[bavarianstance]

Curious as to see what folks think about this system. It's been posted before few years ago but it was quickly dismissed likely due to its price...

BMC CRF704/01 air filters+ Carbon air box

Hi Guys, I was wondering if any of you have the BMC CRF704/01 air filter carbon box kit http://www.carbonracingfilter.com/Brand-new-CRF70401_nws_idnws1_21_ita.aspx. I already have their regular air filters CRF605/08 so what power gains should I see changing to them?. Thanks in advance.

www.r8talk.com

I was able to locate one for well below MSRP and am considering it, but it is still quite a bit of coin...

CRF704/01 - Air Intake Systems CRF | BMC AIRFILTERS

The CRF, Carbon Racing Filter, is BMC's new high performance sports air filter designed for road and competition vehicles. It features a 100% carbon fibre support structure with a cotton air filter. The CRF has been designed and produced entirely by the BMC Racing and Advanced Composite...

www.bmcairfilters.com

BMC is a well respected manufacturer and I am a fan, here is the dyno data

I think the fact that they were able to stuff these two gigantic cone filters with venturi effect likely would give some considerable gains, but they claim a 29.1 KW delta in the dyno chart, which is about 39hp.

Even if real world is half that, I'm content with those gains. I already have a drop in K&N filter but looking to squeeze maximum possible out of the engine without going forced induction.

Thoughts?

 

[FoD]

Please…someone who’s a engineer reply. Explain to me how a giant filter will produce more hp/tq/intake CFM when the intake tube and throttle body/maf is still the same diameter. I keep seeing these huge filter CAI pop up and all they are is huge filters. Maybe I’m way off here but I come from the LS world before this. To increase intake volume, we had to increase intake and tb bore. I dunno.

 

[slngshot]

Look at the factory filters.

Consider these those old school Bic pens with the removable ink center..... you get the "pea shooter" plastic core.

With the pea shooter, you blow but it only passes as much air as the core allows.


Now, look at the BMC/whatever oversized example.

Compare that to a toilet paper roll.

Blow the same force as you did with the pea shooter and taahdaah.

MoreFlowBro.
(I hate the word Bro, just did it for effect)



Sent from my SM-G991W using Tapatalk

 

[FoD]

I get all that. My point is if the designing engineer understood your point as fact, why would the stock filters be so constricting? If a filter the size of a traffic cone resulted in 5% power increase they would’ve done it to begin with. Might as well just add a couple badges to the rear for the same gain.

 

[slngshot]

Cars are overengineered, sir.

The example I can provide is the VF engineering supercharger kit that can bolt on and the engine internals can withstand that extra demand without catastrophic failure.

The car is designed to be as fuel efficient (lolwut) and environmentally friendly as the laws require.

That is why there is an aftermarket for every car on the planet.

Sent from my SM-G991W using Tapatalk

 

[FoD]

Your example of forced induction and an air filter are a strange comparison. We’ll agree to disagree that a filter will change the power significantly. Enjoy the placebo.

 

[slngshot]

Imcorrect.

I stated my point.
Cars are over engineered.

They are working at fuel and environmental requirements, not the limits of the design


So placebo air filter (yet dyno results state your placebo accusation are wrong) or supercharger....

It's anyone's choice of how to squeeze more out of their car.

Dyno doesn't lie.

You can decide if your own vehicle needs placebopower

Sent from my SM-G991W using Tapatalk

 

[R8-Stuff]

A lot of these dyno tests are often done on remapped vehicles with other modifications. Very few stand alone filters-only tests.

The stock filters are actually very good - foam and pretty free flowing. They are not easy to clean and designed to be disposable.

Besides cooling the air, the only way to get more volume or greater density of air into the throttle body would be increase the throttle body size or increase the flow rate.

The most effective proven method for increasing the flow rate for the R8 is by using high flow non corrugated intake hoses. Otherwise you are looking at using filters with bigger holes in them - which become pretty useless as “filters”.

To reiterate, the OEM stock filters are good dry filters thay should not be considered as “restrictive”. We have cut them up and looked at them in detail.

Most gauze filters will need to be oiled, which kind of defeats some of the purpose of them. It also risks damaging the MAF sensors.

Have a feeling that these expensive filter solutions are aimed at those are running out of options on what to spend on mods. Just how much better thermal insulation will you get from a carbon fiber box vs plastic?

Also have some serious concerns with the filter heads not being connected directly to the intake tubes into the throttle body. How many owners have opened their air boxes and seen dirt inside the box? These boxes are not perfectly sealed. What happens to this dirt?

 

[slngshot]

The airbox was filled with dust, muck, salt creep and leaves/debris that these came out of.

So yes, that is a very legit concern Osman mentioned.

Sent from my SM-G991W using Tapatalk

 

[bavarianstance]

hmm not sure about the bit about airbox being dirty because the BMC unit filters air coming in before it goes into the box whereas stock the air comes in unfiltered and then gets filtered going into the TB. but other points somewhat valid, I'm skeptical on claimed gains from the dynos

 

[R8-Stuff]

hmm not sure about the bit about airbox being dirty because the BMC unit filters air coming in before it goes into the box whereas stock the air comes in unfiltered and then gets filtered going into the TB. but other points somewhat valid, I'm skeptical on claimed gains from the dynos

This would mean that the filters are filtering from the inside out. Would still not put our trust in this being a perfectly sealed airbox.

So it filters air inside a larger volume airbox where it swirls around and then gets sucked in bare by the engine? No thanks.

So by logic these filters work from the inside out? Which means they will get clogged with dirt from the inside with nowhere for the dirt to go. Which will lead to them clogging up. With normal filters there is air being blown onto the outside of the filter head, some of which will disperse to other areas of the engine bay. Looks like a very bad idea.

And the purpose of the carbon box is? Ah, OK - profit margin. We should start to offer carbon windshield wipers.

Would rather put on some go faster stripes.

We would never offer these to any customer - often asked about them. Just do not have enough faith in the logic of this system.

Our usual response is - spend your money on proven bang for your buck items. Pedalbox for example.

 

[Tim S]

All very interesting which brings up a question. Does anybody offer a bigger throttle body for these cars
These, I believe are 82mm which are as big as I am aware of.

 

[bavarianstance]

All very interesting which brings up a question. Does anybody offer a bigger throttle body for these cars
These, I believe are 82mm which are as big as I am aware of.

yes, somebody posted this before, but nobody dared to take on challenge?

86 mm TB and 86 mm MAF, who dares?

Hi Who has eggs in their pants and converts to larger MAF housings and TB ? A dyno measurement before to after is mandatory. Tom

www.r8talk.com

 

[torqueit]

After running a Skunk2 air filter (which looks like the same basic material shown here) on my TT a few months and removing it to find a fine coating of dirt inside the intake, I've become pretty cautious about what I'm running on the street for a few potential HP. You can really see it about 6 o'clock next to where I did a finger wipe through it.

 

[R8_LuxV10]

yes, somebody posted this before, but nobody dared to take on challenge?

86 mm TB and 86 mm MAF, who dares?

Hi Who has eggs in their pants and converts to larger MAF housings and TB ? A dyno measurement before to after is mandatory. Tom

www.r8talk.com

I would be happy to do that but haven’t seen anyone who has a larger MAF on offer. And without that I assume the exercise of a larger TB or bigger air filters doesn’t make much sense.

 

[speedrs4]

Hi

What is very bad about the BMC box is that the MAF have no funnels.
They don't have a good flow in the MAF.

Tom

 

[R8-Stuff]

Hi

What is very bad about the BMC box is that the MAF have no funnels.
They don't have a good flow in the MAF.

Tom

i think that this box looks crap in all honesty

 

[cgfen]

many people choose to buy aftermarket items because it makes them feel good.
that's cool and fun for all.

the item may or may not be efficacious.
I've never purchased aftermarket air filters with the hope they would increase performance.

 

[Dr_kb]

Look at the factory filters.

Consider these those old school Bic pens with the removable ink center..... you get the "pea shooter" plastic core.

With the pea shooter, you blow but it only passes as much air as the core allows.


Now, look at the BMC/whatever oversized example.

Compare that to a toilet paper roll.

Blow the same force as you did with the pea shooter and taahdaah.

MoreFlowBro.
(I hate the word Bro, just did it for effect)



Sent from my SM-G991W using Tapatalk

Thats not what's happening though.

It like drinking soda through straw

You sucking on the straw is the engine pulling in the air due to the vacuum created on the intake stroke

The straw is most restrictive part, and thats either the valve opening or the throttle body

The filter/airbox is like the size of the cup

Soooo if you get a bigger cup, you can still only drink the same amount through the straw, unless you get a bigger straw (bigger throttle body or valves) or suck harder, or you pressurize the cup (TT or supercharger)

of course there are lots of people who love their big gulps )

 

[speedrs4]

Hi

The BMC filter box is not bad, because it contains very large filters that don't let any dirt through at all.
Cleaning and the missing funnels from the MAF are unfavorable.
The high price prevents it from being bought often.

Tom