body, runners,intake manifold,cam, and heads.

 

you tune for WOT just like you would tune a carb and mechanical dist for wot

testing and tuning. I dont bother with the o2 sensor, i read plugs, and have an EGT gauge, with these two I find i can pretty much spot anything. Do some searches on the net for "Plug Reading" its a little more involved than you probably think, sort of like a lost art

youll then go to your wot tables and then get everything to where the plugs look ok, no detonation, and then get to the track to further fine tune using your trap speed as a guide to how much HP your making

 

Gears tires weights converter flash rpm are all accounted for in AE and timing, its a matter of how fast ou dial in or out the fuel, on the later PCMs there are actually reasons for knowing the actual numbers, and entries for them, but not in the Gen 3 ecms
(generally), there might be a few limited exceptions, but about all you need to know is that the VSS is reading about right and the ecm is happy

 

For part throttle, shouldn't you adjust the locking of the TC speed if you have adjusted your gears too? This is the conclusion I came to with my 3.23 to 3.73 swap (got all the parts, just need some warm weather) and why I decided to bone up on PROM burning.

Since I will be in 4th a lot sooner with 3.73s at part throttle, I thought it would be a good idea to lock the TC at a reduced speed for street driving.