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If you are worried about fuel economy the get an ecu that can run closed loop for cruise (ie, uses the o2 sensor for feedback and adjusts the mixtures to acheive a set target a/f ratio on the fly).

Other than that get something that you can get tuned locally by a tuner you trust.

Yes closed loop can be an advantage on a factory map, but they are more designed to maintain correct AFR's for ideal emmissions. Maintaining 14.7:1 allows the cat to correctly clean up the exhaust. Running an aftermarket ecu will allow you to run reliably at 15-15.5:1 afr's and get much better economy on a long drive.

Closed loop operation in all ecu's is a correction factor of about 12% on the base map, so it can richen or lean out the mixture by only a small amount. Closed loop is not able to fix a map that is tuned incorrectly by any means.

I'd like you to elaborate on that a lot more on what your trying to say there. Timing control ability, as in at what crank degrees injectors will fire in sequential operation, and at what point ignition will fire is adjustable in wolf and Haltech ecu's. You can also individually retard or advance individual cylinders if required with both ecu's.

By spark capacity i assume you mean spark energy? Has nothing to do with the ecu. All three ecu's allow you to adjust on/off times when controlling dumb coil ignitors which does affect spark energy directly. So long as that charge time is configured the same on all ecu's the spark energy will be the same. If you want powerful sparks, upgrade to a CDI system, start looking thru the Excel and MSD catalogues. HKS ignitions all though being well designed specificly for nissans arent the only option. MSD's top of the line race ignitions can produce 70Kv+ at the plug. Regardless of coils, ignitors or CDI systems spark capacity has nothing at all to do with the ECU.

I do agree the autronics are one hell of an ecu, and i've personally seen one on a RB25/30 thats cranking out an easy 700hp. Installations on WRX's and EVO's, anti-lag and huge turbo's produce an awesome result.

The autronics self learn mode makes it such an easy to tune system, you can very quickly get a good result with them. This has got to be the main advantage of the autronic over all other ecu's, as without self learn you are relying on the tuners ability to tune the ecu manually. The tuner has to understand the dynamics of the engine they are tuning, and this is a big call as a lot of tuners "specialize" in a particular breed or configuration of engine. Stock vs larger or multiple throttle bodies (GTR and others), radical head porting, high lift cams etc all alter how the ecu map will work.

If you go back to basics... remove the turbo and just talk about a naturally aspirated V8. Add the correct sized carburator and mechanical/vac distributor and tune it. Then compare that to its injected counterpart and you'll find the performance is virtually identical. Its been proven. The only minor diferences in performance is due the restriction of the venturi and the sometimes poor fuel distribution to the front and rear cylinders that occurs with some manifold designs.

Speaking from the perspective of an engines builder that wires and tunes ECU's, is a qualified electronics and has been providing high end IT computer support for about 10 years I can say it all comes down to the individual tune. If the HP produced by any ecu is diferent to another ecu on the same engine it just means the tune isn't correct. By same HP i mean within about 5-10hp, as anyone thats done back to back testing on a dyno will know the results can vary this much without changing any settings at all.

Not looking to start a pissing/flaming contest here about one ecu vs another, but i'd really like to hear a logical reason for your comment.

Regards,

Ian

No I'm not so much talking about the point at which injection or ignition occurs but the ability of the ecu to take an input and calculate the exact postion at which it should fire. If you look at an EVO ECU it has a 4 tooth even crank input. Which means it recieves its signal every 90 degrees. How the ECU calcualtes the acceleration or decceleration of the motor in between these signal depicts how good the timing control is. I have tuned a few EVO 8 and 9's with our XEDE processor and have found that it sometimes sets a P300 code(random misfire code). We know that its a problem with the calculation and we have corrected the problem.

Spark capacity, well I could go on but it really has more to do with the current to ionise the gap then it does with voltage. While a high voltage ignition system will ionise a large gap its when the cylinder pressures are sufficent enought that it have more to do with the current than large volatge.

I'm not trying to start shit but different ECU's do have different abilities!!!

Edited by rob82

With the exception of a lexus v8 i've wired, every aftermarket ecu i've installed involved modifying the crank/cam triggering to some degree.

Weather tham means using a custom trigger disc to replace stock ones, or just modifying the factory sensors, 9/10 ecu's will require some degree of alteration to gain the peak performance and tuning capabilities. (that includes autronic, ems, wolf, and haltech, NOT and FC) All aftermarket ecu's on the market at present support input triggering from 2 or 3 independant triggers, and also support many ways of configuring those inputs to achieve the desired tunable result.

All this is irelivent as provided the trigger disc is correctly made and accurate, one brand of ecu will be as equally accurate as another with regards to timing and injection accuracy.

I assume an XEDE processor ecu is like an emanage or haltech interceptor. Not what i'd call standalone by any means. Interceptors still work within the limitations of the stock ecu and are limited by the accuracy of the stock trigger disc and sensoring.

I agree that what you call spark capacity is current derived. The plug is essentially a resistor, where the resistance increases with plug gap and cylinder pressure. The discharging coil discharges voltage from its secondary windings thru its own internal resistance and accross the plug. The larger the gap, the larger the resistance diferential and thus the higher the voltage, but lower the current.

As interesting as this is also, its not at all relivent to the ECU. I've yet to see an ECU, factory otherwise directly fire an ignition coil and magically somehow generate more spark energy thru some sort of superior way in charging it for 2-4ms. 99% of aftermarket ecu installations still use the standard coil packs and ignitors so spark energy can only be as good as it was with the factory ecu installed.

Edited by GTST4Newbie

You have your opinion and I have mine. Sure if it is possible to make a trigger disk setup in every case it will definately make things more accurate. I chose the EVO as an example as with the 4 tooth even crank signal it is very difficult to determine the actual position of the crank. If it is inaccurate in its calculation then it will be inaccuarte in its time of injection(not that it matters to much) and also the time at which it drives the coil hence either overcharging the coils or under charging the coil(reducing the spark capacity).

Motec plugin EVO8 max power 186awkw with 3" Exhaust turbo back on 22psi. EVO8 with our flash on the satndard ECU program 3" exahust back 196awkw. I know there are alot more variables in comparing the two but both more so the MOTEC had been tuned to maximum performance.

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