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Discussion Starter · #1 ·
Right......

I'm toying with a couple of "induction" options.....

1. CAI - expensive, not sure i want the "loud" dump sound

2. just add ducting - mega cheap - but what benefits?

3. The smoothed airbox and 80mm ducting mod - cheap, and highly documented as as near to a CAI as you can get without actually fitting the CAI.

so.....to me its between 2 and 3......

does the smoothed air box and ducting add any sound? i know the performance gains are well documented......
 

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Dont know if the smoothed airbox sounds any different? What gains do you get from the smoothed air box mod and what do you get on avarage with a CAI kit? If its only a couple of BHP is the extra expense gonna be worth it?

Im only running a K&N panel filter so im interested in this also, as i have been thinking about the smoothed air box mod myself.
 

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Discussion Starter · #3 ·
i know the smoothed air box is in the same league as the CAI in power gains, some even say better.

just wondering about the sound improvement by doing the ducting too.
 

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I have the 80mm ducting and standard filter

and havent really noticed alot of differance,

my car is not yet remaped though. when it is (May 7th)

it may be a different story
 

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I guess ducting would give a very slight increase in sound, very minimal.
why though?

surely a smoothed air box and ducting is very similar in setup to a CAI??
The noise a CAI makes is a BOOMY WOOORRRRRRRR type noise - same as a drilled airbox.

You can't get this noise from ducting - ducting is too thin to re-produce the bassy tones. Does that make sense?
 

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The noise a CAI makes is a BOOMY WOOORRRRRRRR type noise - same as a drilled airbox.

You can't get this noise from ducting - ducting is too thin to re-produce the bassy tones. Does that make sense?
Yeah, ducting is too soft to act like a good resonant chamber.

Here's one I recorded earlier [:p]

http://www.lais.pwp.blueyonder.co.uk/sounds/kn_typhoon.mp3

Sounds better with the bonnet closed and engine under load but gives an idea [:)]
 

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I love my Carbonio, I'm remapped and have a turbo back Jetex around 220-225bhp and the Carbonio just sounds awesome under load whistling loudly as the turbo spools and a short aggressive dumping sound when changing gear quickyl, I absolutely love it!

But it has been well documented that a smooth airbox with green panel filter and sensibly placed ducting can lead to a bigger increase in airflow than a CAI. And thats what counts if power is all you're after.
 

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Discussion Starter · #11 ·
its not a massive sound i'm after....a slight increase would be nice.

drilling the air box has been mentioned........

how about a drilled but not smoother box and ducting?

hmmm..........
 

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drilling the air box has been mentioned........

how about a drilled but not smoother box and ducting?
NO drilling all you will do is pull hot (less dense) air in from the engine compartment. Smooth that box, Green Filter (or change the paper one more frequently) and duct in nice cool dense air from down low on the front.
 

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Discussion Starter · #13 ·
i already have the green cotton panel filter.......

so the best option is smoothed and ducting......

realistically what gains in bhp are we talking? 2-3? maybe 5?

and the sound is still in query.......i aint bothered if there is no sound increase, jsut want to know what to expect.....

when i do this mod i'll take a load of pictures by way of a how to.
 

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Ok

Sorry to sound dumb, but I have the 80mm ducting taking air from the front off side lower grill.

But what is ment by smoothing the airbox?
 

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When you look inside the standard airbox you'll see that it has a number of 'ribs' in both the top and lower sections. --- When you smooth it, you just remove these protrusions so that the surface is smooth. The idea being to promote better air flow.
 

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When you look inside the standard airbox you'll see that it has a number of 'ribs' in both the top and lower sections. --- When you smooth it, you just remove these protrusions so that the surface is smooth. The idea being to promote better air flow.
Obviously you do get beter airflow without the ribs or baffles but they are there to do a job - they stop the engine sucking in water. In time you will find if you smooth your airbox that your air filter will clog up much quicker and you will end up with a dead maf which means less power not more.
 

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Ok thanks for that,

I think i will just stick with the 80mm ducting and leave the air box alone.

Water and engines dont mix so well. thanks Patchrico. probably whould have gone ahead a done that

without your warning

may even invest in a carbonio at some stage.
 

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Obviously you do get beter airflow without the ribs or baffles but they are there to do a job - they stop the engine sucking in water. In time you will find if you smooth your airbox that your air filter will clog up much quicker and you will end up with a dead maf which means less power not more.
Ive had a smoothed airbox with green filter and 80mm intake hose for 18months now. Filter gets no dirtier than before, airbox is always clean - no leaves or dead flies etc and a very healthy MAF which reads around 190g/s which is much higher than my previous CAI.

Don't believe everything you read, unless your comments are from personal experience?
 
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