does lid airbox stay closed with cold temperature? - Page 2

dave1 · 09-01-2009, 02:13 AM

noise regs

SpineOnABap · 09-01-2009, 07:23 AM

exactly

**Mark CSL** · 09-01-2009, 08:11 AM

Quote:

Originally Posted by houlbt

Quote:

Originally Posted by mark csl

The only thing i would say is if it works without it why did BMW Motrsport fit it

Why do so many sports cars have exhaust valves these days?

I still think there is more to it than that.
But i do no mine stopped working and i put a new pontomoter on it
and all is good now.

BMsport.com · 09-01-2009, 10:35 AM

Finally, some one understands

the flap is there for noise reasons. It has no bearing on the fuelling. The amount of air entering the engine is controlled by the throttle valves, not the flap and monitored by a MAP sensor. There are many CSLs out there with and without the flap. If it caused rich or weak running then the emission light would illuminate on the dash board. To say it must have a reason as it was fitted by BMW Motorsport is correct, noise. For the same reason the exhaust is quiet.

M3_CSL · 09-01-2009, 11:21 AM

probably someone should make an exhaust with a valve for the CSL too... while the exhaust valve is closed, the exhaust flow is like the original CSL exhaust... and when the sport button is depressed, both intake and exhaust valves will be opened for full race noise..

I used to use an electronic exhaust flap on my highly tuned N/A 350Z (revved to 8200rpm with full engine rebuilt and MoTeC), that car was quite loud with its exhaust, so a flap was needed to go around the suburban streets and i couldn't believe how much difference it made.... but with the flap closed, power loss was substantial and also the engine didn't like it at all

just a wild thought...

cheers,

richie

englebert · 09-01-2009, 11:30 AM

Someone should buy a Kreis-Seig... best sounding out there, goes from a normal exhaust to completely straight through at a touch of a button!

As said before, BMSport removed my flap. Went from their lowest peforming CSLs to one of the best!

NZ_M3 · 09-01-2009, 02:06 PM

Quote:

Originally Posted by BMsport.com

The amount of air entering the engine is controlled by the throttle valves, not the flap and monitored by a MAP sensor.

Kindly explain how does an individual throttle intake system operate on a MAP sensor without an intake manifold (to measure manifold absolute pressure??) - better still point to me an actual MAP sensor BMW part number on the CSL (I've yet to find one on realoem.com - and no not the one on the idle regulator lines - that controls idle). As far as I am aware the car runs without a MAF or MAP sensor - basically Alpha N tune on throttle position and air temp sensors.

Actually, if you can throw up a dyno graph showing that there's no torque loss without the flap operating in comparison to one with the flap operating.

BMsport.com · 09-01-2009, 02:15 PM

Map sensor part no. 13 62 7 833 561. It fits to the air rail so feeds from each throttle body, part no. 13 41 7 833 597.

NZ_M3 · 09-01-2009, 02:16 PM

Quote:

Originally Posted by BMsport.com

Map sensor part no. 13 62 7 833 561. It fits to the air rail so feeds from each throttle body, part no. 13 41 7 833 597.

That one's for idle control ... unless I am mistaken ...

BMsport.com · 09-01-2009, 02:19 PM

And even if it was alpha n, the air flow would still be controlled by the throttle valves, not the flap.

09-01-2009, 10:35 AM	#14
BMsport.com Wonky 'L' after Washing Join Date: Dec 2008 Posts: 16 Casino cash: $992	Finally, some one understands the flap is there for noise reasons. It has no bearing on the fuelling. The amount of air entering the engine is controlled by the throttle valves, not the flap and monitored by a MAP sensor. There are many CSLs out there with and without the flap. If it caused rich or weak running then the emission light would illuminate on the dash board. To say it must have a reason as it was fitted by BMW Motorsport is correct, noise. For the same reason the exhaust is quiet. __________________ www.bmsport.com

09-01-2009, 11:21 AM	#15
M3_CSL S3 - On the open road Join Date: Aug 2008 Location: Australia Posts: 113 Casino cash: $836	probably someone should make an exhaust with a valve for the CSL too... while the exhaust valve is closed, the exhaust flow is like the original CSL exhaust... and when the sport button is depressed, both intake and exhaust valves will be opened for full race noise.. I used to use an electronic exhaust flap on my highly tuned N/A 350Z (revved to 8200rpm with full engine rebuilt and MoTeC), that car was quite loud with its exhaust, so a flap was needed to go around the suburban streets and i couldn't believe how much difference it made.... but with the flap closed, power loss was substantial and also the engine didn't like it at all just a wild thought... cheers, richie __________________ Lamborghini Gallardo LP570-4 Superleggera Lamborghini Gallardo Superleggera - GSL - Gone Lamborghini Gallardo S - Gone Ferrari 360 F1 - Gone and already forgotten M3 CSL - Garage Queen - Gone, but not forgotten

09-01-2009, 11:30 AM	#16
englebert S5 - Full Throttle Join Date: Jun 2008 Location: Kent Posts: 397 Casino cash: $705	Someone should buy a Kreis-Seig... best sounding out there, goes from a normal exhaust to completely straight through at a touch of a button! As said before, BMSport removed my flap. Went from their lowest peforming CSLs to one of the best! __________________ '03 SG CSL - SOLD Making do with a CSL replica, 1M and E90 M3.

09-01-2009, 02:15 PM	#18
BMsport.com Wonky 'L' after Washing Join Date: Dec 2008 Posts: 16 Casino cash: $992	Map sensor part no. 13 62 7 833 561. It fits to the air rail so feeds from each throttle body, part no. 13 41 7 833 597. __________________ www.bmsport.com

09-01-2009, 02:19 PM	#20
BMsport.com Wonky 'L' after Washing Join Date: Dec 2008 Posts: 16 Casino cash: $992	And even if it was alpha n, the air flow would still be controlled by the throttle valves, not the flap. __________________ www.bmsport.com

09-01-2009, 02:13 AM	#11
dave1 S5, Sport Off, DSC M-track Join Date: Sep 2008 Location: CORNWALL Posts: 937 Casino cash: $1432	noise regs

09-01-2009, 07:23 AM	#12
SpineOnABap S5, Sport Off, DSC M-track Join Date: May 2008 Location: Earth Posts: 561 Casino cash: $5714	exactly

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