Can not find: Air box delete (the spare one off intake) delete F355

It's quite interesting to read just how many different manufacturers fit various resonator devices to their engine's air intakes, and have been doing so for over 20 years now - Including Ferrari (who it must be said know a thing or two about engines!).

Between them they are hiring thousands of skilled engineers to design them, using complex test procedures and CFD programs to simulate and modify the intake air flow by using resonators, and then paying Millions to have the resonators manufactured and fitted to their cars.

Apparently though, it turns out that they are all just wasting their time and money as, according to the car owners working from their home garages, these devices do nothing at all and should just be removed!

Someone should tell the manufacturers that their wasting their time!

 

I came up through the ranks. Started sweeping floors at Toyota. Ran the place, became factory rep. back to dealer then owned the place. I started with the celica xx project aka supra. Even knew mr toyoda he liked me I told it like it is. Have some great stories from 1974 on. Ahh the good old days. I still consult for them. Cool stuff down the pike with scions a crossover coming, hope they go awd

Anyway you must have seen the first year lexus, a camry with tons of sound deadening. We needed to quiet down everything. I remember 100's of microphones on these cars driving around trying to ID noise. The sound engineers were insane and did not speak English.

The entire performance theory was quashed by the worm like design of the intake runner that went under the headlight through the radiator support into the wheel well across the frame rail. Were not talking velocity stacks here LOL

 

You can make any argument you want but you can not have one without the other. The resonance you hear is caused by pressure fluctuation in the inlet tubes. Those pressure fluctuations affect the flow in the tubes. PERIOD. This can not be disputed. The effect of those fluctuations could be positive or negative on the amount of charge that enters the cylinders. They will not have no effect. Removing the resonance will eliminate the associated pressure fluctuations. That will have some effect, be it positive or negative. So the question is, was performance sacrificed in an effort to eliminate noise or was the noise removed as a passive result of improving performance? But acoustically tuning intake runners is not different than tuned headers. Performance gains are related to the resonance frequencies, RPM, etc. If you get the wrong resonance it's possible that you could effective starve the intake at a specific RPM. Resonances generate nodes and antinodes and at a velocity node the velocity of the fluid (air) is zero. Last thing you want is a velocity node and the back face of an intake valve.

FDIY, I did my masters research on unsteady flow in ducts. Specifically, pneumatically driven (sack) artificial hearts. The pressure waves in the supply tube had a significant effect on the ability and rate of the heart to fill and empty.

 

Thats awesome! I have always loved Toyota/Lexus. Had several generations of LS. Don't recall the first one having a huge resonator but it has been a long time since I've been under the hood of one.

I really think those early cars were the best. Really a 90 LS is like driving a bank vault compared to a new one.

My current ISF has a resonator on the induction tube and also snakes around the inlet to just behind the grill but also has a solenoid operated flap that opens at 3600rpm, making the air box wide open to the passenger fender. Very loud actually so you couldn't say on that car they were going for absolute quietest induction. (Though the resonator may just be to quell a specific frequency range).

Not sure but would love to see the factory engineering on this stuff.

 

I wonder if the same engineers that designed the air box also moonlighted for the interior plastic companies that decided a soft touch the way to go.

 

Also the intake resonators on the 2.7 cars are pre air box (and pretty big). Some early euro cars had massive resonators that curved around next to the air boxes above the muffler heat shield.

Parts diagram shows valid for Challenge cars as well.

Did the Challenge cars in fact have these fitted from the factory? Just a curiosity as I doubt induction noise was a huge concern for a race car but again, who knows the exact design goal for these things.

 

I don't think so, that resonator doesn't get sticky

 

It is something Toyota pioneered into mainstream. The other issue they wanted to touch was getting the intake as high and protected from the elements as possible ala the land crusher trails.

It really was funny as heck like a SNL skit watching them in lab coats swarming all over the cars. Too bad the engineering was done behind closed doors. Teams were sent out to gather data, make changes gather data. They were and still are very secretive on R&D
They would even patent a dozen things and publish papers just to throw folks off and find leaks. Today they have teams throwing up smoke screens as do all the big players.

 

Hell, all this hi tech stuff is crap. Electronic injection, ignition, Helmholtz resonators, air boxes? All you really need are a distributor, coil, points a carburetor and one of those shinny chrome air filters sitting on top.

 

Nice!

Reminds me of Smokey

Smokey Tells All - Smokey's Vault - Circle Track Magazine

 

I like stacks nice and long, oops you can see the hidden nitrous system
Image Unavailable, Please Login

 

And you can take your pet dinosaur for a ride in it, because that stuff is from the stone age.

 

Don't have that little box on the 2.7 motronic 355's. Obviously you have the 2 separate intakes so might expect 2 boxes, but none.

 

This is an interesting discussion, but I am not convinced that the generator is a significant contributor to power without dyno data to back it up. I am not disputing that it could be contributing meaningfully either without dyno data. As others have said, it's not all that simple and could even be phenomenon that happens at speeds over legal limits due to the ram air effects of the intake design. It was obviously placed there for a reason. As someone who did a fair amount of dyno work, the engine is always right. I have both won and lost on the dyno with mathematically derived designs of both intakes and exhaust. One car in particular was particularly vexing, I was able to pick up 50 HP on the exhaust over another header, but lost 20 HP when I tried my first intake on a 250 HP rotary motor (finally settled for 300 HP at the wheels). The motor decides whether your design is right.

Sent from my SM-G920P using Tapatalk

 

That resonator is for quieting down the induction noise on the intake. First of all, the oriface is to small for it to do anything significant for power. Second, the resonator box is the wrong shape for producing power. Third, it is in the wrong location for producing power. Fourth, it is the wrong size for producing power. If anything it may even reduce power by an insignificant amount. As in a fraction of a single hp at a specific rpm.

What it is the right size, right locating, right shape, right oriface size for is, canceling out audible resonant harmonics at a certain engine speeds. In a nut shell, it's an aero "Bose" noise cancellation "set of headphones". Look at where it is located, on the side of the tube. The intake air passes over the opening to the resonator box. As air is rushing by a portion of the air goes into the resonator. As it does this a harmonic resonance is created inside the box (think blowing into a Coke bottle). It produces an opposite frequency to the frequency produced by the intake tube, and thus cancels out the audible harmonic frequency. I quiets down the induction nose, eliminates the "droning".

Why did Ferrari put it there? Probably to meet noise regulations in certain countries.

 

Oh Bruce you southern boy have such ways with words. You got me all worked up for this sheet. I have got to learn more about this Heimholz fella. Forty posts about a plug.

 

There are two resonators on 2.7 cars. It's on the induction tubes just before the air boxes.

 

Yuup
This one is clearly a speaker in the intake system as mitsubishi put the speaker in the exhaust to change the tone on 3 levels

I love the non natural sounds folks build into cars


Maybe OK for a luxury yacht but not a sports car

 

Quite probable! But can't say definitely can we?

What would a resonator look like that's designed to increase power vs attenuate noise? I think it would be very similar as the resulting functions would be similar.

Again, may not do a damn thing for power but why not test it? I'll donate the dyno time if anyone in the Chicago area has a 5.2 car they want to test it on.

Soarer - The Intake Resonator

"The magazine wanted to try some dyno testing for itself and see if they got the same results as the Society of Automotive Engineers paper. The test car used in the test was a 1500 cc 4 cylinder 12 valve engine with a standard 710 cc inlet resonator (The 1UZ-FE is a 4 litre 32 valve engine with a 1200 cc resonator).

Complete removal of the resonator saw a steady loss of power throughout the rev range of 4kW (7% loss!! peak power was 55kW). 5 resonators were tested, 245cc, 600cc, 710cc, 950cc and a 5000cc coolant bottle. 30 dyno runs showed a trend of small resonators best for high rpm power and large resonators good for low down torque with no straight line relationships between the different sizes. (our 1200cc resonator would look to be designed for low down torque, common for large heavy automatic cars).

The best compromise was the 950cc resonator which gave an increase of 4kW at 3000 rpm over the stock resonator (13 % increase at 3000 rpm!)."

 

Then let's get it tested.

As for the shape, spherical is ideal when talking about a Helmholtz resonator. The size will depend on the what frequency you are trying to generate and for what rpm. Again think of blowing into a Coke bottle. The bigger the bottle the deeper the tone, the smaller the bottle the higher the tone. Tiny opening = high pitch, big opening low pitch. Standing waves are developed inside the resonant chamber and the wave will move as the frequency changes up or down. Timing the wave to enter the cylinder as the intake valve opens is the tricky part. Time it wrong and you can actually loose power.

If there is any gain in power from the resonator on the 355 I will be surprised. But like you said, the only way to know for sure is to test it. If I had a 5.2, and was in Chi Town I'd come over and we'd see what is does or doesn't do. I still have my money on no power, or minuscule at best.

 

You may be surprised that I completely agree ^^ just would feel better about it if we could say it was tested and we are 100% sure rather than we think it wouldn't change anything.

The shop/dyno is in Schaumburg IL, offer is open to anyone that wants to test this.

 

So which one of you guys is gonna strap their 355 to the dyno?

 

Ernie, I don't necessarily disagree with the idea that the resonator may be only to deaden sound. But please leave the technical aspects of the device to those who are educated in the field of acoustics and acoustic systems. Shape of the "box" is not critical and standing waves have nothing to do with how it works. I have great respect for many of the contributions you have made to the forum, but here I must object.