Itg or mrc filters ??

[don0301]

They do discounts quite regularly, hopefully will get some before i buy

Still cheaper than the ITG ones I got before

Cheers

Don

[ATinOf]

Holy thread resurrection batman..... BMC filters

Just thought you guys might be interested on this fleabay item - I used pure20 discount code and got a set for 81 squid.
223438284431

There are a couple left available.....

[welwynnick]

I'm wary about aftermarket filters. I've seen a few specs and tests about filter efficiency, and none of them are as good as OEM filters.

A bit more airflow, yes, but that's a valuable engine they're protecting....

Nick

[ATinOf]

I'm wary about aftermarket filters. I've seen a few specs and tests about filter efficiency, and none of them are as good as OEM filters.

A bit more airflow, yes, but that's a valuable engine they're protecting....

Nick

Just my ten penneth; its all relative;
Stands to reason improved airflow is at the cost of microns of dirty air its passing; but that does not necessarily mean its compromising the engine; its still microns

[Brooner]

Ive had performance filters a mixture of ITG and K&N on all 4 of my RS4's each with an average of 6 years ownership and never had any engine issues
I know not the 6 but same rules apply

[welwynnick]

One percent more power in exchange for one percent more dust penetration sounds like a reasonable trade, so I doubt I'll be able to change many minds. However, I think there's a better way of looking at it, by quantifying and comparing what filters do.

Both K&N and BMC filters claim filter efficiencies of about 98% and independent testing broadly concurs. (Paper filters are over 99% efficient, and foam filters are worse.)

https://nicoclub.com/archives/kn-vs-oem-filter.html

The upside of cotton gauze filters is airflow, and this test measured 6.2 inches water pressure drop for the paper filter, and 4.5 inches for the K&N. Other filters fell in-between.
How much is 4.5 inches? Well, one atmosphere is about 400 inches of water, so the K&N can be considered roughly 99% efficient at flowing air. By contrast the paper filter is roughly 98% efficient at flowing air. Does it sound like a good trade so far?

All of this ignores the actual filtering efficiency of paper filters. In the test above, each filter was tested up until they were clogged (flow restriction increased by 10 inches water).
In 60 minutes the AC Filter accumulated 574gms of dirt and passed 0.4gms. After 24 minutes the K&N had accumulated 221gms of dirt and passed 7.0gms. Compared with the paper filters, the K&N passed around ten times the dust in around half the test time. If you normalize the test time, that makes the K&N at least ten or twenty times worse at filtering than paper filters.

Another test here found a very similar result:

https://www.gmtruckcentral.com/articles ... study.html

I haven't been selective with the tests, they were just the first that I came across, but I think they're typical of other filter comparisons. In summary you get around 1% more power in exchange for 1000% more dust getting through to your engine. That doesn't seem like quite such a good trade.

Regards, Nick

[c3nturi0n]

After 3+ weeks of use (with new set of BMC's) I notice that my vehicle seems noticeably more responsive at lower revs. I also do feel that the car is tad more gruntier too.

[huntersmob]

itg's fall apart bmc have lifetime warranty. euro did a good deal for me