2008 challenger 180 - RPMs seem high

[Carpenter29]

Hello everyone. Just took our challenger out for our first spin and something I didn't notice during the test drive was how high the RPMs run. When the speedo says mid teens, like 16-18mph I'm around 5500 rpm. Hitting the low 20's like 22-23mph I'm at 6,200/6,300 RPMs. Is that normal? I tried looking up what's normal and this seems high. It was just my wife and I in the boat, no towing or other heavy loads on the boat. Thanks

 

[frpole]

It's totally normal. These boats run up to 7800 to 8000 RPM at wide open throttle, and dont worry there is a REV limiter built in. The engine is a four stroke, 3 cylinder, 1.5 liter but it's Supercharged and Intercooled to put out 215 HP, so you need 5000 RPM just to move the boat at 10MPH. Best cruise is around 6000-62000 RPM and should give you about 27 MPH running on smooth water and less if you're running in chop. It's also the best gas consumption.

Open her up at full throttle until you reach 30 MPH, then ease back to 6200 RPM and that's your cruising speed with two people, smooth water and full tank of gas. If you need more RPM to get to 27 MPH then look at the impeller and wear ring as you could be loosing thrust if the're worn.

 

[MacSeaDoo]

I think your speedo is a mechanical wheel based unit not a GPS but I could be wrong.

The unit in my 2011 speedster is mechanical and it is way off. My speedo tops out at 46 Mph when GPS is showing 62 MPH.

Try using an app on your phone with GPS.

If you are using GPS already, just ignore everything I just said.

 

[Carpenter29]

I think your speedo is a mechanical wheel based unit not a GPS but I could be wrong.

The unit in my 2011 speedster is mechanical and it is way off. My speedo tops out at 46 Mph when GPS is showing 62 MPH.

Try using an app on your phone with GPS.

If you are using GPS already, just ignore everything I just said.

I thought about that after because ya I am just relying on the built in speedometer. I've downloaded an app and will try next time I'm out to see if the speed I'm getting is accurate. Thanks for the suggestion.

 

[Carpenter29]

It's totally normal. These boats run up to 7800 to 8000 RPM at wide open throttle, and dont worry there is a REV limiter built in. The engine is a four stroke, 3 cylinder, 1.5 liter but it's Supercharged and Intercooled to put out 215 HP, so you need 5000 RPM just to move the boat at 10MPH. Best cruise is around 6000-62000 RPM and should give you about 27 MPH running on smooth water and less if you're running in chop. It's also the best gas consumption.

Open her up at full throttle until you reach 30 MPH, then ease back to 6200 RPM and that's your cruising speed with two people, smooth water and full tank of gas. If you need more RPM to get to 27 MPH then look at the impeller and wear ring as you could be loosing thrust if the're worn.

Awesome! Thank you so much for the information. This is exactly what I was looking for, kind of a "standard" to measure the boat against. When you guy something new it's easier to tell when the performance starts to change but as the boat is used I don't want to miss signs that some maintenance is required.