Thread: Questions on new mods
04-24-2008, 03:20 PM #1
Questions on new mods
Hey guys, I just added the Riva stage 3 SC, 42LBS injectors and 15/20R to my set up. First time out today I pulled a 76MPH on GPS. RPMs where at 8200-8220 and I saw 9.7 PSI of boost. Does the boost pressure sound right? It was about 80 today. Also I know I need to add pitch to the prop but how much? 1mm sound about right to start with. And when I do repitch the prop will I hit 77+? I think I should. I was happy w/ the results for the first time out. It pulls way harder out of the hole!! Also noticed the SC started making boost about 1000 RPM earlier. Just want to get it dialed in perfect any help appriciated
04-24-2008, 03:36 PM #2
- Join Date
- Feb 2008
Was it 76 even or was it closer to 77. You are close on the rmp, just a little to high. Not sure how much you should add but if it was low 76 than i dont think that you will get 77, but anything is possiable.
Congrats on the new found speed.
04-24-2008, 03:43 PM #3
Stock nozzle? Many of us have done well with the 81mm nozzle ring with a setup like yours. If you only have the stock nozzle, then I would definitely add 1mm to your trailing edge and you might get 77 mph.
04-24-2008, 03:52 PM #4
Yes I have the stock nozzle. Does anyone else make a nozzle w/ interchable rings other than Riva? Its expensive
04-24-2008, 04:09 PM #5
you're bouncing off the limiter... I bet theres a least 1-2mph left on top.
Someone here can/will machine stock nozzles I think. Might take a litte searching...but it's here somewhere.
might be time to look into a lower temp thermo too.
04-24-2008, 04:28 PM #6
04-24-2008, 05:20 PM #7
- Join Date
- Jan 2007
- Lakeland, FL
9.7 is a tad low, considering you were 8200+; you could have a minor boost leak. Did you seal your IC blockoff? All clamps on tight? I think 10.5 would be a more normal boost number at that high of RPM.
04-24-2008, 05:33 PM #8
Blockoff seales w/ silicone and all clamps are tight as far as I know. Will have to inspect closer
04-24-2008, 05:35 PM #9
Keep an eye on your exhaust manifold tip. I run 8180 rpm for about 1 hour (wot here and there not all at one time) and scorched mine pretty good. I had to weld it up and remachine it. The S.S. mod will be next. I'm going to stay around 8100 and see how it does.
04-24-2008, 05:57 PM #10
Users Browsing this Thread
There are currently 1 users browsing this thread. (0 members and 1 guests)
By pinepear in forum Kawasaki PWC Performance (4-stroke)Replies: 3Last Post: 11-06-2009, 03:55 PM
By Yuji in forum Sea Doo Sport BoatsReplies: 6Last Post: 06-15-2006, 09:00 AM
By Pistonwash in forum Yamaha PWC Performance (2-stroke)Replies: 8Last Post: 03-17-2006, 06:16 PM
By The Green MACHINE in forum 4-Tec PerformanceReplies: 7Last Post: 03-16-2006, 10:34 PM
By buddydoo in forum 4-Tec PerformanceReplies: 5Last Post: 11-12-2005, 10:41 AM