Performance filter for 2003 STR??
 

Hi all

I'm trying to find a performance air filter for my 2003 STR. ive made the mistake of buying a 2002 one a few month agon not realising they were different.Seems to be loads for the 2002 but nope for an 03? So I'm on the hunt for another.

I've found K&N do one for a 4.2 litre 2003 but it doesn't say the R? Are they the same air box?

If any ones got a performance filter in their 03 R I'd be really grateful for a pointer

Cheers!

Hi Greg, and welcome to the "S" forum. I have an 03 S-Type R, and Yes, the airbox and filter are the same for the V-8 "S". Go to your favorite auto parts store and order a K&N air filter for an 03 S-Type R (4.2 litre V-8 supercharged) $49 and will come next day instead of 3-6 days plus shipping for an internet order.

And make absolutely sure that you know how to properly maintain an oiled filter. The throttle bodies on these cars are extremely sensitive and prone to issues if anything foreign gets in....

I'm not saying to not do it. I've used both K&N and AEM products in the past with positive results. I know that early on with my AEM intake system I was over oiling and had to clean a bunch of stuff on my Honda's intake. Lucky for me, the components were serviceable.

k&n is the way to go. Once Luigi gets his intake tube out to us it will be even better!

Josworth is on the money. The K&N comes properly oiled (not over oiled). Average Joes tend to over oil em = oil on MAFS.

And be aware that there are NO filters on the market that will give any measurable boost in 'performance'. This includes the K&N.

Oh, Mikey?

+1

There are very clear and known risks in using a K&N (not just oiling but also interfering with MAF reading of air flow) but remarkably little (that's English for "no") trustworthy data to show there's any problem with the STR's intake being restricted by the stock filter (if clean).

But, fit at your own risk :)

And that's the key point. If the stock system remarkably has little (that's English for "no"):icon_wink: tangible losses then an aftermarket filter has nothing to 'regain'.

Why do so many people believe that the OEM design team would have left HP 'on the table' that could be instantly recovered by the simple substitution of an inexpensive air filter element? Please guys..........

Perhaps because the K&N design is proprietary, created at some point after recognizing that automobile manufacturers are not necessarily utilizing, in many cases, the most efficient filters (to save money?)...and the same manufacturers are not necessarily keen (today) to violate patent laws in retrofitting a more efficient design like that of K&N to their future cars.

hahaha, that's so funny!!

Because it's human nature (often illogical) to want to install all kinds of easy to fit, not terribly expensive "upgrades" in the hope that they will give them an edge over the other guys car. Just look at all the crap on the market. I'm not making a statement about the K&N. I have one on my 454 K2500 Suburban and it went from being able to pull 10K pounds to 25K pounds overnight ...

One time in a Walmart this new-to-this-country Mexican couple were burning their re-fried beans over which oil and additive to use. Slick 50 and Royal Purple were gettin' All their attention. So I asked them what they were driving and it's condition. A 175K mile Camry. I handed them the Wal Mart brand oil and told them to save the money for food & liquor.

Yep, it's the old adage of "buyer beware". Some products can truly be beneficial if used properly (Chevron's Techron fuel injection cleaner). Some products are essentially snake oil (Slick 50). As for K&N oiled air filter systems, I just don't think they are worth the risk to the pesky (and costly) sensors that live downstream....

We see real gains from other mods (for example, exhaust). Wouldn't the "why would manufacturers leave HP on the table" apply there as well? Yet, in the case of exhaust (and others), this is in fact the case. I have not found anything to suggest filters are any different, in terms of probability that the OEM filters are not the best option. The relative 'cheapness' of a filter does not exclude it from 'leaving HP on the table', especially considering that this car appears to be infamous for being detuned for tameness.

Please let's not start this whole thread again.

Most of you are forgetting a very simple fact. OEM air boxes are designed and built to give good performance while keeping underhood noise down. K&N filters are designed for maximum airflow - noise be damned.

I have built a great many cars in my time, with dyno pulls, and have always seen an improvement when I moved away from the stock setup and took care to isolate the heat given off by the engine.

The same is true, as Phil says, for the exhaust system. Tuned for performance and silence, performance gains can be had when migrating to a system designed more for performance.

If you want to install a K&N filter do so! I have done a series of product inquiries to identify fact and fiction about Oil treated filters (K&N) and found many myths. To say it is a placebo is an inaccurate statement and to say it causes a problem is also inaccurate and unfair to all who use it and those who want to. I have two cars with K&N installed a Rav4 with 265,000 miles and a XK8 with 119,000 miles and neither one has a problem and do not use oil. You are entitled to your opinion and I would not have it any other way but please note there is nothing wrong with the filters.

Gus - but does it measurably improve performance as the OP asked? Please post the figures for the STR if so. I've seen one set of figures only and the poster admitted the stock filter was dirty so they were useless.

Note that there have been posts where removing the K&N and fitting a stock filter fixed problems. I don't say you have any problems, just that others have had.

I had seen that post you are speaking of and I am not supporting that post I am saying that a lot of information about the filter is at time a misconception on both sides. As for the figures on the STR I do not own one to make a comparison and quite frankly do not wish to do so. I am not trying to prove anything other than if it is what you want (the filter) go for it you will see no harm if installed and maintained properly. If it makes you feel good, go for it!