Cold air feed

AlienZed

Senior member
 Tameside,Cheshire
Site Supporter
Just removed the front grill to check how the cold airfeed to the airbox works and found most of it has a cover on restricting the airflow .so i've removed the cover to help increase the airflow at speed anyone else done this
Moz
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Doesn't that scoop direct the air into the airbox?

By removing it, you're simply allowing the air to go wherever it wants.
 
hmm interesting! would this help at all? not quite sure it will improve anything?
 
Dont think so it looks like a scoop but the only airgap was at the top and i could barely get my fingers in the gap .in the picture i just placed it back to show the area it was in.its shaped like a scoop but in reverse:grin: need to get some flexi tube and create a more positive direct airflow
Moz

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Nova2k7 said:
hmm interesting! would this help at all? not quite sure it will improve anything?

This cover severly restrics airflow and i thought the idea was to get as much cool air as possible into the airbox.??
Moz

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Machine monkey said:
Dose the RPI scope fit onto that pipe but channel more air in?

The scoop thingy i've taken off seems to block more air than channeling in.
Whats yours like this is on my 3.0 se.
Moz


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i cant quite figure out where that is but im guessing its low and behind the bumber grill

could that screen be to keep water out? without it if you hit a big puddle i would worry that you may basically scoop up a massive glug of water which is not good. enough water in a cylinder will hydraulically lock it and possibly f**k your engine.

its just a concern/idea to consider, happy to be proven wrong.
 
I thought the scope was to make sure the air sucked in was from the front and cool, instead of possibly sucking air from around the radiator that was hot?

No scientific basis on that, just my 2p
 
The entry to the airbox through the bulkhead (shown in photo two above) is at the top left corner of the radiator behind the passeger side kidney grill on the ///M so presumably it is in a similar position on other models. When the car is moving, the area behind the kidney grill in front of the radiator is at higher pressure than ambient - this ram effect drives air into the airbox. As pressure has no direction, that the scoop points upwards will not reduce the ram effect. It is reasonable to assume that BMW engineers found an advantage to using an upturned scoop as opposed to simply having an open hole through the bulkhead - whether that is to keep out water I don't know. The RPi scoop is sold on the premise that pointing the intake forward into mouth of the kidney grill will increase the ram effect. From personal experience (first with the OEM airbox then latterly an aFe cold air intake), the RPi scoop has little effect on performance beyond perhaps (and I really mean perhaps) allowing the car to rev slightly more freely at extremely high speed. I suspect that the simple explanation for this is that the OEM intake is very efficient at harnessing the ram effect and that any restrictions to flow through the system are not at the level of the scoop.
OP, if you are interested in this, there is at least one extremely lengthy thread about the ram effect and potential modifications to the OEM induction system. Search for Exdos and review his technical posts pertaining to datalogging his car.
 
Thanks guys( bmwz4mc and monkey )for your replies just read the thread and it certainly raised some discussion :grin:
Think i'll leave it off and have a fiddle see how we go on .
Just read luke/machine monkeys thread re quad conversion..quite fancy that.:grin:
Moz

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BMWZ4MC said:
The entry to the airbox through the bulkhead (shown in photo two above) is at the top left corner of the radiator behind the passeger side kidney grill on the ///M so presumably it is in a similar position on other models. When the car is moving, the area behind the kidney grill in front of the radiator is at higher pressure than ambient - this ram effect drives air into the airbox. As pressure has no direction, that the scoop points upwards will not reduce the ram effect. It is reasonable to assume that BMW engineers found an advantage to using an upturned scoop as opposed to simply having an open hole through the bulkhead - whether that is to keep out water I don't know. The RPi scoop is sold on the premise that pointing the intake forward into mouth of the kidney grill will increase the ram effect. From personal experience (first with the OEM airbox then latterly an aFe cold air intake), the RPi scoop has little effect on performance beyond perhaps (and I really mean perhaps) allowing the car to rev slightly more freely at extremely high speed. I suspect that the simple explanation for this is that the OEM intake is very efficient at harnessing the ram effect and that any restrictions to flow through the system are not at the level of the scoop.
OP, if you are interested in this, there is at least one extremely lengthy thread about the ram effect and potential modifications to the OEM induction system. Search for Exdos and review his technical posts pertaining to datalogging his car.

I was thinking of tinkering in this area, but the more I looked into it the more I thought someone in a white labcoat spent years getting this design the way it is!!
 
i took mine off nearly a year ago & had no problems with water in the airbox. i was intending to make a scoop but i never got round to it. It didnt feel any different to drive either
 
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