RomRaider

Leave the "Fuel Restore - RPM" tables stock (around the 1100 RPM range) and increase the "RPM Hystersis (Maximum)" to a value that is sufficiently high. For example, if "Fuel Restore - RPM" is at 1100 RPM and 'Fuel Cut - Hystersis (Max)' is set to 6900, then the effective Fuel Restore RPM is 8000 immediately after the throttle is closed. After a programmable delay, the ECU will switch to the 'Hystersis - (Min)' value (160 stock) so the effective Fuel Restore RPM will be 1100 plus 160 = 1260 after a short time.

Then adjust the "Fuel Cut - Hystersis Delay Counter" to your preference. Increase value (240 injection cycles is stock) to have the exhaust burble for longer. This value is set to 240 when throttle is closed and is slowly decremented while the throttle is closed but engine speed is below the 'effective Fuel Restore RPM'. Once this delay runs out, the engine speed will be above the effective FR RPM and the injectors will shut off.

OK, cool, will try, and report back.

So, since stock MS41.2 has the ECT threshold as 120° C, the RPM Hysteresis map I should be changing is the (Below ECT Threshold) one, no?

Hmm, good question. Yes, try the (below ECT) tables. Or I guess set the ECT value to the lowest value (-48C) and just take that out of the equation. Then use the regular tables.

So I tried the above settings using the "below ECT threshold" maps, and it did nothing different.




So then:
I lowered the ECT threshold to 80 deg C, and with the following changes:


*apologies if they are not labeled clearly, I can clarify as needed*

And I get about 1-2 seconds of burble ONLY when blipping the throttle, but not after a WOT run to any rpm. Pretty much always after a throttle blip, even very soft.

After WOT, there is no burble at all, just the occasional afterfire pop, which was there before as well.

Maybe add some to where you have "1" in "Ignition Retard - Decreasing TPS - Step size" so it pulls timing a bit quicker. I was running a value of "3" when messing with my deceleration burble and it seemed to pull timing just about instantly.

Keep in mind that ECT threshold is compared at the time of engine start. I recommend setting it to -48C and taking it out of the equation.

Increased the Ignition retard Step Size to over 3, and reduced the temp threshold to -48, minimum.

No change, same effect. Nice short burble/crackle for 1-2 seconds only on throttle blips, or revmatched downshifts. But never after a heavier throttle or WOT run.

I will keep on trying. Any other ideas?
Sounds very nice though, I will be reducing the delay a little, to shorten the crackles, and keep things safe.



Next I am going to try editing the Minimum load difference, and minimum load, to keep it out of fast throttle detection?

Some logs may help to see exactly what is going on.

Raising the "minimum load difference", and "minimum load" helped.

Now it does it about half the time, it's very nice. Maybe I'll fine tune it to not be so aggressive at high rpm (multiple real quick crackles).

Can't quite yet tell what the different variable is when it does it vs. not. True, logs would tell more.

If I get around to making a video with the sports camera I will, if it can catch the sound well enough.

Yeah, logs are crucial. We need to see the relation of ignition timing to the injector pulsewidth.

https://youtu.be/uGaqOs3la0Y

Did that on my s50. But disabled after some time. Now thinking of enabling again...

So i have been playing about with fuelling and timing.
I have now hit a sweet spot and seems to pull great, better than before, im happy but now i want to have a little play.
I read of people playing with deceleration table and getting a nice off throttle crackle,pop.
I get this already but wanting to know how to improve this, i also already get the odd exhaust flash on gear chamge after WOT at high RPM but can this also be worked on.
what can i do with the Fuel Cut Hysteresis to improve this crackle, what table do you use to Retard timinng off throttle as im guessing this would pull it back and great a nicer pop.

What do I have to do if I want to achieve such a result ??


https://youtu.be/6TRWuhU-FHo

Hey guys i have a question, i have a 323i m52b25 and i read alot here in the forum but my english is a little bit bad and i am a newbie in this section, so can someone take my stock file and modify it ?

I want that exhaust explosion popcorn crackle thing. Sorry if i am not allowed to post something like this..

That is easy to do. Have a read of the last few pages of the Hard Limiter thread.