06-12-2005, 06:16 PM #1
- Join Date
- May 2005
Getting cold , fresh air into the motor...am I wrong?
How hot is the air in the engine bay on a S/C Sea Doo? (110? 130? 140?) If my supercharged car worked on this principle (sucking in HOT air from a sealed engine compartment) I would be down 100HP!!
06-12-2005, 06:50 PM #2
if you feed the engine with cold air directly, of course you'll see gains across the board.
PPG's kit is designed to suck cold air into the stock air box
Riva's kit increases air flow
IDEALLY, i pesonally think the best alternative is to extend the Riva kit further towards the box of the boat then fool around with it and modify it with a fan or something and some creative duct work to feed it cold air.
Jeff (05 limited) did something cretive with his RIVA air intake to feed it some cold air i believe.
06-13-2005, 02:30 PM #3
Originally Posted by Shibby1485
- Join Date
- May 2005
What good does the intercooler do if the intercooler is sitting in an enclosed engine bay where the temperature is way above 100 degrees? After 10 minutes, the enigine and intercooler are "heat soaked".
Does anyone make a AIR to WATER intercooler for the sea doo? That would be the way to go. Flipping a switch and changing out the hot water for cooler water ....Where 60,70 or 80 degree water could cool the air going into the S/C instead of 120 degree air....
If anyone wants to pick up nice HP, the best thing to do is get COLD air into the engine. Getting hot air in there isn't doing a damn bit of good as everyone is finding out in the hot weather. its' the air intake temperature and that CAN be controlled. I still like the idea of a small "cowl" so the S/C can suck in cool ambient air.
06-13-2005, 02:38 PM #4
- Join Date
- May 2005
- Cumming, GA
Actually, the Seadoo intercoolers are water to air.
Fresh water is pushed through the system by pump pressure.
The fresh water is used in the intercooler and exhaust.
06-13-2005, 05:10 PM #5
Liquid to air is exactly how these intercoolers work, using lake/ocean water to cool intercooler and exhaust
06-14-2005, 01:05 AM #6
You are 100 % correct... in fact, I think we all agree that "cold is good"!
Regarding the air that is ingested into the engine via the supercharger... it should obviously be as cold as possible. That's why (as shibby referred to) we have taken efforts to exclude any "hull air" from entering the ski's SC. Currently NO air is induced in my engine except ambient air... again, "cold is good"... however, if ambient air is hot, performance will wain.
Same with the intercooler. We have taken every effort to ensure that the water that enters the RR intercooler (thanks GP) is as cold as possible. So, rather than let the water flow from the pump, to the front of the engine, and back to the intercooler (a chance to pick up hull heat)... we routed it straight to the IC. Probably not a huge difference, but again, "cold is good"... and, like ambient air, if the lake water temperature has risen, performance will wain.
Annette and I have been fortunate to have duplicate skis that serve as test beds for modification results. Please understand, if some folks question the benefits of cold air to the engine, and cold water to the RR IC, just ask Annette... she has been very patient... but now wants the same mods.
My ski is 3.5 mph faster... 67.2 vs 70.7. Was it worth it?... damn right!
Jeff & Annette
06-14-2005, 04:40 AM #7
Of course the air is cooled by the intercooler but it gets in there at such a velocity that it doesn't have that much time to cool down.
Anyways there is always an advantage in starting from cooler air, mathematically, the cooler the air is at the air intake the cooler/more dense the mixture will be, no matter what's in between.
People who think any reasonibly sized fan can supply enough air in a hull to lower the temperature is seriously challenged.
Even the Ram Air systems on crotch rockets only starts to be effective over 100 mph.
The vaccum from the motor itself (especially a supercharged motor) is such that the fan is useless, the only way to lower the temp under the seat is to enlarge the air intakes, the vaccum will do the rest.
Some popular mod in the car business is to put the filter into a box that is air tight from the motor compartment and cut a hole in the hood, some even just duct the air intake into the car's fender.
I think on an RXP a good way to do it would be to use the Riva hood, use the front bucket as an airbox and install a small bilge pump on the bottom.
06-14-2005, 08:16 AM #8
11 I think thats is a very good idea. Keeps all the hot engine temp out of the intake.
06-14-2005, 08:20 AM #9
06-14-2005, 10:22 AM #10
Tell that to my daughter who woke me up at 2 am, after she got back to sleep I couldn't....
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