[1897]

Anyone able to diagnose what's causing large timing corrections in two cylinders?
In my initial run there were no corrections:

https://datazap.me/u/1897/log-159335...23-24-25-26-27

but by the third run, IAT had increased and I started to get small corrections on 4 cylinders and very large (up to 7.5) corrections on cylinders 5 and 6

https://datazap.me/u/1897/log-159335...23-24-25-26-27

It was a hot day (mid to high 80's F) and I am still using a factory intercooler. Using 93 octane gas.

other mods:
Injen cold air intake and charge pipe (not sure of brand)
VRSF catless downpipes
MHD Stage 2 tune

Bosch plugs with 8k (according to PO) but have discoloring on all plugs.
aftermarket coilpacks 8k (according to PO) but have lots of discoloring on two

[drwillb]

Factory intercooler has to go. Ambient temp is 80 but IAT is 127 at the end of the second run. Your engine is just trying to protect itself from you.

[Pladi]

The answers are in ur own post.

[mike@x-ph.com]

you need a larger intercooler. I recommend VRSF 7.5" Comp or the Wagner EVO II Comp

[Turbod]

The DEM has safeties as the IATs rise. It will reduce timing and go rich to try and keep the temps under control. Once you're able to keep things cool then you can see if there is an underlying problem causing timing corrections. Honestly most people just want more out of the platform on pump gas.

Solutions
Intercooler
Methanol
Ethanol

[E92xB]

have a FBO 08 335i auto trans tuned on mhd stage1+ 91 flash with 92 octane and having major timing corrections up to -8.8. new plugs and coils, car seems to run fine any suggestions?

mod list catless down pipes, 5in intercooler, charge pipe with tail bov, dci, muffler delete mhd stage 1+

[TheGoodTheBadTheUgly]

Originally Posted by E92xB

have a FBO 08 335i auto trans tuned on mhd stage1+ 91 flash with 92 octane and having major timing corrections up to -8.8. new plugs and coils, car seems to run fine any suggestions?

mod list catless down pipes, 5in intercooler, charge pipe with tail bov, dci, muffler delete mhd stage 1+

Hey man, you in the wrong forum. This is for E-Series 335i with the N55 engine. Your 08 335i has the N54 engine. You will get more tailored support if you do a thread under this section of the forum: https://www.e90post.com/forums/forumdisplay.php?f=58.

If the corrections are big and present on all of your cylinders its most likely due to fueling. Try to flash the MHD Stage 1+ 91ACN map since it is the least aggressive. If you see that the timing goes down, then it might confirm it is a fuel related issue.

[bbnks2]

Originally Posted by 1897

Anyone able to diagnose what's causing large timing corrections in two cylinders?
In my initial run there were no corrections:

https://datazap.me/u/1897/log-159335...23-24-25-26-27

but by the third run, IAT had increased and I started to get small corrections on 4 cylinders and very large (up to 7.5) corrections on cylinders 5 and 6

https://datazap.me/u/1897/log-159335...23-24-25-26-27

It was a hot day (mid to high 80's F) and I am still using a factory intercooler. Using 93 octane gas.

other mods:
Injen cold air intake and charge pipe (not sure of brand)
VRSF catless downpipes
MHD Stage 2 tune

Bosch plugs with 8k (according to PO) but have discoloring on all plugs.
aftermarket coilpacks 8k (according to PO) but have lots of discoloring on two

I would not correlate those corrections with IATS at all. The correction on cylinder 6 starts when IAT's are only 100f lol in the previous logs you have 0 corrections across the entire log with IAT's as high as 120f+

The first log you did a pull with oil temps at 165f...just barely across the line of being warmed up. In the second log your oil temps are 220+ and rising still. I bet your coolant temps are high which will result in drastically more impact on the point of knock than 120f iat's will. Re-do the logs showing coolant temps. Do you run the MHD race cooling settings? that will help get coolant temps back down in-between runs. Lower coolant temps then in turn help mitigate rising oil temps and overall the engine will be able to move heat away from the combustion chamber more efficiently.

[bbnks2]

Originally Posted by Turbod

The DEM has safeties as the IATs rise. It will reduce timing and go rich to try and keep the temps under control. Once you're able to keep things cool then you can see if there is an underlying problem causing timing corrections. Honestly most people just want more out of the platform on pump gas.

Solutions
Intercooler
Methanol
Ethanol

DME compensating for rising IAT's does not present as a timing correction... and I don't think it even begin to reduce target timing advance at all until like 130f+

[anjuna]

Originally Posted by bbnks2

DME compensating for rising IAT's does not present as a timing correction... and I don't think it even begin to reduce target timing advance at all until like 130f+

This is the correct answer.

Timing correction = preignition (knock) has been witnessed and timing is being actively pulled in situ.

IAT rise = Lowering of "target load" by a percent. You will not see timing corrections, just a lowering of max load.

[bbnks2]

Originally Posted by anjuna

This is the correct answer.

Timing correction = preignition (knock) has been witnessed and timing is being actively pulled in situ.

IAT rise = Lowering of "target load" by a percent. You will not see timing corrections, just a lowering of max load.

What's your opinion on a large single cylinder correction? I know I get them on #5 from time to time.

[anjuna]

Originally Posted by bbnks2

What's your opinion on a large single cylinder correction? I know I get them on #5 from time to time.

Cylinders 2 and 5 are the most sensitive to corrections.

I generally disregard -3
If I get corrections of -3 across multiple cylinders, i'll consider it and note it
If I get -6 or more correction on 2 or 5, I'll generally adjust timing for that load/rpm

[TheGoodTheBadTheUgly]

Originally Posted by anjuna

Cylinders 2 and 5 are the most sensitive to corrections.

I generally disregard -3
If I get corrections of -3 across multiple cylinders, i'll consider it and note it
If I get -6 or more correction on 2 or 5, I'll generally adjust timing for that load/rpm

Out of curiosity, why is it 2 and 5 in specific. Is it due to the firing order of the engine?

[mike@x-ph.com]

Originally Posted by bbnks2

What's your opinion on a large single cylinder correction? I know I get them on #5 from time to time.

if it's consistent , it should not be ignored no matter how much the correction is.