N54 Exhaust Burble XDF Tables

[AzNdevil]

So I don't care about burbles,
What I'm curious about is if these tables can affect the down rev? When you free rev the car it takes too long to come back to idle. I'd like that to be faster.

make sure your hardware is fine first...
this can be caused by vacuum leaks, sticky o2 sensors, throttle body, etc

from tuning, this can be caused a combination of the things below
a - dmfw
b - throttle correction map
c - vanos map
d - main ignition map

 

[KClemente]

make sure your hardware is fine first...
this can be caused by vacuum leaks, sticky o2 sensors, throttle body, etc

from tuning, this can be caused a combination of the things below
a - dmfw
b - throttle correction map
c - vanos map
d - main ignition map

You would want a higher LSA on the vanos in the first column right? Less overlap, higher dynamic compression, more engine braking.

 

[Asbjorn]

Agree with @iminhell1
Pretty sure the AT/DCT M and M performance cars have a throttle map that makes the revs climb and fall faster in N than N54s. It must be some kind of M "experience" engineering that makes those cars sound more like racecars in N. The revs dampen down alot as soon as you go into D.

I still remember when I first sat in an M4 and played with the throttle in neutral. The car felt and rev'ed much more like a race car than my N54. This experience eventually lead to me getting the M4 flywheel and later also stiffer engine mounts. However there's a definite software side to it as well that I wish we could imitate.

 

[Jake@MHD]

listening in

 

[Twinperformance]

I contacted the chap who tested the tables on his I8A0S car and he said he used tweaks to the main table.

MHD only manipulates the Timing (Main) table with the burble slider since Jake mentioned that they didn't know about the other table.

I had a look for the toggle that enables/disables the use of the timing offset during trailing throttle and it appears in the MSD81 IKC0S Damos but not in the MSD80 I460S Damos so it's possible that the logic that deals with differential timing during trailing throttle was added in MSD81.

If I drop the timing in the minimum ignition angle table by 1 degree I see exactly the same behaviour in my logs. I'd be interested to see if someone with IJE0S also sees the same behaviour.

I also have an I8A0S in my car and messed around a couple hours with these settings. Manipulating the Fuel cut delay normal/sport and the minimum ignition trailing throttle didn’t really do anything. The only way I can get my car to burble is by messing with the timing (main) while also modulating the throttle. Has anyone found a way to manipulate trailing throttle & burble duration with the I8A0S?

 

[JohnDaviz]

Agree with @iminhell1
I still remember when I first sat in an M4 and played with the throttle in neutral. The car felt and rev'ed much more like a race car than my N54. This experience eventually lead to me getting the M4 flywheel and later also stiffer engine mounts.

What is your experience between your stock flywheel and the M4 one. I know it is 4-5kg lighter and i am aware of the pros.

But are there negative sides? Is it acting any different in your car than in the M4? (On the negative side)

 

[Asbjorn]

What is your experience between your stock flywheel and the M4 one. I know it is 4-5kg lighter and i am aware of the pros.

But are there negative sides? Is it acting any different in your car than in the M4? (On the negative side)

The negative side is that it makes a horrible noise in low rpm high gear high load situations. It basically means I only drive in DCT S mode now. D mode upshifts too early, and the noise starts from 5th gear and up below 50mph. The S55 has a larger front balancer, so I guess that is one of the reasons it doesn't need such a heavy flywheel.

I'm the only driver of my car, and I can handle swapping into S mode. If I knew the car would sometimes be driven by other people, I would not install a lighter flywheel.

I don't know if anything is falling apart when the vibration noise starts, but I would rather avoid it.

 

[JohnDaviz]

The negative side is that it makes a horrible noise in low rpm high gear high load situations. It basically means I only drive in DCT S mode now. D mode upshifts too early, and the noise starts from 5th gear and up below 50mph. The S55 has a larger front balancer, so I guess that is one of the reasons it doesn't need such a heavy flywheel.

I'm the only driver of my car, and I can handle swapping into S mode. If I knew the car would sometimes be driven by other people, I would not install a lighter flywheel.

I don't know if anything is falling apart when the vibration noise starts, but I would rather avoid it.

But you also stated that you have stiffer motor mounts. Wondering how they contribute to the vibration transfer.

 

[Asbjorn]

But you also stated that you have stiffer motor mounts. Wondering how they contribute to the vibration transfer.

Been running the M4 flywheel for almost two years. The passenger side motor mount only happened in august this year. The NVH these two mods produce are not related imho. And dct transmission mounts produce a third type of NVH, not much related to any of the other two. I kept both engine and transmissions mounts stock on the driver's side.

 

[JohnDaviz]

Been running the M4 flywheel for almost two years. The passenger side motor mount only happened in august this year. The NVH these two mods produce are not related imho. And dct transmission mounts produce a third type of NVH, not much related to any of the other two. I kept both engine and transmissions mounts stock on the driver's side.

I am not sure if on the Z4 it is again a different topic. But i contacted a colleague of mine just a few minutes ago. I found out that he is also running the M4 flywheel with two other colleagues of him.

So the bad news for you. They don´t have the symptoms you are stating and he said you are most likely running a defective flywheel. But i don´t know what can fail on a smfw.

 

[Asbjorn]

I am not sure if on the Z4 it is again a different topic. But i contacted a colleague of mine just a few minutes ago. I found out that he is also running the M4 flywheel with two other colleagues of him.

So the bad news for you. They don´t have the symptoms you are stating and he said you are most likely running a defective flywheel. But i don´t know what can fail on a smfw.

Please describe the configuration they run in combination with the M4 flywheel. Which engine, chassis etc.

 

[JohnDaviz]

Please describe the configuration they run in combination with the M4 flywheel. Which engine, chassis etc.

E92 N54 DCT

 

[carabuser]

When the slider is set to " stock" timing values reflect those in the trailing throttle table no the values in my main timing table. How ever if I retard the timing angle in the trailing throttle table, the timing value during decel doesn't match up. It's negative, but no where near the values input in the table and it's not a constant value.

I was looking through the logic on an unrelated subject and noticed that the toggle for "Disable Tq Reduction by Ign" will inhibit the DME from manipulating torque using ignition so when disabled these minimum ignition angle tables are ignored and just the main table is used.

The MHD OTS maps and most freely available tunes out there have that function disabled which is completely retarded but that explains why some people couldn't get the timing table to work.

 

[BloodyZ4]

You guys think it would be possible to get burbles while stationary only in sport mode?

 

[carabuser]

By default the fuel cut delay is common between both modes when static.

You could set the delay of the fuel cut in normal mode to something short then change the minimum speed to 0. That way it would always use the respective duration for the mode.

Upload your bin and I'll change the settings as a test for you. It should work as the comparator for the vehicle speed is just less than not less than or equal.

 

[BloodyZ4]

Thanks! Im gonna try that. If I understand it correctly, the 'duration below min speed table' shouldn't matter anymore, it will never get referenced cuz the speed won't ever fall below zero?
Those where my burble settings:



And they look like this now:



Will report back how it works out!

 

[carabuser]

Looks good for the most part, I would have left the normal mode duration around 0.1. I don't know what the effect of such a short duration would be, might make things jerky when transitioning off pedal.

 

[BloodyZ4]

I just tried it and it didn't work, I guess maybe because I did the MHD quick flash 2min. I'll try it again tomorrow with a full flash. (Burbles in MHD were disabled)

 

[BloodyZ4]

I tried it today with a full flash, still didn't work. Would have been too nice

 

[carabuser]

Are you trying to get the burbles with the clutch pressed?

There's a different table for when clutch switch is active:

Conversion is X*0.01