ally2dextreme
Active Member
- Joined
- Mar 17, 2005
- Messages
- 835
- Points
- 18
For top end runs your better in the 7500 rpm range from what I've seen,if I was running top end with a 260 I would use a 30 pitch...
Its not the prop that's the problem its the hull the boat gets very ill handling there a safe 105 mph boat and a Yamaha prop will lose top end to a chopper 99 percent of the time and the guy who does my props has the worlds fastest and quickest props no dummy25 knob cut and 26 chopper? Are you joking? A good 26 Yam or ET should smoke both of those old school props. No wonder you haven't been able to get the SS to run. BTW, the smaller pitch 4 blade mazcos run very well...a little torquey on the wheel but they're not slow.
Stock 96 260 SS ,well cut heads to 150psiAlly what kind of mods you have done to your motor that runs good??
I think a big number is possible. My SS2000 with my lightly modified XR4, Bobs cone XR4 gearcase, went 89.7 and I'm far from a set up expert or the best driver. 8" setback, propshaft close to even with pad. If we assume speed proportional to square root of HP, and that my motor made 175 HP
300 HP yields 117.5
280 HP yields 113.5
260 HP yields 109.3
225 HP yields 101.7
This assumes someone can actually control the boat at those speeds. If someone got a few mph more, it would not surprise me. As noted above, I'm not the fastest driver or best at set up.
Highest claims on the front page of this site
Yammer 126 w/260, Titus coned 200 case, 28 lab clever (8% slip)
Dru Pobell 124 w/300 drag w/NOS, 22 drag, 10000 rpm (-11% slip)
Dondi Pratt 121 w/280, 31 Triton, 9400 rpm (18% slip)
Dock Boy 120.7, 280, no prop or rpm
John Joachim 120 w/280 30ET 8000 rpm (1% slip)
Scott Gilmore 115.9 28 Triton 30 ET, slight mod 260
Roy Roach 110, I think he said he got more in posts on the board
Mark Smiley listed at 97 with a 150 Promax. I think he changed the tuner. Torquemaster gearcase
I think me and Mr Tiger will be at the flea market that day.Bring to jasper river run would like to see that..
Leaded fuel until 1995 allowed more HP and Compression in the same motor that without leaded fuel would have to have less. There was still leaded fuel around a while after that but its pretty hard to find now a days. An engine designed in the 90,s wouldn't be as potent as it would have been with leaded fuel today. This is particularly true for two strokes. You could run higher compression than you can now with leaded fuel as it helps with detonation thus = more hp. But to know what the comp numbers of a motor from back then to now is a far stretch and your probably right that it wouldn't make the differences in this case. There are to many variables like temp,humity,water temps,water oxygen content.pad design,prop,setback driver weight,Balls ect... to have two light weight setups run the same top speed with different drivers at different locations.I'm not sure fuel is such a HUGE factor. My bone stock never touched 95 Promax was said to push my GS 97mph at one time with a 32pitch. I have been running a even 100mph with a 30pitch at the 6750 rev limiter with today's "crappy" 93 octane with ethanol.
Yes they can go over 105 and are a handful maybe it was just mine it was brand new 2001 and loved 105 with a 26 and you sure would of thought it would of gone faster heck my xr2002 went 109 with a 24,and when I rolled my ss to 115 with a drag on it it was a death trap maybe that's why I have a hard time believing the speeds....Any ways I have a comp ss now like new and I am going to run jasper river run with a 28 14 inch diameter Hoss prop and we will see if it drives good maybe its just me but everyone at the Allison rally agrees same....Jeff one can only say supten aint right.. i cant believe for a min you think 105 is it with a 260 on a SS. Especially when a Grand sport with a 260 is 105-107.
I must be very naive I guess as to what your getting at?
So your using hydro accomplishments to prove you had the right prop on a 20ft outboard? Seems a little oddI was thinking about a re 4 blade masco props my prop guys holds world record speeds of 275 in 3.42 et top fuel I would think he knows what's going on and won two championships the past 2 years top fuel hydro king.....maybe it's just me ...