I have read all the posts concerning exhaust modifications. I am a Sales Manager for an engineering comany, but I am also an engineer. I have been building and tuning engines (mostly 4 strokes since I was 15, and I am now 51. Modern auto-engines are designed to offer a balance of performance and economy. Performance is about cylinder filling. I will not go into the physics and thermo-dynamics, but my experience is that unless you start at the manifold, or better, just behind the valve, any performance gain cannot be measured, and you may in fact lose out. Certainly any modification which does not include throwing the cat in the nearest canal is not worth a carrot. We modify the rear of the systems on our trucks because we like to hear the rock'n roll, so forget performance and economy unless you plan to replace the whole system. Besides, you will need a lot of expensive forming equipment, a dyno, a lot of tubing and a lot of time. Ford have all this, so let them do the work! Know the sound you want to hear, select an outlet that matches it, dont try to justify it with other stuff and be happy.
All time worlds best noises
Rolls Royce Merlin with the throttle through the gate
3 Manx Nortons on Bray Hill (Isle 0f Man)
The Panos cars at Le Mans
The first lap at the Brickyard
My Martin CBX with a straight mega (stuns small animals at 500 yds)
Almost any well sorted V-8
Regards,
Hughie