Does it ever stop??....plus de flap?

[pops]

This "non-modding" business isn't going very well :banghead:

Full set of AP kit on order.

Sniffing around a back box, just unsure on make.

Today bought carbon dash trim / spare steering wheel from Vic (wheel will get sent off to Loz at LGTrimming to get it like new ).

Anyhow, de-flap.

Spoke to a guy today at Silverstone, Alex I think and apologies if I've got your name wrong, it's an age thing :whistle:

The airbox flap had been removed from his car and a quick chat revealed it produces the induction sound earlier on in the rev range. Had a quick search around and can't find any downside to this apart from blocking the inlet up over winter to stop the local cat making it his home whilst the car is stashed.

Is there anything I'm missing on this? Any problems caused by doing this or is it all good?

This can be done on the Mini but the flap is about the size of a 50p piece so isn't going to make the same difference!

[alexk]

I think there is a downside, how the car pulls up to 3500rpm.
It's not there just for noise, but to reduce the air supply in low rpms and increase torque.
If you don't care about low range and just want some extra noise, remove it.

[pops]

I think there is a downside, how the car pulls up to 3500rpm.
It's not there just for noise, but to reduce the air supply in low rpms and increase torque.
If you don't care about low range and just want some extra noise, remove it.l

If that's the case then I think it can stay where it is.

Thanks for that Aex, appreciated.

[cslsuperfan]

l

If that's the case then I think it can stay where it is.

Thanks for that Aex, appreciated.


Pops

I've been flapless for 5 years

Alex is right....but hey you & I are both at the age where lighting up the rears at the lights is a distant memory.

Take it off and enjoy the noise!!!! Its a 5 minute job....and 3 of those are spent fretting about not scratching the airbox. ;)

[pops]

Pops

Alex is right....but hey you & I are both at the age where lighting up the rears at the lights is a distant memory.



Yup, you're right there :whistle:

I see you're in Welsh Wales, in Conwy for a couple of nights mid June if it's your neck of the woods.

[outnumbered]

As long as you don't mind the slightly snatchy throttle effect, you can just press the Sport button to get the same noise as taking the flap off.

[shimmy]

mine has been flapless for 5 years now. slightly more jerky but good thing is you dont drive around for 2 years with the flap stuck shut wondering why your power is 30bhp down

[pops]

As long as you don't mind the slightly snatchy throttle effect, you can just press the Sport button to get the same noise as taking the flap off.

Already in the habit off pressing the sport button before it comes out of the garage.

Was well trained by Peter :thumbs:

[pops]

mine has been flapless for 5 years now. slightly more jerky but good thing is you dont drive around for 2 years with the flap stuck shut wondering why your power is 30bhp down

Good point.

Good to meet you today also.

[Bounce]

As long as you don't mind the slightly snatchy throttle effect, you can just press the Sport button to get the same noise as taking the flap off.But with the flap removed you the noise all the time,You don't with the sport button pressed.

[outnumbered]

But with the flap removed you the noise all the time,You don't with the sport button pressed.

I thought Sport opened the flap all the time.. Does it just open it earlier then ?

[shimmy]

I thought Sport opened the flap all the time.. Does it just open it earlier then ?

no, just a couple of thousand lower in rev range

[cslsuperfan]

Already in the habit off pressing the sport button before it comes out of the garage.

Was well trained by Peter :thumbs:


Pops

Martin AKA Trackm3 said he'd had an order for AP's all round from the forum.....

Welcome to the BBK club.

Just ordered Intrax 1K2 Black Titanium from Martin. Bartlett waiting for a delivery :smokin:

[cslsuperfan]

Yup, you're right there :whistle:

I see you're in Welsh Wales, in Conwy for a couple of nights mid June if it's your neck of the woods.


Yes Pops not to far away.....Conwy is famous for its A55 tunnels..great place to test your new SS lightweight race Back box.......when you order one ;)

[73CSL]

flap removed here too ... cant say Ive experienced any downsides , apart from pedestrains turning round earlier to see what's making that noise:thumbs:

[patphnx]

No flap in mine either!

:beer:

[GregorFuk]

I think running without a flap does decrease the life span of your air filter. It tends to get dirtier faster. I also worry about driving in hard rain, will it cause the filter to get wet? On that one I have no idea.

It's funny this subject has come up as I am currently flap-less but I have a log drive to LeMans coming up. I was considering reinstating the flap for this journey, what are people's thoughts on this?

[MisterCorn]

I haven't looked at removing the flap, but if it really as easy as you say I might give it a go myself, I don't think driving in the rain will be a big issue.

MC

[alexk]

I think running without a flap does decrease the life span of your air filter. It tends to get dirtier faster. I also worry about driving in hard rain, will it cause the filter to get wet? On that one I have no idea.


Yes rain will likely go inside the intake manifold.
That's another reason of not using the sport button in heavy rain, avoid rain going inside the intake ;)

[select]

I haven't looked at removing the flap, but if it really as easy as you say I might give it a go myself, I don't think driving in the rain will be a big issue.

MC


I removed my flap a couple of weeks after i bought my csl roughly a 1 year ago. I didn't have a single issue since.

Here is how you remove it:
You have to unscrew the flap motor then manually turn the flap open to reveal the 3 hex screws. Remove these and then manouver the flap out of the airbox and then simply screw the flap motor back in.

Btw, does somebody know if removing the flap motor will throw a code? If not i will see what happens when you do, in the next couple of days.


Yes rain will likely go inside the intake manifold.
That's another reason of not using the sport button in heavy rain, avoid rain going inside the intake ;)

I don't think rain will get sucked up as far as the air filter. I think the rain drops will hit the first bend of the plastic tube.
Besides i think if they would manage to reach the filter, BMW would have told people in the manuals.

In my opinion the flap is simply used as a means to comply with noise emission laws.
If i remember correctly its actually called "Geräuschklappe", which translates to "Noise Flap", in the ECU.

[alexk]

Besides i think if they would manage to reach the filter, BMW would have told people in the manuals.


I can think of at least 10 things that are not written in the owner's manual :hahaha:

The flap is definitely for torque boost in low rpms - fact.
It's not just for noise.
This is also due to the fact that the CSL gives you full throttle control, something that doesn't exist anymore (in other words, when you hit full throttle with 1500rpm, the CSL will open the throttle butterflies to 100%).
If you were controlling/restricting the throttle opening, you don't need a flap anymore (bikes had additional throttle butterflies to restrict airflow then newer generation had controlled/restricted throttle control).
I personally love the full throttle control the CSL gives to the driver.

Not removing the flap due to performance and risk of rain is my opinion and what I do when there is heavy or torrential rain.
If you check the intake when driving with heavy rain and 120-140, we can discuss again. The water can go to the intake.
Each one can decide for their own of course, since they own their cars :thumbs:
I mentioned my point of view since someone asked and I just give facts.

[cslsuperfan]

I think running without a flap does decrease the life span of your air filter. It tends to get dirtier faster. I also worry about driving in hard rain, will it cause the filter to get wet? On that one I have no idea.

It's funny this subject has come up as I am currently flap-less but I have a log drive to LeMans coming up. I was considering reinstating the flap for this journey, what are people's thoughts on this?


I don't drive in the rain unless of course it's a euro/long drive and the weather turns against you.

The filter certainly gets dirty quick and that's with the flap in place. Not sure if removing the flap increases the level of dirt but it may increase the volume of air passing into the airbox with sport off.

I've been flapless for 5 years and driven in some heavy rain. (Munich 2013 springs to mind). Never had an issue with water ingress.

[terraphantm]

I thought Sport opened the flap all the time.. Does it just open it earlier then ?

From the software, this is when the flap opens in non-sport and sport modes:

Non-sport:
0000 0001 0002 0003 0004 0005 0006 0007 - Gear
2328 2328 2328 1770 1770 1770 1770 2328 - RPM (Hex)
9000 9000 9000 6000 6000 6000 6000 9000 - RPM (Dec)

Sport:
0000 0001 0002 0003 0004 0005 0006 0007 - Gear
0CE4 0CE4 0CE4 0CE4 0956 0780 0640 0CE4 - RPM (Hex)
3300 3300 3300 3300 2390 1920 1600 3300 - RPM (Dec)


In this context, gear 0 means neutral and 7 means reverse. So in non-sport, the flap doesn't open at all in neutral, 1st, 2nd, or reverse. It opens at 6000 in the rest of the gears

In sport mode, it opens at 3300RPM N, 1, 2, 3, and R. 4, 5, and 6 have progressively lower opening points. For gears 3-6, the opening points corresponds to approximately 40mph or 65 km/h

As you can imagine, it is possible to alter this behavior by adjusting the software. On my own car (not a CSL, but running CSL software), I simply set the opening points to 100 RPM in both modes (so flap is always open, but closes when engine is off). Also, I've found the flap still stays closed while the cat-heating function is running (approximately 2 minutes from a cold start).

[Olive]

This is very interresting ! Thanks terraphantm.
I was wondering why it was so difficult to see if the switch was working well. Now with your RPM value I understand better the behaviour => it works well :beer:

Following a problem with the switch, I ordered a new one and have removed the flap in the awaiting of receiving it. I has been received and repaired it...but I never replaced the flap. It was more than 2 years ago.

Today I do not know if I will put on the flap again. I never using my car under rain and ... it is very easy to clean the filter with a vacuum without flap. I guess it is more clean without flap.

Concerning torque. That is the point. I probably do not need to feel it more but I will may be again one day to see if I can really feel the difference.

[cslsuperfan]

This is very interresting ! Thanks terraphantm.
I was wondering why it was so difficult to see if the switch was working well. Now with your RPM value I understand better the behaviour => it works well :beer:

Following a problem with the switch, I ordered a new one and have removed the flap in the awaiting of receiving it. I has been received and repaired it...but I never replaced the flap. It was more than 2 years ago.

Today I do not know if I will put on the flap again. I never using my car under rain and ... it is very easy to clean the filter with a vacuum without flap. I guess it is more clean without flap.

Concerning torque. That is the point. I probably do not need to feel it more but I will may be again one day to see if I can really feel the difference.


Agreed. My ITG filter was boggin' as a result of going flapless.

Never thought of vacuuming! will give it a go!!

[GregorFuk]

Just to add to this thread. I bought my CSL with the flap in a box in the boot, along with the standard brakes. I ran it for over six months flap-less with no real issue but curiosity got the better of me so I sourced a working motor and reinstated the flap. Having now ran for a few weeks with a working flap I would say that the car is much smoother driving round town and at 'normal' road speeds. Even though I miss the full time noise I plan on leaving the flap in place. If it were just for noise control then I'd whip it back out but the car is obviously happier with it in place.

[Olive]

hum ... difficult to know what I will do ...
I will probably try to reflap duing the summer holiday and try to see if I can really fell a difference of behaviour on low rpm.
It is pity to confirm that flap is never open in std mode on 3 first gears :banghead:

[select]

Well my car came the flap in place and i removed it 2 months after i bought it.
I love that low deep rumble it produces in the low rev range. You don't need to drive it like you stole it all the time.. surely helps me keeping my driving license :hahaha:
Altough it has a tendency to produce reactions from bystanders, both positive and negative :hahaha:

Plus you don't have to use the sport button all the time which is way too twitchy imho.

Although i liked that moment when all of a sudden the flap opens and all hell breaks loose :thumbs:

@terra can you shed some insight into the exact function of the sport button?
As i understood it only changes gas pedal sensitivity at least on the normal m3.

Thanks and sorry for my essay.. i am a bit bored at the party, can you tell? :hahaha:

Julian

[Olive]

@terra can you shed some insight into the exact function of the sport button?
As i understood it only changes gas pedal sensitivity at least on the normal m3.

Hello Julian, the last time I connected my ISTA I was looking for an update of the SMG2 and I was reading some lines concerning the "sport button". It seems that not only the gas pedal sensitivity is modify, but also the gearbox reaction. Honestly I have some big doubts about that...
I will make a print screen next time to show it. I need to investigate further on that topic.

[select]

Hi Olive,


Thats interesting, never heard that before albeit i've read dozens of threads about the functionality of the sport button. From what i gathered is, that, at least in the normal e46 m3 it just changes the throttle sensitivity from linear to a more "fake" mapping. e.g. when you push the throttle 50% the butterfly valves are actually open at 70%. (i made those numbers up, but you get the point)

Would be great if someone can shed some insight in what the sport button on the csl actually does.

[nw99]

the question seems to come up quite frequently, and the responses are often varied and erroneous.
1. does the sport button change the engine map?

No, it only changes the responsiveness of the electronic throttles, so that less input with your foot on the accelerator pedal yields more output from the throttles than when in normal mode.

2. does it add power when the sport button is pressed?

No, although the car seems to feel invigorated, again you are only getting more fuel into the engine with less effort from your foot.

3. my petrol mileage seems lower when i drive in sport mode?

Yes, yes it does.
actual mileage may vary, it is likely that you will consume fuel at a faster rate with sport mode on.

[Olive]

I fully agree with it regarding the feeling and behaviour of the car with Sport Button. I noticed also the raising of consumption.
One important thing for me : it is less safe to drive with Sport Button "ON" in the moutains. The car is less easy to control...almost dangerous on very small moutain road.
Then, for me, the removal of the flap is a perfect adding of a driving without Sport Button "ON".

[GregorFuk]

To me sport on gives the most accurate representation of a cable operated throttle pedal. Not too many years ago I had a Lotus Elise running throttle bodies that were functioned with a good old fashioned throttle cable. Sport on mirrors this the best. With sport off I find there is an unnatural dead spot in the first 1/3 of the travel. I guess this helps prevent any jerky throttle inputs and makes motorway cruises easier.

As an aside I do feel the SMG is sharper with sport on. Perhaps it's just in my head.

[glendog74]

As an aside I do feel the SMG is sharper with sport on. Perhaps it's just in my head.

It certainly feels that way with DSC off and 'S6' selected :thumbs:

[cslsuperfan]

To me sport on gives the most accurate representation of a cable operated throttle pedal. Not too many years ago I had a Lotus Elise running throttle bodies that were functioned with a good old fashioned throttle cable. Sport on mirrors this the best. With sport off I find there is an unnatural dead spot in the first 1/3 of the travel. I guess this helps prevent any jerky throttle inputs and makes motorway cruises easier.

As an aside I do feel the SMG is sharper with sport on. Perhaps it's just in my head.

My experience also.

Sport on permanently, sod the MPG.

[MarcM]

To me sport on gives the most accurate representation of a cable operated throttle pedal. Not too many years ago I had a Lotus Elise running throttle bodies that were functioned with a good old fashioned throttle cable. Sport on mirrors this the best. With sport off I find there is an unnatural dead spot in the first 1/3 of the travel. I guess this helps prevent any jerky throttle inputs and makes motorway cruises easier.

As an aside I do feel the SMG is sharper with sport on. Perhaps it's just in my head.

Agree. Having owned and used extensively two M cars with throttle cable can say sport mimics them perfectly. I even put sport on to move the car 15 foot back into the garage. Just bought an E46 320d sport touring as a daily smoker (it's Silver Grey as well :smokin:) it's throttle is probably more responsive than sport off :hahaha:

[terraphantm]

the question seems to come up quite frequently, and the responses are often varied and erroneous.
1. does the sport button change the engine map?

No, it only changes the responsiveness of the electronic throttles, so that less input with your foot on the accelerator pedal yields more output from the throttles than when in normal mode.

2. does it add power when the sport button is pressed?

No, although the car seems to feel invigorated, again you are only getting more fuel into the engine with less effort from your foot.

3. my petrol mileage seems lower when i drive in sport mode?

Yes, yes it does.
actual mileage may vary, it is likely that you will consume fuel at a faster rate with sport mode on.

While sport mode doesn't add power or change timing, it is a bit more complicated than that. In addition to having a more aggressive throttle map, sport mode also allows the engine's torque to ramp up more rapidly.

[select]

Forgive my ignorance but wouldn't mean torque earlier in the range more power aswell?

[terraphantm]

Forgive my ignorance but wouldn't mean torque earlier in the range more power aswell?

When I say it lets the torque ramp up quicker, I mean in term of time, not the rev range. So while you might technically make more power for a fraction of a second, the end result will be the same. What is different is the responsiveness.

[select]

Wow i am impressed, i thought its just some gimmicky feature that makes the throttle way too twitchy.
I shall use it way more from now on. Thank you for clearing that up.

Do you know if the normal m3 shares the same behaviour?
Apart from the function of the flap, of course?

[0836whimper]

I had a normal M3 and the CSL at the same time for a while.

The difference in the sport button on the two was quite marked, the M3 was almost undriveable with Sport on, the CSL less sensitive. Also, the M3 seemed to provide more power lower down in the revs, whilst the CSL is more linear and the fireworks are further up the rev range. Had the effect on making the M3 appear more powerful, but obviously it's the other way round.

The M3 was an early 03 pre-facelift with the SMG logo on the gear stick housing etc, they might have revised the above soon after.

[terraphantm]

I had a normal M3 and the CSL at the same time for a while.

The difference in the sport button on the two was quite marked, the M3 was almost undriveable with Sport on, the CSL less sensitive. Also, the M3 seemed to provide more power lower down in the revs, whilst the CSL is more linear and the fireworks are further up the rev range. Had the effect on making the M3 appear more powerful, but obviously it's the other way round.

The M3 was an early 03 pre-facelift with the SMG logo on the gear stick housing etc, they might have revised the above soon after.

Pretty much all of the maps that deal with sport/non-sport are identical on the CSL and non-CSL; same throttle curves, same delta torques. Main difference is that the non-CSL doesn't have any provisions to deal with the flap.

So the difference behavior comes from somewhere other than how sport mode is handled. There are probably multiple things that contribute. Two things I can think of:

1) The non-CSL does make more torque down low for a given cylinder filling (particularly below 3000 RPM).
2) The CSL goes into open-loop at much smaller throttle angles than the non-CSL

[terraphantm]

Just wanted to update you guys with some info I've uncovered:

The CSL software changes the cylinder filling / volumetric efficiency calculation based on whether or not the flap is open, and it also alters the throttle map depending on the flap status. So if you want to run flapless, it's probably best to keep it open via software rather than just removing it altogether.

[digi]

kool find. thx. :thumbs:

[nw99]

Much appreciated