BMW M3 Forum (E90 E92)

BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read


Go Back   M3Post - BMW M3 Forum > M3 (E90 / E92 / E93) > General M3 Forum (E90 + E92 + E93)
 
Evolve Automotive
Post Reply
 
Thread Tools Search this Thread
      02-14-2013, 07:30 PM   #1
M3takesNYC
Banned
 
Drives: m3
Join Date: Feb 2013
Location: NYC

Posts: 426
iTrader: (0)

Benefit of MAP vs MAF

I know we have only MAP sensors and a similar engine e60 M5 as well as the new M5/6/XM5/6 all have MAF sensors. Also evolve sells a MAP conversion for the MAF e46 and e60 m cars, so what is the real deal on why they choose MAP over MAF?

I was surprised that the new M cars have a MAF sensor so clearly MAP is not "better" and I thought the one real difference was an improved throttle response, although I am not sure why. However if that is the case, you would think surely bmw would have used MAP sensors in the new turbo M cars as throttle response was deemed to be very important to them.
M3takesNYC is offline  
0
Reply With Quote
      02-14-2013, 07:50 PM   #2
CanAutM3
Brigadier General
 
CanAutM3's Avatar
 
Drives: 2008 E92 M3 (2015 M4 on order)
Join Date: Jan 2012
Location: Montreal

Posts: 3,491
iTrader: (0)

Garage List
2008 BMW M3  [0.00]
2006 Audi S4  [0.00]
My guess here is that on a NA engine, the mass flow of air entering the engine can be directly correlated to the throttle opening and RPM, so these 2 parameters combined with air temperature are sufficient to calculate the quantity of air entering the engine. However, on FI engines, the manifold pressure for a given RPM and throttle opening can vary depending on how much boost is provided by the turbo. Here, mass flow varies according to throttle opening, RPM and boost. Hence the reason for a Mass Airflow sensor on the FI engines. However, in my opinion, the system used on the S65 engine is still better as it provides less restriction in the intake tract; just much more complex to execute on a FI engine.

Last edited by CanAutM3; 02-14-2013 at 10:42 PM.
CanAutM3 is offline   Canada
0
Reply With Quote
      02-14-2013, 10:25 PM   #3
Edjay
First Lieutenant
 
Drives: 08 E90 AW, 76 2002
Join Date: Jul 2011
Location: Sacoftomatoes Ca

Posts: 351
iTrader: (0)

Most MAP sensors works with vacuum. Its alot easier to use a MAF sensor when you have boost. IMO theres no real advantage from one or the other. Just preference in tuning.
Edjay is offline  
0
Reply With Quote
Post 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 10:40 PM.




m3post
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