I've put a wanted ad on for an air box to drill to try to capture the 5 cylinder sound.
I know I'll probably run into flat spots but I'll put up with them if the sound is good.
I had an uno 60s (carb) and an Alfa 75 twin spark (inj) and they both had a plenum gurgle, like you get from a twin barrel carb set up eg twin 40's.
The noise occurred with a Wot at low rpm.
If I can't get this on my Coupe, I may have to swap it for a cheap Alfa v6 like a 156 2.5.
Jonscoupe vt sounds great at low speed - check out his vid on the s Wales s west meet thread.
So, has anyone got any ideas on how to make the Vis sound better?
Or had anyone experience of the Alfa 2.5 v6?
Cheers

I had a VIS with a K&N Cone filter on, standard exhaust - It growled like absolute hell on the GO pedal, definately more than a 20vt on the induction side IMO.

Did you fit the k and n so you could compare it to standard?

Any flat spots in the rev range?

I understood that you need the full inlet tract to maintain torque at low revs. So I've stuck with the standard airbox and a K&N panel filter.

Best way to get better sound would be a new exhaust.

here is mine.

https://www.youtube.com/watch?v=zbGo1OnuJag

I agree with Gripped as I have std air filter / box but changed exhaust to a Cybox stainless steel Cat back system and my NA sounds pretty good in my opinion, makes the most of the 5 cylinder burble and growl.

Yes, your car does sound good with that exhaust, Toby. And the engine sounds great too in that underpass.

Cooperman - is yours the single box Cybox? Isn't that really loud? Any problems getting it through the mot?

With a k and n induction kit being £140, a cybox system being £199 and Toby's system being more again, like a moth to a flame, I'm drawn to drilling holes in a spare air box, when I can find one.....

Yes my is a single box and not too loud when at cruise, MOT was no problem at all

Wow. Cooperman, C C Joe mentioned your Coupe and it's epic sound track when you were at Brooklands yesterday.
Thumbs up for the Cybox then.
Have you fitted your Fc performance chip yet?


(I've still yet to find an air box to drill).

If you get a better exhaust you shouldn't need to drill the air box. I would be concerned about the loss of power. The na intake is tuned to give low down torque so altering the airbox isn't going to help performance even if you get more noise. A k&n panel filter will help.

Just my opinion.

I had Bravo HGT VIS and drilled airbox was only thing I did for better sound.. (i fact its a mod I have on every my car.. (from AR 147 1.6, 156 V6, Tipo 16V, coupe 16V, Stilo 1.8)

on stilo, where is VIS and Intaka cam variator was hard to get some sound from intake, unless I disconected the solenoid and timed cams to 107/109°

I also did not noticed any lack/loss of power after that mod.. simpyl because, that you should assure no pressure drop/vacuum before throttle body - which in standart trim occur..due to restrictivepiping, filtrr, and airbox shape..

Thanks Honza, and everyone else.

I have a replacement stock back box on the way from ebay, won for 99p plus p and p.

And as soon as I find my hole drill bit the air box gets it!

Well, the 99p back box arrived, and it turned out to be a cat-back, two box section.
Made by the well known performance exhaust manufacturers Stelco (ahem), it's not of straight through construction at all. But I hope it will parp and chuff a bit when fitted.

I've also drilled four 1" holes in the air box, two low down on the left and right sides. The induction noise is better and made me smile.
As for flat spots, I don't think there are any, but it's hard to tell as flat, straight roads are hard to come by round here. It certainly feels lusty through the rev range still.

A pair of fluffy dice hung from the mirror after the exhaust is fitted, and my 'stage 1' performance pack is complete

Had the chance to give the car the beans tonight - first time since I drilled the airbox.
And, it's great.
I get induction gurgle/warble from 2k rpm onwards, sounds really fruity about 4k and performance is better at the top end.
MPG is falling though - my driving style has changed to make it sing.

It certainly is all about the sound for me.

Good effort mate. Post some vids when you're done. Would love to hear it.