what are the pro's and cons of a super charger

[jellyrug]

That video was full of **** for a few reasons......I wont get into all of them. (Note, I own supercharged and turbo'ed vehicles)

But....

It says an advantage of turbos is the fact that it doesnt have parasitic losses because its using spent energy???? Well, thats BS, it takes a significant amount of HP to drive a turbo. People for years claim its 'free' HP.....well its not.

If you dont believe me put a turbo on your vehicle, dont hook up the up pipe and put a few socks in it (to simulate compressor load and prevent overclock)....see how much HP you have.

I did not watch the video, as I'm at work. The simulation test you describe is in my opinion not realistic though, with proper design the boost is almost free. The sock does two things, one it causes a restriction to the turbine and second the regeneration bonus is gone. If you were right, we would not be flying planes with gas turbines, ejoying the concepts of isentropic compression, isobaric (constant pressure) combustion and isentropic expansion.

 

[ROTREXPOWER]

I agree a turbo will always generate more power to the road per unit of boost as the losses are less. The nice thing about the Rotrex supercharger is that it makes a lot of boost for its size so fits a bike quite well. For the street it has instant response from any revs in any gear and builds boost progressively giving the rider a lot of confidence to drive fast as he knows whatever he does with his throttle has an immediate and totally controllable response. A very nice thing to ride.

 

[jellyrug]

I agree a turbo will always generate more power to the road per unit of boost as the losses are less. The nice thing about the Rotrex supercharger is that it makes a lot of boost for its size so fits a bike quite well. For the street it has instant response from any revs in any gear and builds boost progressively giving the rider a lot of confidence to drive fast as he knows whatever he does with his throttle has an immediate and totally controllable response. A very nice thing to ride.

Totally agree, throttle position on a turbo can be a hand-full to manage.

 

[Eddie]

The centrifugals power delivery is definitely much more linear than a turbo's. This lends itself well to street bikes, especially those with a SWB.

A smaller roots blower, like those used for motorcycles or factory supercharger cars, usually has all it's boost in by 2000rpm. Mountains of low end torque.

Unfortunately, there aren't a whole lot of screw blowers available for bikes. Screw have the best of both worlds, they deliver boost in a hurry like a roots blower but can exceed 100% efficiency (and it doesn't get much better than that). Screw type blowers are used on Japanese based top fuel bikes like Larry McBride's 5 second Kawasaki.

 

[Big Red]

pros lots of fun
cons lots of fun with lots of tickets haha

supercharger always on power its always there but it takes power to make power

turbo has a big of lag especially at low rpm's but creates more power

You can also use a smaller turbo and over boost the engine for lot's of low end and midrange power. I have seen this done on econobox four door cars. The results: a very embarrased corvett owner for one.

 

[Adox]

Just get a S.C. AND a turbo and cover all your bases.

 

[BIG CC RACING]

I both turbocharge & Supercharge motorcycles for a living. When you comapre the two there is a lot to take into account.

The Superchargers just like Turbochargers come in various shapes & sizes but on road going motorcycles there are only two truly available ones that work effectively. The Rotrex & the Procharger. The Procharger will make more beans at the same level of boost because it is relying on moving volumes of air rather than the speed of air. The turn ratio in the procharger is less than the faster Rotrex but the Rotrex does not have as big an impeller or as big a scroll or as big an inlet & it does create more heat through the fact is moves less air faster. The Rotrex is much quieter & a lot easier to fit as the prochargers are more bulky. So they both have their plus points.

With both these types people should not fool themselves by comparing to the old wipple & roots style units that give instant boost. These are in effect turbo impellers driven through gearboxes & a belt from the end of the crankshaft. Neither in a decompressed engine make any more than a stock motor upto 3500 to 4000rpm on a Busa nor do they make any more low down than a correctly sized turbo. The reason is the airflow needs to build via rpm speed to a suitable level where the engine turns from vacuum to positive.

Superchargers are hindered in daily use by the requirent to adjust belts, & replace pulleys, & engine seals & bearings all of which have to be designed to rotate at 11,000rpm under load.

Yes superchargers loose power in their driving by the force needed to rotate the unit.

Superchargers boost all the time after going positive from vacuum. You have to think about this. It means if you are accelerating quickly or slowly or constant cruising or even decelerating or bashing down the gearbox going into a bend the boost is linked with the rpm & thus it is boosting even on deceleration though it may be vented off the hot air is still there...

That is the principal reason why I would never consider bolting a Supercharger to astock engine they heat soak & are more liable to give engine failure due to the increased boost usage. A turbo by comparison only boosts when you load it. In other words pull the the throttle back. You can red line a turbo at 10% throttle & make no boost at all & obviously at a cruising speed on roads it remains off boost.

This then means that the turbo can be mapped with much less fuel usage than a supercharged engine as the enriched state only needs to be when it is generating boost which unfortunately for the supercharger is every throttle postion from 3500 onwards.....

Supercharged engines will naturally make more exhaust noise than turbo engines. A serious consideration at certain race tracks. This is because the increased exhaust gas from aspirated is unchecked & at a higher level, so if your aspirated engine was marginal these will be mucho noisier on the exhaust. The turbo naturally quitens the exhaust by the spinning of the impeller.

Turbos can be linear in boost delivery & should not suffer lag on motorcycles. If yours does then you are using the wrong size or something is ****. if you feel you need immediate power from a set of lights just put it on full throttle & lob the clutch. You will soon realise its too quick anyway when its flipped over backwards. Superchargers do have that instant feel on the throttle that a turbo does not have.

When comparing supercharger power with turbo it is important same as in rotrex v procharger to do it boost level for boost level. Remember with the turbo you can just add more boost by a controller without the need to swap pulleys. You will find the all important inlet temp is much worse on the superchargers than on the turbos this again will restrict the boost on usable road fuels & the power potentials

Either make excellent road going bikes & I eagerly await DAS performance's results with their Procharger on the track as I do TTS's.

 

[BIG CC RACING]

Superchargedv8, you should check out the specs and products for rotrex superchargers on this site TTS Homepage I've been researching bike kit superchargers for almost a year from different companies before deciding to buy one from tts performance. Big CC makes a kit but there chargers use traditional gears vs. rotrex's planetary gearing...the ratio is 10:1 so the power/boost IS always there although it is progressive, another reason I chose a SC. A centrifugal charger is way more efficient than Roots and Screw types. The SC market for bikes is steadily improving and I believe will become OEM on upcoming bikes.

I found this misinformation after I posted. The disadvantage of a gearbox drive is noise. The disadvantage of a planetary drive using oil is it can slip when hot & requires it's own oil cooler & pump & lines & header tank to squeeze on the bike. Very unsightly. The Procharger you drain it & refill it. Simple.
The 10:1 ratio you think is good is not good as I previously explained because it causes a high heat temperature in the inlet charge dropping power which is great if you have an intercooler fitted (that's not on top of the engine) to cool it. The Procharger has a much bigger impeller & does not need to turn 10:1 to create the same but only turns 4.7:1 to create more air so it certainly is not slower to build. You may of researched for a year but you missed the facts & digested the clichés. Rotrex is a great product but until the inlet charge temps come down it will always be handicapped.

 

[gsx1300rr]

Awesome write up!

 

[vampire]

I found this misinformation after I posted. The disadvantage of a gearbox drive is noise. The disadvantage of a planetary drive using oil is it can slip when hot & requires it's own oil cooler & pump & lines & header tank to squeeze on the bike. Very unsightly. The Procharger you drain it & refill it. Simple.
The 10:1 ratio you think is good is not good as I previously explained because it causes a high heat temperature in the inlet charge dropping power which is great if you have an intercooler fitted (that's not on top of the engine) to cool it. The Procharger has a much bigger impeller & does not need to turn 10:1 to create the same but only turns 4.7:1 to create more air so it certainly is not slower to build. You may of researched for a year but you missed the facts & digested the clichés. Rotrex is a great product but until the inlet charge temps come down it will always be handicapped.

For street use Hayabusa/Bking, i guess most time the Rotrex C30-94 is used. 1:1 pulley. Compared to the Procharger street unit and also a good turbo set up, how do the inlet temp. numbers compare for let's say 10, 15 and 20 Psi ?

 

[BIG CC RACING]

I cannot speak for other people & their dyno figures or the Rotrex product range but I have independantly tested 3 types of Rotrex. A small unit that delivers 8 to 10psi, a medium sized unit that delivers 18psi & a 28psi unit. The unit 30-94 you mention is the one we see & tested creating approx 18psi at peak rpm. Power varies according to engine internal specs from 250 to 282hp. You could detune with the pulleys to make less boost for road usage....what the power does I assume is goes down towards the 220 to 240hp we see on the smaller 10psi units.

Below is a Procharger C1 at 10psi & 12.5psi respectively without intercooling or chargecooling. The important thing is at those boost levels you can run it on road usable fuels with a 9.5:1 compression engine like the one below & still get good power with a safe A/F.

I try to base comparative figures on equivilent engines that run not only the same spec engines ie low comp with 9.5:1 & air fuel ratios under 12:1 for safety etc. There are many differences that can alter the power over the inlet tempsuch as bore, stroke, cams, porting, exhaust etc but inlet temp is one of the deciding factors.
When seeing supercharged power graphs its important to ascertain the engine tuning work as it may account for a fair bit & they do like to be better breathing more so than turbo's.

 

[vampire]

Thanks for your reply. It's become a compare between the Rotrex and the Procharger unit. You focus on inlet air temperatures, which is okay and no doubt very important. On a bike for road use, dimensions and all that comes with it, same story. With the Rotrex i can easy make 250rwhp on my bike. But did some extra engine work , oversized valves, Wossner 9:1 pistons, ported head and increased headersize and less restricted exhaustsystem. I immediately believe that when i change for a Procharger unit on this engine, it will make more power on the same boost level. But i also think it will be hard to keep the bike look like factory and as thight as possible with the Rotrex. It's always a choice.
Power and speed you can measure. Also inlet air temp. You don't want to speak for other people which is a good thing. You give dyno figures of both units to compare. When you say inlet air temp. is a handicap on the Rotrex unit, it seems to me you compared the temp. numbers by measuring. I'm curious on the real differences in temperature as measured, also compared to a decent set up turbo unit as you sell.

 

[09vmax]

Then are supercharger kits more or less difficult to install on the busa and would it be recommended for the average to above average mechanic?

 

[racer 44]

In your spare time check out AEROCHARGER Turbocharger is the most advanced form of forced induction, giving you the edge over the competition. First to Boost, First to Win.
Variable vane, internal oiling, very predictable, extremely reliable......
Will post dyno videos and results.....
Ran the same engine combination for over 75,000 miles then added the series 66 aerocharger, lasted another 5,000 w/8lbs of boost on hand.

 

[busarr1340]

I found this misinformation after I posted. The disadvantage of a gearbox drive is noise. The disadvantage of a planetary drive using oil is it can slip when hot & requires it's own oil cooler & pump & lines & header tank to squeeze on the bike. Very unsightly. The Procharger you drain it & refill it. Simple.
The 10:1 ratio you think is good is not good as I previously explained because it causes a high heat temperature in the inlet charge dropping power which is great if you have an intercooler fitted (that's not on top of the engine) to cool it. The Procharger has a much bigger impeller & does not need to turn 10:1 to create the same but only turns 4.7:1 to create more air so it certainly is not slower to build. You may of researched for a year but you missed the facts & digested the clichés. Rotrex is a great product but until the inlet charge temps come down it will always be handicapped.

Wow it's been a while since I've checked this thread! Anyways in response to BIG CC Racing, I understand your on here to sell your procharger "wares" just like Richard is with Rotrex. I laughed at the fact that you claim I'm a sucker for advertisement, maybe even more of a sucker since I didn't chose yours? lol. In my research I ran across your S/C kits...I just simply didnt like them...way too bulky for my taste..maybe because of the 'non-slip' gearbox you speak of? The disadvantage of a gearbox is 'noise' why? Because of friction of the gears and bearings while engaged...planetary is a smoother quieter setup...the main thing that sold me..in addition to the centrifugal compression to keep the gears from slipping. Formula 1 race cars as well as MOST if not all modern cars use planetary gearing in the trannys using several stages. My research was thorough on your kits...the procharger product line...TTS's kits and their rotrex line. They both have their pro's and con's, You talk about inlet temps...not a problem with a intercooler which comes with STG 2 and 3 kits...both with options for front mount. Don't you charge extra for intercoolers? You should post some youtube runs with the rotrex models you've tested vs. some prochargers along with the various temps. I'll be posting some pics, dyno's, etc this spring...or even better set up a race using a kit I chose as a misinformed consumer vs. the one I didn't chose?

 

[MLSDUKE1]

Just use both at the same time. That should do it!

 

[The Big Red One]

I would have went with a sc if it was as affordable as a turbo kit. I picked up a very nice used ceramic coated turbo kit with new lock up clutch, billet aluminum case spacer, lowered oil pan drilled/tapped for turbo feed, new high volume intank wallbro pump, new oil scavenge pump, and everything hardware wise I needed for a complete install for a little over 2700 bucks. You can pick up good used kits for around 3 grand or less with smart shopping. SC's are still just too pricey when a turbo delivers almost the same experience (minus the low end torque, but+the top end hit) for a whole lot less moola

 

[BIG CC RACING]

Wow it's been a while since I've checked this thread! Anyways in response to BIG CC Racing, I understand your on here to sell your procharger "wares" just like Richard is with Rotrex. I laughed at the fact that you claim I'm a sucker for advertisement, maybe even more of a sucker since I didn't chose yours? lol. In my research I ran across your S/C kits...I just simply didnt like them...way too bulky for my taste..maybe because of the 'non-slip' gearbox you speak of? The disadvantage of a gearbox is 'noise' why? Because of friction of the gears and bearings while engaged...planetary is a smoother quieter setup...the main thing that sold me..in addition to the centrifugal compression to keep the gears from slipping. Formula 1 race cars as well as MOST if not all modern cars use planetary gearing in the trannys using several stages. My research was thorough on your kits...the procharger product line...TTS's kits and their rotrex line. They both have their pro's and con's, You talk about inlet temps...not a problem with a intercooler which comes with STG 2 and 3 kits...both with options for front mount. Don't you charge extra for intercoolers? You should post some youtube runs with the rotrex models you've tested vs. some prochargers along with the various temps. I'll be posting some pics, dyno's, etc this spring...or even better set up a race using a kit I chose as a misinformed consumer vs. the one I didn't chose?

I stated the procharger was noisier & yes it is slightly larger but not by much. I have never seen the stage 2 or stage 3 front mounted intercoolers, perhaps you have a picture? It would be great to see.

When you front mount an intercooler behind the wheel you have the issue of overheating caused by the blockage to the radiator. No point in doing the head gasket poodling round town cos the motor boils up.

So intercooled or not its very important to get the effiecency from the boost available on road usable fuels. That is what defines how good a supercharger is or is not. If Supercharger A is making 310hp @ 14psi & Supercharger B is making 280hp @ 18psi then it stands to reason the first is going to be kinder on the engine if running the same boost level. As such the second is more likely to go pop

When looking at the Hayabusa specifically btw the first issue any Supercharger system manufacturer has to overcome is crankshaft deflection because 90% of Hayabusa crankshafts have bent crank ends caused from the starters. If you dont build in a coupling so the pulley runs straight without iscillation it will weaken the bearing & cause the seal to leak. We took that further by also inbuilding a self aligning rear pulley.

The other part of the reason for the bulky appearance is the fat pulleys & wide V belt to ensure a good grip with each other reducing slippage.

Big Red One dont undersell the turbo. The Rotrex or Procharger Supercharger dont make more low end torque than a Turbo. Their impellers are not moving enough air to do so & the drag of the charger further exacerbates that. In fact up to 3500rpm a stock Busa does both of them. They are not the traditional style of charger & their power is very linear & thus controlled by the rpm.

 

[BIG CC RACING]

Misinformed yourself is different to being misinforming others. How informed you are is not for me to judge & I was not referring to that.

Lets explore your words...

the ratio is 10:1 so the power/boost IS always there although it is progressive, another reason I chose a SC. A centrifugal charger is way more efficient than Roots and Screw types.

A centrfugal charger is nothing more than a gearbox driven impeller pulley related to a crankshaft speed. The boost is NOT always there as it does not even go positive on a boost gauge until after 4000rpm due to the slow speed of the charger combined with the air it moves in relation to that speed.

To then say it is more efficient than a Roots or Screw type which will go boost positive earlier is equally wrong. For their compactness the Rotrex & Procharger offer real alternatives to Turbo that can be practically mounted & ridden easily albeit not as efficient. A Roots or screw type that was properly sized for a Busa would not be the case as they would be too bulky & so "efficent" in making boost they would be very hard to ride.

 

[powerfulone]

If a turbo is not spinning it's not making boost, until it reaches quite fast rpm it is totally in efficient, that's why you get a turbo kick that, if controlled feels great. A Rotrex spins much faster than any other centrifugal supercharger, so it reaches it's 'sweet spot' at lower engine revs than others. Making more boost (compressed air) means more heat (laws of physics) so naturally a Rotrex generates more heat than others. On a one hit dyno run a Rotrex without intercooler will show higher temps than say a Procharger as its moved more air and compressed it at lower engine rpms, so by the time a Procharger catches up the boost at higher rpms the air won't be as hot on that one pull. Put both chargers rotating at their same max rpms they are moving the same amount of air and compressing it to the same pressure into the same volume of space then if they are the same efficency they will make the same heat eventually. Rotrex publish their flow charts I have yet to find a Procharger one! I know they make good peak power but they are 'not so hot' at making midrange boost. My lastest generation Rotrex Hayabusa kits make boost from idle and makes more power than the same NA bike from idle, it doesn't take 4000rpm to get the power increase as any of my customers will tell you.