TrentonC

I recently replaced the rotted tubes on my '81. However, while I was waiting for them to arrive I began experimenting with alternatives. I am thinking of rolling some stainless steel and connecting the pieces with blue high-temp rad hose. (Oooh..Pretty!)
I have 2 questions regarding this:
1) Is the hole on the bottom which connects to the cam gear cover more than a positioning device, or does it provide some sort of cooling function to the timing belt?
2) Is there a specific reason why the tubes reduce at the middle? Is it a flow thing or was it just to make them fit for space/flexibility reasons?

I have guys at my place of work who can make SS tubes for me that I can then cut to length and make fit, I think it will look quite sharp.

Lizard928

The reduction in the tubes is for noise.
The holes are for cooling of the belt, though many do not use that and have no issues.

TrentonC

What kind of noise? I wouldn't be able to hear a damn thing over the engine while in the car.......
If the people on the sidewalk complain, well....chances are they won't hear it for long anyways!

Stromius

I redid mine with Mercedes tubes (2 each side with 3" silicone coupler in between. These fit without cutting on a S4: http://reutterwerk.com/forums/showpo...93&postcount=3

TrentonC

Cool. I was just thinking it might look neat with the SS and blue. I have new ones for now, but I might tweak it later. I already have some rolled 1/8 SS tubing to use, I just need to decide how I want to use the hose.

17prospective buyer

I thought the narrow part acted like a venturi which speeds up air velocity and decreases pressure.

TrentonC

Ah, that's what I'm curious about. I don't want to screw up some sort of tuning effect.......

GlenL

In the venturi the air speeds up and then slows down. The sound reflects off the cone.

I went with 3" brake duct. For $50 at Jegs or Summit you get enough for 2 cars.

brutus

Very dead horse topic kicked around many, many times here.