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I bought my M5 used, it has rpi scoops installed by a previous owner.
It did not have block off plates and still had the paper filters and the charcoal filters.
Last week I added the plates and bmc filters and removed the charcoal filters.

My questions are...
The factory setup was already a ram air type, or not?
Air goes in the front bumper holes and to the air box, so how is the rpi setup better?

Why block off the factory tube? Wouldn't that be extra air?

With it blocked off, doesn't it then just trap air, maybe it should be blocked at the front to avoid catching air?

Could the factory intake in the bumper be directed to an area it could help in some way, maybe keep something else cooler?

I have less than a month of ownership and knowledge of the M5, I'm still learning about this car.
 

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Take that crap off your car and get the HP back "up to" 500. It isn't worth messing with the stock paper filters or charcoal filters as they are better for your car. The stock car is more efficient and powerful without all of the after market garbage. The block-off plates rob you of air to your intake and take away power. The scoops are doing nothing except look cool (if you happen to like the look).
 

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I don't believe a dyno run measure with a fan that may simulate 20mph of airflow is enough to convince me that the scoops have any noticeable effect at real highway speeds.

At 20mph air pressure hasn't begun to build up at the front of the radiator, which will force air into the stock airbox ducts.

Later, Steve
 

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It is pretty interesting to note that RPI themselves say that it requires a 70 mph airflow to see their advertised gains of 10 to 15whp. I am not sure what kind of fan setup they have on their dyno, but I doubt it can generate 70mph winds. So, in reality, how did they measure the 10-15whp gain at 70 mph airflow?
 

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Make some dragstrip runs with and without the scoops on the same day and see how the MPH changes.

It's not that hard to get a consistent MPH at a dragstrip. Any gain would be attributed to the scoops.

You should gain around 1 mph if the hp claims are correct.

At the very least install a scoop on the drivers side and leave the passenger side stock. Put small wind speed meters inside the airboxes, where the inlet enters the airbox. You should see higher wind speeds with the scoop, if RPI's theory is correct. Next remove the driver side scoop and install the passenger side scoop and repeat. Make both runs on the same section of road in the same direction.

Later, Steve
 

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Sorry, should have said that their comments are based on their testing rather than opinion.
 

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Stock Setup

I bought my M5 used, it has rpi scoops installed by a previous owner.
It did not have block off plates and still had the paper filters and the charcoal filters.
Last week I added the plates and bmc filters and removed the charcoal filters.

My questions are...
The factory setup was already a ram air type, or not?
Air goes in the front bumper holes and to the air box, so how is the rpi setup better?

Why block off the factory tube? Wouldn't that be extra air?

With it blocked off, doesn't it then just trap air, maybe it should be blocked at the front to avoid catching air?

Could the factory intake in the bumper be directed to an area it could help in some way, maybe keep something else cooler?

I have less than a month of ownership and knowledge of the M5, I'm still learning about this car.
In the process of renewing all maintenance when i bought mine, i also replaced the old (actually good) air filters with AFE dry units and in the process removed the carbon filters...The stock setup sure seems direct and large: with the filters out, you see right through to the bumper opening...big pretty direct holes. I had the full Dinan setup on my E39 (CAI, MAF tunes) and aside from looking cool, and being a complete PITA to even check if the filters were even still attached to the tubes, did nothing on the butt dyno....If you GAVE me a CAI for this car i dont think i would bother...But to each his own.
 
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In the process of renewing all maintenance when i bought mine, i also replaced the old (actually good) air filters with AFE dry units and in the process removed the carbon filters...The stock setup sure seems direct and large: with the filters out, you see right through to the bumper opening...big pretty direct holes. I had the full Dinan setup on my E39 (CAI, MAF tunes) and aside from looking cool, and being a complete PITA to even check if the filters were even still attached to the tubes, did nothing on the butt dyno....If you GAVE me a CAI for this car i dont think i would bother...But to each his own.
You're right. These CAI's and scoops are a complete waste of time and money by themselves. The oiled filters are also bad for your intake and MAF sensor as they gum things up. The only way to get any kind of positive results is to couple them with a much freer flowing exhaust system. Even then, I doubt that the small performance gains would be worth the thousands invested. Additionally, this stuff will void just about every factory or after market warranty. So the question is: are a few HP and little to no performance gains at the track worth all this money? For me...not a chance.
 

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You're right. These CAI's and scoops are a complete waste of time and money by themselves. The oiled filters are also bad for your intake and MAF sensor as they gum things up. The only way to get any kind of positive results is to couple them with a much freer flowing exhaust system. Even then, I doubt that the small performance gains would be worth the thousands invested. Additionally, this stuff will void just about every factory or after market warranty. So the question is: are a few HP and little to no performance gains at the track worth all this money? For me...not a chance.
So all of us that are running BMC filters are damaging our cars?
 

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There is new and better technology out there now with the carbon fiber intakes from Evolve that easily surpass the previous scoops and block-off plate technology. My M6 is believed to be the world's first with it and I can tell you it works. Warranties cannot be voided nowadays unilaterally-they must be able to prove damage directly caused by an aftermarket add-on and specifically what.
Bill
 

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There is new and better technology out there now with the carbon fiber intakes from Evolve that easily surpass the previous scoops and block-off plate technology. My M6 is believed to be the world's first with it and I can tell you it works. Warranties cannot be voided nowadays unilaterally-they must be able to prove damage directly caused by an aftermarket add-on and specifically what.
Bill
Freaking Bill lol dude Evolve should have just given you the set.
 

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So all of us that are running BMC filters are damaging our cars?
If they are oiled filters....yes, you're doing more harm than good. Actually, you aren't doing anything good for your car with any oiled filter.

I speak from experience here. I had a 300C SRT8 and had an AFE2 CAI with a large oiled cone filter. After about 30k miles, my car started having idle issues, so I took it to a local shop. They took off the manifold and intake and we saw that they were all gummed up and filthy, as well as a cooked MAF sensor...thus robbing power and causing drivability issues. These expensive mods that do nothing for power and only provide a louder intake noise under full throttle aren't worth the problems they cause.

If you must go with a freer flowing filter (which really doesn't do anything for power), then go with a drop in dry filter. But keep in mind that the "M" engineers didn't skimp on these cars and squeezed every bit of horse power possible they could while maintaining a decent amount of reliability and squeezed an amazing 500 hp out of just a 5 liter NA engine that can top 200 MPH.
 
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