Angus,

I have used moth the NMP Heade from Central Hobbies and the Hatori rigid headers. They perform the same. The Hatori is a slightly heavier. The NMP header needs a slightly larger clearance to the fuse or Belly pan side.

On my Astral XXc's I have the Hatori. However on the Adventure Bipe I was able to fit the NMP header in it. I prefer the NMP header as it is easier to setup and tighten. I have run hundreds and hundreds on flights on the NMP with very little problem. The Hatori has not given quite as good of service but it has been acceptable. One of my Astrals has about 400 flights on it and I had a header replaced at about 300-350. This was not premature in my mind. However I have the NMP header that have been around for years and never a hiccup.

I have never run the Asano Headers but I know several folks that like them. I think you will get a performance increase going to the Hatori or the NMP.

500rpm in my mind is a little much, but back when I did some extensive testing I found 300rpm with the YS 160DZ switching from the OLD NMP or the CD headers to the New style NMP DZ headers. The 170 could give a similar change. To be honest I have been running 170's for about 2.5 years now and never ran one of the smaller diameter headers on it.

Troy Newman
Team YS