Does anyone on here know whether these are a problem to use in the STi7? Should we be using dry filters instead?

Please don't guess at the answer on this one. Post only if you know for sure.

Cheers chaps

WB @ Xmas

 

i know a few guys in the states have had issues with K&N(same as ITG) filters and over-oiling, if oiled properly you shouldn't have an issue, but if it's dripping with oil i'm not sure i'd run it

 

Wacky,


I run my my01 WRX for 26,000 Miles using an ITG and never had a problem, I was going to fit an ITG to the STi, but have completely forgot about it!

Question is, will it make any difference to a PPP'd STi anyway???

 

Guys,

Thanks. STi Man, don't know, is the short answer. There's a couple of people on here who have now had their Sti7's PPP'd. If you do a search you should find them. Maybe an email to one at random might elicit something.

As I'm hoping to go down the Ecutek/Power Engineering route I suspect that the extra airflow provided by the ITG will be taken into account in the reprogramming, maker for a "better" car all round (that's the theory at least).

 

Fitting ANY different filter to the car will only potentially give you problems. We have never accurately measured any power gains and have seen lots of cars with gradually failing MAF sensors. The first symptom you will get is slightly improved performance as the mixture leans out followed by un-warrantied engine failure.

Regards

Mike

 

Mike,

Thanks. Looks like the original filter is going back in then.

 

mike, i am going to add this info from you to a thread in general on STi7 engine failures.

http://www.scoobynet.co.uk/bbs/threa...=157721&Page=1

 

I would also ONLY fit an OEM filter to my PPP'd STi7.

Edited to say obviously for warranty reasons. It would appear from Mike's comments that if your STi7 engine lets go, and a few already have, then it would appear IM would be quite likely to refuse the warranty claim due to a non standard filter being fitted. Whether that is meritous or not, it's just aggro to have to argue it

[Edited by Dave T-S - 12/19/2002 10:47:44 AM]

 

Has anyone here taken a 01/02 MAF apart? Thought not.

The 99/00 MAF was indeed a fragile part. It was a foil film that sat in the centre of the intake pipe and anything (dust, grit, oil etc) that came down the pipe had a fair chance of hitting it and damaging it.

The 01/02 MAF is a much better part. It has a snorkel type arrangement which samples air from the centre of the intake pipe, turns it through 90 degrees and takes it up a small pipe to the sensor chamber. The sensors are resin encapsulated temperature sensors. There is one that measures air temp and the other calculates an effective wind chill by the amount of air passing up the pipe. The air then goes back down another pipe and returns into the centre of the intake pipe.

It would be extremely unlikely that anything airbourne would make it past the first 90 bend and certainly any airbourne oil would hit the 90 degree bend and fail to make the corner.

On the subject of the MAF on the new cars, Steven Dome pointed out something that is of great concern. As the MAF is part of the air filter box lid, cone filters for the new cars require the MAF to be fitted into the new intake pipe. The diameter of the standard pipe is 66mm. The Blitz cone filter for the 01/02 cars has a 70mm intake pipe. Fitting one of these will result in the MAF seeing 12% less going into the engine with the result that 12% less fuel will be injected. This is very worrying.

There have been plenty of MAF failures on cars using the std paper filter, as I sure Mike would love to tell us, but these have been on the 99/00 design MAF and are almost certainly the result of oil laden recirculated dump valve air contaminting these fragile hot film sensors.

 

Pete

We have

Has anyone yet proved that the airfilter is a restriction to power output? If it's possible to get over 320bhp through the std filter on the later cars and we have yet to see ANY power increase by flowing more air, only by leaning the mixture caused by altering the flow characteristics past the sensor.

The only true way to prove if the filter is restricting flow is to measure depression either side of it.

Mike

 

Pete & Mike,

Grateful for you technical heavyweight guys inputting to this thread. Point is I am no wiser now than when I first started this thread off!

My question is this: granted that there may NOT be any power gains to be had from "non standard" air filters, for those of us who run STi7's, should we, or should we not run oily type filters eg ITG?

Thanks

WB

 

I have argued elsewhere that I think a lot of the gains from exhausts and induction kits are not due to their enhanced flow but due to the combination of overboost, leaning out and advanced ignition from the combination of less exhaust gas restriction (especially combined with inadequate wastegate capacity on VF3x) and MAF under-reads. It is when it goes too far.... Some standard STi 7s audibly det when you put them on the rollers - I just received another report of this.

You can't IMHO, throw mods onto STi 7s like you could the MY99/00.

STi maps have traditionally been MUCH leaner and more advanced than maps for UK cars, and I don't know what is changed in the Type UK map.

I can't prove my assertions as I don't have enough data, and will never have Prodrive quality data, BUT, I would rather work the other way round when modding - test that it is safe rather than fit and forget.

So wacky banana, I am guessing, but guessing on the cautious side. I personally don't think a panel filter is worth bothering with. On the old cars an induction kit once you were over about 280 BHP is worthwhile just because of flow IMHO.

If you compared a car with an ECU remap before/after exhaust/induction I think the gains would be less than some claim if you have the same fuelling/ignition/boost. Slightly more complicated in that removing all the cats allows you to run leaner hence higher EGTs without fear of setting the cat on fire

[Edited by john banks - 12/21/2002 10:52:46 AM]

 

John,

Thanks for that. I had already come to the conclusion that care needs to be taken when modifying the ST17. It's for that reason that I have put up a number of threads over time to get a feel for who has done what out there for the "7", and what the PROVEN results are.

That's why I have not yet jumped on the, eg, Ecutec/MoTec upgrade path, as no one can give me the assurances that I am looking for. I do know that one individual is pleased with their Ecutec/PE conversion but no one yet knows what the long term issues might be (if any).

Anyway I digress. On the basis of sensible risk management it's back to the OEM filter. I am going to struggle to replace the centre cat though, love the noise of the half decat too much!

Contradiction in terms but, hey, choices, choices. Seems a "damaged" MAF, and the potential for serious consequencies, coupled with significant expenditure, means that this risk must be managed more closely than the half decat.

Thanks

 

Sorry to harp on about it continually, but IMHO it is all about detonation/thermal management. My approach is stop the det... and then go bonkers with power , well within reason. But a lot of failures are blamed on other things, whereas det is an ever present possibility that can screw up your pistons, rods more easily than well an easy thing.

[Edited by john banks - 12/21/2002 11:42:35 AM]

 

Mike,

"We have never accurately measured any power gains and have seen lots of cars with gradually failing MAF sensors. The first symptom you will get is slightly improved performance as the mixture leans out followed by un-warrantied engine failure"

If the only change is a replacement "panel filter", and let's assume that it's NOT over oiled, so there are no MAF issues, what would cause the mixture to lean out ?

Mark.

 

Hopefully Mark will be back online in minute to answer R19's question.

I have been out to the car to put back the OEM filter. What I found when I opened the airbox was that the filter sits at a 45% angle to the vertical. As the ITG is oiled some of the oily goo had dripped off the filter and followed the line of gravity down to the base of the airbox. I cleaned this out and put the OEM filter back in.

2 points struck me as I did the reinstall:

- Firstly, if the black switch like thing at the top of the STi7 airbox pipe is the MAF then there is no way dripping oil from eg an ITG would get to it. Question has to be does the engine bay get sufficiently hot, say after a mad dash and the car is left to cool down, to vapourize some of the oil and hence cause contamination to the MAF?

- Secondly the ITG seems to have done a jolly good job of keeping the crud out. Ihave only done 5K in mine since new, however I was surprised by the amount of debris that had collected along the back of the filter. So maybe oily filters aren't so bad after all?

I am not an engineer, I simply give my observations. To those of you in the know, any more to add to this debate?

Thanks

WB

WB

 

Wacky, I don't consider myself "in the know" but ... at full boost, you can suck small mamals into the inlet pipe if you wanted to. So it is easy for a few "drops" to get sucked into the inlet system. I forgot how many litres of air the car uses at max airflow, but the number is quite impressive. If there is enough suction to collaps some aftermarket inlet pipes, there surely is enough for a few drops of oil.

I'm not saying ITG does this or whatever, that's not my point. I'm just saying that it is wise to carefully consider before changing the OEM filter.

 

I use an ITG.
And I don't oil it - I run it dry.

Grant

 

The ITGs foam filters come already treated with a green goo to trap the particles in the air. I would imagine an untreated filter would not filter the air as well.
Leading to potential MAF failure etc etc.

Andy

 

Evil,

Are you serious about the collapse of some after market pipework? If yes then hell, some suction! Anyways I feel easier now the car is back to standard.

 

Somes days ago, I have decided to control and clean the airbox of my STI7 with ITG filter equipped since 12000 km.

As Wacky.Banana, some sticky oily product had dripped off the filter and followed the line of gravity down to the base of the airbox.
The backside of the filter was dirty only in face of the upper aspiration, looking like a dirty grey jelly; apart that all the underside of the filter was pretty clean and this airbox side too for a so big amount of km.
The upper side of the airbox was slighly sticky and it was not a good surprise, so I wass going to look forward 'til the air hose's end. Directly after the airbox, the hose was, surprisingly, not sticky too but a very little amount of dust was present and as my car has 17000 km and no cleaning before, it was clear that the filtration was good (much better than with a previous K&N fitted on my previous WRX).
After a "gentle unmount", a control of the MAF was confirming that it was not sticky but had the same dust as the hose itself. Another "gentle" operation was to clean it with a brake cleaner spray and to dry it with air pistol and moderate air flow. Re-fitting of the parts and all is going as well as before, but cleaner.
The above part of this answer was to describe in what condition you can expect to found the air intake line with this so controversed ITG filter.

Apart that, and if I follow the upper answers, I'm in doubt and even if nothing looks bad, I feel I will go back to the OEM filter...

[Edited by Scooby50WRX - 12/21/2002 7:48:22 PM]

 

Have to be short... Wacky, yes, a samco one IIRC. There are a few threads about it. Hence why people are now welding custom pipes to avoid that, or leaving the OEM one in (hard plastic).

 

Evil,

Cheers. Since I last posted I have decided to err on the side of caution and change the MAF. Might be overkill, unecessary hysteria, call it what you will but the way I see it is this; £70 for a MAF (plus fitting) is a better price option than, say £3K for a blown engine.

Thanks to all contributors to this thread.

WB

 

So, should I put my center cat back in and junk the Nurspec R ?

I thought so long as you left the d/p alone the car would run perfectly happy ?

 

Big goon can you tell me where you junk the Blitz!

 

Deeps, figure of speech

 

Nice one Mike

You are openly slating a product which I have sold in 1000's and which has performed exactly as the graphs on my website (MIRA produced) and has given good reliable, performance to the customers who bought it.

Go ahead and enjoy yourself but be aware that I may one day start talking about the reliability/benefits of some of your products.

I expected better of you.

 

Pete,Ecutek working well.Much better power delivery,mid range punch much better,also revs to the red line much more readily.Glad I kept the car now! Going to have water injection fitted before the next tweak to add some more safety and hopefully a little more power.Have a good Xmas,Deep.

 

Big G,

The way I look at it is this: I'm leaving my centre cat out n my car even though the spiking issues for STi7's are now well documented. Reason for that is that I am working on the basis that the longevity of my engine, in this case, is directly proportional to the judicious application of my right foot! In other words I drive with mechanical sensitivity and don't give the car hell for the sake of it, especially when its very cold like it has been in the last few days. I accept that the logic behind the position I am taking on the decat my be seen by some as flawed, but that's the way it is.

The filter is a different matter altogether. If some oil does drift off these filters and, in some way, can contaminate the MAF in an STi7 (still waiting for a definitive view on this from those in the know on this board) then, no matter what driving precautions I take, I could still get hit with a failure at some point. I'm not saying it will happen, just saying that there is a possibility, hence my decision to revert back to th OEM item.

The bottom line here is for all of us to make our own choices, based on our own analysis and perceptions of the risks associated with any modification applied to our cars. By modification I mean applying anything AT ALL that is not exactly as the manufacturer originally intended it to be.

Please enjoy your Nurspec, as I will enjoy my centre decat and Group N backbox, in spite of John Bank's well intentioned and well understood concerns in this area. I also intend to enjoy my standard OEM filter. Others may take a diferent view but this is what is right for me.

Cheers lad, have a great Xmas.

WB

 

Big Goon
I must have played all the exhaust swopping combinations with the STi7

I ran mine for six months with the standard downpipe, plus Scoobysport decat centre and backbox with no problems. It ran exactly the same boost as Carolyn's standard STi7.

However, I take no responsibility for potential warranty issues etc you may encounter