Hello,
As a hobby I modified my 2003 mini cooper r53 with smaller compressor pulley (I made & install ~15% pulley). As a next step I want to adjust sw.
I identified, relevant i hope, maps and make a modification in base ignition map, “throttle map”, and fuel map.
As long as the first two changes seem correct (I can see changes in the logs), I have a problem with fuel. I started to suspect that I did not identified fuel map correctly. Or something more limiting the fuel. Despite the changes I made, I didn’t notice AFR change at WOT. Which is definitely too high, especially between 2000-4500 rpm AFR~13,5 goes to 12,5 at higher rpm. Would you please advice? Is the map correct? Your help would be very appreciated.

 

Pm adriancl , he's great when it comes to tuning and help tuning. He's tuned my car multiple times now

 

@Bishop.No need to pm me.Even if you try to change the map values, is not enough,because X axis does not match with new air flow made by your supercharger.For 15% reduced pulley will get around 840mg/tdc air mass, and last map value right down must be around 0,56%.Will get the right AFR with this values,but also with the right base spark map moded.Because Spark value strongly influences the AFR values, in particular at WOT,are inversely dependent.For the right tune,you must to use a datalogger to look at air mass values, AFR, Ignition ,SFT, LFT,Knock.If your car is USA version-although I doubt it because as i know you live in Poland-on USA version sw have a lower limiter for EGT, and will get strong ignition retard at WOT if you overtune the fuel map.

 

Adrian,
Thanks for your answer. It's very helpful! I already changed X-axis for spark and fuel enrichment for 810 mg/str (like in stock JCW). It is realy not easy to find axis, i hope I found it correctly. I tested lower enrichment values before, now I changed it, as you suggested to ~0.56%at high rpm. Hope to test it over the weekend . I assumed that formula is: base injection time + base injection time*fuel enrichment factor value. I also set base ignition to ~26 for 810 mg, at high rpm.
I make a logs but true.. without air mass. This is serious disadvantage. Max SFT is +/- 7%. Not perfect for sure but hopefully reasonable for this engine?

ps. For those who want to make a pulley by themselves. Quite easy job. (i suppose that this is pointless in US where pulleys are easily accessible in a good price - completely opposite to that in Poland. But maybe it will be useful for someone). PK cross section.

 

Most important is to see AFR values at WOT.
SFT -7% in cruise mean a little too much fuel , will get high mpg, even AFR will show you 14,5-14.7.Try to get better values for SFT , close to -3% to +3%.That can be done in the best way by mods on base spark map, because will keep the current values of fuel injected amount(more fuel burned correctly=more power) but better combustion,you will easily pass the technical inspection of the car when the exhaust gas analysis will be done.

 

Thanks for your advice. I’ll tray to adjust base spark map. I didn't think about the ignition angle from this perspective.👍

 

After today tests: AFR at WOT is finally correct and the car just flies. Now i just need to precisely adjust base spark. This is fun!​​​​​​.
@Adriancl, many thanks for your support!