Datsun Roadster Forum-311s.org

Was wondering about that! You don't give up much with shorties, but do run some stack as air hates sharp corners. If you already have the filter, personally I would get a set of short stacks and run that filter set up.

I use the ITG filter and use short stacks.

If you run the beautiful, lovely, ultra deluxe beautiful air filter, you can run 50mm stacks! (Just sayin)

With the ITG, you can run 50mm stacks as well. Plus it will breathe better.

Will

Yep both systems work great, and I would have mentioned JT68'S set up except that the owner already has the ITS. The other option would be foam socks, similar to the RamAire ones I currently run, but it is best to have nothing touching or shrouding the stacks.

The K&N filter shown on the aluminum filter assembly is good to 4L. For any non turbo street 2L there would be ZERO realizable performance advantage from the budget foam element ITG. The aesthetics are on a whole different level.

JT68 wrote:If you run the beautiful, lovely, ultra deluxe beautiful air filter, you can run 50mm stacks! (Just sayin)

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i would love to get the solex filter, but hard to find and $$$.

Oh but you see, JT68 has already recreated them, and improved them. They are truly a wonderful piece, and a terrific option for many reasons. They did not exist in a fashion that I liked 30 years ago, so I have been down many roads (KnN style filters, cold air boxes, foam socks, etc). If I were starting from zero, JT68's would be a very strong candidate. Who knows, might may just end up there in the long run.

Yeah maybe.. I do like the classic look. plus my 2000 has a more hotrod feel to it with all the matte black trim.

Thanks Greg! My original post was kind of tongue in cheek since thise were the reproductions shown with both a custom K&N element and stock. I realize it is not a cheap setup, but great stuff usually isn't and there is no way for you to make one for less than the asking price.

You can even run two stock elements, and our friend-down-under Lou has proven it is a great performer on the dyno.

I'll start another thread for a possible option in between the budget filters and the more expensive OEM reproduction. If enough people like it, Ill do a small run on it. Jt

JT68 wrote:The K&N filter shown on the aluminum filter assembly is good to 4L. For any non turbo street 2L there would be ZERO realizable performance advantage from the budget foam element ITG. The aesthetics are on a whole different level.

Only solid filtering of the air being sucked through the carbs, more airflow, and the ability to use the correct length stacks. ITG filters are hardly "budget". They are the best filtering, yet high flow filters I've found to date. There is a reason WRC uses them. Yes there are imposters that are cheap, but real ITGs are worth every penny. I've seen the amount of fine material that washes out of my ITG and its mind blowing. I've never seen any other reuseable filter capture that much fine particulate material. I'm not the only person who says this.

Will

Will you must have read that on the Internet. It must be true! I'll be polite and objective:

If you hate the 67.5 factory aluminum filter, think it's ugly, too expensive, too original looking, too sexy, too shiny, too aluminum, too whatever, that's all totally cool, everyone is entitled to their opinion.

But don't make up nonsense, based on Internet hearsay, that the ITG is a better quality filter than the K&N on any level. It just isn't. Thousands and thousands and thousands of engines run K&N- they are top quality.

Personally, I don't like foam filters otherwise I would build and use them. I consider them a cheap alternative.
Talk with the engineers at K&N if it is your quest to understand why.

Quoting what "other people say" is as meaningful as me saying "thousands of people think Kia makes the best cars in the world". Im sure there are, but that's also wrong. If it is about popularity, for everyone who uses ITG, I can find 5 who prefer K&N.

My real world, impartial, useful and practical point is that neither the K&N nor the ITG is going to be the limiting factor on any normally aspirated street u20.

Any theoretical benefit based on an imaginary increase in flow, is academic, and about as accurate and meaningful as your butt dyno.

Additionally, when you understand how an internal combustion engine works, you understand that only one bore of the Mikunis reaches peak air velocity at any instant. The other three are not moving all that much air at that instant in time.

Do you really think that the massive surface area of the K&N can't keep up with one barrel of a 44 at any particular instant? If so, you might want to consider some engineering and math courses at your local college and less internet based learning.

If you want honest, correct and impartial information: the reality is neither the ITG or the K&N is going to rob your engine of power.

Pick whichever you prefer, can afford , etc, but don't believe any noise that the foamy filter is way, way better than a K&N. It's just wrong.

Our friend down under, Lou has proven on the dyno that the factory designed filter housing is an excellent setup on many occasions! The rest is noise.

Anyone want to buy a Kia? I hear people say it is the best car in the world! Peace jt

I've had enough mechanics who also race their own cars say K&N filters are garbage and ITGs are the superior product I don't give a crap about your claim. I get it, you are trying to market a product. I ran brand new K&N filters before I got the ITG and after a year of driving I cleaned them out, and essentially nothing came out but my velocity stacks had an oily grit all over them as well as in them. Nothing more than slightly dark with an oily sheen to the water came out when washed. When I cleaned my ITG out for the first time, it filled the bottom of my sink with a very fine layer of dirt. The Velocity stacks are always clean and spotless. Lets think about this, the K&N were essentially clean when I cleaned them after 10K miles but inside the filters was dirty, the ITG covered the bottom of my sink with dirt and the velocity stacks were spotless. Clearly, one was trapping dirt, the other wasn't. If you want to sell a lesser product, have at it, but I've learned first hand that it is a lesser product and I'm going to run that which filters better. Will a K&N filter flow more air? It might, but at the expense of the engine. Sure, the stock air filter housing looks great, but the stock filters don't flow well, are hard to find, and the K&Ns don't filter at all. The ITGs filter well, flow well, and don't look stock. I'm fine with that. Sure the stock housing flows fine. Its a very well designed part, like most of the U20. I'm not going to argue that. I wish I had one, with the paper filter that I could throw on the car from time to time. Am I going to run out and buy one? Nope. I've got better things to spend my $ on, like a weekend racing, or tires to do so.

I'll give you one thing, you are great at marketing your product, but I've run both, and I know first hand which flows well and filters better. If its good enough for Formula 1, WRC, BTCC, and several 24 hrs of LeMans teams, its good enough for me. Will an ITG filter last 1 million miles? Nope, it wasn't meant to. Will an engine running a K&N filter run 1 million miles? Nope. Do the ITGs start to break down after 5 years or so? Yes, so you buy a new one. Its a consumable item.

I'm not trying to start anything here, people can buy what they want. I'm simply saying that calling the ITG a lesser filter is a load of horse manure. I've run both, I've discarded one and will never go back. Simple as that.

Will

Unfortunately, again more speculation based on hearsay and presented as fact.

One thing that is certainly correct is that the foam element will degrade over time, and as it does, it will be sucked into your engine. When this happens not only does the foam particle go through the engine, anything that it trapped does as well. That's actual physics and why I don't like foamy filters.

I have thrown away all foam filters, and don't care for them.

Your assertion "plus it will breathe better" , is where the misleading speculation came in to this thread. Then you said the K&N may breathe better, but it doesn't filter as well??? The engineers at K&N would beg to differ and have proven it by careful engineering and testing. They build a great product.

On a real u20, in the real world, all things being equal, there will be no performance difference between the two, so I'm not making any marketing claim here at all, other than perhaps the original aluminum design looks far better on a vintage roadster in my opinion.

The ITG is the cheaper (budget) option, (again a fact), so if that is what you are after, thats ok too.

But don't bash the entire K&N product line, based on comments from whomever, when in fact it filters extremely effectively, with very high flow.

Sloroadster has concluded that K&N filters are all inferior so it must be true, like everything else on the internet.

Somebody should notify K&N right away.

Hearsay or not. I'm simply reporting my observations after 16 years of roadster ownership where I have tried a ton of parts, some have worked, some have not. The K&Ns did not. The ITG did. At $150 a pop, they are not a budget part. I base my thoughts on real world use, not what I read online. I talk to people who make a living making cars go fast, and do so reliably. When zero of them say a K&N filter is the way to go, perhaps the part might not be up to par (as I learned first hand.)

Yes, when the ITGs start to degrade, foam could be sucked through the engine. That said, they degrade from the outside in, so, when the outside starts to die, you buy a new one, before the inside does. (Its also a good idea to pull the filter off and inspect the inside to make sure the inside isn't coming apart.) I'm on my second ITG and after 7 years, its time for a replacement. The outside is starting to degrade, but the inside is not.

Its not just my roadster that I have found how poorly a K&N actually filters, I had the issue on my Alfa GTV, and I've seen the oily, gritty residue on other cars I've worked on that have run K&Ns reinforcing the fact that they flow air well at the expense of filtration. An ITG has more surface area since the filter is 180 degrees of coverage and air can flow through that entire space rather than just a 90 degree angle to the velocity stack. The fastest guys I know run ITGs, they also build their own engines and have been doing so for decades. When they have a choice to run an ITG or a K&N, and they chose the ITG, there is likely a very good reason, and its not because of cost.

If someone wants to run an K&N, go for it. There will never be one found on any of my engines however.

Will