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The BMW questions you were afraid to ask.
Here's a thread where we can leave aside the assumption that we all know everything about BMW's and the mechanical or other aspects about them :hehe!:. As they say there is no such thing as a stupid question!
So have no shame and thou shalt not judge! :smiling:
I'll start...em..carbon air boxes....how exactly do they work. Nice, noise, light weight but what is the science behind the air flow that increases HP and justifies the huge price tag? :huh:
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RE: The BMW questions you were afraid to ask.
Nothing off the top of my head, but I will prepare a big list for tomorrow :p
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RE: The BMW questions you were afraid to ask.
I would assume the airbox is designed with wave tuning in mind. Just like the trumpets length and diameter the airbox will have an effect at what engine speed the air resonates perfectly.
By having an airbox which is not tuned to the trumpets then the system will not be as efficient and will have frictional losses an will not resonate properly I woud think.
I never studied carbon air boxes but my project in college was variable length intake manifolds and they basically worked on the above principal but oddly enough only worked at full throttle.
Here's a previous study. As it's an extension to the throttle body's the airbox would work in a similar way.
http://www.emeraldm3d.com/articles/cat/projects/post/emr-adj-length-intake/
There is also the fact that it provides less of a restriction to the intake of air.
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RE: The BMW questions you were afraid to ask.
I think the main thing with air boxes is they hold air in them so when air is needed all of a sudden (acceleration) the air is there ready to go, quicker induction. The reason they are carbon is more then likely just for weight saving, adding a big plastic box would defeat the purpose of the quicker acceperation, the weight would probably counteract that added speed ;)
Hope that makes sense.
Japs done one few years ago called "arc air" for Vtecs, 4-AGE engines etc but they went out of business for a while, crazy prices now for them secondhand. Think they are back in business but not making the small and older stuff anymore.
Sorry on phone so ignore spelling etc
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The BMW questions you were afraid to ask.
If it's the CSL airbox your thinking of there's another important factor, Alpha-N .
This does away with the MAF afaik. I guess without the MAF there is less obstruction in the airflow.
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RE: The BMW questions you were afraid to ask.
So less flex, more air flow and a combination of tuning and interior design? Thanks men :cool:
Who's next to the confession box so?:hehe!:
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RE: The BMW questions you were afraid to ask.
I don't know what a tracker mortgage is?
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RE: The BMW questions you were afraid to ask.
Sorry less flex ? As aluminium manifold?
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RE: The BMW questions you were afraid to ask.
Quote:
Originally Posted by Valdelisbmw
Sorry less flex ? As aluminium manifold?
I think he said less flex than a plastic box.
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RE: The BMW questions you were afraid to ask.
Would having a cone filter surrounded by a carbon open ended box have a negative effect on performance and response if the car has no additional map for it?
Also as far as i can see there is no cold air feed to it.
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RE: The BMW questions you were afraid to ask.
The carbon fibre resin used in motorsport applications(ie: CSL airbox) is resistant to high temps so when air is passing through, it will remain cool and act as a stronger barrier from the ambient engine bay temps.
There will be less friction for the air to pass over smooth carbon surfaces as opposed to rough plastic so a carbon airbox will be able to move air faster in to the intake.
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RE: The BMW questions you were afraid to ask.
Alot is probably marketing guff though...afe say my intake will give
a max increase of 20 bhp and 27 ft lbs (albeit on a 330)
http://i139.photobucket.com/albums/q...psdb49ucdv.png
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The BMW questions you were afraid to ask.
Why do model designations often not match up to the engine size?
Eg 318i E46 is 1.9
323i is 2.5
740i is 4.4?
320i 2.0/2.2
And many many more...
It's odd. I'd be tempted to badge mine as 319i except you can't get a 9.
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Re: RE: The BMW questions you were afraid to ask.
Quote:
Originally Posted by John_D
Why do model designations often not match up to the engine size?
Eg 318i E46 is 1.9
323i is 2.5
740i is 4.4?
320i 2.0/2.2
And many many more...
It's odd. I'd be tempted to badge mine as 319i except you can't get a 9.
Rounded up or down I assume?
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RE: The BMW questions you were afraid to ask.
most of these differences are made to explain more accurate engine power .not by CC but by BHP ,so its much easier to know which is which . and im not 100% sure ,but have heard that in Germany insurance is by exact model,not CC .lets say E39 523i and E39 525i , 523i will be difference insurance group cos it has only 170bhp as 525i has 192 ,and so on.
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RE: The BMW questions you were afraid to ask.
I always thought it was a marketing exercise, to ensure a greater model spread for prospective buyers.
For example with the E46:
"The E46 323, despite having a 2.5L engine, was designated "323" and not "325", to increase the apparent spread between it and the correctly numbered 328 to appeal to BMW enthusiasts.
http://en.wikipedia.org/wiki/BMW_3_Series_(E46)
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RE: The BMW questions you were afraid to ask.
Quote:
Originally Posted by Gitzer
Would having a cone filter surrounded by a carbon open ended box have a negative effect on performance and response if the car has no additional map for it?
Also as far as i can see there is no cold air feed to it.
just performance filter , dont need any special map.but if its carbon air intake box ,it does need special mapping .
cold air intake -feed ,its little bit wrong in your understanding :wink: usual car ,non CSL which has it from factory , has normal air box ,which is under bonnet ,where its very high temperatures ,temperature of engine heat .air boxes ,most of them ,has air restrictions ,these are made for better power and fuel economy ,and air filter -paper one ,to reduce air intake noise for comfort driving .who would like to drive 7 series with some cold air intake on V8 ,probably non of their owners :hehe!: we not talking about boy racers :tounge: cars from factory are never made to get more as possible BHP ,its made with limits
so carbon boxes gives easier way for air from outside to the engine ,bigger amount and no restrictions and cars still has air guides,air is not coming from under bonnet .
and main fact ,its made for more power ,which should be used properly ,not to get numbers on dyno .
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RE: The BMW questions you were afraid to ask.
I think it's a bit of both to be honest ^ e36 325's 2.5 has 192bhp out of the box and a 3.15 diff, the 323 with a newer 2.5 has 170bhp (thanks to a restrictive intake manifold and exhaust) and has a 2.93 diff which has a pretty noticeable negative effect on performance. If they called the 323 a 325 it would be as if they made the 325 worse rather than better. The replacement for the 325 was the 328. They obviously named it a 323 as it was more powerful than a 320 but not as powerful as a 325.
Luckily someone somewhere discovered that by fitting the old 325 manifold and a 328 exhaust onto a 323 you can get even more power than a 325 :D and you can choose between acceleration / top speed or a balance between them with a shorter/longer diff. It is somewhat annoying when someone thinks a 323 is a 2.3 and so it is more appealing to have an appropriately badged car. Even the z3 got a "2.3" badge when it was in fact 2.5.....
As far as I understand the 318iS got the 1.9 M44 to cope with the extra weight in the later e36 models. etc
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RE: The BMW questions you were afraid to ask.
Quote:
Originally Posted by Peter-E36
I think it's a bit of both to be honest ^ e36 325's 2.5 has 192bhp out of the box and a 3.15 diff, the 323 with a newer 2.5 has 170bhp (thanks to a restrictive intake manifold and exhaust) and has a 2.93 diff which has a pretty noticeable negative effect on performance. If they called the 323 a 325 it would be as if they made the 325 worse rather than better. The replacement for the 325 was the 328. They obviously named it a 323 as it was more powerful than a 320 but not as powerful as a 325.
Luckily someone somewhere discovered that by fitting the old 325 manifold and a 328 exhaust onto a 323 you can get even more power than a 325 :D and you can choose between acceleration / top speed or a balance between them with a shorter/longer diff. It is somewhat annoying when someone thinks a 323 is a 2.3 and so it is more appealing to have an appropriately badged car. Even the z3 got a "2.3" badge when it was in fact 2.5.....
As far as I understand the 318iS got the 1.9 M44 to cope with the extra weight in the later e36 models. etc
i would say u completely wrong . its nothing made wrong !!! all this just made more options for very wide customer range . and what would be the point to get only one or two different engines
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RE: The BMW questions you were afraid to ask.
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Re: RE: The BMW questions you were afraid to ask.
Quote:
Originally Posted by Bayerische
What does BMW stand for?
Is it not something to do with the Polish joke about them constantly robbing cars in Germany? I think the punchline is......and pardon the spelling.......'bild mien wagon'
Sent from my WT19i using Tapatalk 2
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RE: The BMW questions you were afraid to ask.
Quote:
Originally Posted by Bayerische
What does BMW stand for?
Breaks My Wallet. :wink:
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RE: The BMW questions you were afraid to ask.
Bayerischen Motoren Werke or Be My Wife
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RE: The BMW questions you were afraid to ask.
Quote:
Originally Posted by Valdelisbmw
Bayerische Motoren Werke or Be My Wife
Fixed that for you Valdas :tounge:
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The BMW questions you were afraid to ask.
No it's Break My Wallet... Only messing it's really Brings Me Women.
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RE: The BMW questions you were afraid to ask.
Here's one.
Are we (those that do) flushing money down the drain sticking with Castrol at every oil change, or will anything that meets the Longlife standards do the exact same thing. My head says it does but my heart won't let me change. :/
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RE: The BMW questions you were afraid to ask.
Personally would never use castrol. It gunked up in an engine before and I changed to a different brand and it was fine afterwards.
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RE: The BMW questions you were afraid to ask.
Quote:
Originally Posted by voodoomelon
Here's one.
Are we (those that do) flushing money down the drain sticking with Castrol at every oil change, or will anything that meets the Longlife standards do the exact same thing. My head says it does but my heart won't let me change. :/
Very interesting (and long..) oil thread on M5 boards, basically saying the TWS oil is not what it use to be and there is cheaper oil out there doing the same thing if not better.
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The BMW questions you were afraid to ask.
I decided to stop sticking to Castrol and use anything(within reason) that meets the LL standard.
Currently using Total Quartz.
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RE: The BMW questions you were afraid to ask.
Quote:
Originally Posted by voodoomelon
Here's one.
Are we (those that do) flushing money down the drain sticking with Castrol at every oil change, or will anything that meets the Longlife standards do the exact same thing. My head says it does but my heart won't let me change. :/
Top grade oils are good due to additives I guess but, engine dependent, unless you periodically do engine flushes you may not get the best from the oils you use.
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The BMW questions you were afraid to ask.
Here's another one.
What's the advantage (if any) of coilovers over equivalent springs and shocks?
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The BMW questions you were afraid to ask.
As in a McPherson strut as opposed to separate spring and shock assembly?
Good question. Perhaps the layouts lend themselves differently to different body shapes. For example with the E46(and many others) rear suspension if the springs were on struts like the front you would need more room and thus loose a few inches of boot space. Maybe not so big a deal on bigger cars such as the e39 which are wider.
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RE: The BMW questions you were afraid to ask.
Quote:
Originally Posted by JohnH
Here's another one.
What's the advantage (if any) of coilovers over equivalent springs and shocks?
Handling essentially, less roll through corners and a better feel for the road surface through the steering. The cons are that they can cause a harsh ride depending on the road surface e.g A lumpy road will transmit every defect through the car. A big pro is that driving on smooth roads e.g motorway cruising is enhanced, you trade bouncing about like mad for a bit more noise but overall smoother comfier driving.
An aftermarket spring/shock combo usually falls in to a price range that isn't far off an adjustable coilover kit so you can tune the damping to your liking and eventually find a happy medium for every type of driving that you do.
Coilovers are much lighter too...
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The BMW questions you were afraid to ask.
So was the question about aftermarket coilovers vs oe struts? Or struts vs seperate spring/shock ?
I'm confused.
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The BMW questions you were afraid to ask.
Quote:
Originally Posted by John_D
So was the question about aftermarket coilovers vs oe struts? Or struts vs seperate spring/shock ?
I'm confused.
It was about coilovers vs separate spring/shocks but not necessarily oem.
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RE: The BMW questions you were afraid to ask.
Why aren't there any decent e30 so left in the country????:hehe!:
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Re: The BMW questions you were afraid to ask.
Age, at +25 yrs old most have rotten away and good ones are snapped up and kept as keepers
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The BMW questions you were afraid to ask.
Does the immobiliser allow the engine to crank or does it cut everything off so that it wont even turn?
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RE: The BMW questions you were afraid to ask.
Are winter tyres a 'must have' for rear wheel drive cars?
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RE: The BMW questions you were afraid to ask.
Nope but you can get around with much more confidence with them on as you sail past jeeps [emoji3]
iv had them on my e36 and e39 through bad winters the difference is incredible , i changed brakes last year to bigger ones so sold my winter wheels but luckily last winter was very mild the coupe was the worst in snow/ice loading up the boot helped a bit but not much