FZR400, FZR400RRSp. FZR400RRSpFIII.
Click on thumbnails to see full size.
Please Note these are details /pictures are from
Yamaha Kit Manual, I will post a picture of our valve assy' asap.
The Headers are tapered, Exup shafts and butterflies are Titanium, and the body is Stainless.
Total weight of the valve assy' is 400g.
The valves are controlled bettween 8k & 11.5k when they open fully.
My Bike is now making over 90bhp at the Rear Wheel, The Exup and headers gave it about 5bhp across the range.
The main advantage is that you can run large header pipes for top end,
without getting a big hole in the midrange power to go with it.
Note, Now running to 15750rpm and 92bhp.