As I explained to you on the phone Kin, I did not have exactly the same job done as I was a bit worried about the noise level. I dealt with the fitter Dave, who has had experience of spannering for several race teams, and described to him what I wanted to achieve, that is a reduction in back-pressure combined with a more sonorous note with no flatulence. I also wanted the outlet to look teh same as the OE sidepipe, rather than a rolled pipe.
Here are the pictures, taken in haste I'm afraid:
As you can see, he has sleeved the outlet in the same way as the original pipe, but the pipe is 2.5 inches compared with the OE pipe with an internal width of 1.5 inches. Externally, they are both the same diameter.
The exhaust note is excellent and back-pressure is definitely reduced and there is a real basso profundo depth to the exhaust. At high revs, they measured 101 db's (and this was inside), compared with 108 db's for your system, so it should be all right for many track events. However, Dave has taken the measurements of the tail pipes and if I need less sound for track days, etc, he will send me alternative tips (of 1.5 inches internally) which will considerably reduce the overall noise level.
For now, I'm more than happy with the new set-up and just love the enhanced V8 woofle and the reduced back-pressure too, that seems to mean that the engine is more willing to rev. Probably imaginary, but I'm happy.
For Cereal, I spoke to Dave about your headers and he said that they can fabricate them exactly how you want them - 4 into 1, 4 into 2 into 1, equal length pipes, etc, and they also have catalysts for racing which he says make an enormous difference. If you phone JP Exhausts and ask for Dave he can discuss more fully with you on what is possible and your own particular requirements.
