macswrx

hi, got myself a gt spec2 fmic, its going to be fitted to a v6 impreza, looking for opinions on whats the better option on what to replace the standard airbox with ?. kinda looking for something thats a reliable set up regardless of cost. many thanks in advance

just123

iTrader: (1)

I've just fitted a Hybrid GT2 fmic from Harvey on my UK MY99, i looked into the induction side of things in depth and all the professional advice was go for a K+N kit so thats what i went for £100 from Roger Clark motorsport avoid ebay in case of cheap fakes

gc8-r

iTrader: (21)

the best one is the apex'i one...
as some k+n's are oil based,which will play up your maf...

macswrx

thats the opinion that ive been hearing most about, oil based ones affecting the maf, cheers lads , anymore views anyone ?

just123

iTrader: (1)

Dry foam filters can let tiny particles through, the K+N has a tiny coating of oil thats how it works it will not affect the maf

macswrx

anymore opinions on this lads ?

Aarts

iTrader: (1)

check the airbox:
https://www.scoobynet.com/members-ga...ations-14.html

you can make it or let someone to make
and use AEM dryflow , easy to clean.

53

iTrader: (41)

+1

harvey

iTrader: (48)

GC8-R: You are correct in that the K+N is lightly oiled but there is absolutely no truth in the Scooby myth that the K+N will screw your MAF sensor because of oil on the element. The K+N from the factory is very lightly oiled and it does NOT cause any issues with MAF sensors. When the filter is dirty it can be cleaned and reoiled. I guess if you are stupid and apply too much oil then it could cause a problem with 99/00 MAFs but you would have to be pretty stupid to oil the filter to that extent.
I have been using oiled K+N filters on Subarus over the last 9 years, 16v Vauxhalls and a variety of Jaguar engines before that. I am yet to find a single MAF that has failed because of oil from the K+N filter as supplied by K+N. This really is just another Scooby myth that gains credence because people repeat it without indepth knowledge.

53

iTrader: (41)

And go large

harvey

iTrader: (48)

That is a very good photo and a neat installation. I am sure it will help others to see what you have done. Why not post it here.

https://www.scoobynet.com/trader-ann...rid-fmics.html

scooby1doo1

iTrader: (7)

I have a book mark on the laptop at home, apexi's the best on the test that was done.
If you would like me to post this test up the feel free to ask. But the K&N was far from good, along with the like of top brands.

53

iTrader: (41)

JDM_Stig

iTrader: (3)

I agree but think that sometimes the vibrations from poorly fitted inductions kits is where that myth is based.

joz8968

iTrader: (13)

+1

A lot of info - and associated links - here re. the myth:-

K&N Response to Mass Air Flow Sensor Concerns

But obviously K&N may be biased, as they're hardly going to admit to it (seeing as they did the tests!)

scooby1doo1

iTrader: (7)

Here you go

http://www.mkiv.com/techarticles/filters_test/2/

macswrx

some very interesting posts made lads, i for one hold my hands up and say that over time i have read about maf issues when using oily filters but would agree now with jdm stig on it more than likely down to poor fitting and on other posts down to over use of oil on filter maybe, 53 wrx thats a fine example of a good looking induction kit fitted like it was already made with the car, the general opinion over here is the apexi kit which looks a good kit for the money so leaning strongly towards that now, thanks very much to everyone for their opinions,
cheers.

TonyBurns

iTrader: (3)

Unless you bolt down your induction kit to reduce the vibration to the bear minimum you will have issues with the pretty (very) sensitive MAF sensors fitted to the MY99/00 cars
Also your gains will be minimum unless your going for big power (which isnt really an option on a classic engine unless you go for a rebuild as the rods suck on them all as they are the same across the range of uk/wrx/sti classic 2ltr's) so its take your chances really, but these maf's are not exactly expensive though there are a fair few people who have gone through them in a few months, it just depends what you want?

Tony

joz8968

iTrader: (13)

JGM mapped one of those Apexi Power Intake filters to about 401bhp IIRC - I don't think they have sufficient CFM to flow much more air and achieving higher bhp than that. So if, ultimately, you want more power than that either now or in the future, then the mantra is to fit the biggest possible filter in the available space.

I have exactly the same large K&N cone/alloy trumpet as in 53WRX's setup for that very reason! (yet to be fitted with 740s/FMIC/remap - damn! lol).

macswrx

been doing a bit more research and have decided to do away with the maf issue altogether by going with simtek instead of ecutek, reckon either the apexi kit or k&n kit will suffice for the set up which im planning on which is vf35 turbo , fuelpump, fuelreg, replace up pipe and full decat exhaust, lightweight pulley set.and few more bits and bobs, and of course the fmic and induction kit, not looking for mad power from it, have heard a good 320 / 320 classic impreza is nice for use as a good fast everyday car which is what im looking for from this set up really.car is standard 210 or 220 bhp now so be a nice jump in figures i hope,


cheers lads

joz8968

iTrader: (13)

Yeah, the VF35 is a sub-350bhp turbo (should easily get 320) - so yeah, that Apexi filter should be fine.

Good move to get Simtek and go MAFless.

macswrx

cheers lads, some excellent advice i got from here as always , many many thanks

harvey

iTrader: (48)

Scooby1doo1: I don't doubt the Apexi is a good filter but they do not have the range of filter shapes and sizes that K+N provide and they don't have a technical department that I can access for information and advice.
A few years ago I conducted tests on the OE Subaru panel filter, K+N, HKS and STi.
The results were not what I expected so much so that I repeated the tests the following afternoon with exactly the same results.
The difference between the best and worst filter in terms of power was 1.7 bhp.
The filter that passed most air was the HKS foam followed by the OE Subaru and K+N panel which were equal trailed by the STi filter. We are talking about a difference of 1.7 bhp.
Subsequently I did tests to determine the filtration ability and not surprisingly the STi filter gave the best filtration. Filtration from the K+N and OE Subaru were good. Filtration from the HKS foam was very disappointing and although this had been the filter normally run on the car in question it was immediately changed in favour of a K+N.
There is nothing wrong with the OE filter but it has to be thrown away at regular intervals. 5-10,000 miles. If it is a car I am keeping I go with the K+N which can be cleaned and oiled as required.
At the same time I did experiments with and without the inner wing snorkel. Removing the inner wing snorkel and doing nothing else dropped power output by 7 bhp. At the time I did not have the facility to put in a link pipe as a delete for the snorkel and no effort was made to remap the car but the conclusion I came to was that the air was so disrupted past the MAF sensor when run without the snorkel that a power loss was inevitable.

scooby1doo1

iTrader: (7)

Harvey i under stand about limited size in the apexi's but plenty of peeps on here are using them up to 400 bhp, as joz states.

But the link i posted shows the apexi's filtration to be better then the rest and a filter should filter, the OP having a V6 classic maf probs and all and wanted a reliable set up, Zero Maintenance Lifetime Use Hence the link, but if he wants more then 400bhp then i would say K&N, if he dont well it's up to him just my 2p worth, and want to give op all options, not just K&N.