Mark Sorry dont want to have a dig but........
As a retailer of unifilters,Please explain why I should use an aftermarket filter that carries more oil in it than an OEM, offers no measurable performance increase and potentially brings my warranty in to question on a very expensive engine. Oh and for the record the engine failure on my old classic STI was attributed to Maf failure so I am perhaps a bit touchy on this subject.
With a decat exhaust you yourself are seeing 1.75bar thats quite high wouldn't you say, have you changed your restrictor diameter to compensate for spiking. I cannot understand how you can be so dismissive of all the discussion here STI's are sensitive to exhaust mods and this is well known as a fact not just talk.
Too many STI7's have gone bang, the Jury is out at this time as to why, but IMHO sorry but only the brave, rich or daft would go outside of PPP and OEM parts at this time.

 

That's Mike

And this is a PERFECT example of the point I was trying to make.

EG.
Please produce independant (or other) data proving that there is no measurable performance gain. Please indicate why your warranty may be compromised by any such filter?

Bear in mind before answering the above, that there that there is a broad wealth of data clearly proving performance gains of such filters.
Also in the case of failures like adair has suffered, (Aarons failed cars were pretty much OEM i believe) there is legislation covering the onus of responsibility to the vehicle manufacturer to prove that the/a replacement part caused the failure, whether that be an exhaust or a filter or ...... you get the picture?

Due to the general way this thread has ran, nobody now trusts anything other than OEM filters (which are also oiled)!
There have been as many (if not more) OEM and PPP'd cars that have failed in almost identical circumstances without ANY unapproved mod's as well.

And understandably so. It doesn't make your suspicions or mistrust any more valid though. I'm answering this query not by way of seeing it as "a dig", but I'm trying to point out how easy it is to leap to conclusions and make assumptions which don't necessarily hold water.

Below is a technical description of how/why (specifically) Unifilter works.
UniFilter uses an open cell foam which is 3% to 5% product and 95% to 97% void space. This open cell structure allows air to be pulled through the foam with 40% to 60% less effort than conventional paper cleaners.

Sticky filter oil then comes into play - UniFilter's "Filter Fix" filter oil is a heavy weight mineral oil mixed with non drying glue agents. (Mineral oil is used in preference to synthetics as mineral oil will not "dry" or effect the cell structure of the foam). This mix of oil is very important for good filtration - as it must be liquid enough to travel and meet the dust as it builds up on the surface of the foam and thick enough so as not to drain from the foam.

The formulation of "Filter Fix" has taken many years to perfect, since 1978 there has been several improvements, on each occasion some two years of field testing has occurred prior to acceptance of that formula - the present formula is simply the best on the market.

So to compare a UniFilter with a conventional paper air filter, as mentioned, far less effort is required to pull air through the filter - giving a performance increase particularly when it comes to fuel saving (better air flow or what should be stated - less vacuum - resulting in smoother running and therefore less fuel being sucked into the system). Dust retention wise, a paper filter is, in fact, a sieve which must have holes large enough to allow air to pass through. That hole size will allow dust particles of 35 to 40 micron to pass - UniFilter's sticky oil catches everything above 4 to 5 micron. Given that engine wear is caused by dust particles larger than 15 micron - UniFilter air filters are way out in front when it comes to dust retention.

No doubt that will raise other queries that I can see already but this post is long enough already without me pre-empting them.

Indeed it is high and restrictors, had I fitted them while the system was on my car, (about 3,000 miles) would have smoothed out those peaks.

Yes, I'm fully aware of how sensitive they are. Usually on the plus side though; please supply me with the paperwork supporting the "fact" you mention above? I'm not being dismissive so much as saying that perhaps people shouldn't be ramming theories down other peoples throats as if they have been 'cut in stone'(if you see what I mean).

In the sense that it is unfortunate maybe, but I see little other than speculation (which constitutes the main drift of this thread) to the causes, and certainly nothing that implies it is as the result of any aftermarket part whether it be an exhaust or a filter or a combination of?

Err, who appointed a Jury.... who are that jury, who is presenting the "evidence"?

Hmm, but the relevant point here is that those PPP and OEM cars have been failing too.

I endeavour to find out and assess impartially where things are bad, speak to various (knowledgeable) people at many levels, I speak to Bob, John and a relatively small list of other "True experts" about this and other matters, in the hope that each one of them has spotted another piece of the jigsaw which could point to the definitive cause of the problem.

The unfortunate thing though is, that without huge resources all that whittles down to just a list of "most likely causes".
From what I can see so far the failures are across the board inthe same way that they were with classic cars, both UK and STi. The book is open and the story is running.


Mike.

 

Mike,

Interesting response. My view is that irrespective of whether the evidence exists that, eg, 3rd party filters are fine, there is an understandable nervousness amongst STi7 owners (and I am one of them) about the robustness of this car's engine.

Granted the reasons why some have "gone bang" may be speculative and not in the public domain. However you must understand that until these causes are known and IM adopt a more consistent approach to warranty claims then I guess STi7 owners are more likely to be cautious and wary about altering their cars from the OEM standard just in case theirs is one of the ones that fails.

What we STi7 owners need are the facts so that we can make informed choices. Sadly I went back to the OEM filter recently because of concerns expressed on this board re oily filters.

Now you may say that was unecessary and hasty but, with the utmost respect, I doubt you would consider footing the bill for a new engine from, say, a customer of yours if IM refused a warranty claim on a blown engine which they might attribute to, say, an oily filter, purchased from your company.

STi7 owners need to be aware of the risks so they can make informed choices. You can't beat us up for playing safe!

WB

 

Sorry about getting your name wrong Mike! Apologies.
Thank you for your detailed response, a lot of which I cannot respond to as I am sure you know, however I would say that it is not up to me to prove anything, I'm only an interested potential customer, its up to you to provide us with a yes or no on warranty issues such as do Subaru (IM) approve the use of your filters.
As for the issue over performance gains,AFAIK on a turbo engine boost pressure and fueling maps along with exhaust characteristics are the major players with respect to performance (by which I mean power and torque)I dont know if you remember but a couple of years ago Power Enginnering tried swapping panel filters on the same car at the same time and doing power runs, the results showed no more than 1 bhp between them. There is a rolling road day coming up at P.E. why not bring your car along and show us the major gains your filter provides I would be interested to see any...!
As far as paperwork supporting the "fact" that STI7's are sensitive to exhaust mods (especially full decat systems) your own post supports what I say! Also do you suggest all the posts and info posted on this BBS on this subject is insignificant , I suspect a few would be surprised by your stance on that

Oh! "Jury" thing.....just a phrase, meaning those, unlike me, who know all the facts and are qualified to indicate what or who is guilty or not for the failures that have occured.

For the record I stand by what I have posted and although you have dissected my post I dont see where you have moved things along here.




[Edited by scoobycar60 - 1/19/2003 5:13:58 PM]

 

Ok.

My point was not that anyone should be "beat up", not at all and if it read that way I apologise.

As for gains, Car people are terrible for measuring stuff.
I'll gladly participate in any "gains" testing with my own car, I conduct that type of stuff routinely for myself anyway.

Remember though end figures from a dyno prove nothing, lets measure the area underneath the torque and or power curves. Let's include time as an element and spool up of the turbo? Some of the gains are feelable but difficult to measure/quantify.


There are items out there which are "dangerous" in their own rights, but I didn't mean to make this either an advert or a dig at any other companies' products.

All I was trying to say earlier was lets not start burning witches, (IYSWIM).


Mike.

 

Fair enough Mike, got to agree with you there!

 

Look boyos.
Since having my new engine I have spanked the living daylights out of my PPP`d car and it has performed faultlessly.
If it breaks agian it go`s back agin.
Thats what the warranty is for.
I personally will only put IM approved bits on my car for that one reason.
But I say again I have spanked the monkey.
I drive it flat out all the time just like I did in my P1 and it seems fine.
The engine on the P1 was the only thing that didnt **** up mind you.
If I had an import then I would have an ECU-TEK map jobby done straight away and thats it.
Sorted.
Nuff said.
Bo selecta

 

Look boyos.
Since having my new engine I have spanked the living daylights out of my PPP`d car and it has performed faultlessly.
If it breaks agian it go`s back agin.
Thats what the warranty is for.
I personally will only put IM approved bits on my car for that one reason.
But I say again I have spanked the monkey.
I drive it flat out all the time just like I did in my P1 and it seems fine.
The engine on the P1 was the only thing that didnt **** up mind you.
If I had an import then I would have an ECU-TEK map jobby done straight away and thats it.
Sorted.
Nuff said.
Bo selecta

 

LOL@Arron. Poor car.

Anyway, i was bored so i went to the garage, fished out my old air filter i swapped out 2 weeks ago and took some tin snips to it. This is a genuine STi item part number ST165464S000 mike at scoobymania imported for me.

MAF facing side

Air inlet side

Compressed fibre backing

fluffy fibre side

side view of the various layers of fibre

Thin foam layer


The filter is not paper, it is a series of layers of synthetic fibres that are compressed together, the further in to the fibre layers, the more compressed it becimes until it's almost a solid. It has a thin foam layer between the fibre consertina and the aluminium mesh that sandwhiches it all. The whole asembly has a thin steel frame that is rubber bonded. The rubber acts as the dust seal for around the edges. There is no oil in the fibres or on the foam, it's bone dry. The MAF housing is also bone dry and clean.

I tried a UK spec paper filter in my STi in the time between me seeing how knakered my original filter was and getting the ones mike imported for me, that killed engine performance masively above 6500rpm. The car felt strangled. Installing a genuine STi filter gave me all the performance back, so i am not surprised you will see gains in peforance changing from a paper filter to an aftermarket jobie, but STi filters are not paper and are free flowing enough to allow the engine to rev cleanly to 8200rpm.

 

Thanks for your effort John, nothing like real physical evidence to prove a point! (No bull here!)

Mike, it sounds like you could do well promoting the STI spec filters for imports, as things are, I am sure many would go this route as a safe and efficient option right now, irrespective within reason of the cost. (I know I would if I were running an import).

 

LOL @ Arron

And you wonder why you're on your 3rd (right?) car

Maybe IM will say you haven't run it in according to the manufacturers guidlines and that your warranty's fubar'd

Stefan

 

I had on my old MY99 MAF sensor go wilst feathering the trottle close to Rev limit around a corner
I did find some slight staining on the MAF side of my air filter So I can only surmise that the ReCirc Dump valve got either got confused or stuck causing a blowback into induction pipe.

Tony
Ps.
With PPP and extremly happy and with warrentee and agree with Arron if I had an import MilTek and EcuTek

 

Ozzy.
I did run it in mate just not a 1000 miles under 4000 revs and the usual service then think its ok to thrash the t1ts off it.
I work on the gradual build up method
Did at least 600 miles before anywhere near the red

 

John you really do need to get out more.
Oh and it appears that God taketh hair away from your head and placeth it on your hands

 

hahaha

Your the second person to comment on that from those pictures. At least my palms aren't hairy.

 

I thought those were just wrinkles on John's hands

The words "Dog Soldiers" spring to mind

Stefan

 

I'm ditching the MAF in pursuit of power anyway (which you can't do with the ecutek method), our exhaust system for the STi is made (under license) by Miltek, as it always has been.

GEMS ECU with VVC mapping is due any day, results will be posted as soon after, as mapping results allow.


Mike.
Scooby Mania

[Edited by Mike Tuckwood - 1/20/2003 12:34:00 PM]

 

How much are the STI filters? and can you get them for a 97my uk turbo as I have noticed more restriction further up the rev range since I have taken off the k&n 57i kit due to this and other threads like it.

Cheers

 

I think people are missing a rather important point. The phase one engines use a diferent MAF sensor to the Phase two engine as fitted to the STi5/MY99 onwards.

Phase one MAF's have a self clean routine on startup which burns the oil off the hot wire element, so they can cope pretty well with light oil contamination. Obviously if it's dripping in the stuff then its going to fail, but normal filters that arent over oiled will be OK.

Phase two MAF's use a hot film, which doesnt have the same self cleaning system, this is what you should avoid using an oiled filter with if you want to be safer with regards to MAF sensor failure.

 

John, its also worth noting that the 01/02 cars have a completely different MAF again.

Apart from a much better designed air sample intake, it has neither hot wire nor hot film sensing.

 

Oh gawd, so what is it they are using then? Any techie info?

 

Could you still give me a price John as I seem to like the original air filter at the mo as it seems to pick up at speed a bit quicker (could be my imagination)and it does seem to be a bit weasier at 6000 rpm plus

Cheers.

 

Mike,I presume you are talking about the Gems. 'ditching the MAF in pursuit of power,almost ready'.This has been 'almost ' ready for six months,I hope you are'nt holding your breath.

 

Hehe, oddly enough.... no I'm not.

It's completed bench dyno testing and is now running on a "mule" road car, further progress and availability still has no 'published' release date, it will simply be released when they're happy with it.

Soon as I know, I'll let you know.

Mike.

 

Pete, its got to be a hot something (or are we not allowed to ask) Lol

Bob

 

Hmmmm. I am currently contemplating putting the original STi exhaust back on my STi7. The Subaru dealers aftermarket partner assures me the car has been checked for overboost and lean running and there are no problems. The system is mostly 2.5" which seems to cause less issues than a 3" system. Supposedly there have been no problems/failures and some also have other mods with over 300BHP. I dont like the performance with the original exhaust because the car becomes very bad off boost.

What caused these cars to go bang, there must be a reason? It seems that det was the cause. On Arrons car it appears to be 95RON (although here 95RON is the minimum as per Subaru South Africa but we are at 1600m above sea level)? On adair69s car possible MAF contamination and/or the decat exhaust. Was this car checked for overboost and/or running lean?

So is a Knocklink essential for an STi with a full decat? The only other option is to go back to the standard exhaust? We have had no problems with blown STis here other than one but this car was heavily modded with NOS etc etc.

 

LOL at Bob

OK, I'll take one apart and post some pictures up in a minute.

 

This is a cross section. Air enters through the left hand side and goes up a pipe into a plenum at the top. From the plenum it decends back down past two hot sensors (just to keep Bob happy ). The actual amount of air that gets sampled is quite small and is equivalent to the size of the 45 degree bevel around the centre hole. This bevel acts as a trap for any dust (and oil?). As the sensors are in the exhaust from the plenum, the air has travelled through 3 90 degree turns and a plenum, through which it will travel more slowly, before it gets to the sensors. It would be almost impossible to contaminate these.



This is the intake side. The blob at the side is the intake air temperature sensor.


Looking down the exhaust side, you can just see the sensors.


Overall view.

 

Oh, and as for cleanliness, this particular one has been running with an ITG for 44,000 miles

 

bloody hell pete! Couldnt you have made them any bigger?

Interesting design, looks like they learned a few lessons from the last MAF design!