Well guys, the time has come. Overhaul Gasket Set coming one day. Porting will be finished this weekend [as long as I don't run into any more snags]. And I am going to pick up a Torque Wrench this weekend, clean everything up and start the install back up. Since I really didn't change a whole lot of stuff, I am going to keep the stock PROM for initial start-up and for the driving test. That will hold me over until GM Tuners gets everything squared away [or until I know everything is cool to throw the chip in].

Now, in my Top End Rebuild thread, I mentioned I was quoted $160 for the whole schebang. Well, this is what it includes.

- Moats G3 16 Bank PROM Switcher
- EZ Remote [so I can switch on the fly]
- Three Programmings [more on this in a sec]

Now, you may be wondering what this stuff all relates to. Well, this means I can have UP TO 16 programmings and switch them on-the-fly [kinda doubting this.. but all I need to do is drop the car in Neutral, shut off engine, switch, start engine, back in gear I go.. not difficult]. The Remote makes it so I don't have to switch the programmings on the ECU itself.

The three programmings are for: Economy [I want to have the highest Fuel Economy on an 87-91.. we'll see how this turns out], 87 Optimized [Have the maximum ** of timing for 87 Octane.. and up the ante on some other various stuff, I think], and Race Gas [Self Explanitory].

Here'* where I need you guys' help. Economy? I don't know what constitutes higher fuel economy from programming. I'm guessing retarding timing? However, I do not know this. I just want to have some serious fuel economy.. not too interested in power with this prog. I know I will be putting a lot of miles on Pearl, and power isn't always going to be necessary.

87 Optimized? Not quite sure of the limits of 87 Octane Fuel. A few Hot Rod Magazine articles state their engine started detonating at 38* with 87. Not sure if that applies to all engines and whatnot.. but is that a good limit to stop at? What about Fuel Maps? Could the engine use more Fuel or is the AFR good stock?

Race Gas? This is going to be one sick tuning. May only get used once or twice, but I want more timing than friggin' imaginable. I'm thinking lengthening the fuel injector pulsing and increasing spark duration [if possible] will be real nice with this. All I know is I want this sucker to really come alive with this tuning. I want it to utilize the most timing that is absolutely possible.

I also have not gotten an answer from Ryan [at GM Tuners] about what all is configurable on my ECU. Does anybody have a complete list of this? I really would like to know what I can change, and what I cannot. Any list will help.. I really don't know where to start with changing stuff, and I don't want to go into this blind [not that I don't trust Ryan, I just like being educated on everything I can be educated on].


-justin

Sounds pretty cool but,
You really need a baseline for all those values once you get your car running.
fuel trims(integrator and block learn memory for you?)/timing/knock retard/injector pulse width/and some other stuff i can't think of at 2 am.
Once you get the base line values, you can begin tweaking from there.
Whatever octane you want to run your fuel economy chip with, get all the inital values for that, then adjust your fueltrims to be as close to 128 as possible, then advance the timing as far as you can untill you get knock then set it a couple degrees back. Do this all while looking to see if all other values are acceptable like the idle air control valve, maf, injector pulse width, etc.
And for the race gas chip, put in race gas, and do the same thing.
^^ just some basic stuff i picked up, not to detail or anything.

Sounds good.. minus one thing. I don't own a scanner .

For Economy I should have the most advanced timing? Why would I want that?


-justin

I recall jr's3800 saying something about the 87-91 PCM'* being resistant to 'chipping'.

The ECM'* in the LN3 engines can be chipped just fine. The question is if it does any good. Ryan @ GMTuners redid my old Fastchips 93 octane chip with reduced timing for my turbo setup. He sent me the timing tables for the stock chip, the Fastchips and after he modified it. The key is to get the maximum advance for the fuel you are using and of course boost if you have it. From the testing I did several years ago, the stock chip from GM is pretty well matched for plain old 87 octane. I would occassionally see a degree or two of KR right after a shift point so the stock chip was right close to the edge for the fuel it was designed for. The Fastchip I had programmed for additional advance beyond their standard premium fuel chip because the car felt "dead" off the line. The additional advance picked up the response and seemed to help the top end somewhat. An easy test is this, try a couple of full power starts off the line with the fuel you are using now (N/A engines). See how much wheelspin you get. Try switching to a higher or lower grade and try the test again. Even the old vin "c" engines should get some rubber if the timing is correct for the fuel. Premium fuel in a good running engine designed for regular will usually slow the engine response, as the peak pressure occurs too late for optimum torque production.

You should have some dyno/scantool access unless you're doing small incriments.

Actually I believe the problem is that between 87 and 91 there were at least 3 different types of PCMs..... one difference is the engine LG3 to LN3 and the fact they were also SFI and MFI.

Jetchips (or Hyperchip) used to make a chip for the 89 or 90, but never the 91 because something was different..... I think that (and the weird logic that no one would want to chip an 87-91 Bonneville) is why no one made chips for them.