View Single Post
Old 12-07-2010, 09:44 PM  
Poolside OP
Poolside's Avatar
Joined: Apr 2003
Location: Long Beach, CA
Oddometer: 11,887

Originally Posted by Lobby View Post
And you're not doing that?

I assumed from your posts that you were creating new control algorithms using, or re-using, sensor data (air temp, and oil temp) to reprogram the ECU.

Is this not correct?
How can I say this? We are inputting externally-controlled changes to the ECU, to cause it to operate in different parts of it's internal algorithm. I hope that's not too ambiguous, cause I'm not trying to be.

JJ says something about it in the quote below. I'll explain more about it later if you like, or I can point you to reference material. I'll try and explain it briefly here.

The stock ECU has 'rules' that it follows. These rules go something like, find out where the throttle is at, and the motor RPM, and what the other inputs are, and determine the fuel and spark outputs. That is an algorithm, a set of rules.

Any external change to any input creates differences in the outputs. Some changes are small, others large. Some are desirable, some are not. Some happen when you want then to, others don't. I'm meaning desirable from a drivability point of view.

Replacing the ECU is only necessary if it is. That may sound vague, but causing the ECU to operate in different parts of its algorithm 'rule set' makes a huge difference. If it's done right, it makes all the difference that people want made, and sometimes it exceeds expectations. What I mean by that is, many people do not know what truly excellent throttle response is, so they literally don't know what to expect. They know how one bike compares to another one they've owned, but often they don't have an absolute frame of reference.

With every stock motor I've seen, the stock ECU is capable of proper fueling. Capable of making the motor run as good as it can. To achieve that performance requires the ECU to operate outside the margins say, of its 'rule set'. That is possible to do with outside modification.

Causing the ECU to operate in different parts of 'rule set' can sometimes be a fairly simple process, or it may need to be more complex to work well, or work at all. Our 1st device is fairly simple. The 2nd one is fairly complex with microprocessor control, and it also interacts with the 1st one. That's the way it needs to be given the 'algorithm' in the Motronic ECU. Nothing else would, or could, work.

What you want is the removal of the undesirable aspects. That generally doesn't mean a 'flat power output'. I don't think I can explain here all that's entailed in the phrase "flattening the power output". But I can say you probably wouldn't like it, most people don't.

That undesirable dip in the powerband, it takes a big bite out of that.

Originally Posted by johnjen View Post
This reaches all the way down into the specific functional and mathematical algorithms that are used for the various portions of the EFI ‘states of operation’ themselves. Which means that depending upon in which ‘operational state' the engine is running, certain variables become important and thus/can be/are externally modifiable without having to re-write the algorithm itself. This is a decidedly GOOD thing for all of us because it means we only have to fuss with certain knobs to get the desired effects in a particular state of engine operation.


IICE Air Hotrod your GS  Fuel Injection  Tech Info  Buy  Order List  Installation

Poolside screwed with this post 12-08-2010 at 12:04 AM
Poolside is offline