FSH 210 Sport
Jetboaters Fleet Admiral
- Messages
- 7,123
- Reaction score
- 8,680
- Points
- 502
- Location
- Tranquility Base
- Boat Make
- Yamaha
- Year
- 2020
- Boat Model
- FSH Sport
- Boat Length
- 21
"A 250hp vs 290hp at 7500 with the same impeller/pump setup will net no increase in speed. " But 290hp at 7500 will give you the ability to re-pitch and in turn can pick up top speed.
Yamaha just launched a 1.9ho 200hp and the stock wave runners picked up 4mph. So more HP and a different impeller then the 1.8. I know this was also talked about here during the Yamaha launch of the 1.9 in the boat there was some added speed on the top end on the 222.
"I still maintain that going the route @Wicked92 did to fine tune the impeller is the most effective way to improve performance at a given location, altitude, without sacrificing reliability / longevity / warranty."
"There will be a loss in mpg by going to a lower pitch impeller, my personal experience was a loss of .3-.5 mpg but it was well worth the gain in performance in my case, there’s always a trade off. If I was going to be running a lot of longer distances and fuel range was a concern I’d drop my oem impellers in and sacrifice some top end speed for up to 25 miles greater range."
@FSH 210 Sport You are worried about a completely different end results then we are looking for. You keep talking reliability / longevity / warranty/ 25 miles greater range.
We are talking more power more fun
These motors are more than capable of more HP and a bit more RPMs.
Wicked is @ sea level best case for hp and top speed. He has a set of the twin impellers that were pitched for best results and he lost top end speed. Can he get it back? maybe. Still waiting on this season testing.
@FSH 210 Sport Aren't you scratching every ich you can find to MOD your TR1's to gain maybe 4mph. I could literally copy and past all of your posts from this thread to "Tuning a TR1 - Riva Tuner" and poo poo on your journey.
Not trying to pop poo the 255XD journey. My intentions are true, I would be remiss if I did not share what I’ve learned with fellow members. And from what I see from map tuners dyno charts the SVHO motor won’t achieve the 35 hp increase in power unless the rev limiter is raised to 8300 rpm for a target of 8100 rpm, and that means lower pitch impellers thereby increasing the effective displacement.
The TR-1 project seeks to increase volumetric efficiency across the midrange and on up to the oem rev limiter, I think I was pretty specific about not wanting to raise the rev limiter. This would be using cams that open faster, open farther, stay open longer and close faster, and these cams are in between the stock TR-1 cams and the Viper variant used in the side by side, so nothing radical at all.
The 1.9L engine did several things to increase power, added 100cc of displacement, and increased volumetric efficiency, via longer intake runners, different cams etc.
As far as warranty goes, I’ve seen some other posts here where people did things and got their warranties cancelled and then they were not happy, so that’s my angle on the warranty thing. I’ll be waiting to see what the testing here in this thread comes up with.
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