Karter16's Silbergrau E46 M3 Journal

[karter16]

This is a good comparison of the difference.

This is the resultant VE table error of just mapping the correction to the standard interpolation points:



And this is exactly the same data, but with interpolation points optimised - I have also specified certain areas of the surface as having a greater weighting (e.g. low dr_rel/rpm combos the relative error matters more).

[Bry5on]

That is too cool. And on a Mac no less! Guess I’m glad I sprung for the beefcake M4 in my latest machine.

[ac427]

Well we seem to finally be coming out of the months of winter sickness in our house. I've been very patchy the last couple of months in terms of car stuff - hopefully I haven't missed replying to anyone!

Few quick updates: I'm likely taking the car on a trip at the weekend. In preparation for this I thought I'd better revert to the standard community patch v2 software (I was running a customised version for testing something) and took the opportunity to take the car for a decent drive and do a long VE tuning run to capture some more "spirited" driving. Very much enjoyed the grip of the wider tires up front, and the rigidity in the rear from the RACP brace makes a really big difference. I'm looking forward to getting Heinz's front brace installed as it's definitely noticeable that the front isn't quite as focused now in comparison to the, improved, rear.

Doing the VE tuning reminded me to have a play with something I've been meaning to do for a while. With high rate CAN logging there's enough resolution in the logs to go more granular with the VE tuning process. I'm just playing around at this point, but have tried things like building a correction map at a higher resolution, and then essentially brute-force solving (my M1 Max seems to be able to do about 150,000 fits per minute) an optimal 20x24 table.

In this quick example below, the best-found table has an RMS error of 0.0046 vs 0.0109 on the starting corrected table (e.g. standard interpolation points) - a 57.95% improvement, and a reduction in the max error point of about 20% - not bad.

Lots more playing round with this to be done.

Great stuff. Is the higher resolution logging enabled in the community patch?

[karter16]

That is too cool. And on a Mac no less! Guess I’m glad I sprung for the beefcake M4 in my latest machine.

I must say it's nice to finally have a reason to need such a powerful processor haha. I don't think I've really stretched its legs all that much!

[karter16]

Great stuff. Is the higher resolution logging enabled in the community patch?

It's not released yet - the code is done, but I'm still finishing documenting all of the variables (there's thousands). I'm actually making some progress on that so hoping to have it out there in the not too distant future.

[Obioban]

I love it...

... and am scared, as I've been trying to limp my M1 Air along till the MacBook Ultra comes out...

[karter16]

Car managed to function as a car for 3 consecutive hours yesterday - I’m away this weekend so brought it on a short road trip. Really love the extra grip up front, but need to do something about a stiffer sway bar now I have more grip to play with.

Lovely glamour shot of the missing diffuser and broken exhaust hangers


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[Bry5on]

Car managed to function as a car for 3 consecutive hours yesterday - I’m away this weekend so brought it on a short road trip. Really love the extra grip up front, but need to do something about a stiffer sway bar now I have more grip to play with.

Lovely glamour shot of the missing diffuser and broken exhaust hangers


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Easy - cabrio front sway bar

..if you're still on stock bars, that is

[George Hill]

Easy - cabrio front sway bar

..if you're still on stock bars, that is

And reinforce the sway bar mount

[karter16]

Back from my weekend away - car was flawless. I'm super happy with where the tune is at, got a really good mix of driving conditions and loads and don't have any complaints of note. Since dialling in the tune something I've noticed is how when I'm just cruising I'm generally sitting at lower RPM than I would have pre-CSL intake. I suspect there must have been something non-optimal with my MAF setup, because the CSL setup is actually better in my case.

Easy - cabrio front sway bar

..if you're still on stock bars, that is

Yep still on stock bars - how much stiffer is the cabriolet front bar do you know/think? It feels like I need a decent bit more stiffness?

And reinforce the sway bar mount

Yes absolutely! this would be the first thing for sure. I'm lining up to do Heinz's E86 front strut reinforcement and Bryson's fender reinforcement both of which need epoxy bonding, so would do the sway bar mounts at the same time for maximum efficiency!

[Bry5on]

Cab bar is 27 vs 26mm, so a ~16% increase. The sway bar contributes more to roll stiffness in the front than the springs too, so it’s not a small change. Maybe 10% total. And you increased your front tire width by, what, 10%?

[karter16]

Cab bar is 27 vs 26mm, so a ~16% increase. The sway bar contributes more to roll stiffness in the front than the springs too, so it’s not a small change. Maybe 10% total. And you increased your front tire width by, what, 10%?

Yep spot on! Awesome thanks heaps!

[karter16]

Something else I forgot to mention is how delightful the SMG is now, particularly in terms of downshifts and rev matching. From all the different things I've done I think the proportion of improvement in this regard is approximately as follows:

SMG relearning/adaptions: 20%
New rear diff bushes + RACP reinforcement: 30% (I did these two things together so can't rate them separately)
Nailing filling (RF) in the tune so that the engine is responding as the SMG model expects: 50%

Me from a few years ago would never have dared doing something like coming to a stop with foot completely off accelerator downshifting from 2nd to 1st. Now I do it pretty much without even thinking - it's smooth, accurate and reliable. Good fun.

[Bry5on]

Something else I forgot to mention is how delightful the SMG is now, particularly in terms of downshifts and rev matching. From all the different things I've done I think the proportion of improvement in this regard is approximately as follows:

SMG relearning/adaptions: 20%
New rear diff bushes + RACP reinforcement: 30% (I did these two things together so can't rate them separately)
Nailing filling (RF) in the tune so that the engine is responding as the SMG model expects: 50%

Me from a few years ago would never have dared doing something like coming to a stop with foot completely off accelerator downshifting from 2nd to 1st. Now I do it pretty much without even thinking - it's smooth, accurate and reliable. Good fun.

If I’d s54ed this car myself it would probably have an SMG in it! I’m not surprised how much better it is.

[0-60motorsports]

Something else I forgot to mention is how delightful the SMG is now, particularly in terms of downshifts and rev matching. From all the different things I've done I think the proportion of improvement in this regard is approximately as follows:

SMG relearning/adaptions: 20%
New rear diff bushes + RACP reinforcement: 30% (I did these two things together so can't rate them separately)
Nailing filling (RF) in the tune so that the engine is responding as the SMG model expects: 50%

Me from a few years ago would never have dared doing something like coming to a stop with foot completely off accelerator downshifting from 2nd to 1st. Now I do it pretty much without even thinking - it's smooth, accurate and reliable. Good fun.

That is amazing news. Would love to do it as soon as I get a chance LOL.