Karter16's Silbergrau E46 M3 Journal

[Bry5on]

Yes I've found the same with the first round of VE tuning - threw one cell to the lean side. The other thing I've done is built out a histogram of RO/RPM/Lambda at 100rpm intervals to better see where there are peaks and troughs between the RPM interpolation points in the CSL VE table which is interesting, as I fine tune I may well end up adjusting the interpolation points to smooth things out more.

Yes am keeping the VL table in mind, but wary of doing too much there until I get a Wideband and get it in play. I've found logging STAT_VL_EIN useful for understanding in the logs exactly when the car is in the VL operating mode.

If I can get the VE map tuned well enough I theoretically should be able to then use the lambda measurements to help evaluate tweaks to camshaft timing to identify where VE is improved/worsened (will have to experiment to see if this works in practice).

Yep, you’ve got it. If you’re logging via D-bus and not CAN, it’s really hard to trust the data at 100rpm fidelity. There’s a lot of latency on the D-bus for request/response (testo logging is alternating requests) and the polling frequency is super low. For the higher fidelity logging TPS, RPM are both on CAN and a wideband should be plenty responsive.

While you’re in there disassembling, if you’d like to continue your current approach, you should really see if there’s a way to broadcast more useful values over CAN.

[karter16]

Nice. Some areas of the map are sensitive to fueling and can ping if they’re not right on. Others are sensitive to throttle and cam timing. I found the same, translating 100% didn’t really work but it gets you real close. My advice is always sanity check your VE tuning with logic and ideally the wideband. I’ve found it’s thrown a few cells lean, but mostly works. Keep in mind how the full load table is incorporated while you’re doing this.

Yes I've found the same with the first round of VE tuning - threw one cell to the lean side. The other thing I've done is built out a histogram of RO/RPM/Lambda at 100rpm intervals to better see where there are peaks and troughs between the RPM interpolation points in the CSL VE table which is interesting, as I fine tune I may well end up adjusting the interpolation points to smooth things out more.

Yes am keeping the VL table in mind, but wary of doing too much there until I get a Wideband and get it in play. I've found logging STAT_VL_EIN useful for understanding in the logs exactly when the car is in the VL operating mode.

If I can get the VE map tuned well enough I theoretically should be able to then use the lambda measurements to help evaluate tweaks to camshaft timing to identify where VE is improved/worsened (will have to experiment to see if this works in practice).

[Bry5on]

After a few days of Mr Three being in hospital we got him home yesterday morning. Yesterday evening and today I tested v3,4 and 5 of the tune. 3 and 4 were duds (in comparison to v2) in various ways (pushing the boundaries of the theory covered above too far, but on the plus side helping me get a feel for the various adjustments) but I'm very pleased with how v5 has turned out and am happy that I have a good base now to build on. To that end I ran the first round of logging for VE tuning this evening as the tune is currently rich across the board. After a few rounds of VE tuning I'll then start making fine adjustments to the tune as needed once the larger adjustments are out of the way. I managed to force some pinging under heavy load from about 1100rpm, which is interesting as I'm entirely Euro tune in that range so would be interested to know if that happened on my original tune as well - I don't recall having come across it before. But aside from that it's feeling good.


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Nice. Some areas of the map are sensitive to fueling and can ping if they’re not right on. Others are sensitive to throttle and cam timing. I found the same, translating 100% didn’t really work but it gets you real close. My advice is always sanity check your VE tuning with logic and ideally the wideband. I’ve found it’s thrown a few cells lean, but mostly works. Keep in mind how the full load table is incorporated while you’re doing this.

[karter16]

After a few days of Mr Three being in hospital we got him home yesterday morning. Yesterday evening and today I tested v3,4 and 5 of the tune. 3 and 4 were duds (in comparison to v2) in various ways (pushing the boundaries of the theory covered above too far, but on the plus side helping me get a feel for the various adjustments) but I'm very pleased with how v5 has turned out and am happy that I have a good base now to build on. To that end I ran the first round of logging for VE tuning this evening as the tune is currently rich across the board. After a few rounds of VE tuning I'll then start making fine adjustments to the tune as needed once the larger adjustments are out of the way. I managed to force some pinging under heavy load from about 1100rpm, which is interesting as I'm entirely Euro tune in that range so would be interested to know if that happened on my original tune as well - I don't recall having come across it before. But aside from that it's feeling good.


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[Bry5on]

That last bit is the ticket. Now compare the tune numbers from CSL vs euro and you’ll find that the euro intake cam timing should actually be making more power (and run smoother) above 3k rpm than the CSL values in most cases

[karter16]

Ok I think this approach is helping my brain. Here's another interesting view - this is the difference between the Euro M3 tune and CSL as it pertains to the crank degrees at which the intake valve is completely closed.



And correspondingly for when the intake valve opens:



Arguably the point at which the intake valve completely closes is the most important of the 4 (intake close, intake open, exhaust close, exhaust open), so I wanted to isolate that and examine the difference between the two maps. The intake open difference is directly related, plus an offset to account for the extra duration of the CSL cam.

As could be expected we can see that at higher RPM the CSL is configured to to close the intake valve later (by between 5-10 crank degrees) than the Euro M3 tune which will drive more top end power. we can see at low load between 4300 and 6300 RPM that the CSL closes the intake valve earlier than the Euro M3 tune. I presume this is to keep drivability decent with the bigger cams, as presumably is the other island at low RPM thru mid and high load.

[heinzboehmer]

I've peeked at similar spreadsheets on Bryson's laptop, but the visualizations towards the bottom of the post are awesome. Thanks for sharing.

[karter16]

To Bry5on's point I need to make sure I understand the theory of cam timing well. I understand the individual concepts, but where I've been struggling is putting it all together and visualizing what it means in different scenarios. To this end I decided that some spreadsheets would help (spreadsheets always help).

First up I took the interpolated AVAN and EVAN tables for both the Euro M3 and CSL tunes and calculated the cam overlap for each for each point on the tables:





As you'd expect we have low overlap at idle, high overlap in the midrange, sloping down to high RPM.

So how does that work out as a difference between the two?



The CSL generally runs more overlap everywhere apart from high rpm low load, and particularly in a few different islands in the low and mid ranges.

However - we need to remember that the CSL cams have somewhat greater duration than the standard M3 cams. For the purposes of comparison then we should account for this.




That's cool and all, but what it still doesn't tell us is whether the Euro M3 tune and the CSL tune differ in where the centre of the overlap occurs (e.g. before or after TDC) which is also important information in understanding the differences between the two and why.

So I calculated the centre of the overlap for each of the tunes





And from there we can compare the difference in overlap centre between the two:



Interesting stuff to look through anyway - I feel now with this view I can better visualize and understand the impact of the various tweaks etc. that I'll make. I've only just put these together and haven't worked through them in detail to look at various areas of interest but will update here as I do.

[Bry5on]

Haha - I would love to compare with your work but at this point agree - sometimes it's good to have separate efforts and then we can compare later. In terms of my process, I'm still figuring that out haha. At the moment all I really have is a tune that transitions from the Euro M3 tune to the CSL tune, with injection timing erring on the side of the CSL tune (which is generally richer) to be safe. I intend to try out a couple of different things from here to see how it goes. I ran a logging session this afternoon with LTFT off and adaptations reset to confirm my assumption that the midrange would be running rich - which it is. Plan from here is to play round with exactly where in the various maps I bring the CSL values in as I suspect I could bring them in at a lower RPM than I currently am in higher RF conditions (we'll see if that's a correct assumption or not ). Really what I'm battling at the moment is my own level of understanding.

One thing I'd love to know (it doesn't relate to any particular issue I'm having, I just was reading the other day and saw it and am super curious). In one of your first posts on the Mullet Tune you said you had to adjust the exhaust cam advance at mid throttle in the high 3k rpm range. How did you work out that was what was needed? From my (admittedly limited) understanding it seems like that would be one of the less consequent things to change and I'm curious as to how you zeroed in on that being what needed to be adjusted?

Good question, honestly hard to think back on that specific moment now that I'm through it. If I can venture to guess, there was probably a lump in the power delivery as you rolled into the throttle. This is one of the tricky things about the tuning in all honesty, throttle application rate changes fueling and can lead you to chase your tail a bit (think, "that just worked last time, what the hell?!").

In the end, doing some homework on cam timing, first intake and then exhaust, would be a smart move if you're still at the basics. You might find that you'll prefer more euro values than CSL in many cases

[karter16]

I’m enjoying watching your approach as well and resisting the temptation of sending you the files to compare. I don’t want to interrupt your process and would really like to see if we converge on the same answers, particularly since I’ve been doing some maps with the wideband O2 sensor in the loop.

Most of my imperfect running is the first 60 seconds from full cold starts in ambient temps below 60F/16C. Lots of variables to chase in the cold start tuning, and to tune via AFR you’ve got to disable secondary air, etc etc. Plus you only get 60 seconds per day to tune while you’re taking meetings for your day job.. Fun.

As you get some seat time, I expect you’ll find idiosyncrasies to chase - looking forward to you getting more time in it, and happy to share notes if you find some odd stumps here and there. It was helpful for me to have a few friends cars here (thanks Heinz) to load tunes on to hone in on what worked best, as each car responded slightly differently to some changes, but all run well on a single converged file.

Haha - I would love to compare with your work but at this point agree - sometimes it's good to have separate efforts and then we can compare later. In terms of my process, I'm still figuring that out haha. At the moment all I really have is a tune that transitions from the Euro M3 tune to the CSL tune, with injection timing erring on the side of the CSL tune (which is generally richer) to be safe. I intend to try out a couple of different things from here to see how it goes. I ran a logging session this afternoon with LTFT off and adaptations reset to confirm my assumption that the midrange would be running rich - which it is. Plan from here is to play round with exactly where in the various maps I bring the CSL values in as I suspect I could bring them in at a lower RPM than I currently am in higher RF conditions (we'll see if that's a correct assumption or not ). Really what I'm battling at the moment is my own level of understanding.

One thing I'd love to know (it doesn't relate to any particular issue I'm having, I just was reading the other day and saw it and am super curious). In one of your first posts on the Mullet Tune you said you had to adjust the exhaust cam advance at mid throttle in the high 3k rpm range. How did you work out that was what was needed? From my (admittedly limited) understanding it seems like that would be one of the less consequent things to change and I'm curious as to how you zeroed in on that being what needed to be adjusted?

[Bry5on]

I’m enjoying watching your approach as well and resisting the temptation of sending you the files to compare. I don’t want to interrupt your process and would really like to see if we converge on the same answers, particularly since I’ve been doing some maps with the wideband O2 sensor in the loop.

Most of my imperfect running is the first 60 seconds from full cold starts in ambient temps below 60F/16C. Lots of variables to chase in the cold start tuning, and to tune via AFR you’ve got to disable secondary air, etc etc. Plus you only get 60 seconds per day to tune while you’re taking meetings for your day job.. Fun.

As you get some seat time, I expect you’ll find idiosyncrasies to chase - looking forward to you getting more time in it, and happy to share notes if you find some odd stumps here and there. It was helpful for me to have a few friends cars here (thanks Heinz) to load tunes on to hone in on what worked best, as each car responded slightly differently to some changes, but all run well on a single converged file.

[karter16]

Hell yeah! Glad it's working out well. Listen for any pinging or bogging around 1800-2100 starting at roughly 2/3 throttle opening once you get a bit more seat time in it.

Do you have a Wideband O2 sensor? I still haven't gotten cold starts totally dialed in factory non-CSL perfect. I'm curious to see if you end up chasing the same thing I'm chasing. Congrats though!

I'm really very grateful to you for coming up with this approach. I remember thinking a couple of years ago how nice it would be to have a "standard" tune or set of tunes for cars running a CSL airbox without the cams, etc. but I doubt I would have ever thought of achieving that in this way, you having come up with this approach and proving it out is what gave me the encouragement to give it a go!

Yeah I just need more seat time in it now I think. I loaded "v2" this afternoon which has fixed the murkiness through the 3300-4000 rpm range, now seems super smooth in a bunch of different load/throttle conditions. I don't have a Wideband sensor yet but intend to get one to help with the next layer of fine tuning, WOT tuning, etc.

For v2 (having proven that v1 wasn't a dud) I added in the various cold start/warm up maps (I had to dive into the disassembly to validate a couple of things as some of the table values are very different between the 0401 binary and the 1901 binary that my car started with) and from an almost completely cold start (coolant temp a few degrees above ambient on what is admittedly a summer day here) the warm up seemed as it was on the standard M3 tune. I'll give it another go in the morning when it's cooler and the car is completely cold, but it seems a lot better than before.

[Bry5on]

Hell yeah! Glad it's working out well. Listen for any pinging or bogging around 1800-2100 starting at roughly 2/3 throttle opening once you get a bit more seat time in it.

Do you have a Wideband O2 sensor? I still haven't gotten cold starts totally dialed in factory non-CSL perfect. I'm curious to see if you end up chasing the same thing I'm chasing. Congrats though!

[karter16]

The divider is functional (assuming you duct to the front bumper)! Just saying

Hmmm this is a very good point - I shall ponder these implications some more.

If you want to test volume, try it without the snorkel. Sound is managed by throttle input.

Great point - thanks I'll do this first to get a feel for the difference in volume that we're talking about while I think more about Bry5on's comment

[karter16]

Well the initial couple of drives have been very successful. Couple of one time codes on first start up related to TPS and 1 misfire code, which I think was the engine being mad at the change of program plus blowing out the carbon from the throttle body cleaning. No repeats of any codes in the two 20 minute drives I've done since.

First impressions: the base CSL tune was not as bad as I was expecting. The warm up was rubbish as expected and lots of idle hunting, etc. going on. Once the SAP turned off things settled down. Driving around at slow speed was much smoother than I was expecting. The up and go was a bit muted, but tip in with the SMG was exactly the same as before and there wasn't any jerkiness under light/moderate acceleration. I presume that the reason for this is that my car is a Euro car, which differs less from the CSL than a US spec car does. I know that the US and Euro tune vanos maps differ significantly in places, so that would explain why the standard tune is worse on a US spec car. The car was quite reasonable to drive in the various conditions I tested it in.

Given this I wasn't entirely sure how much of a difference I would notice with v1 of my tune (which I must point out again is simply me making my own version of the approach which Bry5on has pioneered). I loaded it up and the improvement was immediately noticeable. The CSL tune wasn't rough driving around the neighborhood and it wasn't enormously noticeable that it lacks in peppiness under those conditions, but when you bring the peppiness of the standard M3 tune back at those low load, low speed conditions it is immediately noticeable as an improvement. I've logged the run in TestO and will go through it later. I need to adjust a couple of the timing maps in the 3300-3900 rpm range (I haven't quite got the crossover lined up right with the VANOS maps crossover and need to adjust slightly, but it's not off by much).

Extremely happy with how this has all gone. No installation issues, no programming issues and a good success with v1 of the tune!