standalone and piggyback discussion

[Vteckidd]

One of the disadvantages of using the factory computer is you are limited to the inputs and outputs Honda provide, although you can alter their function

This is my definition of a PIGGYBACK. You must stay within the ECUs parameters or original code. Yes you can write your own code that coexists, but your still having to abide by their rules, correct?

Also, if you can run KPRO on B series motors and do coil packs, then why arent people doing it? That would eliminate the need to buy a $1500 EMS with a $300 CDI2 box correct?

I also understand that the Emanange was interpreting signals with a seperate microprocessor. maybe that was a bad analogie, my apolagies.

Doug or whoever this is, im not bashing, you make a great product, and we use it all the time, especially KPRO. its a great system and i reccomend it to alot of our customer OVER the AEM simply for price and functionality. this thread was about the difference between the 2

Mike
Vteckidd
Mainstream Performance

[Hondata1]

This is my definition of a PIGGYBACK. You must stay within the ECUs parameters or original code. Yes you can write your own code that coexists, but your still having to abide by their rules, correct?

No, we make the rules, because we write the code. For example we turn a purge control valve output into a boost control output. We could turn the ECU into an environmental control system for your house for example.

Also, if you can run KPRO on B series motors and do coil packs, then why arent people doing it?

Probably cost. K-Pro would cost a little more than something like an AEM EMS in this situation. The number of units we would sell for doing coil pack ignition on a B series would not justify our effort and the subsequent tech support.

OVER the AEM simply for price and functionality. this thread was about the difference between the 2

The stock Honda ECU has far more comprehensive mapping than any after market engine management system. Literally, there is an extra third dimension to tuning - the cam angle.

The stock K20 Honda fuel maps consist of 6 lowcam maps, for each cam angle 0-50 degrees and 6 highcam maps for each cam angle.

The fuel data is stored in 16 bit resolution, 20 RPM by 10 map sensor positions. So, we have 2* 6 * 20 * 10 = 2400 data points of 16 bit resolution.

Hondata increases the map sensor resolution, so the K-Pro maps have 2 * 6 * 20 * 16 points = 3840 points of 16 bit resolution.

Here is an example of just the low cam fuel maps. Double this to include the high cam fuel maps.



There are two reasons for the multiplicity of maps. The first is that the volumetric efficiency of the engine varies considerably between each cam angle. You can see this clearly if you look at any of the 2d maps for the highcam fuel on a tuned NA motor.

The second is something called cam lag. If you examine datalogs, you will find the actual cam angle sometimes lags behind the specified cam angle. When this is the case, the stock Honda mapping provides the fueling and ignition for the angle the cam is actually at, and not what you specify.

Have you gone through the training videos here?:

http://www.hondata.com/techk-protraining.html

This will teach you the best tuning techniques.


Aftermarket engine management systems do have more flexibility than the K-Pro, like real time programming and specifying inputs and outputs - using 4 EGT probes for example.


You cannot condense all the many maps Honda uses in their ECU into one (or perhaps 2) maps and expect the car to run as well across all conditions.