[Moaus]

Update..
As i mentioned i had few misfires in all cylinders with no pattern. I've decided to try 98 octane in my last stop at the gas station (different one from where i usually go). Guess what, ZERO misfires ! (I'm using torque app in every drive to monitor misfires). What a joy 😜. Next step, logging some pulls and eventually going back to stage 1 (it's so slow right now, it's embarrassing)

[tpoddar]

Originally Posted by Moaus

Update..
As i mentioned i had few misfires in all cylinders with no pattern. I've decided to try 98 octane in my last stop at the gas station (different one from where i usually go). Guess what, ZERO misfires ! (I'm using torque app in every drive to monitor misfires). What a joy 😜. Next step, logging some pulls and eventually going back to stage 1 (it's so slow right now, it's embarrassing)

If you were having misfire issues on the regular fuel that you used, im pretty sure that's what caused the piston issue in the first place. Atleast now you have conclusive evidence for why it happened and can peacefully run your car on good quality fuel.

[Luverse]

Originally Posted by Moaus

Update..
As i mentioned i had few misfires in all cylinders with no pattern. I've decided to try 98 octane in my last stop at the gas station (different one from where i usually go). Guess what, ZERO misfires ! (I'm using torque app in every drive to monitor misfires). What a joy 😜. Next step, logging some pulls and eventually going back to stage 1 (it's so slow right now, it's embarrassing)

i believe the fuel quality is the main cause of your broken piston
i've been running stage 2 BM3 91oct for 8k miles, drives hard, no problem so far on my B48 engine

[Moaus]

Hi, will appreciate your thoughts on those logs.
1. https://www.bootmod3.net/log?id=6028...0b4346b9c7c33a
2. https://www.bootmod3.net/log?id=6028...729b454c0c5f55
3. https://www.bootmod3.net/log?id=6028...0b43474d7f52d5

[tpoddar]

Originally Posted by Moaus

Hi, will appreciate your thoughts on those logs.
1. https://www.bootmod3.net/log?id=6028...0b4346b9c7c33a
2. https://www.bootmod3.net/log?id=6028...729b454c0c5f55
3. https://www.bootmod3.net/log?id=6028...0b43474d7f52d5

These logs look perfect. Timing is ramping up smoothly with no corrections. Is this on the new fuel station you tested or the old one?

[Moaus]

Originally Posted by tpoddar

These logs look perfect. Timing is ramping up smoothly with no corrections. Is this on the new fuel station you tested or the old one?

Yes it is with 98 octane. Actually I'm concerned about the third one as i saw a few knocks...

[tpoddar]

Originally Posted by Moaus

Yes it is with 98 octane. Actually I'm concerned about the third one as i saw a few knocks...

Knocks under partial acceleration are absolutely normal as the ECU is optimising for fuel efficiency. Your WOT logs are smooth and clean so no need to worry.

[Moaus]

Ok, so I've tuned it to 91acn and did some logs.
1. https://www.bootmod3.net/log?id=602a...729b45d64d076d
2. https://www.bootmod3.net/log?id=602a...90c61a188c24e8
3. https://www.bootmod3.net/log?id=602a...729b45d64d076e
4. https://www.bootmod3.net/log?id=602a...90c61aac721f85
5. https://www.bootmod3.net/log?id=602a...90c61a188c24e7

Your thoughts would be appreciated.
On the first pull (the third link) i see a knock 😬

[tpoddar]

Originally Posted by Moaus

Ok, so I've tuned it to 91acn and did some logs.
1. https://www.bootmod3.net/log?id=602a...729b45d64d076d
2. https://www.bootmod3.net/log?id=602a...90c61a188c24e8
3. https://www.bootmod3.net/log?id=602a...729b45d64d076e
4. https://www.bootmod3.net/log?id=602a...90c61aac721f85
5. https://www.bootmod3.net/log?id=602a...90c61a188c24e7

Your thoughts would be appreciated.
On the first pull (the third link) i see a knock 😬

Logs look good. I don't see any knock at WOT. I think you'll be safe running this map. Since you have little to no timing correction, you can try the regular 91 octane map too. Also, go to datalog settings and start logging target ignition timing and timing correction for all cylinders.

[thejeremyman9]

Originally Posted by tpoddar

Logs look good. I don't see any knock at WOT. I think you'll be safe running this map. Since you have little to no timing correction, you can try the regular 91 octane map too. Also, go to datalog settings and start logging target ignition timing and timing correction for all cylinders.

He does have a knock at WOT in the 3rd link he posted as he mentioned. Overall, the timing does look clean though, just some minor corrections on one cylinder after the knock. It does recover though.

Its not great to get knock at WOT but if your timing is otherwise clean with little to no corrections and your IATs are in check, its really no cause for big concern. If you were consistently getting knock in every pull, then yeah, you should investigate further, but if its rare, not a big deal.

If you want to learn about how to interpret datalogs you can read my thread here: https://f30.bimmerpost.com/forums/sh....php?t=1732327

[Gaz908]

Im having the same issue. Could i please have a quick feed back of CP carrillo forged pistons ? from where did you buy it please ? did you also change the rods ? do you recommend 11:1 or 10:5 compression rate ? Thanks a lot !

[edycol]

Those of you having B46/48 engines, tuned or not, run oils that have MB229.52 approval. Problem is Low Speed Preignition (LSPI) which plagues smaller turbocharged engines.
Turbos are delivering too much boost for low rpms. New transmissions with eco mode and programming to shift to highest possible gear is greatly contributing.
Band aid are oils with less calcium in additive package. MB229.52 approval has specific LSPI test. So oils that have both LL04 and MB229.52 approvals (not those that say "recommended") will be best option.