Has anyone dynoed before and after removing the intake flap

Obioban · 20-07-2014, 12:52 PM

Recently a good number of members with CSL (and replica) air boxes have been retrofitting the full CSL ecu tune (and associated wiring changes), and basing their custom tunes on that instead of the stock M3 tune.

Some of them have started retrofitting the intake flap as well, under the assumption that it has a DISA like effect in addition to noise control.

e.g. http://www.m3forum.net/m3forum/showt...p?p=1066740021

From reading this forum over the years, I've always been under the impression that the flap was for sound control only. But, seems like that might not be the case? Have any of you done before and after dynos after removing the flap?

shane@mbtech · 20-07-2014, 01:44 PM

It will NOT effect any power that you will use to make you faster.
It might effect power low down where a standard CSL tune may think it's closed, but I highly doubt that, and the power effected low down won't be noticeable and when driving fast you will NEVER be in the low rpm range anyway.

mattCSLnut · 20-07-2014, 10:15 PM

I wouldn't bother with the CF air box flap on a CSL clone as it can rob you of about 30 BHP when it (and it's friend the potentiometer) decides not to open when they should

... don't ask me how I know

Sufic to say I've been flap-less since 2010

JBird · 22-07-2014, 11:14 AM

Quote:

Originally Posted by mattCSLnut

I wouldn't bother with the CF air box flap on a CSL clone as it can rob you of about 30 BHP when it (and it's friend the potentiometer) decides not to open when they should

... don't ask me how I know

Sufic to say I've been flap-less since 2010

Do you recall what rev range /gear you noticed this Matt?

mattCSLnut · 22-07-2014, 11:03 PM

Quote:

Originally Posted by JBird

Do you recall what rev range /gear you noticed this Matt?

Not exactly but it was well into the rev range, say 4000 RPM and above

irrespective of which gear I was in.
It felt like I left the hand brake On ... and Yes I did have a quick looky down

to make sure it was Off while on a flying lap @ the Ring.

20-07-2014, 12:52 PM	#1
Obioban S2 - Picking it up Join Date: Dec 2010 Posts: 34 Casino cash: $842	Has anyone dynoed before and after removing the intake flap Recently a good number of members with CSL (and replica) air boxes have been retrofitting the full CSL ecu tune (and associated wiring changes), and basing their custom tunes on that instead of the stock M3 tune. Some of them have started retrofitting the intake flap as well, under the assumption that it has a DISA like effect in addition to noise control. e.g. http://www.m3forum.net/m3forum/showt...p?p=1066740021 From reading this forum over the years, I've always been under the impression that the flap was for sound control only. But, seems like that might not be the case? Have any of you done before and after dynos after removing the flap? __________________ Current Cars: 2005 IR/IR M3, 2001 LMB/blk M5, 04 M3 wagon, 2017 i3 Past cars: 04 M3, 03 530i, 96 M3, S50B32 e36 M3 CM race car

20-07-2014, 10:15 PM	#3
mattCSLnut CSL Register Uber-poster! Join Date: Sep 2009 Location: Cambridge Posts: 6,460 Casino cash: $27763	I wouldn't bother with the CF air box flap on a CSL clone as it can rob you of about 30 BHP when it (and it's friend the potentiometer) decides not to open when they should ... don't ask me how I know Sufic to say I've been flap-less since 2010 __________________ UK CSL No.020 ... after 7 years of ownership I've now SOLD it !!!

20-07-2014, 01:44 PM	#2
shane@mbtech CSL Register Uber-poster! Join Date: Feb 2009 Location: warrington Posts: 5,419 Casino cash: $19783	It will NOT effect any power that you will use to make you faster. It might effect power low down where a standard CSL tune may think it's closed, but I highly doubt that, and the power effected low down won't be noticeable and when driving fast you will NEVER be in the low rpm range anyway.