M3 3rd gear DataLogs

[elim11]

Hi guys,
I just picked up the BMW Datalogger Software. Here are some 3rd gear data logs I did. 2008 e90 m3, 6mt, all stock. 91oct gas M mode activated.





Coming from a 335, datalogging is pretty common. I am pleasantly surprised that the IAT remained very stable thru the runs (NA FTW).

One question I do have is regard the IGN. I'm not very familiar with how the m3 IGN is suppose to be but is this normal? I see a couple timing drops and the timing seems to reduce around 6000rpm range and then pick back up towards redline?

Let me know.

[Longboarder]

Missing boost log. Time to add a supercharger

Can you log AFR's?

[M3takesNYC]

I am glad I found this board and starting reading. I also was in the 335 crowd but had been off the boards for awhile. I did some data log recently and your ignition timing appears to be significantly retarded. I am catless but otherwise stock and have a tune from one of the big tuners. (won't say which only because I don't want to post data without them knowing that gives away what they do).

Anyway, I did 2nd and 3rd gear WOT pulls with IAT in the 68 F range and just looking at the 6500-8500 range which is all I cared about my timing was pretty much 34 degrees throughout that range with AFR of 29 (these numbers were give or take .0x of a number).

Your timing, unless I am missing something appears to be as much as 10 degrees or more retarded than mine. I use 94 octane fuel.

Logging knock values I showed no knock until I reached 8500-8600 where timing dropped to 31 degrees and some knock showed up on the logs. I am guessing the higher load at that high of an RPM is too much to handle.

I was going off the basis that I believe the stock timing targets for a WOT run given ideal conditions was max of 32 degrees. I was a bit surprised I was only 2 degrees higher than this with a tune and pretty ideal conditions with no knock tells me timing was not being pulled.

Of note I did have a LTFT value of 4 that was logged. Not sure that matters here.

It is very hard to find information on datalogs for the m3 or any sort of stock targets for AFR, ignition timing etc. I would love to see a stock timing map or atleast see the max stock timing targets to compare.

But something appears to be yanking timing and I am guessing you may be on 91 octane? IAT's look the same as mine which was in the cool range and unless you were going uphill or something I don't see why timing would be pulled over 10 degrees almost steadily throughout the last 2k rpms which is essentially the entire powerband in 3rd gear.

I would love you to do more data-logs and I am going to continue the same with 2nd and 3rd gear runs.

I would include a value to pick up whether or not you are knocking and maybe the AFR to see a bit more data to determine whats going on with timing. 10 degrees through the powerband under cool IAT's with no other problems would be a significant loss of power and something you want to reclaim unless I am absolutely wrong about the stock max timing target of 32 which in that case maybe the stock max target is in the 24-25 range?

[urBan_dK]

Here are stock timing and lambda targets:

[M3takesNYC]

Wow, perfect, that is so helpful. As I suspected to the OP your timing is way down. On the other hand I would have thought a tuned car would offer more than 2 degrees of advance but maybe that is where the power increase ended as I know more advance does not always mean more power. AFR's are right on target for me but again OP to really see whats going on we need some AFR and personally I want to see the knock events.

I am surprised logging is not a bigger part of the m3 community. I understand for a turbo car it is significantly more important to really dial in boost and monitor the engine safety but still I find it really interesting stuff to log the various effects of temperature, humidity, octane use any any other variable and see directly how it is effecting the engine output.

Quite amazing how exact and precise this engine can monitor and adjust at the speed it does!

I have also read that the stock max timing (which appears is 32) is quite aggressive so I wonder if a regular stock car on 91 or even 93 in real world conditions actually ever hits that?

Anyone know how a catless setup would show up differently on any of these logged values? I figure it would not effect AFR, timing etc necessarily.

[M3takesNYC]

By the way, can anyone tell me if logging a 3rd gear vs a 2nd gear would show different values on the ignition timing? I cannot think of a good reason why except maybe there is a higher load at higher speeds on the engine? I looked at the 3rd gear logs with every other value in place they are consistently 1.5-2 degrees retarded than the 2nd gear runs.

I need to get these graphed but doesn't really change the numbers I am interested in.

[elim11]

Originally Posted by Longboarder

Missing boost log. Time to add a supercharger

Can you log AFR's?

Nope, Cannot log AFR yet. I believe developer may add additional parameters to log. I hope I can get some SC action. Your car is a beast sir!

[elim11]

Originally Posted by M3takesNYC

By the way, can anyone tell me if logging a 3rd gear vs a 2nd gear would show different values on the ignition timing? I cannot think of a good reason why except maybe there is a higher load at higher speeds on the engine? I looked at the 3rd gear logs with every other value in place they are consistently 1.5-2 degrees retarded than the 2nd gear runs.

I need to get these graphed but doesn't really change the numbers I am interested in.

I think the 3rd gear datalogs are preferred because in 3rd gear you (typically) eliminate the chance of wheel spin, etc, and it gives a longer gear so more data points. I guess I will do more data logs, but I wanted to see how I stack up against some stock m3s and of course against some tuned m3s.

Curious to see what the differences are.

[elim11]

Originally Posted by urBan_dK

Here are stock timing and lambda targets:

Thank you for this info. I am indeed running 91 octane, so I may be further away from the max timing #s.

[elim11]

Input from a respected tuner like @MikeBenvo or @Evolve would help a lot.

[M3takesNYC]

I would get a BT tool if you have not done so. Are you sure you cannot log AFR? No Lambda probe value before the cats on your logging tool?

Anyway I have no idea how 10 degrees of timing retard translates to power but losing 10 degrees throughout the entire powerband I would have to think equates to a significant amount of power lost from potential peak power.

I don't think it is surprising however as from my research these cars so rarely if ever hit their timing target in real world driving, especially on 91 and often not even with 93.

These are the kind of objective data that really illustrates that while on a controlled dyno with perfect conditions and a couple pulls 91 may hit peak power, in real world pulls, 91 simply does not come close to cutting it in terms of making the stated power of this engine.

I still get knock using 94 octane but like I said a tuned file is a bit different but hitting upwards of 34 degrees, in the higher RPMS I still get some knock above 8k with 94 so you can imagine straight 91 you would be nowhere near able to hit even stock 32 targets

I wish more dyno places would include some basic logs with a dyno. A dyno plot with some timing info, IAT and AFR (which some do) would really allow more accurate comparisons across different dynos.

Would explain why one car with the same mods may be putting out more/less than another identical modded car if the timing on 1 of them was a lot different for example.

[elim11]

Originally Posted by M3takesNYC

I would get a BT tool if you have not done so. Are you sure you cannot log AFR? No Lambda probe value before the cats on your logging tool?

Anyway I have no idea how 10 degrees of timing retard translates to power but losing 10 degrees throughout the entire powerband I would have to think equates to a significant amount of power lost from potential peak power.

I don't think it is surprising however as from my research these cars so rarely if ever hit their timing target in real world driving, especially on 91 and often not even with 93.

These are the kind of objective data that really illustrates that while on a controlled dyno with perfect conditions and a couple pulls 91 may hit peak power, in real world pulls, 91 simply does not come close to cutting it in terms of making the stated power of this engine.

I still get knock using 94 octane but like I said a tuned file is a bit different but hitting upwards of 34 degrees, in the higher RPMS I still get some knock above 8k with 94 so you can imagine straight 91 you would be nowhere near able to hit even stock 32 targets

I wish more dyno places would include some basic logs with a dyno. A dyno plot with some timing info, IAT and AFR (which some do) would really allow more accurate comparisons across different dynos.

Would explain why one car with the same mods may be putting out more/less than another identical modded car if the timing on 1 of them was a lot different for example.

Agree with what you say. Currently I am not able to log AFR. The developer of the software I am using (http://www.m3post.com/forums/showthread.php?t=793891) may include that in the future. I'll try to take more data logs and see what I get. Maybe try different gas stations as well (I believe gas used during that run was from 76 station). Perhaps I will find some race gas and do some logs with that also.

[m33]

Originally Posted by Longboarder

Missing boost log. Time to add a supercharger

Can you log AFR's?

Here's mine for comparison , VT650

[Longboarder]

Originally Posted by m33

Here's mine for comparison , VT650

Cool. Although it doesn't appear your meth was flowing given the IAT spike at higher RPMs. Although looks like you were logging in cold winter air.

[M3takesNYC]

Yes no joke, meth above is not flowing!

[m33]

Originally Posted by M3takesNYC

Yes no joke, meth above is not flowing!

Guys, pay closer attention. My IAT on the dyno only rose 5
degrees. Here's Drew's kit where IAT rose 10 degrees with meth
on. Here's some more examples:

Izzy dyno (no meth):
Ambient temp: 59 dF, IAT: 114-118 dF, Rise over ambient: 58 dF
http://www.s65dynos.com/showDyno.php...ype=1&dynoID=2

Alekshop IAT stress test (no meth):
Ambient temp: 83 dF, IAT: 130-170 dF, Rise over ambient: ~87 dF
http://www.m3post.com/forums/showthread.php?t=702956

M33 dyno (+meth):
Ambient temp: 87dF, IAT: 95-99 dF, Rise over ambient: 12 dF
http://www.s65dynos.com/showDyno.php...ype=1&dynoID=2

DLSJ5 dyno (+meth):
Ambient temp: 72 dF, IAT: 82-95 dF, Rise over ambient: 23 dF
http://www.s65dynos.com/showDyno.php...ype=1&dynoID=2

Without meth, IAT rise over ambient was 58-87 dF, and with meth
IAT rise over ambient was 12-23 dF. Absolutely no doubt meth was
working just fine thank you very much, Silly Rabbits Trix are for Kids

If you follow my threads you'll know that I log and dyno more than most individuals on this forum!

[M3takesNYC]

Woops didn't look at the scale correctly! The way it is graphed the increase looks huge but the increments are large spaced apart!

[m33]

Originally Posted by M3takesNYC

Woops didn't look at the scale correctly! The way it is graphed the increase looks huge but the increments are large spaced apart!

I scaled it like that so you can get a detailed broad outlook of the results cramped into a tight chart

[elim11]

Update:
Just an update with another datalog from today. 61F ambient, same road. Switched up the gas this time from 76 (91 oct) to Shell (91 oct). Gas did not make that much of a difference. I'll try again with another brand (probably Chevron) and then move my way up to race gas to see differences.

[M3takesNYC]

Something is wrong with your car. Brand of gas likely does not matter. 91 octane in 60 degree weather should be hitting atleast 30 degrees pretty much throughout the last 2500 RPMS and really should be hitting 32 in 60 degree weather. You are down in the 25 range. Either your spark plugs are really old and its screwing with the ionic knock recognition causing you to knock which you could measure if you had the BT tool. Its worth the expense.

Race gas may mask things and get you to spark at 32 but if it takes race gas to get you to 32 degrees at 60 degree weather that means when it gets 90 degrees out you are going to be back down to 25 or lower degrees of timing. Race gas would be a bandaid. I feel something is not right. BT tool would tell you if your cams are lifting properly etc .

If you spark plugs are new, you measure cam lift and it is normal and you use 91 octane which you are and your air filter is new, I then have no idea why your not hitting withing 8 degrees of timing. I would guess a good 25-30hp is being left off the table across the board which is a lot

[urBan_dK]

Originally Posted by M3takesNYC

Something is wrong with your car. Brand of gas likely does not matter. 91 octane in 60 degree weather should be hitting atleast 30 degrees pretty much throughout the last 2500 RPMS and really should be hitting 32 in 60 degree weather.

Really? You're stating he should hit full timing advance with 91 octane at 60 degrees ambient? I don't think so. Go look at the stock targets I posted earlier. You can't even hit those with 93.

What are you basing your numbers on?

[M3takesNYC]

You can't hit the 32 degree timing from the 6k-8400k range on 91 but I have also logged fuel with 91 and 95 and 91 on a 50-60 degree day if run hard a few times was still able to hit 28-30 degree timing target. With more pulls or a summer day, 91 would be likely in the under 25 degree range but 60 degrees without heat soaking the car with too many runs, 30 degrees should be quite attainable.

93 pretty consistently hits 32 degrees unless temps are above 90 with quite a few hard pulls and then it dials back to 26-27.

Using 95 octane (race fuel mix) is the only stuff that virtually always hits the targets in cold or warm and consistently.

I am not saying I am sure but datalogging since he is doing it already with a 199 dollar BT tool would save a lot of headache and speculation as he can assure his cams are hitting their timing marks and A/f was good etc