Chips?

[mbeach]

Standalones have great power capability (I'd choose the newer and more advanced AEM unit over the Haltech) but they require much tuning/dyno time, and they do not have the adaptive capabilities that the stock ECU has. The AEMs are coming close, but think of it this way:
If you tune on a 80* day, with 40% humidity at sea level, the first time you drive up into the snowy mountains, your car will run like poo -because the ECU is no longer there to "learn" the weather and make appropriate changes.
The bottom line is that standalones only tune for optimum performance that ONE day, at those EXACT conditions.

I've had far better luck with ECU reflashes. They maintain the stock driveablity of the ECU, but modify the fuel/air/timing curves for more aggressive performance (if desired).

My WRX had 3 "maps" on the stock ECU. Each one was toggled by pressing the rear defrost button at WOT.
1 -street gas map, 18psi, 304 whp.
2 -race gas map, 24psi, 362 whp.
3 -valet map, no boost, <3000 rpms.
The ECU was also configured to ignore some CEL codes (like burnt EGT sensors and missing O2 sensors).

The "cracking" of the Subaru ECU was accomplished by some dedicated nerds who saw the potential $$$ possibility in it. There doesn't seem to be that kind of market here in the Isuzu community.
The question is, is Isuzu's ECU an Isuzu product? Or could we find a suitable (or exact) replacement sitting in a GM parts bin. If it's a GM ECU, then we're in business already.

[Joe_Black]

and they do not have the adaptive capabilities that the stock ECU has.

???? They wouldn't work at all if they didn't adapt. That's why they use sensors for temp, pressure, speed, O2 input... that's all for the computer to deliver the proper timing and fuel charge for conditions. That's the whole basis for why computers in cars were developed! And you're absolutely right, if they can't adapt your vehicle would run only under a specific set of environmental conditions. Which is exactly why they do adapt.

My point is for a little more investment in time and money, someone wanting performance rather than hoping another will drop a custom chip in our laps can have it, now. Grass Roots Motorsports has an excellent article this month about this very thing, including going over installation (couple hours) and tuning (couple more hours) on a street car.

Again, if custom ECU replacements didn't adapt they'd be worthless. All the works teams, racers and performance enthusiasts wouldn't be paying for and installing them. Adaptability is the most basic feature of an ECU. The ones I installed and tuned over ten years ago had features just now appearing on OEM ECU units.

addendum: After looking over the AEM unit mentioned in the previous post I can certainly say it's not advanced at all over the Haltech unit. The AEM unit is a daughterboard which is piggy-backed with a stock ECU. The Haltech unit is a complete replacement unit. The AEM unit is limited to OEM ECU's that it can work with, whereas the Haltech is only limited by various engine configurations, which is addressed by the various models they have. Additionally, the Haltech allows "in-flight" tuning where the AEM unit is a static download/upload arrangement. Apples to Oranges folks.

[thedutchguy]

Here's another link : http://www.dtafast.co.uk/

The prices of these systems are less damaging to your wallet!

[MachineVX]

Is featherfoot's friend still working on something and will it be available for supercharged VXs? I'd love to be able to remove the speed limiter, adjusted the rev limiter and shift points.

[jayfotos]

That rev limiter pissed me off at the track, with out that a SC VX can easily be in the 14s(my best time was 15.6). Now with my new exhaust(duels) I have better exhaling and feel a little more pep....gottta do another dyno run.

[mbeach]

???? They wouldn't work at all if they didn't adapt. That's why they use sensors for temp, pressure, speed, O2 input... that's all for the computer to deliver the proper timing and fuel charge for conditions. That's the whole basis for why computers in cars were developed! And you're absolutely right, if they can't adapt your vehicle would run only under a specific set of environmental conditions. Which is exactly why they do adapt.

Simply having the ability to "sense" variations in temp, pressure, speed, etc. does not mean that a standalone unit has the ability to react to each variation. These reactions must be programmed by the user. In the case of the factory ECU, there have been armies of engineers and programmers developing maps/logarithms/algorithms for each potential situation. These "maps" are a closely guarded secret, and directly impact the performance of each vehicle under all conditions.
-Are you saying that you have the tuning abilty to match the driveability characteristics of the stock ECU??

Again, if custom ECU replacements didn't adapt they'd be worthless. All the works teams, racers and performance enthusiasts wouldn't be paying for and installing them. Adaptability is the most basic feature of an ECU. The ones I installed and tuned over ten years ago had features just now appearing on OEM ECU units.

I'd say that user tunability is the most important feature of a custom ECU replacement. Racers also have legions of techs and $$$ to keep up on the electronics driving their investment. They also have the ability to make continuous measurments of environmental conditions and adjust their programming/performance to suit. Joe Average driver does not have this ability, money or concern. Will I sacrifice reliability and utility (read: transparancy) just for a few horsepower? I think not, and those I know (I came from the Subaru community -the most tech-savvy bunch of geeks you'll ever want to meet), who have switched over to a full-standalone unit have been dissapointed. Most who want *some* user definition will go with a piggyback unit that simply modifies signals in/out of the factory ECU. Even this alternative is a headache -I was always faster, and my laptop was used for games and porn, rather than tuning. BTW, what feature of a custom ECU 10 years ago is just now available on a factory unit?

After looking over the AEM unit mentioned in the previous post I can certainly say it's not advanced at all over the Haltech unit. The AEM unit is a daughterboard which is piggy-backed with a stock ECU. The Haltech unit is a complete replacement unit. The AEM unit is limited to OEM ECU's that it can work with, whereas the Haltech is only limited by various engine configurations, which is addressed by the various models they have. Additionally, the Haltech allows "in-flight" tuning where the AEM unit is a static download/upload arrangement. Apples to Oranges folks.

My experience with Haltech has been a unit in an MR2, and various Halmeter products in other cars. I find it hard to believe that any unit is better than the newest AEM system (the EMS) which is NOT a piggyback. The AEM also has real-time adjustment capability via a hand-unit, which I believe the Haltech does not.

Back to the original spirit of the thread.
There is no piggyback or user adjustable unit available for our ECUs that I know of. If someone had the ability and the desire, this could be done, but again, the market is not there.
I'd just like a simple speedo calibrator for larger tires.

[Joe_Black]

mbeach, please take a little time to review your research. You'll find the correct answers to many of the questions you brought up. I don't wish to get into any arguments or unpleasantness over readily available facts. Look into ECU's in general as a fundamental understanding of what they do and how they work will help you a great deal.

As for your wish for large tire speedometer calibration, you may want to check with St. Charles Isuzu. I'm not certain if this is available for the VX, but should as there was a "large-tire" gear for the Trooper's speedo sensor. As I understand, it was available for folk running 31X10.50 rubber. Failing that, or if you want more adjustment resolution, you can get an electronic speed calibrator that fits inline to modify the speed sensor signal from the transmission: TruSpeed Signal Recalibrator.