There has been alot of interesting posts lately about props and speed. I am curious to hear how fast 18 and 20 footers have gone. Backin the early 90's our team was running yamaha 200hp twins on an 89 hydodyne 20ft. I dont remember prop pitch but I do know they were aluminum. We were seeing about 54mph according to the yamaha digital speedos. I almost forgot to mention it was not counter rotating and had cable steering. It was a beast to drive.
My boat is no speed boat. With a torque shift it will go about 55. It is an 18 with 150 Faststrike. With the modified 17 it hits the rev limiter below 50. jim
2005 Dyna-Ski 20' Open bow/250 E-Tec 67 gps with a 22 Raker If driveable I am sure an 18 could do 70, but it would be scary.
I only drove my boat once, right after I bought it, in freezing cold October weather in Indiana. It had a 1983 Mercury ELPT 150HP engine and a soaked, rotted floor full of waterlogged floatation foam. It had two rear mounted tanks in the middle of the floor near the tow pole - 15 total gallons. It nearly sunk when I was launching it with the heavy, wet foam and rear mounted tanks, combined with the shallow draft of this boat. It had a very nice stainless steel prop on it which I stupidly sold with the motor. I don't have any idea what the pitch was. It had an older airguide but no pitot (pickup) so I bought one just for that day so I could see what it would do at WOT. Top speed? 44 MPH. On plane immediately. Had never driven any boat like it. Felt like 100 MPH to me. Although I've driven boats faster than this, it really felt fast. My kids hated it. Of course, I was sitting in the only seat available in the boat. The kids were sliding all over the floor as I had a blast throwing the boat around in 40 degree weather!
When I had my 18' it had an Optimax 150 with a high five. Top speed was bouncing off the bottom of the Airguides, so I do not know. They register to 50mph, so your guess is mine on that one. Now Bob has a 250 Opti on it, and I am interested to know what it does. It's gonna be scary, that is for sure. I still call dibbs on first ride Mark. So Bob, have you taken it out on the water yet? Greg
Greg, No haven't had it out yet. I hurt one of the motors on my Cigarette boat at the end of last season and have been down in Ottawa the last few weekends working on that. This weekend I'm going up to Karens place in Green Lake so hopefully the following week. I did get the new rope guard made up and installed..put on the carbon fiber steering wheeel and put in the foot rest for the passenger seat this week. Took it to the graphics place today and they are going to make exact duplicates of the rear decals. I'll let you know where I'm going to put it in and you can meet up with me if you'd like. Bob
