Chips?

[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.

[Tone]

I also offer a similar (and cheaper product) from the company that builds the Interceptors for us called the Recalibrator - $149.00 w/ free shipping.
http://www.autotransinc.com/recal.htm
Excellent for correcting the speedo which then helps the ABS function etter with the taller (or shorter) tires. It has already been installed and tested on a VX - email me for install instructions if interested.

[mbeach]

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.

I appreciate your maturity and I do not want to begin an arguement as well. However, I did not just fall off the turnip truck. As near as I can tell, you are stating that a standalone user programmable ECU provides better driveability than a stock unit. This is just plain WRONG, and any tuner will tell you this. Driveability and convenience are tossed out the window when you are looking at replacing your factory ECU. You might be able to get *close* to the stock unit's reliability and adaptability, but you will always have some compromise.

The original poster wanted a quick boost in performance, not the headaches of hours of dyno time, potential replacement of the stock engine harness, and the high probability that a user-tunable unit will give the owner just enough control to blow up their motor.
In this case, a simple piggyback unit that modifies one or more of the factory sensor signals will do the job. Units on eBay alter the IAT sensor signal to trick the factory ECU, others advance timing, whatever. The point is that they are quick, cheap and reversible. Your car's ECU will protect itself should anything go way out of allowable parameters. -Thank you Limp Mode.

I challenge you to hook up a Haltech unit to a VX. We'll dyno before/after, and I GUARANTEE that you loose power across the board compared to the stock ECU. This is not a dig against the Haltech, this is any standalone unit. They have their applications, but this truck just ain't one of them.

[jayfotos]

What he said....

"The original poster wanted a quick boost in performance, not the headaches of hours of dyno time, potential replacement of the stock engine harness, and the high probability that a user-tunable unit will give the owner just enough control to blow up their motor."

[Joe_Black]

Fair enough, merely wanted to share some personal experience and optional solutions to the question at hand.

[Joe_Black]

I challenge you to hook up a Haltech unit to a VX. We'll dyno before/after, and I GUARANTEE that you loose power across the board compared to the stock ECU. This is not a dig against the Haltech, this is any standalone unit. They have their applications, but this truck just ain't one of them.

After thinking about this for a while I decided to accept your challenge, but only if you're certain enough in your guarantee to wager your VehiCROSS.

[mbeach]

I don't think that my bank (or my wife for that matter) would be too keen on me betting the VX

I'm visiting with some shop owner/tuner friends of mine on Sunday. If there's a way to pull more power out of this truck with some electrical wizardry, they'll know it.
They are Haltech fans as well, I believe that's what they are using on their 700whp Evo. But then again, it's not really a "street" car

[Joe_Black]

Darn! There goes my chance for a rally shell! Thanks for being a good sport though!

While at your friend's shop ask about wide-band O2 sensors. It's a handy tuning tool that's really getting some good feedback of late. Not a lot of use just yet for us VX folk, but more information about what's going on under the hood is always a good thing.

I may have a line on getting the replacement ECU done anyway (Haltech, DTAfast etc.) as part of a well-known magazine piece. If the dollars fall the right way and they decide to do it then one of my VX's may return to rallycross afterall. Then I'll have to find a home for the three XR4Ti's!

[mbeach]

I've been using widebands for a few years.
We just need to weld a bung somewhere into our downpipe (oops, no turbo here -maybe in the x-over pipe.). I believe that we have been using an M12 x 1.25 nut welded over an appropriately sized hole. That way it's also easy to plug up when not tuning.

I've roadtuned cars (2 x Nissan Silvias) that have used Halmeter A/F meters connected to a wideband O2 sensor. Very accurate and easy to see when dodging obstacles while simultaneously turning knobs on the MAF signal adjuster.

I was into the dash last night (considering cutting it apart to make a double DIN opening -need to find donor (small) vents first), and considered cracking open my ECU. I find it hard to believe that it is a proprietary Isuzu unit. I'll bet a dollar to a dogturd that it's a GM product, likely for a 4.3L with a little adjustment for the DOHC configuration of our motor.
Has anyone even tried using a Hypertech PP on it? My Actron works fine, but it's OBD II protocol and that's to be expected.

Three XR4Ti s!!
That sounds like a donor yard for an RS200 clone project. Might be fun!