I’ve just been debating the whole performance / lifetime air filter vs OE paper issue and I know it’s a question regularly asked - although not as regular as which oil should I used, lol.
Anyway in my search I came across this;
https://www.fastcar.co.uk/tuning/performance-car-air-filter-test/
And thought it was worthy of a share as it wasn’t just a forum thread of various people’s opinions it actually seems to be a reasonable and almost scientific test and review.
I’m still none the wiser though.
Interesting read. Not entirely sure I agree with the conclusion about standard air box not being the way to go.
While calculating the flow is one thing, the engine also heavily depends on other things like heat and particle filtration.
For example, I had a stainless filter (like in that test) on a 20v bora, which took out my MAF.
Also, if you have a big cone filter in the middle of an engine bay with no protection :-X it's also going to suck hot air in and your performance will drop off.
A lot of air boxes (especially modern) have designs to take cold air through ducts being rammed in from the front of the car, ideal for combustion.
I've actually seen a few different videos that have simply bolted different filters to a car strapped to a dyno.
They all suggest a standard box with a performance filter is the right way to go.
Well I'm glad you said that as I have no intention of fitting a cone filter induction kit, but was looking at flat panel direct replacements. My old one came fitted with a flat panel ITG, The ITG ones do look well made. But I later changed it for the Pipercross all foam bottom airbox replacement:
(https://www.heritagepartscentre.com/media/catalog/product/w/c/wc129pk056c_1_1.jpg)
That was on K-jet.
Anyway the current one, Digi, has a standard paper filter fitted, the airbox has a cold feed pipe going into it and it goes in via the back of headlight cover. The pipe routes to the grill. Not sure if it's original or someone's attempt at a mod, but hey-ho.
It's service time and before just going for another paper one I started contemplating the 'lifetime' panel filter options and came up with a mixed bag of options and rumours. I guess maybe it's not such a worry on a stock engine, but even if there's no benefit in performance as long as theres no negative effect then over time there will be a cost saving plus a few less air filters going to land-fill so maybe I'll do it as an environmental statement :))
Not advisable to fit a performance filter on Digi especially if it's an oiled one, can clog up the MAF
I had a K&N panel filter in my 91 digi for years then when I had an issue after a "tuning session that went wrong" I was recomended by a local MK2 specialist to fit a Mann filter because the K&N no longer seated correctly.
It would be interesting to see how much power the engine has..now 170K.
That’s why if I do I’ll be looking at itg or piper as they’re dry foam not oiled cotton