Modern Vespa

Hello,

I have installed the Arrow Urban exhaust on my 2023 GTS 300 scooter. There are two types of dB killers designed by Arrow for this particular silencer that I'm aware of. In the attached picture, the one that came with my silencer is the lower one. The upper one is also available for purchase.

Does anyone know how these two may differ in terms of sound or performance?

Top one should be louder, bottom one looks more muffled probably cause of Euro 5…

the bottom one with the holes is the same as the one in my Euro 4 Arrow Urban
(53525ANN).

Edit: I checked by sticking an endoscope camera in there

Bigger hole will always be louder, less restrictive. Looks like you could get pretty close to the accessory part by just cutting the end off the one you have.

Make sure the photo you're looking at is what you'll get. A lot of times, manufacturers change the product without updating the photo, or dealers will use the first photo they received or took, even though the product has changed. You might get the same product, no matter where you get it.

In the lower one the sound waves are being split and forced to change through 90 degrees to enter the side holes whilst a small portion ( the tuning) go straight through. On the top two there is no side attenuation just the restriction. So I would expect a deeper louder more distinct sound where each exhaust pulse can be heard.

The best thing about removable db killers is you can swap back to stock, which most folk want to do as the drone of an un silenced zorst gets very tiring on a long run.

Now if it was a Pops Yoshimura on a four cylinder screamer……thats a different kettle of fish 🙉

I don't often ride in groups but when I was behind the guy who had no baffle (think was a malossi) it was not nice riding behind him.

I assumed the same, but after reaching out to Arrow support, they informed me that despite the different designs, the backpressure remains same and there is no variation in noise and performance between the two.

I'm not seeking additional noise, as the Arrow already generates considerable sound even with the baffle. It's enjoyable for city rides, but on highways, especially where there are hills, it can become tiring.