[95blkmax]

Need help please to figure out why I'm not getting anywhere close to target boost being requested by the JB4. I've sent the last few days teaching myself how to read and interpret JB4 logs, but I could use help still.

For those in the mobile app that cannot see my mods, they're Custom intake, GPlus Intercooler, BMS charge pipe, catless downpipe, Megan racing mufflers, and JB4. This is a 2011 so it has a PWG. Currently running 5 gallons of E85 (for an E30 overall mix) on Map 5.

I'll focus on my 3rd gear logs.

YESTERDAY- I did a log (Map 5) and I realized that JB4 is targeting a peak of 13.9psi, and the most boost I got was 11.4psi before the expected tapper-off began. 11.6psi is the most my turbo put out during a 1st-3rd gear pull log. I started researching and decided that before I did anything to switch to Map2 and log that.

TODAY- Switched to Map 2. Still running the same E30 fuel from yesterday. Did my a couple logs. To my surprise, the JB4 on 3rd gear targeted 14psi and my turbo put out 12.4psi before the tapper-off. See below:

Log 1st-3rd gear E30 Map2

https://drive.google.com/file/d/13N_...ew?usp=sharing

Here's a visual of this pull


So my ignition timing seems great (likely due to the E30 mix). The HPFP is very happy with the lowest value in this pull being 11 (so 1650psi at the rail), the AFR looks normal and the trims for it are MINIMAL (per BMS, a value of 25 here= 0% trim).

*******
Note- I'm running stock N55 plugs with about 3k miles at stock gap. At this point I do not feel any symptoms of spark blow-out. Not really having any crazy timing pulling to indicate knock either. All pulls were done on Sport+ mode, and transmission on Sport mode.

Just for ish n giggles, here's another one for just 4th gear (also E30 fuel, Map 2)
https://drive.google.com/open?id=1j2...wED6XzOAb0eCOX



So here I'm a little confused, I THINK my wastegate DC looks fine(no where close to maxing out), but shouldn't it be fully closed to achieve the target boost then start opening??

Also, I have that constant difference between target and actual boost. AM I RIGHT to think that if my wastegate is in fact operating correctly, that I likely have a boost leak somewhere? Unless my WG is pooped and not actuating properly? Or my turbo is perhaps on it's way out? NEW- how do I tell if my BOV isn't holding boost and may be constantly venting?

What say you guys?? Thanks in advance!

[95blkmax]

Well I'll keep this thread running with what I do and update you guys with my findings.

After researching further the last few days, I've narrowed it down to either a boost control solenoid that is on its way out, or a small boost leak somewhere, or a combination of both lol. There is a slight chance that it is the FF function of the JB4 tuning just needs to be turned up, but I'd rather start with the more likely stuff before I go bother BMS.

I ordered a Pierburg solenoid from FCP today. In the next week or 2 I'll also arrange to do a smoke/ pressure test.

See we shall!

[BimmerHausPerformance]

You might of already addressed this but....

If you floor it from a complete standstill our stock turbos CAN'T make that much boost. In that situation our engines can consume everything that the turbo throws at it and the turbo can't build up higher than around 12 psi.

However, if you are low RPM's in 3rd or 4th gear, and you floor it, well then it's a different story. Because the engine can't rev high enough to consume all the air we are shoving at it, it allows are stock turbos to build more boost giving higher #'s. I can hit 19lbs of boost in this situation but to say "I run 19lbs of boost" is kind of a false statement. See attached image...

When you can run 20 or 22 lbs of boost from a dig with PS2, that is not a gain of only 3 lbs of boost, that's a gain of 8 to 10 lbs of boost! Apples to oranges comparison there.

Bmwdoubles_ has a boost leak video on you tube that's good.

[95blkmax]

Originally Posted by BrowBMW

You might of already addressed this but....

If you floor it from a complete standstill our stock turbos CAN'T make that much boost. In that situation our engines can consume everything that the turbo throws at it and the turbo can't build up higher than around 12 psi.

I hadn't adress this but it makes sense. This is likely due to the gearing on our ZF8HP. 1-3rd are so quick that the engine "outrev's" the boost buildup.

Originally Posted by BrowBMW

However, if you are low RPM's in 3rd or 4th gear, and you floor it, well then it's a different story. Because the engine can't rev high enough to consume all the air we are shoving at it, it allows are stock turbos to build more boost giving higher #'s. I can hit 19lbs of boost in this situation but to say "I run 19lbs of boost" is kind of a false statement. See attached image...


Bmwdoubles_ has a boost leak video on you tube that's good.

Yes! this would make sense! like a spike in boost then decrease to the target would be expected to a certain degree. But as you can see by my 4th gear pull (mind you that i didn't really mash the pedal until about 4000rpm) I was nowhere close. Perhaps I should re-try that from a lower rpm and see what that looks like. I think I have a 3rd gear pull log'd from lower down in the rpm range but I'll have to check later.

Yes I did see his video! Very helpful! and wtf at the IM leak he had at the mounting screw hole! I'd say the bracket only needs one screw and pack that hole with JBweld

[ziekxq]

I have yet to see my car with PS2 run 20psi from a dig lol... Maybe with launch control.

Plus remember, 19 psi with stock turbo vs 19psi with pure stage 2 is two different power.

[BimmerHausPerformance]

Ah man, seriously? What do you hit from a full on dig?

I am starting to have my doubts on PS2... Big boost stage 3.

[95blkmax]

Originally Posted by ziekxq

I have yet to see my car with PS2 run 20psi from a dig lol... Maybe with launch control.

Yea that much makes sense now. But let me ask you. During spool up even on those low gears, what sort of wastegate duty cycles are you guys seeing? Because the most I'm seeing is in the low 30s%. I would think that it would be at/ close to 100% (closed) in order to let the turbo spool up as quickly as possible and then begin opening as it approached. That's the main reason why Im suspicious that SOMETHING isn't jiving.

[ziekxq]

Originally Posted by 95blkmax

Yea that much makes sense now. But let me ask you. During spool up even on those low gears, what sort of wastegate duty cycles are you guys seeing? Because the most I'm seeing is in the low 30s%. I would think that it would be at/ close to 100% (closed) in order to let the turbo spool up as quickly as possible and then begin opening as it approached. That's the main reason why Im suspicious that SOMETHING isn't jiving.

Around 65% dropping to 30% during gear changes.

I never hit 100 percent because of custom inlet pipe I got.

[95blkmax]

Originally Posted by ziekxq

Around 65% dropping to 30% during gear changes.

I never hit 100 percent because of custom inlet pipe I got.

wow, so with a less restrictive intake pipe, your WGDC is still about double mine lol. And at your power levels is clearly works! So lets see if my new boost solenoid fixes anything. I may not be able to do a boost leak test until the end of the week (if at all this week).

I recalled that when I upgraded my charge pipe I broke 1 of the 2 "squeeze tabs" that secure the vent line to it. It's pretty sturdy with just the 1 tab holding it but who knows with 11+ psi pushing from underneath. It doesn't have to come off for the o-ring to break the seal against the inner bore of the fitting. Anyway, new vent line will be here tomorrow.

I ALSO recalled (siiiiigh) that during this same CP upgrade, I noticed the o-ring of my MAP sensor had a small tear on the upper side. It was minute but enough to notice the little thing sticking outward like a hair. I wrote it off thinking it wouldn't do much being that it's such a tight fit... but in the name or crossing off variables, I got the measurement of it from some BMW forum (dont recall now, but it's listed as 14mm OD, 10mm ID, and 2mm thick, viton material) and ordered a pair on Amazon. ETA on that is Saturday.

We shall sees!

[Bmwdoubles_]

Here's the o ring for the Tmap sensor

https://www.fcpeuro.com/products/bmw...-13621743299oe

Hit it with some oil before installing to avoid tearing again.

I did the same thing but replaced all the seals and some hardware. Solenoid, solenoid vacuum lines(def check these they're likely cracked and dried from 2011) seals replaced were: Ecu , inlet, intake manifold, intercooler pipes, TB, sensor o ring and still found leaks! Its fine now but what a pita.

Leaks aren't the only enemy. Look out for unmetered air. As a bonus lookout for your valvetronic motor seal leaking oil from high boost:

https://www.fcpeuro.com/products/bmw...ng-11377502022

[95blkmax]

Originally Posted by Bmwdoubles_

Here's the o ring for the Tmap sensor

https://www.fcpeuro.com/products/bmw...-13621743299oe

Hit it with some oil before installing to avoid tearing again.

I did the same thing but replaced all the seals and some hardware. Solenoid, solenoid vacuum lines(def check these they're likely cracked and dried from 2011) seals replaced were: Ecu , inlet, intake manifold, intercooler pipes, TB, sensor o ring and still found leaks! Its fine now but what a pita.

Leaks aren't the only enemy. Look out for unmetered air. As a bonus lookout for your valvetronic motor seal leaking oil from high boost:

https://www.fcpeuro.com/products/bmw...ng-11377502022

OMG $0.31 cents for it! I just paid $5 for 2 of them on Amazon . Lesson learned. But the post will help someone Im sure. I'll be sure to go over all that, AND my bracket mounting holes lol. How did you end up fixing that one anyway? I made a joke about that a few posts ago but I really would have fixed it with JB Weld lolol. It's such coarse thread there that I wouldn't think teflon tape on the screw would help.

[Bmwdoubles_]

Originally Posted by 95blkmax

OMG $0.31 cents for it! I just paid $5 for 2 of them on Amazon . Lesson learned. But the post will help someone Im sure. I'll be sure to go over all that, AND my bracket mounting holes lol. How did you end up fixing that one anyway? I made a joke about that a few posts ago but I really would have fixed it with JB Weld lolol. It's such coarse thread there that I wouldn't think teflon tape on the screw would help.

Heavy wrapping of plumbers tape fixed it right up. Going to replace the intake manifold though.

[95blkmax]

Originally Posted by Bmwdoubles_

Heavy wrapping of plumbers tape fixed it right up. Going to replace the intake manifold though.

oh wow! haha well glad that worked out as a temporary fix then.

UPDATE- I replaced the vent pipe (BMW calls it the "suction pipe"... connects the charge pipe> T's off into the fuel vent solenoid behind the alternator> continues to the turbo inlet). So yes, the end I knew had one tab broken at the CP was broken, yet I had to put some muscle into pulling it off! Upon inspection, the o-ring on this end had 1 pinch/ tear probably from having installed it dry to the new CP (got upset because I know better ). The T-end to the vent solenoid was intact, but...

TO MY SURPRISE, the end that goes to the turbo inlet pipe had BOTH tabs broken. I could swear ~2 months ago when I installed the JB4 (the last time I removed this connection) it was intact. I may have broken them at this point and didn't even realize it. This is obviously a boost leak. Yes, the end that is pressurized was tightly in place (with a questionable o-ring), but under boost conditions, some of that is diverted to the turbo inlet pipe via this end that was basically loose.

Progress and findings are being made! New boost control solenoid arrives Thursday. O-ring for MAP sensor on Saturday. And I may have an opening to do a boost leak test tomorrow or Thu.

[BimmerHausPerformance]

Originally Posted by Bmwdoubles_

Heavy wrapping of plumbers tape fixed it right up. Going to replace the intake manifold though.

Nice, are you doing an aftermarket one or stock replacement?

[Bmwdoubles_]

Originally Posted by BrowBMW

Nice, are you doing an aftermarket one or stock replacement?

Haven't decided. I'm not doing meth personally or mechanically. I already have an addiction called modding.

So probably stock. Plus stock is lightweight.

[burro_blasta]

Sorry I can't actually help you like you helped me on my thread, but just saw this and thought of this thread

[Trainwreck914]

Originally Posted by burro_blasta

Sorry I can't actually help you like you helped me on my thread, but just saw this and thought of this thread

Lmfao. :seesaw: I know the fewling

[95blkmax]

Originally Posted by burro_blasta

Sorry I can't actually help you like you helped me on my thread, but just saw this and thought of this thread

LMAO! Benefits of having a garage huh? lol

I guess I saw this just in time. Going out to the garage now (with clothes LOL) to change out my boost control solenoid, and the MAP sensor O-ring, then time for a log if the street in Mexico is clear

[95blkmax]

Now I wish I had done a log after I did the vent line, and another today after replacing the boost control solenoid. Because now I don't know which of the two made this improvement lol. The pipe HAD to be replaced, but now idk if my solenoid was in fact worn out or not.

The end result of replacing just these 2 items was great!
- I make target boost in all gears!
- With this added boost, the HPFP is still happy (lowest value shown in today's logs was 12, so ~1800psi rail pressure- higher than prior by pure chance, nothing to do with what I've done), fuel trims are still minimal - BTW I am still running the same E30 mix tank as prior.

However, having this improvement has yielded a new problem; wherever I may be with power output, I must be at the limit of the stock-gaped N55 spark plugs. Looking at the logs' ignition advance I am seeing sudden retarding in timing that I wasn't seeing prior (drops from like 12* to 8* within the gear... this sucks but it's a good sign that I'm making power!).

At this point, the next thing to do is to swap spark plugs to N20 plugs gaped down. Then next week I'll do a leak test to make sure I don't have anything else going on/ fix what leaks I find. At that point, this baby is ready for dyno and dragway fun .

There is the graph of the 1st-3rd gear log of today (again, E30, Map2). I added the line for the HPFP. Note that now actual boost meets or exceeds target boost in all gears. There's still a gap after this peak, but it's not as wide a margin as it used to be.


This is 4th gear from 2500 to about 5500rpm (ran out of space in my Mexico road but this is passed the point where boost drops anyway). Note that in the high load of 4th gear (which I actually made 15psi!!!), the HPFP is still very happy with redline being at 13 (1950psi)


Here's a few pics of the progress

Original Vs Pierburg boost control solenoid. NOTE- I saw in quite a few posts throughout N55 platform forums people referring to that donut on the innermost port as a plastic washer... Guy this is a rubber seal! BMW added it as this is the output vacuum to the PWG. With the vacuum line pressed firmly against it, it creates a pretty solid vacuum seal. But 9yrs and 112k miles later, it now feels like plastic. This should be in everyone's maintenance schedule at 100k IMO.


Breaks of the ends of original vent pipe



Old Vs new Vent pipe

[95blkmax]

SIDE NOTES-

- I did not get to replace the MAP sensor o-ring yet. Because of where it is and the coolant lines to the transmission cooler just below, it's very difficult. Decided to hold off on this until I did a smoke test to see if there's even a leak there prior to doing the work of removing the charge pipe.
- I will continue doing my troubleshooting in Map2 (target peak 14.5psi), as this is a static Map. Once I've changed the plugs and fixed any other boost leak I may have (if any at all), THEN I'll go back to Map5 (adaptive from 12psi to 17psi).

[AlexRF10]

Originally Posted by 95blkmax

Now I wish I had done a log after I did the vent line, and another today after replacing the boost control solenoid. Because now I don't know which of the two made this improvement lol. The pipe HAD to be replaced, but now idk if my solenoid was in fact worn out or not.

The end result of replacing just these 2 items was great!
- I make target boost in all gears!
- With this added boost, the HPFP is still happy (lowest value shown in today's logs was 12, so ~1800psi rail pressure- higher than prior by pure chance, nothing to do with what I've done), fuel trims are still minimal - BTW I am still running the same E30 mix tank as prior.

However, having this improvement has yielded a new problem; wherever I may be with power output, I must be at the limit of the stock-gaped N55 spark plugs. Looking at the logs' ignition advance I am seeing sudden retarding in timing that I wasn't seeing prior (drops from like 12* to 8* within the gear... this sucks but it's a good sign that I'm making power!).

At this point, the next thing to do is to swap spark plugs to N20 plugs gaped down. Then next week I'll do a leak test to make sure I don't have anything else going on/ fix what leaks I find. At that point, this baby is ready for dyno and dragway fun .

There is the graph of the 1st-3rd gear log of today (again, E30, Map2). I added the line for the HPFP. Note that now actual boost meets or exceeds target boost in all gears. There's still a gap after this peak, but it's not as wide a margin as it used to be.


This is 4th gear from 2500 to about 5500rpm (ran out of space in my Mexico road but this is passed the point where boost drops anyway). Note that in the high load of 4th gear (which I actually made 15psi!!!), the HPFP is still very happy with redline being at 13 (1950psi)


Here's a few pics of the progress

Original Vs Pierburg boost control solenoid. NOTE- I saw in quite a few posts throughout N55 platform forums people referring to that donut on the innermost port as a plastic washer... Guy this is a rubber seal! BMW added it as this is the output vacuum to the PWG. With the vacuum line pressed firmly against it, it creates a pretty solid vacuum seal. But 9yrs and 112k miles later, it now feels like plastic. This should be in everyone's maintenance schedule at 100k IMO.


Breaks of the ends of original vent pipe



Old Vs new Vent pipe

I was also trying to find any boost or vacuum leaks on mine. I took off the same vent pipe you replaced and inspected it. If I blow into the charge pipe end it comes right out through the intake pipe end. I'm wondering how that pipe holds psi in the charge pipe if I can easily blow through it, or my vent pipe needs to be replaced. Do you know if your new pipe does the same?

[95blkmax]

Originally Posted by AlexRF10

I was also trying to find any boost or vacuum leaks on mine. I took off the same vent pipe you replaced and inspected it. If I blow into the charge pipe end it comes right out through the intake pipe end. I'm wondering how that pipe holds psi in the charge pipe if I can easily blow through it, or my vent pipe needs to be replaced. Do you know if your new pipe does the same?

No sir this is a purely un-checked pipe. Under vacuum conditions the fuel tank vent valve at the T of the pipe clicks to vent vapors into the intake tract, and closes during boost conditions.

I honestly don't understand why this is just an open pipe between the CP and the turbo inlet pipe. I can only make an ASSUMPTION that BMW engineers felt that releasing some of the boost at the CP and dumping it at the turbo inlet assists in spool-up (and in a way, create a scavenging effect/ vacuum pull so as the fuel tank vent valve could still vent out even during boost conditions). But again, these are assumptive theories lol.