Was the Solex 44PHH Type S5 ever used on Roadsters?

[JT68]

That's all fine Will, you obviously have convinced yourself. I'm sure the ITG will shave 1/1000's of seconds off your lap times.
You just can't put this stuff out there and expect people to take you seriously.

It's really funny that you think you understand more about air filter design, filtration, and air flow than K&N. To be polite, some of your comments just indicate a lack of understanding of how air flows in the housing.

I don't think K&N will be too concerned about your opinion since all the major car manufacturers allow the use of K&N filters without affecting factory warranty. If there was really any significant filtration issue, I think there would be major failures by now affecting 10's of thousands of vehicle.

This is no skin off my nose, I could just as easily make a ITG foam element for the reproduction aluminum filter as the K&N!

Everyone let me know (pm) what type you prefer, and I will build to your preference!

[harrison]

Got my fuel lines all mocked up with a pressure gauge and cutoff valve. Should be removing to old craptastic exhaust tomorrow.

[spyder]

Oil filters use a coalescing action to trap contaminates. I have not examined the physical differences between the K & N filter and the ITG, but the ITG oil is very sticky and has it's own soap to clean it. This I think is the difference in the dirt capturing ability. I suspect they flow similarly.

[JT68]

Correct, K&N also recommends their own oil and cleaners. They also state improper cleaning will damage the element. (See the website).

All of us have seen material get past a filter.----typically it isn't going through the element, Its working its way in around the perimeter. If it got trapped in residual oil, that is a good thing.

You just really shouldn't just bash a fine company's product with annecdotal claims and racer folklore. That's about as scientific and accurate as fisherman's tales.

Where's the filtration data?

The real way to assess flltering capability is under controlled test conditions with a properly designed test method, flow rates, particulate etc. What happened to Julio's motor on track day has little bearing on the product overall, but K&N has spent 100's of thousands of peso's in testing their elements.

Would be just like me saying " i ran Mobil 1 and my engine blew up" and my lawn guy Bubba'a lawn tractor threw a rod, and he said he was runnin Mobil 1 too! I just use valvoline now, i'll never use Mobil 1 in any of my engines! " ...not very likely it was the Mobil 1.....just like the K&N, 10's of thousands of engines are running M1 with zero issues.

If one doesn't test scientifically, the conclusions aren't supported. That's how car forums get filled up with myth and incorrect information.

The statement " the guys that go fast use ITG" is basically equivalent to "the fisherman that catch the trophy fish use
Zebco".........not exactly based in fact. I'm sure there are plenty of guys that still go slow and also use ITG.

JMHO, your mileage may vary. j

[Solex68]

They are both great solutions.

I like the look of the factory Solex and JT's air-box, but I have similar experience to Will and gotten less particles and less restriction with the ITG setup. With that said, my experience was using the non restrictive Solex air-box (early?) with the Mercedes Benz 190 K&Ns and not JT's improved K&Ns which have more surface area then the 190s version.

Honestly, either choice you make is a great choice. I have never been disappointed with a JT product that I have seen or purchased.

[SLOroadster]

That's all fine Will, you obviously have convinced yourself. I'm sure the ITG will shave 1/1000's of seconds off your lap times.
You just can't put this stuff out there and expect people to take you seriously.

It's really funny that you think you understand more about air filter design, filtration, and air flow than K&N. To be polite, some of your comments just indicate a lack of understanding of how air flows in the housing.

I don't think K&N will be too concerned about your opinion since all the major car manufacturers allow the use of K&N filters without affecting factory warranty. If there was really any significant filtration issue, I think there would be major failures by now affecting 10's of thousands of vehicle.

This is no skin off my nose, I could just as easily make a ITG foam element for the reproduction aluminum filter as the K&N!

Everyone let me know (pm) what type you prefer, and I will build to your preference!

I don't care if people take me seriously or not. As its been noted, others have noted similar findings with the gritty mess that went away with the ITG. Ever heard of a guy by the name of Gron Perry? He is pretty well known in Weber carb tuning circles. There are an awful lot of people who listen to him. He happens to know a thing or two about airflow, air filters and carbs. He was one of the people who said I should steer clear of K&N filters for all the reasons I have listed. Dave Rebello also advised me to steer clear. Clearly he doesn't know what he is talking about either (according to you.)

As for the air filter design, its pretty simple. You have an air filter that sits in the stock housing with aluminum plates at the front, and back, with the filter sandwiched in between them. Clearly air will not flow straight into the velocity stacks through the aluminum plate. With the ITG, it can. Sure, there will be a low pressure area inside the stock housing, and air will flow into that area, swirl around, and eventually enter the velocity stack. Any way you look at it however, since the filter sits at a right angle to the bell of the velocity stack, there is no direct unimpeded way for the air to enter the velocity stack. Yes, the ITG will cause the air to swirl as it goes through the stack, but it has time to smooth out by the time it enters the velocity stack, assuming the velocity stack bell is more than 1 inch from the inside of the filter. (This is also why sock filters are a bad idea.)

No skin off my nose if people chose to run something else. I'm simply stating my own experience. I'm done this topic.

Will

[bakerjf]

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[Linda]

I don't have Solexes, and if I did I would sell them so fast it would be a blur..... So, I am mostly interested in the dynamics of the argument. Kind of like a judge, Who wins and why? Well first off, any hint of personal attacks, deducts 10 points. That always seems like desperation. Then personal experience testimony is only as good as the expertise of the person, and their credibility. Next we have expert witnesses. So in this case we have "K&N engineers" vs Dave Rebello and the other guy mentioned, all acknowledged experts. Both guys claim lots of racers support their preferred product. So is this a case of a baseball player endorsing Wheaties for money? Not likely if Dave Rebello's claim is true. More of a bias for K&N engineers and JT, since it is a product sold by both. Profit motive can muddy the waters but is not a deal breaker if there is enough evidence.
Conclusion: Need more expert witnesses on JTs side otherwise I lean towards Will's side in an argument I don't really care about.
Just doing a post mortem because I can
Kind of why lawyers often ask what was convincing in a trial so they can learn what seems true and what works.
Good discussion when you break it down.
Linda

[bakerjf]

Kind of why lawyers often ask what was convincing in a trial so they can learn what seems true and what works.

Correct! Except it's important to understand that "what seems true" and "what works" are not always completely interdependent, and sometimes are actually mutually exclusive!

Sincerely,
A lawyer

[Linda]

I agree! Which is why it seems the weaker your case the more you would want a jury member who falls for any irrelevant argument. Guess that is what the judge is for! "Overruled!" "Objection!" LOL
Still we apply as much wisdom as we can muster even here on a little forum in this little discussion. Why not? I, at least, can always use the practice.
Linda

[JT68]

I'm glad Will is done with this topic. Now we can put an end to the nonsense, conjecture and slander of K&N's nice product.

Final closing comments (at least in theory):

Here is what started it all:

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


No worry about the stacks, but the rest is just conjecture and speculation.
Where is the data? This is inadmissible and should be stricken from the record.

Apparently Slow Roadster was offended that I put up a photo of the stock element and the K&N. - there were no non-factual claims made.

I don't care if people take me seriously or not. Ever heard of a guy by the name of Gron Perry? ...He was one of the people who said I should steer clear of K&N filters for all the reasons I have listed.
Will

Wonderful, but again, unsubstantiated hearsay.. Repeat of an alleged conversation? Where is the data? Inadmissible and should be stricken from the record.

"Dave Rebello also advised me to steer clear-Will "

Doesn't matter, just hearsay...Repeat of an alleged conversation? rumor? speculation? Inadmissible.

Even if Mr. Rebello came here and commented, without valid, scientifically collected data, he's just another guy with an opinion.

"Clearly he doesn't know what he is talking about either (according to you)-Will."

Irrelevant. and a whole different topic. Let's stay focused.


"As for air filter design, its pretty simple-Will".

Members of the jury, I must LOL.

I did not realize Slow Roadster is an expert in automotive engineering and design too. K&N and any other engineer will tell you how far off base this statement is.

Will, perhaps you could create for us all an accurate computer model of the impulse and steady state characteristics of the twin Mikuni PHH, the factory housing and any filter element for us all. Do you have a masters degree in ME or perhaps aerodynamics? You are going to need it.

Optimizing flow capability, long term reliability, environmental and temperature stability, and proper filtration capability, is anything but trivial. If you don't believe me ask K&N AND ITG!

Back to reality, K&N has 20 years of engineering data on file. They will politely share real data if you ask nicely. (It's on the website too for all to see, not imaginary)

"You have an air filter that sits in the stock housing with aluminum plates at the front, and back, with the filter sandwiched in between them. Clearly air will not flow straight into the velocity stacks through the aluminum plate-Will."

Somehow we are forgetting the substantial (huge in relation to the carb intake) volume of air that resides in the large dome of the factory housing, right in front of the velocity stacks at any given instant. The stacks are over an inch away from the dome which is one reason it is such a nice design----the whole dome is full of air, at least on this planet.

"Any way you look at it however, since the filter sits at a right angle to the bell of the velocity stack, there is no direct unimpeded way for the air to enter the velocity stack- Will"

Um, again, the entire housing is full of air and air is fluid......again, a fundamental lack of understanding, flow dynamics, and design concepts. Air will take the path of least resistance flowing into the velocity stack, so it will draw from the sides and the empty space in front (almost zero resistance) rather than directly through an ITG element. ( ITG will tell you if that is happening, the stack is too close to the foam.)

Atmospheric pressure essentially instantly forces air in through the entire outer filter perimeter to maintain quiescence.

Gentlemen and Lady of the jury, Let's do a little simple math to show you how really dumb the whole flow discussion is in this particular case. The 44 Mikuni has a cross sectional surface area of 2.35 sq-in. technically less because of the outer venturi. If the carb were the limiting factor (which it isn't) max flow would be limited by that surface area. (Rem, only one side of one mikuni reaches peak flow at any instant since only one cylinder is on the intake stroke at a time)

The outer perimeter of the stock filter is 41.5" and with a 2" cross section, That's over 80 sq-in of surface area, so a factor 35:1!

As if 35:1 isn't good enough, the pleated design of the K&N increases that surface area by about a factor of 4. If 35:1 can't keep up with your U20, I think 140:1 can.

Did you guys ever notice that on the late model Solex AC, there are only about a dozen 3/4" holes in the outer perimeter? How can this work at all?? It is because only one cylinder is on the intake stroke at a time. That is pretty much all the filter has to keep up with!

I guess the engineers at Nissan did not understand?? Yep, it was still 150 HP.

"I'm simply stating my own experience." That is great, but it is hardly expert testimony and should not be considered as such.

Let's stick with the facts. Will manages to slander a million dollar product (K&N) without a shred of supporting evidence---only hearsay, conjecture, speculation and an overt absence of fact. I just took off a K&N that has been on a year and the carbs look new. Guess I should throw the K&N's away.

Obviously Mikuni didn't understand either. (Note the K&N elements):

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[bakerjf]

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[JT68]

Great photo!

Every intake cycle and closing of the intake valve creates a flow dynamic or pulse. Even though this is occurring, for any given RPM and load, flow briefly reaches a steady state flow pattern through the housing and element. That changes almost instantaneously. Considering all the shapes and surfaces involved, the dynamics are anything but simple. Nissan did a nice job with the housing design.

A banana looks simple to a monkey. Try making one.

[Alvin]

Enjoying the lively discussion!
A couple of things come to my mind.

I just took off a K&N that has been on a year and the carbs look new.

JT, how many miles and what were the conditions said filter went through over the course of a year? Can we see the roadster it came from?

If it helps, if anyone wants to donate an OEM solex air filter w/K&N filter and a Solex ITG unit we can dyno test them on Sora. That would answer the flow question. For filtration, I'm sure we can come up with a nice controlled experiment. Weird Science!

edit: dyno testing may not be accurate, right? Aren't carbs usually re-adjusted to maximize changes in induction? If that is the case one would have to do some kind of bench flow testing.

We should also test the 2 filters with say 10k miles on them and compare flow. I'm guessing when new the differences might be negligible?

[bakerjf]

For filtration, I'm sure we can come up with a nice controlled experiment. Weird Science!

Alvin, Jim, Will, and K&N rep unraveling the mysteries of filtration?

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