Supercharged VS Turbocharged

[SEAdooingFREAK]

this ought to make out for a good discussion. Turbo or Supercharged? What is the better performer on the seadoo? I believe it to be turbocharged but I want to hear opinions. This ought to possibly open up some doors. Lets hear it guys. Performance, sound, top end, acceleration etc etc

 

[seadoosnipe]

Supercharged.....

This is an easy one. I don't know of any applications being used by Sea-Doo at the moment that incorporate the turbo, but since a turbo is a double fan type compressor......on one end, you have the fan the exhaust passes through and on the other, the air induction fan that's forcing the air into the engine. It is totally dependant on wind up. This would be a more fuel efficient type setup, but for the horsepower, a superchager has it hands down, no questions asked!......it's a geared compressor, that compresses the air/fuel to unbelievable proportions...........not even in the same category.

 

[SEAdooingFREAK]

so you would stick with the supercharger. I was thinking about the turbo but sounds like supercharger is the way to go.

 

[meirvin]

changing to turbo is the latest craze for speed and racing, no supercharger rebuilds every 10 hours or so plus with the right engine management the lag is reduced to nothing. Because alot of people are switching to turbo bigger Superchargers are being sold left and right so you cant go the supercharger route on the cheap now.

 

[meirvin]

turbos are producing higher boost than SC because SCs create too much heat at higher boost I think

 

[SEAdooingFREAK]

so you would switch to the turbo? Is that the average run for the supercharger? Just 10 hours, before they need to get rebuild!!!!

 

[meirvin]

Im where I want to be and dont want to do the wrenching so I personally wont switch but if someone is looking to the big dog it seems turbo is where they are going

 

[SEAdooingFREAK]

anything on the rebuild for the supercharger? how long are they lasting? any word on price for rebuild?

 

[seadoosnipe]

Logic?

I don't understand the logic on a turbo being capable of giving a better/larger boost than supercharged. Only because a turbo charger is totally reliant on the exhaust gases to provide boost on the intake. So therefore, the turbo has to wind up before any boost effect can even take place. The supercharger is driven by a direct gear, with a lower gear ratio to the engines rpms, so in essence, if the engine is turning out say, 4000 rpm's, the supercharger may be turning out 8000 rpm..those numbers are hypothetically speaking, not exact. So with that boost being instantaneous, I don't see how a turbo charger can compete with a supercharger.
Oh, and I don't think the rebuild time on them is 10 hours.........I'm sure it's a whole lot longer than that. The supercharged 4-TEC engine is the most sought after engine in the world right now. The competition can't even come close. That is stock, no mods..........
The complaints on the chargers are there, but they are truly far and in between, so I'd expect those with the supercharged engines, come on in and give us some input as to any problems you've faced with them. Mind you, this forum only represents less than 1/2% of owners of the supercharged Sea-Doo's.
Personally, myself, I'll always stay naturally aspirated. Just because I'm old school and like to keep my toys simple.

 

[kustomkarl]

I have seen in a couple of my friends Dodge Chargers with HEMI's, get the biggest horsepower gaines, with not the turbo but the supercharged systems. Personally I wouldn't install either in any of my seadoo's ...the life span of either system that is after market would stress the engine well beyond it's limits. Unless you got your seadoo for free, the re-sale market of this rocket ship is like nothing. These machines aren't designed for doing 100mph, and for a quick burst of 70 most all should be satisfied. uh... where can you go on public water and do that speed and not danger life or property? That is another issue... The life span is critical to the seadoo engine and if you really want to go fast you should get out of the water and on the road.

 

[Mirage]

if you really want to go fast you should get out of the water and on the road.

I TOTALLY disagree with this...

 

[seadoosnipe]

Out there!...

Mirage, I don't think Karl meant that as it was said. This is a statement easily taken out of context.
I believe he means that with the engines' on the water now, the horsepower generated and the speeds achieved are almost topped out for the hull designs, as stated in his post. The only real way to go any faster is to go on land and build a drag car.
I know Karl and I that he was a champion stand up jet ski racer for several years running. He too has a need for speed, as seen in his purchase upgrade from the 787cc to the 4-TEC. So please, don't quote and take that sentence out of context.
I expect he'll read it and explain the context a bit better.

 

[SEAdooingFREAK]

I just like to take things to the limit, I have a 96 GTI VR6 that I have done 152 and thats almost max and scary thing is NATURALLY ASPIRATED and I wasn't redlined yet close but not quite. Couple of mods done. Speed is my disease.
I knew this would open up a can of worms but its good feed. To be honest I am shocked that the thread hasn't been replyed to more. Out of my 23 years experience you can get more out of the box with superchargers, and less with turbo but you could do more things to the engine with the turbo to surpass the super. Since the turbo is exhaust driven. That is just my opinion. Lord knows I'm probably wrong but that is how I understand it.

 

[SEAdooingFREAK]

It also comes to question. Life span for the super is probably why people are switching. Not spending the extra $$$$, even competition. Not sure waiting to hear some replys. Damnit we need more people in this forum!?!?

 

[Mirage]

snipe

Mirage, I don't think Karl meant that as it was said. This is a statement easily taken out of context.
I believe he means that with the engines' on the water now, the horsepower generated and the speeds achieved are almost topped out for the hull designs, as stated in his post. The only real way to go any faster is to go on land and build a drag car.
I know Karl and I that he was a champion stand up jet ski racer for several years running. He too has a need for speed, as seen in his purchase upgrade from the 787cc to the 4-TEC. So please, don't quote and take that sentence out of context.
I expect he'll read it and explain the context a bit better.

I'm not upset!!!

 

[meirvin]

the 10 hours is related to hard core racing (bouy and Drag) and wanting it in top form (spec) at all times. I dont know enough to explain why turbos are now popular just that there are about 10 of them around the US I just remember hearing that SC get too hot, the turbos are putting out 20-30 PSI of Boost.
The biggest SC is 15 lbs

Stock RXP x is 9.5

There is a turbo RXT in Pureto Rico Doing 88 mph

The top European Racers are turbo.

 

[seadoosnipe]

Thats cool!...

Mirage, I didn't think you were upset, just noticed your exclamation in the word "totally", and when I read the two post together, I took it out of context myself. My post was probably needless.
SeadooFreak, you hit the nail right on the head. The cost to maintain an engine that is supercharged is high because of the heat and rpm generated by the blower. The turbo-charger on the other hand is not maintenance free itself. Over the years, I'm sure the bearing systems have changed but at one time, there was a journal bearing in the middle, between the compressor of the exhaust and the intake fan. The heat created a thermal shock type effect. On the exhaust end, the faster you went the hotter it got and on the induction end, the faster you went, the colder it got. The distance between the two compressors are normally just a few inches apart, with the journal in the middle. There is always one dedicated oil line for that journal too.
Is turbo popular........yeah, probably for the moment. But if your someone who thinks about speed, then think about this for just a second. It was a fully blown supercharged engine that broke the 1/4 mile in less than 5 seconds at over 300 mph. I've never seen a turbo charged racer come close. I'm not saying turbo can't be fast and Seadoofreak is right, you can do a lot more to your engine with the turbo, but for top end speed, I don't think anything but a rocket could be faster than a properly configured blown (supercharged) engine...............:cheers:

 

[SEAdooingFREAK]

Since heat is the problem with superchargers. Is there something you could get to keep it cool other then running SLOW or with the engine cover off? I realize that when you get forced induction that you are gonna be spending more. I just want to try to minimize the cost. Even though you do have to "pay to play". This is another positive in maine cooler waters= cooler engine. Damn SNOW all this talk wants me to be on the water with soon to be new rxpx.

 

[meirvin]

well if you run any after market SC you should be running an after market Intercooler as well. As Far as helping Fresh air is good and I cant confirm this helps but I feel warm air coming out of it all the time. They are called Flow-Rites and used in snowmobils, the screen covers are water repellent.

 

[seadoosnipe]

Heat generation

Because the turbocharger and supercharger work on two different principles, the heat generated is also created differently.
The turbo creates heat along the path of the exhaust system that is directed into the fan. So in the turbo charger, the heat generated is mostly in the casing of the exhaust side and along the bearing surfaces....
The supercharger is actually more efficient in cooling, since the exhaust system has nothing to do with it. The supercharger only creates heat due to the high rpm generated at the ceramic slip plates. The air compressed by the charger is actually cooler. If you've ever had some form of void with compressed air in it and you open a valve to let the air out, you'll notice the frost created. The super charger is like a compressor, that it compresses are into the induction system. The casing of the supercharger itself should not be a source of heat, only the geared shaft end where the oiliing takes place.

 

[meirvin]

hmm I dont know about that SC's melt the plastic pipes exiting on its way to the intercooler with bigger Sc Boost rates you have to replace with metal piping or else

 

[seadoosnipe]

Stand corrected.....

Meirvin, you are absolutly right. I don't know what I was thinking about. Must have been before I had my morning coffee.
In our blowers (superchargers) that I work on, which by the way are twin vane mounted, the air compressed does get hot. While that air is under pressure, it will remain hot. The air will only create a cooling effect as it is being released through an orifice, like what we use on ours.
Where our superchargers build up pressure, it goes through an after cooler, then, because it isn't regulated (by throttle response) the excess pressure created by the chager is released. At the point of the released air, as it travels through the piping back to the atmoshpere, the piping gets so cold, it creates frost.
But you are right, at 45,000 rpm from the 4-TEC chargers, they do create heat from the fan turbine and the air being created for boost.
I stand corrected...............:cheers:

 

[CragarShinoda]

I am not sure about PWCs, but in the automotive industry superchargers produce cooler charges than turbos... in many cases such as with Procharger's setup which includes a 2 core, and optional 3 core intercooler, we find that the boost temp is close to if not the same as ambient. As air pressure increases so does temp, it is a basic law of physics. Turbos we find make more boost, or rather have the ability to produce more boost, due to the fact that they are spun off of exhaust gases, whereas a supercharger relies on the motor's crank, thus creating drag on the engine and somewhat limiting the amount of boost that they can run. All in all, I recommend a supercharger hands down due to it's effectiveness, charge, and cooler charge, but that is in the automotive world.

 

[seadoosnipe]

Boost....

I'm going out on a limb here Crager, because I have to disagree about which has more boost. Your logic that the supercharger is only as effective as the engines speed, because it's geared to the crank, is no different to the fact that a turbo can't make boost, unless the exhaust gases pick up.
The supercharger makes a lot more rpm (14,000 in the 4-TEC, I think) than the engine does, therefore, it will provide more boost at lower rpms.....although, both the SC and TC booth make their best boost at higher rpm.
The other thing I would point out and you being in the automotive side. How many professional drag cars have you seen running a turbo and how many have you seen running a charger?...........I watch NHRA....and I have never seen a turbo on any drag car.........:cheers:

 

[jr86]

Turbo all the way...

For autos and larger watercraft. The turbocharger works off of thermal expansion. That is the gas that leaves the exhaust port and hasn't finished expanding. (That's why you can hold an engine at high RPM without a load and the turbo will not boost.) The power is free, meaning no drag on the engine. The power is adjustable through the wastegate, and the turbo life span is very long. The main drawback for the turbo is the lag. VW has developed a turbo that boosts at 1800 rpm. A supercharger gives boost immediately. Drag cars use SC only because of the immediate boost. The boost pressure is so high that they are igniting almost liquid nitromethane!

Now for the PWC market it would not be a good choice. The extra heat and plumbing would make it unfeasible for the doo's. (Imagine how much cast iron and cooling capacity would be needed.) Also you would have to think about oil fouling of the exhaust side due to the two stroke engine.

ALL large marine applications use turbos ONLY. It is purely for the free power and long life.