Dyno'd today any suggestions on tuning tweaks?

[Hoffbrohaus]

During the run we dropped the timing advance at high rpms down to 30 and saw some improvement. Here is my dyno chart. I have not seen a torque curve like that before, the up and down from 2500 to 3500. But wondering if it was just the way the guy ran it on the dyno? The HP is smoother though.





MSPNP2, GM IAT, Wasted Spark, 48# injectors, no cat, Supersprint exhaust, Innovate LC2 wideband, E36 TPS

Not sure how to post my log and config file. So here is a link to google drive.

Any input is appreciated before I go tuRbo!

[digger]

its a lack of smoothing thing, the numbers are small a couple ft-lb here and there nothing to worry about

[Hoffbrohaus]

Thanks Digger. How about this drop off in timing advance (in green) and then the red duty cycle drop? What's weird about the ignition advance in the log viewer on the graph it says it dropped to 18, but on the right in the advance table it's at 30.

[e30davie]

Why is the mapdot all over the place? that implies lots of change in map. but your throttle is 100% pinned, which should mean the map is basically at atmospheric condition (101.3kpa) for the whole run, with mapdot basically zero. what does your raw map signal say during this run?

your tps is also showing 102% with a max of 104%. might need a calibrate?

[Hoffbrohaus]

Why is the mapdot all over the place? that implies lots of change in map. but your throttle is 100% pinned, which should mean the map is basically at atmospheric condition (101.3kpa) for the whole run, with mapdot basically zero. what does your raw map signal say during this run?

your tps is also showing 102% with a max of 104%. might need a calibrate?

Here I changed graph 2 to include the raw MAP data. It looks pretty steady on the line. Maxes at 96.2 and holds steady around 95kPA, then starts to drop to 94, 93 before redline.



And yes I will have to re-calibrate the TPS, I wonder if that had anything to do with the timing drop? More specifically something with the acceleration enrichment and the TPS dot? I don't fully understand this but I'm getting there.



Also I saw this in the logs, "rev limit retard" corresponds perfectly with the timing change. Looks like it kicks in at 6112 RPM, then peaks at 6318 RPMS at 12, when timing is 18 degrees, so 12+18=30 where it is in the ignition table! This has to be something :) now I just need to know if I should or need to adjust anything here?

[e30davie]

yep id say that rev limit is whats causing your ignition to be pulled. Pending what you are doing with the car the RPMs doesn't rev that quick, so i don't think there's much need to have a soft limit come in so early. id have to check mine again but i think i have my hard limit set to 6500 and soft at like 6400. but i've very rarely hit it, maybe once or twice on the skid pan the other week. Theres quite a few settings in the rev limit to play with, hard limit, hysteresis (essentially soft limit where it stars to retard) iginion retard, which looks like by default the spark retard is set to 12degrees, so that's where your number is coming from. this is quite a lot, id prolly look at like 5 degrees retard at 6400, just to slow it down a bit before it hits that hard limit of 6500. (if that's what you choose to limit it to).

For the purpose of tuning id just turn it all off and run a single hard rev limit at your desired rpm. Can see the map sensor signal gets a little wavey at the top end there, which is where your mapdot is coming in.

you should pick up a fair few more hp with that ignition retard off, can see in your dyno graph it starting to roll over once the ignition retard starts to come in.