I'm getting into playing with the fuel and ignition maps in the ECU via computer. Software is similar to that of Hondata. I've seen how other racers fine tune their maps using a laptop in the track...though some are datalogging.

I would like to know the basics of tuning the ignition and fuel maps. I do not want to simply advance ignition and dump more fuel and assume this will do good.

If I want more bottom end...which areas should I be looking for to tune? Should I advance or retard? How about fuel? How about mid and top end?

I know this is a very extensive topic and nothing beats tuning by an expert with a dyno and wideband O2. But I just want a basic overview from which I can learn from.

 

What ECU do you plan to use? What sensors does it use (in particular, does it use the mass air flow sensor?) I tuned a car with a Haltech ECU using only the TPS and running closed loop. I can't imagine what I would have done without a dyno (though it was a crappy one).

If your ECU controls a distributorless ignition, you can tune advance. The general rule is that advance increases with rpm, and decreases with throttle position or engine load. I am not an experienced engine tuner and stuck as close to the stock advance curve as I could. The other major variable is injector pulse width, or how long the injectors open per cycle. Longer pulse widths result in a richer a/f ratio, shorter ones lean it out.

Speaking as someone who tuned an engine for the first time, I adjusted the pulse width and tried to get maximum power over every rpm range and throttle position, nothing more.

 

Thanks for the reply!

I'm running a simple system. It isn't a tuneable ECU per se since I'm running a stock ECU with a programmable chip. It isn't as advanced as the haltech...but it allows me to plug in ignition and fuel values in an rpm/mbar table.

I also plan to stick as close to the stock curve too. I just wanted to know how tweaking the ignition and fuel tables at a given rpm range will affect the car's performance.

I've been reading and playing around with basic EFI tuning...but I want to know some things I can do and use at the track.