Dump valves ???

[lemond]

Leave it standard for a bit.... then get advice on the next step from a reputable company... MRC seem to get lots of good press so I'd say 'MRC it'

Just get a loop recording of a bog flushing for the CD player if the dump (ahem) valve noise is what he craves!

Mine only has a Milltek dual on. I doubt if it is worth any extra power at all, but the car goes pretty well. I had a nice 'thrash' today from Sheffield to Ambergate and back!.... Might visit MRC at some time, but I can't get the most from my standard S4 and I don't think I ever will be able to.