[STREET_B335T]

Hi guys

I am a new member on this forum from South Africa, but I have been lurking for a while. I am hoping that someone can assist me with what exactly could be wrong with my car. It is a 2007/08 335i E92 6AT. Mods are as follows:

Catless DP's
Custom exhaust
Cobb charge pipe
AA sport FMIC
BMS DCI

The problem is that the car is just not performing at low rpm. After 4000rpm it feels like the boost just hits hard. The car was recently walnut blasted. The car does have wastegate rattle at low rpm and light throttle and on decel. It is almost as if the wastegate is not closing fully but I am not sure what the problem is. Here is an attached dyno graph with a local flash tune on E40 fuel. If you look at the shape of the torque curve, it is just not what it should be. This is not the file as i've seen many other N54's with the same tune with different torque curves. I also logged for the first time today, 3rd gear pulls. These logs are with MHD stage 2+ 95RON with 95RON fuel. At higher rpm I noticed the LPFP dipping into 40s and hitting as low as 39psi. I've read that anything below 50psi is not good, but I am no expert. Any help with the low boost issue will be much appreciated

http://datazap.me/u/nikhyg/mhd-stg2-...og=0&data=3-21

http://datazap.me/u/nikhyg/mhd-stg2-...og=0&data=3-21

[madmantwo]

Hard to tell on my phone, but your fuel trims seem high and you definitely need to upgrade your lpfp if you want to run that much ethanol. Your IATs are pretty high too, at least on the first log. Didn't look at the 2nd one

[Aqid]

Subscribed.

Wow comparing this: http://datazap.me/u/nikhyg/mhd-stg2-...&data=2-3-5-21
To my: http://datazap.me/u/aqid/mhd-stage-2...&data=2-3-5-22

Seems like we have the same slow build in boost. I posted this log yesteday in the MHD topic since I also felt it wasn't what it was supposed to be. Mine feels the same, before 3.5k RPM not a lot of power, after that it pulls hard.

So far I've been thinking boost solenoids, vacuum lines or leaking DV's. I also have some WG rattle, which leads me to believe it might not have enough vacuum. I had a broken vacuum canister at the end of last year, causing the boost to drop to 0. During that time the WG rattle was horrid.

omg OP you are running outrageously lean! After looking at those STFTs, please for the love of God, reset all adaptations before you blow something up.

As mentioned, you likely have tired solenoids and/or vacuum leaks. Might as well check for boost leaks while you're at it too.

Look to buy an upgraded LPFP in the meantime.

[Aqid]

Originally Posted by FCobra94

omg OP you are running outrageously lean! After looking at those STFTs, please for the love of God, reset all adaptations before you blow something up.

As mentioned, you likely have tired solenoids and/or vacuum leaks. Might as well check for boost leaks while you're at it too.

Look to buy an upgraded LPFP in the meantime.

Pardon my ignorance but what do those values represent? I tried google but there's a lot of things with those abbreviations lol.

Originally Posted by Aqid

Pardon my ignorance but what do those values represent? I tried google but there's a lot of things with those abbreviations lol.

https://cobbtuning.zendesk.com/hc/en...nd-Definitions

[STREET_B335T]

madmantwo Thank you for your input

Aqid Our boost issue looks the same. I am hoping that it is just a vacuum leak or solenoids and nothing to do with the wastegate bushings, flapper arms etc.

Originally Posted by FCobra94

omg OP you are running outrageously lean! After looking at those STFTs, please for the love of God, reset all adaptations before you blow something up.

As mentioned, you likely have tired solenoids and/or vacuum leaks. Might as well check for boost leaks while you're at it too.

Look to buy an upgraded LPFP in the meantime.

Thanks for your input. I have reset all adaptions and went out and did a few more logs. What do you think?

http://datazap.me/u/nikhyg/18feb-stg...og=0&data=3-21
http://datazap.me/u/nikhyg/18feb-stg...og=0&data=3-21
http://datazap.me/u/nikhyg/18feb-stg...og=0&data=3-21
http://datazap.me/u/nikhyg/18feb-stg...og=0&data=3-21

[madmantwo]

Just looked at the first log... your short term fuel trims are off the charts and you're running very lean. IATs are high too, probably should get a bigger intercooler. I would not run E40 anymore if I were you, I tried E30 back when I had stock LPFP and it just couldn't handle it. Some cars can, some just can't. I'd try a more conservative tune for now and see if you can get the fueling sorted out, then upgrade your LPFP and try gradually getting more aggressive. At this rate you'll melt something.

[STREET_B335T]

Originally Posted by madmantwo

Just looked at the first log... your short term fuel trims are off the charts and you're running very lean. IATs are high too, probably should get a bigger intercooler. I would not run E40 anymore if I were you, I tried E30 back when I had stock LPFP and it just couldn't handle it. Some cars can, some just can't. I'd try a more conservative tune for now and see if you can get the fueling sorted out, then upgrade your LPFP and try gradually getting more aggressive. At this rate you'll melt something.

Sorry the first log might not necessarily be the first run and I did a few pulls so IAT's climbed. It is below 100degF in at least one log. All the logs are with 91oct/95RON , 0% ethanol in tank on MHD stage2+ 91oct/95RON tune

[madmantwo]

Ah sorry, missed that you already have a FMIC so I assumed that was the first run. Interesting, is the fuel generally good quality there?

[Aqid]

Originally Posted by FCobra94

https://cobbtuning.zendesk.com/hc/en...nd-Definitions

Thanks for that, so STFT is the DME adding or subtracting fuel with a maximum of 34% on the n54. Yeah seems its extremely lean on his log then since it 34 during the entire spool. Learned something new today, thanks

[madmantwo]

Originally Posted by Aqid

Thanks for that, so STFT is the DME adding or subtracting fuel with a maximum of 34% on the n54. Yeah seems its extremely lean on his log then since it 34 during the entire spool. Learned something new today, thanks

Most direct way of seeing if it's rich/lean is to just look at AFR though. His is >16 in the middle of the rev range which is extremely dangerous, he's going to melt his engine.

OP you need to upgrade your LPFP ASAP

[STREET_B335T]

madmantwo The fuel seems decent judging by timing corrections. It's Shell Vpower branded 91oct/95ron

Originally Posted by FCobra94

OP you need to upgrade your LPFP ASAP

Going to go with Boost Concepts LPFP. Hoping this solves the lean AFR issue. Thanks for the help

[STREET_B335T]

UPDATE:

Fitted Boost Concepts LPFP and the LPFP psi is looking much better. Also replaced one boost solenoid for now, the old one was actually broken..



Flashed MHD E40 v5.1 and did a log. Boost seems way under target. Any help will be much appreciated

http://datazap.me/u/nikhyg/mhd-e40-v...data=3-5-16-21

Rest all adaptations and check all your vacuum lines, etc. again.

Why did you only replace one solenoid?

[STREET_B335T]

Thanks @FCobra94
Will do that.
Only replaced one because that one was broken. But going to replace the other one and log again. Is the fuel trims and AFR okay?

[dreyo27]

Originally Posted by STREET_B335T

Thanks @FCobra94
Will do that.
Only replaced one because that one was broken. But going to replace the other one and log again. Is the fuel trims and AFR okay?

Wow I saw that first log and I cringed.
Its nice for the n54 community to be so helpful.

Your AFR is still not good, that why he asked you to reset adaptations.
Also please check your vacuum hoses.

[STREET_B335T]

Got another new boost solenoid and here is some updated logs:

http://datazap.me/u/nikhyg/e40-v51-l...3-5-9-15-16-21

http://datazap.me/u/nikhyg/e40-v51-l...data=3-5-15-21

[titium]

Originally Posted by STREET_B335T

Got another new boost solenoid and here is some updated logs:

http://datazap.me/u/nikhyg/e40-v51-l...3-5-9-15-16-21

http://datazap.me/u/nikhyg/e40-v51-l...data=3-5-15-21

did you replace all your vacuum lines? either that or you have a boost leak. AFRs look much better.

Also would not run V5.1 maps as they have desensitised knock tables AFAIK. just YouTube "desensitised knock tables vtt" and see how that ended . not worth it imo for the tiny bump in power, also worse in your case where you're running e40 as ethanol/oct rating isn't 100% consistent.

[yuli8466]

I have the same logs as yours.

My problem is boost leak, my outlet has a hole.

So please check your pipes: outlet intercooler chargepipe and their connectors

good luch

[STREET_B335T]

Hi guys

Still battling this issue. I had all the vacuum lines replaced. Logged again and it didn't make a difference. I then swopped out the diverter valves with another pair and the logs were still the same. I'm thinking it will have to be sent somewhere to do boost leak and vacuum testing. I read up a bit on the vacuum testing. Any more advice on these tests?

Here are the latest logs:

http://datazap.me/u/nikhyg/log-14924...=0&data=3-5-21

http://datazap.me/u/nikhyg/mhd-stg2-...=0&data=3-5-21