superchargers and warm weather???

[wango tango]

is it true that rotax supercharger loses performance in warm water and weather ???

 

[Jgorm]

Yes. Cool intake temps pack in more air.

 

[Scottintexas]

I have no answer for the Rotax but this is from our FAQ tab where they have upgraded the intercooler on the yamahas

https://jetboaters.net/faq/how-to-upgrade-the-intercooler-on-a-supercharger.124/

 

[wango tango]

Is 400 rpm loss normal for a 85 day and water temp at 79?

 

[Speedling]

Look up info on supercharger heat soak an you will gain understanding.

 

[Scott E]

Warmer water and air temp, the less the intercooler can reduce the intake temp. So there will be some impact on performance. Heat soak is also an issue.

There's a few upgrades if it's really.

You could upgrade to a Fizzle external cooler. I'm assuming you have the 215hp motor, the 255 has an external intercooler already. Not sure if you need larger injectors with the external intercooler. It is more efficient than the internal.

There is a company making a water cooled housing for the supercharger now as well.

 

[JetTech72]

On worse case conditions yes you could see a up to 400rpm drop, but that would be caused by
Lake temperature above 85F
Engine compartment temperature above 110F
Poor gasoline quality or low octane.

The colder the intake charge (engine compartment + Intercooler) the better.
The Rotax engine have build in sensors (Air intake temp, Knock, ...) that will do what it takes to protect the engine.

 

[Speedling]

On worse case conditions yes you could see a up to 400rpm drop, but that would be caused by
Lake temperature above 85F
Engine compartment temperature above 110F
Poor gasoline quality or low octane.

The colder the intake charge (engine compartment + Intercooler) the better.
The Rotax engine have build in sensors (Air intake temp, Knock, ...) that will do what it takes to protect the engine.

I forget, do all the supercharged rotax require premium or just midgrade? If super hot out i would consider premium to combat some of the heat.

 

[wango tango]

I have a thermometer in engine compartment And in was about 110-120 in there. Water temp now 77f .
Full tank of premium, just me on boat max RPM 7800

 

[wango tango]

Thanks for input!!!

I tried 3 different gas stations, Meijer, Sunoco, and shell (I like the shell premium gas).
Is there any recommendations on gas stations for good premium, just Incase my stations are not good quality?

 

[wango tango]

hey everyone,
i did notice something on this new scarab/rotax is that the air filter is right over the exhaust manifold, my last sea doo's had the air cleaner on opposite side away from that heat! also the filters were closer to the engine compartment vents not further away like the scarab .
just wondering what people think of this with performance issues.

 

[viggen]

Some say there is a difference between gas, I haven't seen it however I also only use name brand gas station.

Heatsoak is common on any engine, especially on a turbo or supercharged engine. New IC, exhaust work and all that stuff doesn't eliminate it, just greatly reduces it. These items also allow everything to run more efficiently, getting the heat out of the engine compartment much quicker!

GM is presently being sued by C7 ZO6 owners due to after sometimes only 15 minutes at a racetrack the car pulls back power. Some state this is occurring when driving on the street as well.

 

[wango tango]

viggen,
thanks for feed back about GM and heat soak but it seems like im the only one with this issue, everyone is saying that they are getting max or close to max rpms with these conditions.
GM guys are all experiencing similar issues.
that is one reason i posted this to see if this is common issue or something wrong with my engine/cooling. so far not very common with scarab/rotax , unless conditions were worse (water/air temps)

again thanks

 

[wango tango]

i did hook up the hose and flush intake for a minute the last time i had it out of water just in case some lake crap in it , well before the flush, engine temp would range from 190-205 and now it doesnt go above 198, range now is 188-195 most of the time. could it had something in it ? did not expect that.

 

[wango tango]

Dealer and brp are looking at it now
Thanks for the great feedback guys!!

 

[viggen]

Keep us posted on the outcome

Some power loss is normal however a substantial drop isn't