Well I have again updated the pipes on my road and track bike.. this time I feel I have the exact combination of looks and performance that I was after...!! So The GRAVES Motorpsorts pipes are all fitted and ready to go. I had to do a bit of fibreglass trimming for it to fit perfectly with just the clearance I required, but even that looks factory..!!

Interestingly the pipe dimensions are quite different as are the dyno graph figures. The Akrapovic, M4 and Graves pipes all start off with a 54mm collector pipe at the main junction, the M4 stays 54mm all the way into the muffler, but again gets larger finishing off with almost a 60mm bore.. very large but a great deep sounding note (but perhaps not enough back pressure?) The Akrapovic is also a large bore pipe at 54mm but the muffler bore reducing to around 52mm, but a much longer muffler (so it's quieter with that well known akrapovic note). Where the Graves starts at 54mm, reduces to 52mm at the muffler then reduces again to 50mm for the muffler bore.. This reduction definitely causes more back pressure, hence more low to mid tourque boost. With a mid boost coming in from 6000 to 10,000 rpm. So a much smoother line with the mid range filled in. The Graves still sounds really tough, but slightly higher in pitch than the M4 and possibly a bit louder, but all good for the track.
Look they are all very similar, but the graphs definitely show the Graves boosting more in the area where this model is lacking slightly.. Worth a try and looks fantastic. Another thing I noticed immediately is the bike idles much smoother with no surging at all.. Win - Win for me...

Macca.
