M5POST
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read

Go Back   M5POST - BMW M5 Forum > F10 M5 Forum > Engine, Exhaust, Drivetrain Modifications

Post Reply
 
Thread Tools Search this Thread
      12-25-2012, 12:40 PM   #1
Charlie Brown
Lieutenant
Charlie Brown's Avatar
United_States
53
Rep
563
Posts

Drives: F10 M5 Azurite Black
Join Date: Jun 2012
Location: USA

iTrader: (1)

BIMMERPOST
     Featured on BIMMERPOST.com
I'm leaning heavily towards the axle-back Eisenmann race with 90mm tips. This setup removes the valves that control the exhaust passage at the rear. My questions are; what does that valve really do? Is it just noise control or does it add back-pressure at low rpm for fuel economy or pressure at part throttle for low RPM torque? How will the computer react to the missing valve? Thoughts?
Appreciate 0
      12-25-2012, 12:43 PM   #2
BarryB
Lieutenant Colonel
BarryB's Avatar
United_States
865
Rep
1,758
Posts

Drives: 30Jahre M5 plus a few more M's
Join Date: May 2012
Location: Palo Alto CA

iTrader: (0)

Garage List
No negative effects. I think the valve is closed upon cold startup to help the cats warm up faster?
__________________
Current non-BMW's
20 Jeep Grand Cherokee
03 Cooper S (Maxi Tuned 50bhp)
60 Impala (43k orig mi)
15 Turbo S (Kobb tune and Kline exhaust)
Appreciate 0
      12-25-2012, 12:59 PM   #3
Nate@IND
Nate@IND's Avatar
2862
Rep
11,374
Posts

Drives: BMW
Join Date: Oct 2006
Location: Chicago

iTrader: (19)

Quote:
Originally Posted by BarryB View Post
No negative effects. I think the valve is closed upon cold startup to help the cats warm up faster?
+1

The valves are in place to reduce emissions during start up. Just make sure that the vacuum lines are plugged during the install or you will get a CEL. My installer uses a small drop of adhesive and two small license plate size screws to block the line.
__________________
IND DISTRIBUTION | 866-963-4520 • FACEBOOKINSTAGRAMFLICKR
Appreciate 0
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



All times are GMT -5. The time now is 02:10 AM.




m5post
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