2008 Speedster 150 Supercharged WOT RPM and Speed

[LTW]

I have a 2008 Speedster 150 Supercharged. Super charger has been rebuilt and boat has around 150 hours. We boat on lake powell ut elevation is 3530.
At full throttle 2 people in the boat we are getting RPM of 6840 and top speed around 33 mph to 36 mph.

I feel the rpm and speed should be greater than we are getting.

What is the best prop to run for top end and what do you all think the WOT speed shoud be.

Thanks for the help.

 

[MacSeaDoo]

I have a 255 HP version of your boat. It has a larger external intercooler.

HP is relational to air density. The 2 things that affect that are altitide and temperature.

I am at sea level and can hit 8100 RPM and 62 MPH in the cooler beginning of the season. Mid season when the water and air are warmest, that drops to 7800 ish and 58 MPH. Back to the higher number as the season ends.

Just your altitide alone would be approx 23 HP loss. If you think of mine that drops from 61 to 58 with a loss of 300 rpm.

From what I read your machine should do 54 mph and 7800 rpm.

I would guess that at your altitide you would be talking 48 and 7300. Now like mine if the temps water and air are warm, I would say 45 and 7000K

Again I am just guessing. Maybe someone else who has altitide experience could chime in.

One big factor on the speed is to use a GPS, because my speedo says 48 mph at top speed but I am doing 62.

 

[LTW]

Thank you for the reply. The MPH reading was on GPS.
I just dont know what prop/impeller I should go with to gain RPM I feel just like you said . We should be getting 50mph and more RPM.

 

[LTW]

Found out the prop/impeller it is a 14/19 Solas

 

[LTW]

Re pitch Solas SRX-CD-14/19 pitch to 14/17.5
High Elevation 3600- 4000'

Getting 8100 RPM now and 54 mph on gps.

Sent it to ImPros in So cal.
These guys are great to work with.

 

[MacSeaDoo]

Awesome, glad you found ImPros as it sounds like to me they tuned the impeller right to what you needed.