RCU Forums - View Single Post - SAP 180 (Syssa Performance)
View Single Post
Old 07-26-2011, 07:19 PM
  #1459  
tele1974
Senior Member
 
Join Date: Jan 2007
Location: Olmsted Falls, OH
Posts: 478
Likes: 0
Received 0 Likes on 0 Posts
Default RE: SAP 180 (Syssa Performance)

I have been reading about pipe set ups because I was curious about the physics. I am wondering how you guys came up with your header length. Did you start out with the formula for a flat disk pipe and then adjust from their?
I'm just trying to understand the numbers. I measured the exhaust port timing and came up with 170 degrees. Correct me if I am wrong.

Exhaust port timing (1200) / RPMs. = Length from disk to face of piston

Calculating it backward with estimated RPMs of 7500 that would equal the reccomened disk to face measurement of 27 inches.
But here's where I'm confused, ghoffman was turning 10g on a 18x6 prop with the same setup. Wouldnt the timing be off at that RPM? Interesting to learn about. I must be missing something thou.