I am led to believe that some of the newer Honda's ECUs are capable of reprogramming themselves to dull the gains given after some enginge modifications ie: cold air intake. For example, an engine with a cold air intake. The ECU recognizes the change in air intake(more air) and retards the timing to dull if not correct the gain in power. In lieu of all of this, I have heard that there is a way to "trick the computer" to not recognize and correct the gains. If anyone has heard of anything similar to this please reply to this post. Any info would help me settle this dispute.


[Modified by 00prelude-type-s, 1:45 AM 1/7/2003]

 

http://www.ntpog.org/mods/fifth-afc/ecu.shtml

 

that blows, i have an sh. i cant do a obd1 conversion, and an aftermarket from what i have read will kill atts as well. im screwed and can only get 280 at the wheels unless i want to wast the money i spent on getting the sh. damn the luck, screw you murphys law

 

Just to clarify... It's not just the Honda Prelude ECU or Honda ECUs that do this. It is not unique to Honda. ALL OBD2 ECUs in ALL cars are designed to monitor engine exhuast and trim fuel and/or timing with the goal of keeping emissions levels in check.

Andrew

 

You can get pretty decent fuel/timing with an EFI PMS if you want to go all out on your SH. It's about the closest thing that you can get to a standalone, bonus is that you can easily find it used for $500! I'd pick one up myself, too bad STS doesn't allow something that controls fuel and timing.

 

The only time your ECU will retard your timing is if it dectects nock. So, just adding CAI/Header will NOT do anything to your timing. However your ECU will adjust the amount of fuel intering the cylinders such that your A/F will be a perfect 14.7:1 (this ratio will burn all fuel and oxegen). So if your CAI is letting more air in, your ECU will automatically add more fuel to bring the ration back to 14.7:1, which is a good thing! Now if your want your car to run a little rich like 12.5:1 (some cars get better HP when they run a little rich) your ECU will NOT like this and tune it out, back to 14.7:1.

One way around this is to let the ECU keep your car running at 14.7:1 when the throttle is less than 90% open. Then at 90% to 100% throttle U tune your car to have 12:5:1 or what ever your car needs for max power. Your ECU runs in open loop during 90% throttle or more, thus it will never tune this out. This can be done with a A/F controller that lets you tune your fuel as a function of throttle position. Thus let your ECU tune your car for part throttle, and you tune the full throttle.

... or you tune the hole thing and reset your ECU every time U get in the car. If you have no way of changing your A/F, then don’t reset the ECU let it do it’s work.