52 replies to this topic

[MartinS]

My car is a tad loud and though I have db reducers that get it down to 92 db static, I regularly have trouble with 102 db drive by. Most of the noise is the sc coming out of the cone filter I believe. I have packed the area surrounding that with soundproofing but to little effect, so wondered if its worth putting back on the standard airbox as I was told that flows as much air as a cone filter . The other options are to make a removable box or something like the ITG case that Mango does, does that reduce noise much? I have Zandvort and Donington and Goodwood coming up and they all have low noise limits that will give me grief. Any ideas on how easy it is to put the original airbox back in, will it flow enough air, will it quieten down the car. I assume that when a cone filter is totally enclosed as in an ITG, as long as there is air directly piped in, I assume that it works fine. So if air is piped in directly from a vent, does that mean I could put any form of enclosure around the cone filter and it would still work as well? If so any box would do wouldnt it, perhaps even a modified original airbox or would that be better using its original filter? My idea would ideally be to have something removable between track days, so a sound proofed box with an air pipe that could be clipped easily around the existing filter without cutting power, just noise and maybe, also add heat shielding as a bonus. Thanks Martin s ps I'm no engineer hence so many questions just to confirm things.

Edited by MartinS, 01 August 2013 - 06:46 AM.

[CocoPops]

It does reduce it, I'm running the ITG. How much, I'm not sure though

[Bargi]

Is it the CS cone filter? I don't have any troubles with it although I've got a Milltek exhaust. You've got a couple year old 2bular don't you? Worth a repack if possible?

Edited by Bargi, 01 August 2013 - 06:59 AM.

[Goosenka]

I thought that fitting the original airbox was a no no due to space?

[fezzasus]

I thought that fitting the original airbox was a no no due to space?

 

I think you can get away with using the original airbox, it's just the location of the ECU that's a problem. If the ECU is moved closer to the engine or to the older position used by CS on the header tank mount then it should be fine.

Edited by fezzasus, 01 August 2013 - 07:07 AM.

[Goosenka]

I thought that fitting the original airbox was a no no due to space?

  I think you can get away with using the original airbox, it's just the location of the ECU that's a problem. If the ECU is moved closer to the engine or to the older position used by CS on the header tank mount then it should be fine.

Ah fair enough then. I can't remember what JG summarised on the ITG modification he did with regards to noise?

[MartinS]

Ecu is on the backwall.

Its the normal sc cone filter cs fit.

Exhaust isnt any louder then when it went on (loud), but the db reducers cut that down. Its the sc that seems to trigger drive by problems.

 

Been looking at air filters and heat shields and it looks like if I made a box to fit around the cone air filter then fead air straight in that would be the same as an ITG set up. But I would be thinking of making it removable and adding heat shielding/sound proofing within the airfilter box . Wouldnt be a tight fit just totally enlose the cone.

 

Am just woried this would effect the amount of air getting in so make the car run richer, but as ITG do it I assume its ok and there would be less heat, less general dust and dirt so thats not bad either.

Feel free to criticise or tell me I have no idea what I'm doing.

 

Martin s

 

[JG]

ITG made the one that Lee and I use based on a set of parameters i gave them.

I wanted sub 5µm filtering (still not as good as paper but very nearly) and i wanted it rated for 300hp.

Thats why the box is so huge.

Agree with Lee, its a subtle reduction but i think the biggest change is outside the car.

 

 

[MartinS]

How does that fit on if you dont have the bar coming down that Lee has?

 

What does teh original airbox flow?

 

Martin

 

[davemate]

fit a harrop

[ArticMonkey]

How does that fit on if you dont have the bar coming down that Lee has?   What does teh original airbox flow?   Martin  

I'd hope you do have that bar as its a major part of the frame.

[Rosssco]

fit a harrop

 

Or a turbo

[techieboy]

You do have the bar, it's what the buttresses cover and supports your rollover bar.

 

Standard air box flows plenty but no way to fit it without moving the ecu, I've tried.

 

I fitted a Pipercross VM7000 fully enclosed filter to mine and made it a worthwhile difference and much cheaper than the ITG as it's plastic (and I reckon that wont resonate as much as carbon fibre or metal). The supercharger whine on mine is quieter with the smaller stage 3 pulley and this airbox, than it was as with the standard stage 2 sized pulley.

[davemate]

how about a single exhaust pipe mod to reduce noise and stop the system acting like a trumpet?

A downturn on the pipe will also reduce the percieved noise as it will break up the sound.

 

 

[fezzasus]

Are you sure it's the induction noise?

 

The reason I'm asking is this; pretty much all supercharged cars struggle with noise limits, while most tracked turbo cars are fine. Both modified turbos and supercharged cars run similar (if not the same) cone filter set ups, therefore why would only supercharged cars have issues with induction noise?

 

I could be completely wrong here, but some food for thought.

[techieboy]

Most turbos don't run a cone filter at all and retain the panel filter and airbox.

 

Yes, there's definitely a problem with SC induction noise as well as exhaust noise.

[fezzasus]

Really? I would have expected most turbos to have ditched their airbox due to the crap design of it

[Rosssco]

The difference in noise is to do with the different compressor types. The SC has a postive displacement unit which "chops" air up and spits it inot the intake manifold. The noise is a by product of this process and the resonances associated with it. You could fit a Rotrex instead and I'm sure it would be alot quieter.

 

Also why running smaller pulleys, plugging silencer holes, and running an 'open' filter makes the noise loader. Perhaps the standard plastic airbox has a dampening effect on the resonant sound waves.

 

The Harrop uses different a different rotor design (more like a twin-screw unit, I think), therefore make different / less induction noise.

[techieboy]

Really? I would have expected most turbos to have ditched their airbox due to the crap design of it

Only those who like the chav sound of the current forum favourite of the Apexi. Everyone else runs the standard airbox or at least a modified version of it.   When the new engine and ECU finally go in my car, I'll definitely be relocating the ecu to get a modded NA airbox (which is actually better than the turdo's) back in the car and hope to lose most of the supercharger whine. Especially if I fit a slightly larger pulley.

[Rosssco]

 

Only those who like the chav sound of the current forum favourite of the Apexi. Everyone else runs the standard airbox or at least a modified version of it.

 

Oi.! I run an Apexi.. Only because my header tank is in that location, so a standard box wouldn't fit..

 

And I like the SC noise, it gives the car a more unique noise compared to the usual loud exhaust and wooshy turbo / dump valve brigade.