575 Fabio Exhaust Question

I'd say it's only loud if you want it to be. IE if you leave the windows up / valve closed it's very mature inside the car. If you open the valves at a stoplight it drones/booms but you control that. However, I do think it's pretty loud outside the car under full throttle. If it's too much Fabio can make an extra pre muffler silencer or just put OE mufflers on.

 

I was in Fabios' 575M and I did not find it loud at all.

My 550 with Fabio's race headers (no cats), Fabio's double H pipe and unvalved mufflers is clearly louder, particularly on cold start ups but absolutely fine when driving. I may add Fabio's mufflers at some point as my current mufflers are a little too bassy and drone a bit too much below 2000 rpm, though they offer a wonderful medium pitch on full load whereas Fabio's headers were designed for a high pitch tone.

In terms of loudness alone I am pretty sure you will be absolutely fine with Fabio's full set up.

 

Quoted for correction.

 

I ran Fabio's headers>cats>h pipe > OEM mufflers and it was very sedate even valves open.
The lack of resonance means while a delightful sound, its very nice and balanced.
I ended up adding Fabio's muffler too as I wanted it a touch louder. Now I think the balance is just right.

In contrast, my Tubis (combined w the later 575 straight midpipes) were horribly loud with lots of resonance. Very happy to have dumped that.