Extreme Power House
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N54 Turbo Engine / Drivetrain / Exhaust Modifications - 335i > JB4 E85 Boost Range

Thread Tools Search this Thread
      08-06-2013, 06:58 PM   #1
PTek Will
Second Lieutenant
PTek Will's Avatar
Drives: 335i coupe
Join Date: Jun 2012
Location: san jose

Posts: 260
iTrader: (0)

JB4 E85 Boost Range

Hey Guys,

The first time I tried E85 (about 30%) mixed with 91 on map 5 I hit 17 psi consistently. Now it doesn't even reach 15 psi with the same mixture. It hovers right below the 3/4 line (14.5psi?), whereas before it was about 2 ticks above 3/4. Any ideas why?
PTek Will is offline   United_States
Reply With Quote
      08-06-2013, 08:03 PM   #2
BoostAddict's Avatar
Drives: SGM 335i
Join Date: Jan 2010
Location: Boynton Beach, FL

Posts: 912
iTrader: (4)

Map 5 auto tunes to conditions. Perhaps the weather was cooler last time you tried, your fuel quality was higher, or maybe it just hadn't fully adapted yet. A number of outside factors could do it.
I do Installs and flash tuning in South Florida
-2008 335i SGM on Terra 6mt
-1997 Jetta TDi 16v ABA Pt6266
-1997 M3 Pt6766
BoostAddict is offline   United_States
Reply With Quote
      08-07-2013, 11:16 AM   #3
BimmerPost Supporting Vendor

Drives: 07335i
Join Date: Dec 2008
Location: Earth

Posts: 14,348
iTrader: (86)

You'd want to do a datalog to see what you're actually targeting. If the JB4 detects knock, higher temperatures, running lean, or other issues, it will lower it's target. If the target is high but boost is well below it, then that indicates another range of issues with the car. Boost leak, wastegate issue, vacuum line loose, etc.

Mike@N54Tuning.com is offline   Canada
Reply With Quote
      08-07-2013, 11:20 AM   #4
2014 435M-Sport/MPPK
BEAR-AvHistory's Avatar
Drives: 2014 435M-Sport MPPK
Join Date: Jun 2011
Location: NC - USA

Posts: 2,147
iTrader: (0)

Also E85 is not exactly E85. The blend changes by state & month. You can do a search on the EPA site to get the blends & months for your state.

2014 435M-Sport - 2013 135is Cab JB4/ISO 6MT - 2009 V-Star - 2009 Ford Expedition EL 4X4 - 2003 Xterra 4X4 - 1998 Ranger 4X4 - FFR Cobra MK-IV work in progress
BEAR-AvHistory is offline  
Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Forum Jump

All times are GMT -5. The time now is 04:21 AM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
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