DARKMAZ8

I don't see why they wouldn't since they're selling a $300 intake.......unless??? It's unbelievable how many biased members we have here.

coupe07

yeah, agree with u.... many here are biased towards the REVi....

juz becos K&N made a mistake with the first intake doesnt mean they cannot produce a better one this time round... i also do feel the new design is so much better this time and i tink the gain is better than revi....

k&n is the expert in air filter... how lousy can they get?

Razz1

RB does developement work for Mazda. They are restricted from providing that info due to legal reasons.

therm8

I'm the first person to call RB on their claims and what-not. I don't own a Revi. In fact I've never owned a RB product. K&N on the other hand, I have owned, and the FIPK2 for the LT1 F-bodies was a fabulous product. I just don't believe in products without proof, and a dyno by the manufacturer isn't proof in my book. I am about as unbiased as you can get, give me independent before and after testing and I'm happy.

DARKMAZ8

shouldn't be a problem to get a decent dyno with the new K&N since it is much easier to install. I can say that at our rxclub dyno day in toronto. The 8 with the most power was running the old k&n typhoon. I can't rely on it though because it was not a before/after dyno. I definately think that k&n must have done some considerable r&d on this new unit to make up for the 1st one.

I am waiting patiently for a dyno so we can make assumptions based on real data and not spreading nonsense like these revi lovers.

DARKMAZ8

This really makes no sense. what difference does it make if rb publishes dynos or we do?

staticlag

Because it would be like the American Dental Association marketing Hershey's chocolate bars. Counter-productive. As long as the dyno isn't released by anyone affiliated by Mazda, they can play the plausible deniability card when it comes to engine problems or hp claims.

Thats because logic has nothing to do with it, its pure physics. Particle motion and standing waves whatnot. Basically, what u missed in college general physics.

Logic is syllogisms. (reasonable predictions)
Science is observable fact.

Okay, RG correct me if I'm wrong, but I'm gonna take a stab at explaining this.

Basically, when an engine sucks in air, it doesn't suck it in as constantly as you think. When air moves inside the intake tract, it pulses with a certain frequency. This is caused by the particles mashing against each other as they try and ram into the engine as it is cycling.

Basically, the REVi works well by using a very specific length of tubing so the air entering the engine will not encounter interference waves generated by the column of air already moving through the tube. If it was to encounter interference waves, then there would be a vacuum pocket of air generated and the pulsing would amplify itself as it rushed into this pocket of air, creating..... rough idle and HP problems.

The problem with making any intake, is that any engine is not designed to ONLY flow one amount of air. If the engine only flowed one amount of air, then it would be relatively simple to create the perfect intake on your first try.

When the engine works it requires greater or less amounts of air depending on what RPMs you take it to. This changes the resonance frequency of the column of air moving thorough the intake tract. It is up to the designer of the intake to design their intake to work reasonably well with any resonance frequency the engine might produce. This is why the gradually increasing radius in the piping of the intake tract is so vital to both the stock and the RB intake design. The box works as a reservoir(not to mention a heat shield) to draw air into the system from from. This large mass of air inside the box works as a buffer to help stop the nasty pressure displacements that I was talking about earlier. More energy will be required to pulse the air in the box and the waves will dissapate before they can cause any airflow problems.

Now:

WHY K&N flows better:

Basically, K&N did what I said eariler: tuned the intake for only 1 amount of airflow, they punched the maximum amount of airflow the engine can consume into their design computer and they got a tube diameter and length. They made their first intake solely around this! With filters of this size and efficiency, you can pretty much negate them from your intake calculations(at least in this simple example).

The K&N flows better at high RPMs because it is short, meaning the waves have less chance to propagate themselves along the intake tract and resonate out of control.

This is why the K&N has a bigger maximum HP number, but falls flat on its face everywhere else, because its only tuned for one maximum airflow amount. This is why "area under the curve" is so important, because you want to reap the benefits of your intake at 2000 rpms, 3000 rpms, 4000 rpms, and so on.......... not just at 9500 rpms where you get a single surge of air.

This is why the new intake looks so stupid, because they focused on fixing the problems created by the first, basically band-aiding their original design. There is no originality here, no inspiration. RG has pretty much already explained why this design is flawed and his theories are sound.

end rant.

r0tor

iTrader: (1)

will the revi fans please tell me if its so great why they are the only higher end intake i have ever seen that was cheap enough to not replace the accordian style rubber tube feeding the throttle body with a higher flowing replacement... you know, the piece that actually effects what the airflow looks like when it enters the intake manifold

brightnova

Sorry, but this is funny. :D An argument on the flow of each intake based on no observed fact. Just observing the shape. Come on guys. Lets just wait until somebody can dyno this new intake. It could be good. Or it could just perform well at 9000rpm and get its 10hp gain there. I am not biased either way, just show me a dyno, not theories.

Tamas

iTrader: (1)

I'm guessing this might have to do something with isolating the intake from engine movement. That's why they kept it rubber - and for the accordion style, it's because they wanted to allow easy separation of that tube from the intake.
Had they replaced that with a straight rubber pipe, that would have made installation and removal (for cleaning) more complicated, because then it'd much harder to push that tube backwards (almost impossible).

r0tor

iTrader: (1)

its called using an expansion joint...

Tamas

iTrader: (1)

OK... I'm not that big of a car guy - what would that be like (design-wise)?

rotarygod

I will say that both intakes from an airflow standpoint can flow more air than the engine can physically handle. This is true as far as the intake tubes are concerned. Whether or not this is true with both filter elements is debatable. The RB filter (which is a K&N) is much larger than that in the K&N kit so if the filters are a restriction at all, the K&N kit will hit that point first. I do know that the RB filter isn't a restriction. The K&N? Maybe. Maybe not.

There is far more to intake tuning than just airflow. As was mentioned there is actual tuning. RB found through testing just how critical this tuned length is. Remember they work on rotaries and test rotaries all day to understand how they behave and what they want. What does the competition do all day, build filter elements? They found that a very small change in length could cause a change in the powerband so they optimised theirs around the average powerband rather than the peak. Other systems out there spend so much time on trying to get "cold" air however they can by shields and whatnot and also just trying to get the idle smooth (thanks to RB for telling the world how to do it), that they all pretty much ignore the critical tuned length. Ususally we see a setup of X amount of length and then they just dyno it to make people happy. I'm not going to name any names but there is a new one on the market that is just a long aluminum pipe that puts the filter down front. Maybe it works but they didn't do testing to the design to arrive at that length but rather just said "hey a filter would logically work good there". I know they worked on getting the idle smoothened out though. BTW: The stock accordian pipe is NOT a flow restriction on this engine so that is not a valid excuse.

Don't focus solely on airflow. The LeMans 3 rotor engine right now is breathing through a 2.1" hole but it is tuned (they also don't run an airfilter). That is the important part, tuning. How does anyone know that other systems out there have the proper research done in actually tuning these systems to the car? I know one company that actually does it properly. Unfortunately today, alot of people don't care about a product that was designed and tested properly for it's intended application but rather base their choices solely on price. I guarantee that there is only 1 current intake kit out there that has been tuned and refined not only on a dyno (which too many people put too much faith in) but also with GPS to actually show chassis acceleration improvements.

The world knows I support Racing Beat but understand why I do. They deserve it. They test and test and test and do it for your benefit. They don't just throw out some kit that they think will make you happy because it looks pretty (theirs does btw). They probably should though and just make it cheap. They make sure you will be happy and they want you to know exactly what you are getting. They won't go quoting things like "guaranteed an X amount of horsepower". Those are worthless marketing statements that mean nothing as we have power at more than 1 spot. Quotes like that aren't telling you the whole story. Come to think of it, late night infomercials don't either. RB obviously also understands that the dyno is a tuning reference but not the be all end all gospel on how much power a car is putting down. That's why they only use it as one of their tools to design rather than the only one. I don't know about you but how my car behaves on the street is far more important that how it does on a dyno. Understand they also have an engine dyno and a pretty complex setup that guarentees that they can test accurately. I highly doubt K&N and others are doing this. Dyno testing sure, but on a chassis dyno which was all know is not accurate on the car anyways. Stop believing you car doesn't make close to rated power people! How nice of a product are you going to have if you designed and tested it on a system that gave you inaccurate results? I think I know the answer to that one.

Racing Beat relies on their reputation and honesty to sell their products. They don't bs and they don't quote some random number. Believe me, that quoted number is always going to be the max gain over another at one point in the powerband. Where exactly? Most companies out there choose the number after they see the dyno chart. They'll even quote power spikes and call them the max gains. The others rely on the marketing departments to sell theirs. Apparently their marketing departments are good. It really comes down to this since you are obviously reading comments from a biased individual who believes in proper design and testing over bogus chassis dyno charts, pick the one that you like and you think will make you happy. Don't just pick the cheap one because it is cheap. The cheapest one came on the car so if money is the only factor, save it. Remember you get what you pay for (again?). Look at the build quality, how was it designed, can they verify their testing methods as being thorough and properly done? Can you really trust a 2nd design after they obviously didn't put any time and effort into researching the 1st one. Is it once again trial and error or were they corretions made to their system after seeing how RB did it on theirs? Strangely enough the other systems didn't get their completely finalized versions out there until after RB disclosed some valuable info. Hmm... Obviously other little things such as how does it look and sound will be personal preferences and those tastes will vary.

That's my rant. Choose what you want but do it for the right reasons.

guy321

It's just $300 bucks, hell I gave my intake to RG.

DARKMAZ8

RG---I see the point you're trying to make but you still don't see mine. sure k&n messed up the first time around but so did mazda. Doesn't mean that it renders them incapable of making a great product. You also seem to forget that RB put probably a lot more research into the sound than the actual air flow. I have seen bigger #'s at our dyno day with my own eyes with the k&n over the revi. And this was with 5 cars.....2 with k&n and 3 with the revi. The gains were even until 6000rpm....where the k&n would blow the rb outta the water. I could say that the revi had it beat with sound quality but it was clear which one was making more power. I'm pretty damn sure that k&n did their homework this time around and had time to evaluate the competition and react. I expect even better gains in the entire power band and still a significant gain at peak. The only worry I have is sound quality. I suspect that they worked on that aswell.

r0tor

iTrader: (1)

I'd like some proof on that because last time i tested something similar on a flowbench the accordian tubes flow absolutely horribly

SHOWOFF

Yes. Both intakes use the stock intake screens.

SHOWOFF

I like my K&N.

rotarygod

Then I guess you should buy the K&N. Why is this thread still alive if you've made up your mind? Believe me, you're not huring my feelings or anyone elses. Just do it. It's your car. What makes you happy is all that matters.

DARKMAZ8

I havn't made up my mind and I will wait and see the results before I do so. The reason why I am backing k&n is because everyone else seems to be writing them off and I still believe they have made a descent intake for the same price range. You are in the same boat as me but on the RB side. I've seen no proof from either product to justify picking favorites. You like RB and the way they do business but it doesn't give you the right to say their intake is better. You are biased and that's what I dislike about this forum. Just like that thread you made last year about how ram air intakes are pretty much useless. Now that RB came out with one you are telling ppl that it's the best thing on earth.

staticlag

I don't understand, so:

1)You say we are biased and are picking the RB intake because we have no proof it lives up to its claims(lol), yet you are backing the K&N solely because of its underdog status?

2)You say that because a company actually produced an intake that works and sounds great without giving people are hard time, that they haven't earned the title of best?

Huh???

This post just took a massive nosedive.

rotarygod

I never said the ram air system will yield huge power gains like everyone else on the internet claims, not even with Racing Beat's. I do like the way they designed the system though and feel it is the proper way to do it for a street car. The problem is with the term ram air. I still don't actually consider Racing Beat's to be completely appropriately named as it isn't truly 100% sealed off to the airbox. It is still a cold air system although it may actually do something in a small way for a ram effect but obviously not until at very high speeds. ON the other hand, what if it truly is a ram air system that does give gains? Will you see them on a dyno? Nope. Many people are reporting a gain at higher speeds.

If I am in the same boat as you but on the RB side, and you say I am biased and that's what you hate about the forum, that means that you are biased too. I'm not trying to be mean and believe me I really only want to see you happy with your car, regardless of which product it is. I absolutely do have a right to say theirs is better. You're saying it's not. It's called an opinion and we all have them and I'm fine with that. I also say that everyone should only be using Royal Purple synthetic oil in the rotaries too. That's what I like about this forum, everyone has their own opinion. Go "next door" and you'll find that most everyone thinks one way and that if you are different, something is wrong. That's being biased.

I am absolutely sincere when I say get the one that makes you happy. That's all that matters. If you are waiting for test results to do so, do it properly. Test them all in the car while moving and choose the one that you like best. You called this thread a "showdown" yet you don't like my shootout approach to support the one I like. It's my opinion and I'm sticking to it. It's not a law so it doesn't have to be followed.

staticlag

I don't mean to bash, but observed shape is more than enough information.

You do know, that before computer simulations got so sophistocated, that engineers used to construct small clear plastic replicas of whatever they wanted to build, then they would look at them through a polarizer while subject to stresses from different directions to see where stress cracks might occur???

You do know, that all of organic chemistry is based solely on shape? One drug atom twisted 90 degrees along the wrong axis could kill you.

Honestly, I could go on all day.