[rk2323]

Hello all,

I have a 2015 335i xdrive MPE (Power kit + PE), it has a N55 EWG. I recently just flashed MHD stage 1 and the car was stuttering a bit while at WOT and the idle has randomly been jumping on startups. I have 2 logs for 4th gear pulls. The car is on a 91 octane tune(gas from Shell). Id like to know if anything seems weird in the logs.

https://datazap.me/u/rk2323/log-1711...og=0&data=3-13

https://datazap.me/u/rk2323/log-1711...og=0&data=3-14

[thejeremyman9]

Looked at one of the log and it looks generally fine. Boost a little below target but could just be stage 1. Do you have any shadow codes? If you uninstall the tune does the problem persist?

[rk2323]

The only shadow code I get is 1FBD08 which is MSA deactivation. I believe thats because i disabled the auto start/stop function through bimmercode. I just installed a new bms CAI so I will do another log in 4th gear and see how it is. I havent tried taking off the tune and testing (was a bit busy with work) so I will definitely try that if the problem is still there.

[oem.plus_440gc]

Are these issues on the BMS intake? Or stock intake?

[thejeremyman9]

Originally Posted by oem.plus_440gc

Are these issues on the BMS intake? Or stock intake?

+1

BMS intake can cause issues, mostly due to affecting MAF readings. Which one is it, the plastic hot air intake?

[rk2323]

Originally Posted by oem.plus_440gc

Are these issues on the BMS intake? Or stock intake?

Issue was on the stock intake.

[rk2323]

So I did another log of a 4th gear pull and the startup idle issue doesn’t seem to be present anymore (I believe it may have been due to mhd burble settings because once I put the burble style back to oem the issue didnt happen again). But the stuttering issue is still present. Using the idrive horsepower gauges as reference, I get a stutter at around ~260hp, 300hp and 350hp when doing a 4th gear WOT pull from 2500rpm to 6500. The mods on the car as of right now are a vrsf chargepipe, bms intake, stock dp, stock FMIC.

Also I was curious as to what the sucking jet pump (vacuum hose that goes to the intake and chargepipe) does?

https://datazap.me/u/rk2323/log-1712...ata=3-4&solo=4

[thejeremyman9]

I dont really see anything in the log that would be a stutter, HPFP, timing, etc, looks OK. Boost control is a little 'wavy' and below target but that could just be stage 1 behaving that way

[rk2323]

Originally Posted by thejeremyman9

I dont really see anything in the log that would be a stutter, HPFP, timing, etc, looks OK. Boost control is a little 'wavy' and below target but that could just be stage 1 behaving that way

Hmm alright, I will take a log after flashing the car to stock as well and see if the issue is there and if not I’m assuming it might just be a stage 1 thing. My other friend did say that the AFRs seem wonky to him and he thinks the car might be running lean.

Thank you to everyone for the help thus far

[thejeremyman9]

There's one little blip in the AFR at 3042 rpm but in general STFTs are +/- 5% and AFR looks reasonable

[rk2323]

Originally Posted by thejeremyman9

There's one little blip in the AFR at 3042 rpm but in general STFTs are +/- 5% and AFR looks reasonable

I reflashed stage 1 on 93 and took off the mhd multimap. I also reset some adaptations(lambda,throttle,mass flow). I did another 4th gear pull and there was no stutter this time. Is there anything sticking out on the log that I should be worried about?

https://datazap.me/u/rk2323/log-1712...-4-16&solo=3-8

[thejeremyman9]

Looks basically the same with slightly better fuel trims. As i tell everyone you should upgrade your IC sooner rather than later if you are going to run a tune. You can see that your IATs increased 40 F in just those few seconds of WOT.

Oh and you should also enable boost (mani) as a parameters, as in my log for example: https://datazap.me/u/thejeremyman9/2...&data=4-5-7-22

[rk2323]

Originally Posted by thejeremyman9

Looks basically the same with slightly better fuel trims. As i tell everyone you should upgrade your IC sooner rather than later if you are going to run a tune. You can see that your IATs increased 40 F in just those few seconds of WOT.

Oh and you should also enable boost (mani) as a parameters, as in my log for example: https://datazap.me/u/thejeremyman9/2...&data=4-5-7-22

I have added that option to my data logging. I didnt think id need an IC for stage 1 because my car was running the power kit at decent temps but clearly I was wrong, do you have any recommendations for good and affordable IC? I plan on doing stage 2/2+ at most with this car. Also is there anything you can think of that would explain why my boost was 3 psi off target at around 4.1-4.3k rpms. Could it be a possible boost leak?

[thejeremyman9]

Originally Posted by rk2323

I have added that option to my data logging. I didnt think id need an IC for stage 1 because my car was running the power kit at decent temps but clearly I was wrong, do you have any recommendations for good and affordable IC? I plan on doing stage 2/2+ at most with this car. Also is there anything you can think of that would explain why my boost was 3 psi off target at around 4.1-4.3k rpms. Could it be a possible boost leak?

Yeah you can run stage 1 without an IC but the stock IC is undersized as it is, so it really can't control IATs as you turn up the boost.

The most cost effective ICs are the VRSF or MAD race ICs. It will future proof the car for whatever you want to do. You could get away with a smaller one if you dont drive the car too aggressively (like a 5'' HD) but frankly i would just get a race... i had a 5'' HD and eventually swapped to a race, running MHD stage 2+ E20 map.

Here's a 0-150 mph pull, look at IATs: https://datazap.me/u/thejeremyman9/dig-150

The boost variation could just be stage 1. Not many people run stage 1 but i think ive seen that before. I wouldn't chase a boost leak unless you have the problem on other maps.

[rk2323]

Update: The car is throwing up codes for mixture too lean on MHD.

118001,118401 and 11CF30.

Any help would be appreciated

[thejeremyman9]

Originally Posted by rk2323

Update: The car is throwing up codes for mixture too lean on MHD.

118001,118401 and 11CF30.

Any help would be appreciated

The AFR and fuel trims looked fine in the last log, has that changed?

[rk2323]

Originally Posted by thejeremyman9

The AFR and fuel trims looked fine in the last log, has that changed?

Haven't logged it since then because it started snowing and I had to last minute swap to my summer tires because one of my winter tires got a bump(). I just flashed it back to stock as I can't be bothered with troubleshooting right now since I have exams coming up. If I get the time I will do a log in stock form and see how it is. I have also ordered a new sucking jet pump because on my old one the clip that secures it fully has broken. The hose is still attached to the intake but it isnt as secure as it could be and doesnt seem to be fully seated. I am hoping that is my issue and the new hose fixes it.

[rk2323]

Update — Fixed the issue via smoke test, one of the meth bungs on my vrsf chargepipe was missing. Previous mechanic that installed it most likely didn't tighten them. Posted are two 4th gear WOT pulls and a launch from 1st gear to about 4th. With my limited knowledge on logs, they seem pretty good to me.


https://datazap.me/u/rk2323/4th-1st-...og=0&data=3-18


https://datazap.me/u/rk2323/4th-2nd-...og=0&data=3-18


https://datazap.me/u/rk2323/launch-1...og=0&data=3-18