New Gen4 Snorkel

Just been out for a quick drive round.

It sounds nice when you stand with your ear next to the head. Sounds like an exhaust rumble. 

Driving wise I couldn't say if it has altered low end torque or pulling away speed. Didn't feel any different to me in that respect. 

At certain rpm/load I did get the acoustic vibration and felt it through the accelerator pedal. But I will have to go for more than a 10 minute drive to find out more.

Plenty of clearance between snorkel and door edge on mine.

Today I went for a drive with the Head reversed as much as it would (doesn't quite rotate 180o ). It didn't make any difference to the harmonic vibration, however with the window open, you can really hear the induction noise. Sounds great until the vibrations start, it's like an exhaust rumble only you can hear!

I did wonder if this vibration was a trade off with not having the snorkel fastened to the A-post. Whilst going up hill and the vibration/noise present i grabbed the snorkel through the open window to see if I could feel it vibrating. I could not, so I don't think it's a hardware mounting issue, it must be the harmonic vibration with the snorkel if that makes sense? 

Is it possible it's the flexible pipe as it's just appears to be resting on top of the engine?
If it is just resting may be worth trying a few cable ties to hold it tight and stop it moving, see if it makes any difference.
just going off pictures, hard to tell.

 

Thanks for the suggestion. The flexi pipe is secured by one cable tie, a bracket is supplied for this purpose.

One option would be to get some exhaust wadding and insert it into the tube (making sure it cannot be sucked into the engine). This would de-tune the intake.

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I think the vibration is a natural result of the flexi. hose fluttering with the movement of air and the engine in the engine bay. I don't think that the flexi hose supplied will ever be the answer. The original hose is heavy section rubber with suitable flexibility for bending purposes. I believe that the strange device that plugs into the end breaks down the natural harmonics created by the movement of air that is being disrupted as it passes through the corrugated section of the hose. I mentioned previously that a pipe made from pvc gutter downpipe which could be assembled from straight sections with suitable bends could replace the flexi pipe and could be fabricated to include the original harmonic device.
Or.
The connection to the air box is via the original entry which is at the front of the box. Could a new entry at the rear of the box be fabricated? This would dramatically reduce the length of hose/pipe required and you may even be able to reuse the original rubber hose complete with harmonic damper.

Roger

Scrub my second suggestion, the air outlet gets in the way. That leaves PVC guttering downpipe. This is available in round or square, both approx. 65mm. Both of these pipes will flow appreciably more air than the Suzuki original so if you can find a supply of smaller diameter pipe then you may find it easier to fit the space available. The square pipe can be had with adaptors to fit round pipe.

Roger

I was going to say, there is no room at the back of the airbox.

I have a couple more things to try next, will keep you posted.

So tonight on my way to Morrisons, I removed the convoluted pipe from the bottom of the snorkel and just left tucked in by the battery. The harmonic vibration did not occur,  it had gone away. This still leaves two possibilities:

1. It is the harmonics within the snorkel itself causing the noise and not the pipe.
2. The noise is caused within the pipe and the snorkel just amplifies it like a gramophone horn.

At the moment I am swayed towards N⁰1. I think if it was the pipe, I would still hear it, but somewhat muted by the bulkhead. 

I am beginning to think it could be the shape at the base of the snorkel, the way the airflow is split at the base? Just a theory?

 

 

How thick is the wall section of the flexible pipe? I know it's supposed to be flexible by nature but it looks like it would begin to resonate with the intake without too much effort. I might suggest looking at a suitable diameter piece of twin wall conduit as it will take a fairly tight bend but it's smooth inside and quite rigid for what it is.

That kinky bend at the base of the snorkel will do you no favours. Any bend that creates very sharp kinks with variable cross sectional areas will create buffeting and that means noise. Combine that with the very basic flexi. hose and noise is inevitable. I used 75 mm bore twin wall flexi. to join my 3 way air valve that enabled me to use air from the passenger compartment when I needed a snorkel. The rest of the time air was drawn in from the double skinned wing panel. This was on my LC. You could try a suitably sized twin wall flexi. It will certainly be better that what you have. There is a dealer in Redditch who supplied me and I could have a look to see what he has to offer if my idea seems ok to you.

Roger

I am also suspicious of the flexible pipe. Is it possible the shape at the bottom of the intake pipe is a restriction, this is causing the flexible pipe to contract/expand like an accordion. You see this effect it you block the flexible pipe on a vacuum cleaner.
Maybe try a few extra fixings to stop it contacting or fit a small camera under the bonnet and film it, see what's happening.