Question?

[Cruachan]

Rover 75 2.5 V6. If one had to install a new back silencer which one is appropriate? I looked at Rimmers and they had a plain looking one and one that was ridged. My car has the ridged one. Rimmers stated that the ridged one had been superceded by the plain one. Confused.Me

[Odd Job]

Generally speaking, O.E. silencers are "ridged", this goes for pretty much any car with a factory silencer.
The shape and size reflects on the amount of silencing and performance that a manufacturer designs that particular exhaust to have.
These tend to be quite expensive to produce, but work well at keeping the noise down and performance good.

Now an aftermarket silencer, a budget one, tends to be made cylindrical with no ridged outer. This is mainly down to keeping the price low, easy to manufacture compared to an O.E. one.

I'm not saying that the one thats been "superseded" is no good, but you may well find that it doesnt silence as well as the O.E. style one, it may perform about the same, mainly because what it looses in size and shape mayallow it to flow a little better. It's hard to say.

There is a complicated science with exhausts with flow rate, back pressure, sound wave / pulse wave and scavenging effects, and of course bore size.

Bosal, Klarius and other branded aftermarket exhausts tend to be quite good even when they dont quite resemble the O.E.shape. The ones to watch out for are the ones you've never heard of.

Hope this helps.