Originally Posted by
topcat-lll
Did some testing today and what I found was surprising. When I first changed
over to the 9886 pipe from the 9901 and a 7mm venturi to a 7.5mm I made
a slight needle ajustment and ran from there. What I found out today is that
you have to completely retune the engine. I mean start with the HSN I ran it
up and down my street until it was set. Then the LSN leaned it until I got a
constant steady idle (before the idle was blubbery and not constant) I let it
idle for about 10 seconds then yank the throttle and it accelerated with
out stumbling.(before when I did that the engine would almost die or did die)
Well anyway the engine runs like a champ now, the lag is basically gone. I race this Saturday and I will let you know how it went. The 9853/41005
combo sounds interesting, but I would think the two 90 degree bends on the 41005 would hamper the top-end?
no it doesnt and yes , every time you change pipesets that have different characteristics a complete retune is in order , i recommend just richening needles at least 1/4 turn on high and low before you go out and run or bench tune .
top end pipes will have leaner bottom and richer top balance and opposite for low end based pipes
a little tip from your uncle larr'
