Sunbeam Alpine: Exhaust back box comparison

[Tim R]

This video shows a direct comparison of the noise (dB measurement) of a standard Alpine back box compared to the quieter three section stainless steel silencer back box that we fitted. This will not be something that will appeal to everyone as many people like the sound of the 'straight through' style of original silencer. We use the car regularly and prefer the more civilised sound that the quieter exhaust gives, particularly at motorway speeds.

Tim R

 

[DanR]

Tim, you did good as usual with this demonstration.....

I am curious as to what the "back" box (s) look like from behind the Alpine at a distance of say 20 to 30 feet.

What amount of clearance do you have from the bottom of the box (muffler) to the road surface?

Better yet, can you provide the diameter of the box/muffler ?

 

[Tim R]

Dan, I will get some photos and measurements for you in a few days time. The distance from the bottom of the box to the road surface is the same as for the standard back box, the extra size is in the offset bulge to the side. The original is a pipe with holes in it surrounded by some wadding in a larger canister, the gas can just pass straight through along the pipe and out. This alternative type has three sections, two of which have wadding in them. The exhaust gas has to travel through the first chamber packed with wadding, then into an open central chamber, then into the third chamber packed with wading before it flows out of the tail pipe. This results in the noise being greatly reduced because the energy has passed through the wadding. On the original most of the exhaust bypasses the wadding completely.

 

[DanR]

Thanks,

 

[Tim R]

Dan, here a couple of photos from behind the car. I did a 60 mile run yesterday at motorway speed and it was noticeably quieter in the cabin. It is not something that everyone would want to do and I get that but if you use the car a lot and want it to be as civilised as possible it works. Tim R

 

[DanR]

The rear shot looks like one of mind from a few years ago. Thanks much....

From the looks the ground/road clearance is about the same as "stock".

 

[Tim R]

Yes it is wider (offset to one side) but the same ground clearance.
Tim R