ECM upgrade (1227730) for stock 2.8 (Page 40/107)
Darth Fiero DEC 16, 11:20 PM

quote
Originally posted by fkossegi:

Thanks Mr. PBody - That won't work for me -- (I've got a Mac)

Thanks Darth Fiero. So when I'm ready, just send this chip to you to reprogram (of course filling out your form)? It'll be for a stock 2.8 with egr and 5 speed.




When you are ready, shoot me an email at sinisterperformance@dtcc.cz28.com and I will send you that form to get the process started.

-ryan
Doug85GT DEC 17, 03:46 PM
I've gone through pages 1,8,9, and 10 of this thread. I don't see where anyone has posted any MPG improvements or a little more solid performance improvements such as dyno run or at least a 1/4 mile run.

Is there something hiding in pages 2-7? Or could someone give some of that type of information?
Mr.PBody DEC 17, 04:38 PM
No one claims any 0-60 gains, any mpg gains, or any hp gains. The Fiero ECM updates every second or 1.5 seconds, and uses a cold start injector. Which causes rough hunting idle. The 7730 uses a knock sensor, updates ever 0.1 second, has no cold start injector, and uses digital EGR. Its purely a swap for driveablility and run ability. Of the like 3 people that have it done they say possible MPG gains (the car the thread was started about gets damn good mpg for an auto), another person said the car feels like it pulls harder at high rpms. Once I finally do my swap (January-ish) I will do a before and after run on the G-Tech Pro RR and post the numbers here.
Pyrthian DEC 18, 08:31 AM
I am expecting my milegae to increase. I am also expecting better power in the 4500-5500 rpm area.

right now, I get just under 20 mpg with a 3.1 & 4.10 4-speed, & ADS Superchip. I know the chip is the main problem with my milage. next being the 4.10 gearing.

and, since I will be using DIS, I think the timing advance & the fuel deleivery will be ALOT better with the 7730 over the stock ECM in the upper RPMS.

but, since I have no existing baseline for my power - I will never know.....I was gonna dyno last spring, after I gutted my intake, but my dist gear failed, and that set off a chain reaction of internal failures....
Will DEC 18, 02:05 PM
The programs available for the 7730 are much more tunable than those available for the Fiero ECM.

You can't just liberate power through a computer. A stock engine's already tuned about as well as it can be tuned and still run well on any gas from any pump anywhere in the country. What little gains in power that can be had over the stock tune can only be had in relatively restrictive conditions like 91 octane only, runs poorly in hot weather, etc.

[This message has been edited by Will (edited 12-18-2007).]

Pyrthian DEC 18, 02:13 PM

quote
Originally posted by Will:
The programs available for the 7730 are much more tunable than those available for the Fiero ECM.

You can't just liberate power through a computer. A stock engine's already tuned about as well as it can be tuned and still run well on any gas from any pump anywhere in the country. What little gains in power that can be had over the stock tune can only be had in relatively restrictive conditions like 91 octane only, runs poorly in hot weather, etc.



yup. but, I always was under the impression that the stock chip & ecm just dont do well after 4500 RPM. not sure if this is a ECM limit, a chip limit, or just a programming limit, since the intake dont let anymore air thru anyways. I expect there is also timing advance limit when using a distributer, but, I dont think a OHV motor will ever acheive RPM's to hit that limit. you can only adjust the timing within range of the rotor hitting the post, after all.
Doug85GT DEC 18, 03:49 PM
I believe that there will be hp and fuel milage increases from what I have read. Here are my reasons why:

1. The new ECU incorporates a knock sensor. This usually means that the ECU will advance timing a lot more than a ECU that does not have a knock sensor. Once it sees knock, it will then back off the timing just enough to stop knocking. The end result is more power.

2. The ECU updates much quicker which means that real time adjustments will be quicker and smoother. The stock ECU updating every 1.5 seconds is the very bad for high rpm performance. At 4500 rpms the engine rotated 112.5 times between ECU updates. At 10 times per second only 7.5 rotations go by between updates. Combine that with a knock sensor and the ECU can be much more aggresive with fuel and timing since it can correct 15 times faster than the old ECU. This means it can run higher timing advance and leaner A/F ratios resulting in more power. How much more power is my question. I have no doubt that there is more power, though.

3. The electric EGR valve can increase gas milage. To understand this, you have to recall how and why the EGR system works. It reduces emissions by recirculating exhaust gasses into the engine. Those exhaust gasses have much lower oxygen content and in effect, they reduce the amount of air going into the engine during cruising. Therefore, it reduces the gasoline consumption. A drawback to having a vacuum acutated system is that you do not have fine control over the EGR valve. The amount it is open depends strictly on how much vacuum your engine is drawing. With an electric EGR valve, the ECU can control precisely how much exhaust gas is being recirculated and can therefore reduce the amount of fuel going into the engine. This should result in higher gas milage.

So my question is simply, how much power and gas milage will increase. I'm going to take a guess here and I will predict 5-8 more hp and about 2-3 more MPG city and 3-4 more MPG highway.

[This message has been edited by Doug85GT (edited 12-18-2007).]

Will DEC 18, 04:01 PM
I would say 5-8 HP might not be out of the question. Remember, if there were significant gains to be made by shaping the timing and fuel curves above 4800 RPM, GM would have mapped the stock ECM with appropriate curves. I think the fact that they chose to develop the stock program with flat timing and fuel curves above 4800 RPM means that they didn't think there was anything more to get in that part of the map. I believe this is a hardware limitation. The 2.8 isn't doing anything but making noise in that RPM range.

I think that 1 MPG on the highway is about all you'd see from the digital EGR.

My Formula would return 27.5 mpg on the highway at 80 mph or so. A 3-4 mpg gain would put it at 30.5-31.5. Fuel mileage gains from EGR come from reduced pumping losses, which occur through the reduction of manifold vacuum. I just don't think there's that much pumping loss in that engine at that power level.

[This message has been edited by Will (edited 12-18-2007).]

Blacktree DEC 18, 08:27 PM
What hardware and software is best to use for tuning the 7730 ECM?
Mr.PBody DEC 18, 08:35 PM
Sinister performance tuning lol, for $50.00 why mess around