E90Post
 


The Tire Rack
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N54 Turbo Engine / Drivetrain / Exhaust Modifications - 335i > Boost Creep



Reply
 
Thread Tools Search this Thread
      05-15-2012, 09:15 AM   #1
CosmosMpower
Brigadier General
CosmosMpower's Avatar
2051
Rep
3,714
Posts

Drives: F87c, GT3, MK7 GTI
Join Date: Apr 2011
Location: Frisco, TX

iTrader: (1)

Boost Creep

I'm experiencing some boost creep/spikes on JB4 Map 5 with the 5/11 firmware that's supposed to be locked to 17 PSI max. Running a mix of 70% 93 pump gas and 30% E85 on an otherwise stock 335 6MT. Car runs great 90% of the time, did some logs in 3rd and Terry said everything looks good.

But in 4th and 5th when I'm rolling and boost is building I'm getting occasional spikes up to 18-20 PSI. I actually had one yesterday on a highway on ramp that triggered safety mode in the JB4 so that I couldn't boost over stock boost in any map until I restarted the car.

I'm not getting any DSC or lights, no CEL, no limp mode so I wonder if it's a weak/faulty wastegate on my stock turbos @ 60K miles? Could it be a clutch slipping at high load?

Also wondering how the car can boost past 17 psi if the firmware has that absolutely locked down? I don't seem to have this problem on map 1, holds to the correct boost levels.
Appreciate 0
      05-15-2012, 09:28 AM   #2
Rotary Rasp
Lieutenant Colonel
Rotary Rasp's Avatar
241
Rep
1,857
Posts

Drives: 2009 E92 335i 6MT
Join Date: Aug 2008
Location: SoCal - Torrance

iTrader: (6)

I had that same problem. I contacted Terry who had me set future use D to 2, which resolved the issue. You should contact him, he might have you do the same.
__________________
Appreciate 0
      05-15-2012, 09:38 AM   #3
CosmosMpower
Brigadier General
CosmosMpower's Avatar
2051
Rep
3,714
Posts

Drives: F87c, GT3, MK7 GTI
Join Date: Apr 2011
Location: Frisco, TX

iTrader: (1)

What does the future use D adjust? Terry is out of office for a few days. Are you using the latest alpha firmware for E85 testing too?

Last edited by CosmosMpower; 05-15-2012 at 09:47 AM..
Appreciate 0
      05-15-2012, 12:33 PM   #4
Rotary Rasp
Lieutenant Colonel
Rotary Rasp's Avatar
241
Rep
1,857
Posts

Drives: 2009 E92 335i 6MT
Join Date: Aug 2008
Location: SoCal - Torrance

iTrader: (6)

http://www.e90post.com/forums/showpo...8&postcount=15
__________________
Appreciate 0
      05-15-2012, 12:40 PM   #5
themyst
Major General
themyst's Avatar
South Korea
177
Rep
6,631
Posts

Drives: '16 MK7 GTI
Join Date: Feb 2009
Location: NYC

iTrader: (8)

Fud2 enables throttle closure to prevent boost creep IIRC.
__________________
E90 LCI N54 6AT
Appreciate 0
      05-15-2012, 01:07 PM   #6
CosmosMpower
Brigadier General
CosmosMpower's Avatar
2051
Rep
3,714
Posts

Drives: F87c, GT3, MK7 GTI
Join Date: Apr 2011
Location: Frisco, TX

iTrader: (1)

Thanks guys, I would think everyone would want this set, no?
Appreciate 0
      05-15-2012, 01:16 PM   #7
wtfmateim65
First Lieutenant
17
Rep
305
Posts

Drives: AW 92 335i JB4
Join Date: Sep 2008
Location: Vegas

iTrader: (2)

hmm, i'm using future use d = 99 for the wastegate rattle fix, although its still present. Seems like it mightve helped a bit though.

This JB4 safety and stock boost on every map situation also happened to me at the end of a 2 hour drive, however, i had maybe 2 gals of 45/55 e85 left in the tank and had to fill up with 91 oct. By the time the tank was half (near the end of my 2 hr drive), i'm guessing the ethanol was flushed out mostly and the car probably creeped and reset into stock mode after seeing the change in fuel and timing, even though I switched to map 2. Refilled with 5 gals e85 and restarted the next day and its pulling like a slingshot again. So in my case i'm pretty sure it was from running out of e85. Let's see if this happens again while there's still plenty e85 in the mix.
Appreciate 0
      05-15-2012, 01:28 PM   #8
CosmosMpower
Brigadier General
CosmosMpower's Avatar
2051
Rep
3,714
Posts

Drives: F87c, GT3, MK7 GTI
Join Date: Apr 2011
Location: Frisco, TX

iTrader: (1)

Quote:
Originally Posted by wtfmateim65 View Post
hmm, i'm using future use d = 99 for the wastegate rattle fix, although its still present. Seems like it mightve helped a bit though.

This JB4 safety and stock boost on every map situation also happened to me at the end of a 2 hour drive, however, i had maybe 2 gals of 45/55 e85 left in the tank and had to fill up with 91 oct. By the time the tank was half (near the end of my 2 hr drive), i'm guessing the ethanol was flushed out mostly and the car probably creeped and reset into stock mode after seeing the change in fuel and timing, even though I switched to map 2. Refilled with 5 gals e85 and restarted the next day and its pulling like a slingshot again. So in my case i'm pretty sure it was from running out of e85. Let's see if this happens again while there's still plenty e85 in the mix.
Mine was after a fairly fresh fill up on the mix, had over 3/4 of a tank left. Were you able to get a log when your situation happened? I've read quite a few threads like this and there is rarely any explanation or follow up. What gear were you in when it happened and how high did it creep? I was on map 5 and nearly hit 20 psi. It almost felt like it was boosting like hell but the car wasn't going anywhere like a slipping clutch.
Appreciate 0
      05-15-2012, 01:28 PM   #9
Mike@N54Tuning.com
Joint Chiefs of Staff
Canada
4908
Rep
115,980
Posts

Drives: 2007 335i, 2015 M3
Join Date: Dec 2008
Location: N54tuning.com

iTrader: (89)

With alpha firmware you will need to contact BMS for help. If you start entering random settings without their direction you may damage your car. If you are unable to wait for BMS to get back to you then switch back to non-alpha firmware.

Mike
Appreciate 0
      05-15-2012, 01:37 PM   #10
CosmosMpower
Brigadier General
CosmosMpower's Avatar
2051
Rep
3,714
Posts

Drives: F87c, GT3, MK7 GTI
Join Date: Apr 2011
Location: Frisco, TX

iTrader: (1)

Quote:
Originally Posted by Mike@N54Tuning.com View Post
With alpha firmware you will need to contact BMS for help. If you start entering random settings without their direction you may damage your car. If you are unable to wait for BMS to get back to you then switch back to non-alpha firmware.

Mike
Didn't plan on changing anything yet except to up a setting Terry told me after checking out some logs.

Can you even run non alpha firmware with E85 in the tank?
Appreciate 0
      05-15-2012, 01:48 PM   #11
Mike@N54Tuning.com
Joint Chiefs of Staff
Canada
4908
Rep
115,980
Posts

Drives: 2007 335i, 2015 M3
Join Date: Dec 2008
Location: N54tuning.com

iTrader: (89)

Quote:
Originally Posted by CosmosMpower View Post
Didn't plan on changing anything yet except to up a setting Terry told me after checking out some logs.

Can you even run non alpha firmware with E85 in the tank?
Sure, many run various E85 mixes on the normal firmware. It just isn't designed to take full advantage of it. On your car if I were to completely speculate I'd say you left your boost limit safety setting at the default 17psi, and then map 5 which has the authority range to target 17psi pushed boost up to around 17psi, and you are hitting an over boost safety system. So the solution would normally be to raise the over boost safety to say 18psi so you don't trigger it as easily. Keep in mind boost is read before the throttle body. So if you jump over target for example the throttle will close to prevent the engine from seeing that boost level despite what is shown in the gauge.

Bottom line is if you are running alpha firmware you should only be communicating with BMS on it. If you are unable to follow those rules you should be running the 3/25 production firmware.

Mike
Appreciate 0
      05-15-2012, 02:30 PM   #12
CosmosMpower
Brigadier General
CosmosMpower's Avatar
2051
Rep
3,714
Posts

Drives: F87c, GT3, MK7 GTI
Join Date: Apr 2011
Location: Frisco, TX

iTrader: (1)

Quote:
Originally Posted by Mike@N54Tuning.com View Post
Sure, many run various E85 mixes on the normal firmware. It just isn't designed to take full advantage of it. On your car if I were to completely speculate I'd say you left your boost limit safety setting at the default 17psi, and then map 5 which has the authority range to target 17psi pushed boost up to around 17psi, and you are hitting an over boost safety system. So the solution would normally be to raise the over boost safety to say 18psi so you don't trigger it as easily. Keep in mind boost is read before the throttle body. So if you jump over target for example the throttle will close to prevent the engine from seeing that boost level despite what is shown in the gauge.

Bottom line is if you are running alpha firmware you should only be communicating with BMS on it. If you are unable to follow those rules you should be running the 3/25 production firmware.

Mike
That makes sense, thanks.
Appreciate 0
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 04:25 PM.




e90post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST