E90Post
 


ECS BMW
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N54 Turbo Engine / Drivetrain / Exhaust Modifications - 335i > Learning About the N54 Engine



Reply
 
Thread Tools Search this Thread
      02-22-2013, 11:38 AM   #1
StealthFish
Private First Class
 
Drives: 335i E92 (Crimson Fury)
Join Date: Feb 2012
Location: Houston, TX

Posts: 171
iTrader: (1)

Learning About the N54 Engine

Hi all,

I am trying to learn a few things about the N54 motor. I have a few questions in regards to the engine.

1) What is the compression ratio of the N54 motor?

2) a. What is the max boost (PSI) that we are getting from the stock ECU?

b. I am currently running the Cobb Accessport Stage 1 Aggressive, what is the max boost (PSI) that I should be getting?

This is what I got today but I was not flooring the car nor driving it hard, approx. 16.4 at highest so far:
http://img.photobucket.com/albums/v7...222_082155.jpg
StealthFish is offline   United_States
0
Reply With Quote
      02-22-2013, 11:43 AM   #2
3.1L Z
Enlisted Member
 
3.1L Z's Avatar
 
Drives: '08 335i, Cobb AP
Join Date: Jul 2012
Location: San Antonio

Posts: 32
iTrader: (0)

Stock PSI is 8.8, if I recall correctly. 16.4 is where the Stage 1 should max out at in the 4000 rpm range and decrease as rpms increase.
__________________

'08 335i, E90 Black
6 SP/3 Pedal
Alu Trim, No Run Flats
DCI, Cobb AP
3.1L Z is offline  
0
Reply With Quote
      02-22-2013, 11:44 AM   #3
3.1L Z
Enlisted Member
 
3.1L Z's Avatar
 
Drives: '08 335i, Cobb AP
Join Date: Jul 2012
Location: San Antonio

Posts: 32
iTrader: (0)

Use the data log feature and download the entire run to your pc.
__________________

'08 335i, E90 Black
6 SP/3 Pedal
Alu Trim, No Run Flats
DCI, Cobb AP
3.1L Z is offline  
0
Reply With Quote
      02-22-2013, 12:10 PM   #4
straightcashhomie
Lieutenant
 
straightcashhomie's Avatar
 
Drives: 335i
Join Date: Aug 2012
Location: home

Posts: 545
iTrader: (1)

theres a sticky right at the top of general forums....

http://www.e90post.com/forums/showthread.php?t=38856
straightcashhomie is offline  
0
Reply With Quote
      02-22-2013, 12:29 PM   #5
marv85
Colonel
 
marv85's Avatar
 
Drives: '07 335i MT
Join Date: Jun 2010
Location: Portland

Posts: 2,558
iTrader: (4)

Compression is 10.2 if I remember correctly.

Max boost depends on your environment(load based), mine is usually around 7.5psi. I've seen 8.5psi when the elevation increase.
same goes with COBB stage1 agg, it depends on your environment. I've seen no more than low 15's.
Make sure you are not looking a the boost spike as well...
__________________
'10 E92 335i , COBB
marv85 is offline   United_States
0
Reply With Quote
      02-22-2013, 10:12 PM   #6
StealthFish
Private First Class
 
Drives: 335i E92 (Crimson Fury)
Join Date: Feb 2012
Location: Houston, TX

Posts: 171
iTrader: (1)

I saw a max boost of 17.1 today. That's what it read in my AP. One the wrx that I used to have, I would get a max of 14.5 max. But that was 8:1 compression. If I'm running 8+, I'm scared it's not good for my car. Could it be because I'm running the aggressive map? Should I switch to the sport map?
StealthFish is offline   United_States
0
Reply With Quote
      02-23-2013, 11:02 AM   #7
ErvGotti
Major
 
Drives: 2008 135i 6MT
Join Date: Jul 2010
Location: Bury St Edmunds UK

Posts: 1,164
iTrader: (5)

Garage List
2008 135i  [3.00]
Quote:
Originally Posted by StealthFish View Post
I saw a max boost of 17.1 today. That's what it read in my AP. One the wrx that I used to have, I would get a max of 14.5 max. But that was 8:1 compression. If I'm running 8+, I'm scared it's not good for my car. Could it be because I'm running the aggressive map? Should I switch to the sport map?
Is it 17.1 sustained or spike. You need to data log in order for anyone to help you. Typically Stage 1 aggressive should run 15.5-16 PSI sustained from about 2400 RPM to about 5200 PRM with it tapering down towards redline.

The reason these engines can tun high PSI with high compression is due to direct injection and it's cooling effect on the combustion chamber.
ErvGotti is offline  
0
Reply With Quote
      02-24-2013, 10:55 AM   #8
a7med606
Second Lieutenant
 
a7med606's Avatar
 
Drives: 1 ///M
Join Date: Nov 2011
Location: bahrain

Posts: 229
iTrader: (0)

compression is 10.4.1
a7med606 is offline   Bahrain
0
Reply With Quote
      02-24-2013, 11:00 PM   #9
StealthFish
Private First Class
 
Drives: 335i E92 (Crimson Fury)
Join Date: Feb 2012
Location: Houston, TX

Posts: 171
iTrader: (1)

Quote:
Originally Posted by ErvGotti View Post
Is it 17.1 sustained or spike. You need to data log in order for anyone to help you. Typically Stage 1 aggressive should run 15.5-16 PSI sustained from about 2400 RPM to about 5200 PRM with it tapering down towards redline.

The reason these engines can tun high PSI with high compression is due to direct injection and it's cooling effect on the combustion chamber.
Thanks everyone, I have not taken the data log yet as I am not driving my car until I get back home but I think it is a boost spike. 10.4.1 compression is in between 8:1 and 11:1, what I was thinking of, thanks.
StealthFish is offline   United_States
0
Reply With Quote
Reply

Bookmarks

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 10:58 PM.




e90post
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