Thread: Turbocharged vs Supercharged
08-28-2008, 04:13 PM #1
Turbocharged vs Supercharged
Hi guys, now in some days a lot of posts are about turbo....and so i have a question: what are benefits and worse thing of turbo and of supercharged...
what are the differences?
Why don't make a simple guide to the FINAL conversion to turbo?
Thank you to every body.
08-28-2008, 06:30 PM #2
Just to add... are there any guys with Turbo conversions using the ski's as social ski's (ie: everything from wave jumping to long rides) or are Turbo ski's more just race/ drag type set ups? (thinking long time reliability).
(PS: The old saying that the candle that burns twice as bright burns twice as fast is true for any engine - meaning that the more boost/rpm/power your run the shorter the life of the engine will be... but once sorted, do Turbo ski's remain reliable?)
08-28-2008, 08:38 PM #3
a supercharger constantly spins making boost, therefore, there is no lag. but with a turbo, you must spool up the boost before you really get the extra punch of the charger. sea doo's supercharger design has caused engine issues, but using metal washers for the sc clutch helps eliminate the chance of the failure
08-28-2008, 09:11 PM #4
- Join Date
- Jul 2008
For the instant throttle response leave the supercharger.
For all out HP and a mean torque curve the turbo will blow it away.
Think your goals out with your ski.
When turbocharging (or supercharging)a motor the main
concern is proper tuning.I cannot stress this enough.
If the a/f and or timing is off or setup to require higher octane
than you have,It will END the motor the in short time.
Detonation will tear the top rod bearing apart quick.
considering we stay at WOT constantly.
At one point the stock fuel pump may not be adequate enough
depending on the size turbo you plan on running
08-28-2008, 09:47 PM #5
Now i can only speculate this but take it as an educated theory. The supercharger uses HP to make HP. This is called parasitic drag. On our 4 tec i think it's an estimated 15hp to drive the SC at WOT. Under the same boost at WOT the engine with a turbo would consume 15hp less to make the same HP at that boost putting it 15hp ahead of the SC ski. Now when you start getting into modified skis i think the tuebo has more of an advantage since RXPs (for example) tend to leap out of the water and get very nasty upon launch. Now if you are an excellent rider and have the boat tuned to the max this might not be such and issue but many customers boats i've water tested which we were not testing for "launchability" but rather for promised max speeds they were very unfriendly to anyone but th guy trying to do a back flip even with trim all the way nose down. This is where that 3 seconds of lag (from idle) comes in handy. By the time the ski rises to plane the turbo's power goes now from lag to an exponential increase i power giving the term so loved by turbo 4 tec owners "pulls like a freight train" . Now from say 3500 to 4500 rpms this lag on all but the largest turboed (the actual turbo size) shuld be all but non existent. I ride in choppy water 99% of the time so a turbo also means no clutch problems.You can start to see where a properly sized turbo (for the application) should surpass the performance and lifespan of any SC.
08-28-2008, 10:03 PM #6
- Join Date
- Jul 2008
I also should have emphasized proper size.
Turbo will ultimatley make the most power and have the
best pull thru the rpm range.
It can be at max boost (depending on the size) by 4000rpm
your supercharger wont see max boost till max rpm
This is why the turbo has insane midrange power in comparison
08-29-2008, 07:20 AM #7
- Join Date
- Jul 2008
- Aurora Ontario Canada
As in most cases the turbo always makes more power. If the setup is efficient, you are using exhaust gases to turn the turbo therefore somewhat free hp is being made. The SC does take some power to make power and is a trade off.
The big limiting factor in this system is you cannot really change pulley sizes to speed up the SC wheel speed. You are basically only playing with wheels or housing trying to create more boost / more effieicent setup at the given RPM. There would likely be little need for increased RPM as with Riva ECU's if we could make more boost at lower RPMS with the skis.
The turbo allows the user to make all the boost they want at whatever RPM level they are going to run the ski at, within reason. I would have to honestly say a properly setup turbo setup would have little to no lag what so ever. The Honda FX15 my bro in law has, is lag free. My turbo apex (yamaha snowmobile) is lag free. Most turbo setups that are efficient have the turbo spooled at 2500-3000 rpm anyways.
Generally the turbo will also use less fuel because its producing less boost when the engine is not under load IE cruising, however on a ski I am not sure on this as the pump is always loading the motor so I could be wrong on this sense.
08-29-2008, 11:25 AM #8
- Join Date
- Jun 2006
- Richmond, Va
When thinking SC versus TC I always think it terms of psi. The SC is limited by the wheel style. WE have to keep changing wheels to get more psi where a TC you have unlimited amounts of psi, even a small TC can push 20+psi since it is only limited by your exhaust flow. With a TC boost control is critical since you can push past your limitation and blow the engine where with a SC we know no matter what you will get to a max boost based on your RPM's. To me the TC even though some are using for wave jumping and cruising is meant more for all out speed. I would stay with the SC if the main purpose is to have a fast reliable ski that meets most of our needs.
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