Forum » Understanding AFR » Fuel map good or bad?

Fuel map good or bad?

Understanding AFR

Discussion and questions related to the course Understand AFR


Page 1
Author
1470 Views

Hello im new here and just started tuning my own feul map for my car. It had a fuel map on it that was a goo starting point but for the most part was really off. I know you cant tell much of how its going to run just by looking at the graph but i want to see if im going in the right direction as in to making a good smooth map. I attched a pic of it so let me know what you think thanks.

Attached Files

You're right, it's a little hard to give much useful feedback solely based on the fuel table graph. You generally have a smooth shape to the table which is great however I would expect the fuel table values to begin tapering off or dropping at high rpm. The shape of the efficiency table should closely match the shape of the torque curve (since torque is airflow), which should see the efficiency values peak around the peak torque rpm, before dropping off towards redline.

Ok cool thank you for the pointers im still trying to understand it but atleast im making it smooth. Idk what to say beacause i took my car to get tuned and ill post the pictures of the maps the tuner made. Im no expert but i think its completly off. So i tried my maps and the car runs 100% better. Please tell me what you think about these maps because i know they are wrong and i want to contact the tuner about it but be sure be for i do so.

Attached Files

Ill give you more info on the car too. Its a rx7 fc with big streetports, 1000cc/2000c injectors, 50 trim @20psi on e85.

Attached Files

fuel and ignition maps that look like that are the exact reason why we founded HPA. You're right, there is little to no chance that what you had was a thorough and correctly tuned ECU.

With a decent port on a 13B, it's not uncommon to see the VE peak at high rpm. Ultimately the wideband will tell you if you're heading in the right direction. One other point I'd make is that with a turbocharged engine the VE won't continue to step up indefinitely as boost increases. The increased air density from positive boost is taken into account in the main fuel equation. What we usually see is the VE increase with boost before plateauing and even dropping off once you start going beyond the turbocharger's efficiency and the engine begins choking.

Whoever did that tune doesn't know much about Adaptronics.

Your ecu has adaptive fuel learning which means it will read the output of the O2 sensor and trim the fuel to suit the revs and conditions and this learning is then transferred to the tune. This takes time but it does work and works well. The important thing is to have the basics set up properly before you start tuning.

I knew it this guy was trying to break my motor! Thats why i signed up im learning quick thanks to the course and the help. Im so scared to keep trying it beachse i dont know what i should set the timimng ar to be on the safe side but not pull to much out. Do you guys have any ignition mals i can try to base mine off of? Or ones i could maybe use as a starting point?

Sorry can't help you with a start map for either fuel or ignition but I recommend you do Andre's Road Tuning course that will help you work out the basics and you can go from there. The only other thing I would recommend right now is that you find a way to listen for engine knock. There area few tools available, they are not cheap but then again neither is an engine rebuild. Also worth considering is an AF sensor like Innovate Motorsports LM2 so you can watch the Air Fuel mixture (and log it) to make sure your engine isn't running to rich or leaning out.

Just thinking the guys at Adaptronic might have an ignition map to help you start off with.