Freestyleriverrat said:
Single line = 6-7.75mm id (mine measures 7.75mm id)
Restrictors (mm) for #.0
3.5 (2) + 2 + 1 = 10mm of flow + psi loss through pinn holes in head pipe
10mm > 7.75mm supply -> lower system psi
**10mm can flow 129% what a 7.75mm line can supply
FP system reccomendations a 4mm res on bypass w/ single line system
4mm + whatever stinger is 6mm(**)? > 7.75mm -> flow on exhaust side of system
**= 10mm, so a restrictor on the stinger might help keep a little pressure in the system to operate the water injectors in the head pipe. A simple 3mm restrictor after the FCV on the stinger plus the 4mm pisser would flow 90.3% what a a 7.75mm line can supply. 51.6% of that is bypasses through the pisser while the other 38.7% can go to the stinger. Leaving 9.7% for injector function.
For the dual circuit cylinder side line (7.75mm) a 6mm pisser can flow 77.4% what that line can supply.
#.0 Water goes the path of least resistance so more should flow to the cylinder side of your set up, which is fine.........you don't want the exhaust too cool. From the temps you listed sounds like yours is working just fine.
**I think all setups work it is just a matter of tuning them according to system setup/psi. I think I am looking at things way to analytically now :banghead: I apologize :smile: I'm pulling the fugures out of my arse.....but they are based only on diameter of the lines and restrictor size.
The way I came up with different restrictor sizes on my one supply line system was by testing on a flat lake at different speeds for many weeks in 85° water. I used digital temperature gauges on the three bypass fittings with a built-in, maximum memory alarm feature and an infrared pyrometer to measure the exhaust chamber temperature. Two probes were mounted via a plastic T-fitting at the bypass fitting to measure the front and rear cylinder head temperatures. One probe was to measure the water temperature coming out of the head pipe going to the stinger and out the pisser. The front and rear cylinder head temperatures were about the same (around 117-128°) with the front cylinder always about 2-3° warmer. On a one-mile, full throttle run, the temperatures would never go above 127° on the front and 125° on the rear. The head pipe water temperature had a maximum of 155° coming out of the pisser, during long WOT runs only. After long WOT runs, the exhaust chamber temperatures measured around 250° when stopping to check it with the infrared pyrometer.
I used various sizes of restrictors in the pissers, head pissers, and stinger inlet during the testing and found this setup to work the best for me. At one point, I had the cylinder temps. up to 136° and found the engine to have very good low-end grunt, but lost almost 300 rpm in the top end. It seemed like the hotter the head chamber water temps. got, the more power it would produce throughout the entire rpm until the point of burning my skin from the water coming out of the pisser being the limit. My water screws seemed to work with the best setup as a half turn on the bottom screw, with the top and middle screws closed, and 1mm restrictor in the stinger inlet keeping the water box dry.
This is all something you have to find out by testing your setup to see what's best. A half turn on the top screw has a completely different effect if you have dual cooling, single cooling, 3 bypasses, 1 bypass, huge pump nozzle, stock pump nozzle, etc. All of those things (plus more) effect the water pressure in the head pipe and that affects how much water is injected, plus little things like how much carbon buildup there is in the head pipe at the injection hole.
People want cut and dry answers on tuning, but tuning is a lot of testing on the setup you have to see what does and doesn't work.
