Still Feeling Paranoid About my HKS SRI

[DaleNixon]

The title says it all. I've had my HKS SRI on since early November. I've had no CELs, and the Dashhawk reports AFR's fluctuating around 14.69:1 while cruising/idle and has gone as low as 10:1 at WOT.

I read some criticism of this intake for "bad fuel trims" (with nothing to back that up) as well as some people criticizing the foam filter it comes with does a horrible job of filtering based on a study that's over 6 years old.

So the car SEEMS just fine with the HKS SRI. There is no air straightener before the MAF that I'm aware of, but I've read that the mushroom shape of the intake serves this function.

I don't want to hurt my baby, and the intake seems fine, but peoples' comments do worry me a bit. I plan on changing my wet filter for a dry filter after 5,000 miles then sticking to dry filters from there on out.

I just don't want this intake to wreck my engine with bad fuel trims and/or destroy my turbo with a subpar filter.

Can anyone chime in on the HKS SRI? There isn't much information out there about this intake for our cars. It SEEMS like a fine piece, but I'll switch to Cobb or something similar if someone can tell me that this intake poses a real threat to my engine.

Thanks!

[Circle9]

If it worries you that much, get a CPE or Cobb so you can stop stressing.

[eg6motion]

I wouldn't worry if you can monitor your AFR yourself...
But like stated above, if you can't manage to feel safe running it, then you should get a cobb, cp-e, AEM, or Mazdaspeed intake.

[DaleNixon]

Well I can monitor the AFR, but I'm not exactly positive on what to look for. I'm not positive on what are considered "bad fuel trims". Can any experts chime in?

And yes, I realize I could just switch to a more common for our car intake, but the quality of the HKS is top-notch, I don't have any CELs. I know this doesn't mean there isn't harm being done.

I'm thinking I'll keep the HKS on and check my MAF sensor after the first filter change to see how dirty it may or may not have gotten. I would think that would be a good indicator of how well the filter works.

[AutoXRacer]

You should monitor your LTFT (long term fuel trims)...they should ideally be at 0.0%; most people I think are in the 0.0-4.0% range. Mine are exactly at 0.0% after getting the AEM airflow straightener for my MSCAI and a little tuning. Just setup a screen in your DashHawk that shows STFT (short term fuel trims) and LTFTs...they should be ideally both 0.0% at idle once the car is at operating temperature. The LTFT is basically telling you how much the ECU is having to add/remove fuel to run at target. The number closer to zero is the best. If you are running 7.0-16.0%, then its bad...not bad to where your engine will blow up or anything...never heard of engines blowing due to LTFTs, but its definitely not running ideally.
I hope that helps.

[DaleNixon]

Thanks AutoXRacer. I'll try that when I get off work tonight.

Does anyone have any input on HKS filters sacrificing good filtration for airflow? http://www.mkiv.com/techarticles/filters_test/2/ <--- This is the original test that had me worried, but the conclusion made a lot of sense:


It is questionable how accurate the original source of data is, as HKS are proven to sell more induction kits than any one of the others featured in the test, and yet there induction kit rates as the worst kit in the test. This suggests that either HKS rely upon their brand name to sell their 'poorly' manufactured air filters, or that the original Japanese test was nothing more than a PR stunt to promote the lesser known equipment. HKS and Blitz continue to be the best selling induction kits in the UK, and are used by Middlehursts, Hiteq and Abbey Motorsport as their first choice when the induction kit modification is carried out.

One thing that does stand out is the fact that all the induction kits seem to offer similar performance gains, of around 13 - 14 bhp. This would seem consistant with actual power gains that have been confirmed by using a rolling road.

So the question still stands, "Which Induction Kit is the best?". Well, if you can trust the original source of data, then the clear winner is the Apexi Power Intake. For those of you that are more sceptical, the choice is probably more to do with the cosmetic looks of the induction kit, as the performance gains are very much the same.

[DaleNixon]

I haven't pulled off the filter and checked out inside yet, but it's only been on for less than 1,000 miles. I'm using the wet filter that came with the intake, but I'm planning on switching to their dry filter when that one is used up.

I wonder if this hydroshield would fit over the HKS, and if it would give me even more filtration:

http://siteground207.com/~protegeg/product_info.php?cPath=160_258&products_id=1521

If anyone else on this board has the HKS SRI and would like to chime in, please feel free! I know AAMGuy has one and loves it, but he's only talked about the performance gains. Longevity of the engine/turbo is just as important to me.

[Yamaha72]

Usually foam filters do a much better job of filtering particulate then the K&N style wet or dry filters.. Coming from an off-road application perspective most individuals in harsher climates run a foam filter opposed to a K&N style because it does a way better job doing what its supposed to do; FILTER! While K&N style filters do allow a little more airflow volume the foam will filter smaller particulate. Read this article (quite extensive) and it will explain why.. But in all honesty I wouldn't be worried about it that much, just keep it clean and oiled and you'll be fine..

--http://www.bobistheoilguy.com/airfilter/airtest1.htm

[DaleNixon]

Yamaha72,

I've read the opposite actually. I've read that foam filters aren't as good as the canonical style filters. Of course, this is usually just people shooting their mouths off in forums trying to justify what they've purchased.

[Huligan]

here's where some wiseass will chime in with this gem:

if it aint broke.......................

[DaleNixon]

My dad always told me "If it ain't fixed, don't break it!"

[AllLostThings]

I have read that test before. My ex roommate also had an HKS intake years ago and it sucked in and failed to filter dirt particles which ruined his turbo. He was told this after everything was taken apart. It was an Eclipse GT-S and he had to put a new turbo in it. Now mind you this was YEARS ago and I'm sure HKS has developed since then and the filters are possibly better. Personally though I'm ditch the mushroom filter on the end and get a dry mesh one like Apexi or Fujita or something. Just my two cents.

[DaleNixon]

Do you know if your roommate replaced the filter frequently? I've read running a dirty filter for a good while will pretty much guarantee dirt in the turbo.

I was considering maybe an Apexi filter. Which one would I need to get and how would I mount it on the HKS piping? Also, would AEM's air straightener fit in the HKS piping with the Apexi filter? Thanks.

[AllLostThings]

Honetly I have no idea if he changed it a lot. I'm not sure which Apexi filter you would need to use. When I was looking into getting an HKS and changing the filter out I remember they all were measured by the ID i think. I'm not sure how diffrent they are but te Fujita filter LOOKS just like the Apexi so that may be an easy alternative.

Sorry I can't help more.

[eg6motion]

Usually foam filters do a much better job of filtering particulate then the K&N style wet or dry filters.. Coming from an off-road application perspective most individuals in harsher climates run a foam filter opposed to a K&N style because it does a way better job doing what its supposed to do; FILTER! While K&N style filters do allow a little more airflow volume the foam will filter smaller particulate. Read this article (quite extensive) and it will explain why.. But in all honesty I wouldn't be worried about it that much, just keep it clean and oiled and you'll be fine..

--http://www.bobistheoilguy.com/airfilter/airtest1.htm

that site says foam is just as bad as K&N style...but thats why you would use oil. Most other studies will all agree that foam is the worst...flows well, doesn't filter worth a damn. And generally, offroad filters have 2 parts, foam is the outer part and paper or K&N style on the inner part along with oil.

[DaleNixon]

So I've been on the phone with HKS a couple of times. They tell me that the intake will not harm my turbo (of course they will say this about their own product). They stress that maintenance is the key (you gotta change those filters). The woman I spoke with has a boosted S2000 and an Evo. Of course she's running HKS intakes on both of them.

She told me the bigger threat to the turbo is "oil blow by". Supposedly a catch can install can keep some of that crud out of the turbo. Any truth to this? They are really helpful and reassuring on the phone, but I know they won't badmouth their own products and ultimately it's up to me.

[DaleNixon]

You should monitor your LTFT (long term fuel trims)...they should ideally be at 0.0%; most people I think are in the 0.0-4.0% range. Mine are exactly at 0.0% after getting the AEM airflow straightener for my MSCAI and a little tuning. Just setup a screen in your DashHawk that shows STFT (short term fuel trims) and LTFTs...they should be ideally both 0.0% at idle once the car is at operating temperature. The LTFT is basically telling you how much the ECU is having to add/remove fuel to run at target. The number closer to zero is the best. If you are running 7.0-16.0%, then its bad...not bad to where your engine will blow up or anything...never heard of engines blowing due to LTFTs, but its definitely not running ideally.
I hope that helps.

My LTFT is definitely within 0-4%. The STFT would spike pretty high in either direction, but this was on my commute home with lots of stop and go traffic and some A/C action.

[DaleNixon]

Ok so I think I'm going to ditch the HKS.

Obviously, I want to get the right intake this time! I'm trying to decide between CPE or Cobb.

I'm leaning towards CPE because the filter is dry and the air straightener can't be bent and I haven't read anything about the mounting bracket breaking anything.

HKS just can't tell me anything technical on the phone other than "an intake won't harm your engine". I can't get them to get Mazdaspeed3 specific for me. I don't think HKS USA would know anyway... they seem to be primarily sales. This intake might be perfectly fine, but I'd like a little more assurance that a part as trivial as an SRI won't damage my turbo. It will probably be for sale on here soon!

[eg6motion]

either intake works. The Cobb bracket problem is rare, but you can run it without the bracket anyway...its light weight. I removed the bracket on mine and it moves very little and doesn't sag at all without it.

[MTuning]

and if it does move itll be yanking the maf wires...

[08_MS3_GT]

i've had the hks for several thousand miles and no issues.

it seems to be a well-built piece, and i am not planning on switching to another intake in the near term.

is there any proof that the hks is directly associated with engine problems? and that the Cobb and CP-E units are NOT associated with engine problems?

it's possible that the air straightener can make a difference. that said, if you consider airflow, it might not be necessary to have an air straightener. while the straightener can reduce turbulence and direct the flow more effectively, it is just as possible that HKS designed a unit such that the air flows smoothly past the MAF and doesn't require the air to be conditioned.

[DaleNixon]

I can't find any proof one way or the other. I have read a few accounts of turbos getting wrecked (not on speed3's, but these are still new cars).

I was hoping HKS could defend themselves against some of these claims but all they can tell me is that it won't hurt my turbo if I change filters when needed.

[08_MS3_GT]

hmmm i suppose that a lack of proof either way isn't favorable.

and HKS' lack of comment is one of the reasons why mass-production aftermarket manufacturers can be disappointing.

that being said, i cannot think of a reason why an intake would cause the turbo to fail. can you please elaborate?

[DaleNixon]

The way I understand it, if the filter fails to do its job and allows larger particles into the intake tract, they could end up in the turbo impeller and damage (chip, knock holes through, etc) the blades spinning at 100,000+ RPM.

I'm still open to suggestion as far as keeping this intake, but my current status about it is nervous and ready to switch to something else.

[08_MS3_GT]

understood. i may take some time to research the existing filter and figure out what it can accomplish versus what is required to deliver clean air to the turbo.

that being said, i'm not sure how big the particles would have to be to damage the turbine impeller. has anyone actually had an HKS intake and found that their turbo failed due to impeller damage?

my understanding was that heat was the biggest foe to a turbo. given improper cooling and/or driving aggressively without proper cooldown, it's possible for any number of nasty things to happen given thermal expansion/contraction.

are you considering switching because of the filter, lack of air straightener, or both?

[DaleNixon]

The lack of air straightener doesn't bother me. I've pretty much confirmed with my Dashhawk that the fuel trims are where they need to be.

At this point I'm purely worried about damage to the turbo. If you find anything further on this subject I'd be thrilled if you'd share it here. There really isn't much info out there. I really like the HKS intake and would love to keep it.

Another avenue is to replace the filter with a canonical style and buy the AEM air straightener. I don't know what to buy or how to do it though.

[eg6motion]

and if it does move itll be yanking the maf wires...

haha...have you looked at the intake? The MAF wires have about an extra 10 inches of wire on my car..... Certainly enough wire to make it halfway down the CAI that CP-E makes, as they have the MAF mount in a different location.

[GoFast]

instead of buying a whole other cai wy dont oyu just see if there is another filter that will work with the one you have? probably a lot cheaper.

[DaleNixon]

I love that idea but I'm not sure whether it would fit easily and whether or not I can get an AEM air straightener for that. If someone has done this please share it here!

[GoFast]

as far as the air filter fitting that is just going to be a trial and error process. i would start by figuring out what your piping diameter is and comparing that to what is already out there. That is going to be your most important criteria. the rest of it can be adjusted. if ther eis a filter that has the correct piping diameter but the filter is an inch shorter, thats ok. just take a look at what it takes to make that work. The same goes for the air straightener. figure out what you I.D. piping is and see if that matches aems. but in your case, do you really need the air straighter? i believe you already said your fuel trims are where they need to be.

no matter what, a new filter, air straightener and a little ingenuity will cost a lot less than a new cai or short ram

[DaleNixon]

Well removing the HKS filter would also remove the mushroom shaped part that acts as an air straightener. If someone has done this, and it is fairly simple, I'm up for it. I do wonder if replacing the filter and adding a straightener would be good enough to level out the trims vs. buying something like the Cobb or CP-E that has been tested repeatedly for optimal trims etc.

[FMOS Racing]

There is absolutely no way improper filtration will cause a turbo to fail unless we're talking about GRAVEL or SAND getting past the filter - and I seriously doubt we are.

There are no contact parts in the airstream. Even the journal bearings are not at risk because the airstream is directed away from them.

Your concern for improper filtration should be the long term effect on the cylinder walls. That is where grime in the intake stream causes wear.

[DaleNixon]

Thanks for the info man. I am still learning all of this and appreciate being corrected without getting flamed. I had enough of that shit back in my college days when I was learning to build Linux from source. I will never claim to be an expert any time soon. Honestly I would love to see HKS come in and prove to me that their filters offer great filtration. They just can't seem to tell me anything aside from "an intake won't hurt your engine".

I realize this intake is probably just fine and I am probably being over paranoid. Having said that, I really want to see HKS come out and announce a test or something that makes threads like this look ridiculous.

[Yamaha72]

that site says foam is just as bad as K&N style...but thats why you would use oil. Most other studies will all agree that foam is the worst...flows well, doesn't filter worth a damn. And generally, offroad filters have 2 parts, foam is the outer part and paper or K&N style on the inner part along with oil.

Very, Very wrong.. K&N flows more CFM (air rate) than Foam style filters but lacks in filtering capability, especially dry-style conical filtration systems. I have been involved in Off-Road Racing (ATV GNCC) for several years, Foam filters simply filter out sand and the finer particles a lot better than K&N Style filters. Every individual that I know who runs a K&N down here in FL has to run an Outerwear's pre-filter to keep the fine particles from being sucked up.. My UNI filter Which is a big brand name in off-road filtration, is a dual layered foam filter, no K&N style material, and i've NEVER seen the configuration you mentioned. If you could be so kind and find a link to one I'd be baffled. Think logically, a dual-layer foam filter with foam filter oil (which is super sticky) will filter finer particles better because of the dual-layer and filter oil, you do have to wash them a little more often but I'd rather wash more than worry more... Here's a perfect example my buddy has the same bike as mine same year ('03 Raptor 660) and he runs a K&N style and I run UNI Foam; his motor blew two years ago due to improper filtration and his cylinder walls were all scored up... No Joke Guys.. K&N style filters are great but when you get into the finer stuff especially sandy conditions FOAM is the way to go..

[DaleNixon]

My intake is off and the stock airbox is back on. I looked inside the HKS tubing and I see a few scrapes which could have been caused by particles, or they could have been there all along. I'm really not sure. The filter was on for less than 1000 miles. It was dirty, but not uniformly so.

I saw some dark spots on the INSIDE of the filter, but the intake tract and MAF sensor were pretty much clean.

In any event, I'm going to get myself a CP-E Nano or Cobb with Amsoil filter and try that for a while. I'm not necessarily done with the HKS, but I might be. If so I'm going to try to sell it... I'll link to this thread in the F/S thread if I do!

If anything, this is an experiment for me. Curiously, my LTFT's with HKS were a lot more stable and probably healthier for the engine if not slightly on the lean side. This might just be due to the ECU freaking out about the sudden change in airflow characteristics (yes, I reset it).