Turbocharger vs. Supercharger Thread

This is a thread SPECIFICALLY to discuss the differences between turbos and superchargers, and to discuss the applications of both. You can post your turbo vs supercharger questions in here, such as which to buy for your car, what size to buy, etc, etc...but NO OFF TOPIC POSTS WILL BE PERMITTED! I hope to have a moderator be watching this sticky closely...maybe even 00GTZ00 or myself could be allowed to delete posts in this thread (and only in this thread!)?

Keep it clean, non-personal, and professional. Turbos vs. supers...Let's go!

Turbocharger:
Advantages: Efficiency, Higher Final HP numbers, no parasitic drag, Lag (see below for explanation)
Disadvantages: Non-instant power, Heat buildup

Supercharger:
Adavantages: Instant power, less heat build up
Disadvantages: Less max hp, parasitic drag, less efficient.

My take on the matter is this:
Turbos are for small engined, low displacement, torque-less imports. The supercharger pulley takes a lot of energy to spin, and a small displacement motor lacks this torque that is required to spin the pulley. Upping the boost on a supercharger saps more power away, as switching to a smaller pulley that is even harder to turn is necessary. Turbos are much more efficient, as well...A supercharger is approx 40-50% efficient, while a turbo is 70% or more efficient. There is almost no parasitic loss, except in the form of lower exhaust gas velocities until the turbo is spooled, or close to being spooled. The off-the-line power presented by a supercharger is more than enough to spin the wheels like mad on a launch, because the weight transfer at launch takes traction off the drive wheels of a FWD car, and is more than enough to overpower almost anything but slicks. With a turbo, lag actually becomes your friend! Once you are moving, the weight transfer effect is almost negligible. You are unlikely to spin once the turbo kicks in, unless you are running massive boost. In import racing, you can play catch-up. You may not have the fastest 60' time, but you can still win the race. Muscle cars, however, just play kick-your-ass. There's no time to catch up if you don't have power off the line. Plus, they have more than enough torque to spin the supercharger, making the power losses insignificant in light of the incredible power put out by their motor.

In import racing, a turbo's: Lag, Efficiency, and Lack of Parasitic Drag outweigh the disadvantages of: Non-instant power and High-torque.

Lag allows you to get off the line without spinning.
Efficienct design allows you to gain more horsepower out of a motor.
Lack of Parasitic Drag: see above.

Non-instant power: Lag is a bad thing, however, once you get off the line and are moving. However, in most turbochargers, by the time you are off the line, you are already spooled and ready to go.
High-torque: no small displacement engine has "high torque." We live for tire-melting horsepower and 7k redlines, not 350ft lbs of torque at 4500 RPM's. Besides, we have time to play catch up

In domestic racing, a superchargers: Instant power and High torque
outweigh the disadvantages of: lower final hp numbers, Efficiency, Lag, and parasitic drag.
10 second quarters are all about the launch and subsequent acceleration. There is no catch up time. If you are not off the line instantly, you will lose to someone who is. How many NHRA dragsters have you seen get off the line slower and get moving, but still win the race? Not many. That's because a 10 second quarter is over so damn fast. There's no time to playt catch up. The domestic guys need power, and they need it instantly. There's no time to wait for the turbo to spool. In this case, the speed and torque off the launch outweighs the disadvantages of max final hp numbers and efficiency.

OK...Discuss!!!! 8)

[Khopari]

Which one is easy to service it..

when i say that,, mean which one u can work on it home,, and fix lil prob.

<div class='quotetop'>QUOTE(Easy Company)</div><div class='quotemain'>Which one is easy to service it..

when i say that,, mean which one u can work on it home,, and fix lil prob. </div>
Probably a supercharger, simply because it has fewer parts. I have no experience with superchargers, but I can tell you that turbos are tough to work around, especially when hot...
Turbos are more likely to seize, warp, or break because of the massive stress levels they encounter during rapid acceleration/decleration and then to turning off the car.

The only issue i would see is that a replacement turbo can generally be found for like $150. A replacement supercharger can cost upwards of $600, i would imagine.

Someone with experience with both forms of FI can probably answer this better than me.

[mjc1055]

what i want to know is how do you know how much boost it is safe to run on stock internals? and how hard can you drive running said stock internals? all the power created by forced induction is for naught if you blow a piston or the head gasket out

<div class='quotetop'>QUOTE(mjc1055)</div><div class='quotemain'>what i want to know is how do you know how much boost it is safe to run on stock internals? and how hard can you drive running said stock internals? all the power created by forced induction is for naught if you blow a piston or the head gasket out Â*:(</div>
these are the kinds of posts that belong in the regular section...do a search or post a new thread, not in here. This is specifically for TURBO vs. SUPERCHARGER questions and comments.

Sorry man.

[TWISTED II]

you honestly need to get a life phase.....remind me why scootin should get off this site? maybe YOU need to let the mods do their job and worry about who stays and who goes. is it such a bad thing that he made a topic where people can discuss turbos and SDS? you need to back off and grow up. sorry, that was kinda off topic. i better add some FI input. i think if you would like a quick car, with pretty easy maintainance, go with a SDS. they install easy and from what i hear, work well. now, if your lookin for crazy fast, i would opt for the turbo. on the V6, i would opt for a twin mua haha. i think with a 5 spd and stand alone, you could use a turbo more to your advantage tuning wise and get more power out of them. so, my vote goes to turbo.

[00GTZ00]

Good Start…here we go (for the record, I am not 100% for Superchargers. Both Superchargers and turbos have their own place in theis world. But for arguments sake, I am going to be bias toward the SC side. thanks for playing!)


<div class='quotetop'>QUOTE</div><div class='quotemain'> The supercharger pulley takes a lot of energy to spin, and a small displacement motor lacks this torque that is required to spin the pulley</div>

Well, yes the SC takes some energy to spin BUT because the Supercharger does run off of the belts it does create instant power…and because that power is instant the supercharger will ALSO produce power to run itself. So once it gets spinning it is essentially driving itself. IT takes about 1% of the total power produced by the Supercharger to spin its self…so if you are putting down to the wheels 100 extra hp that means that the SC is producing ABOUT 10 hp more than what you are putting down to drive its self. And this 1% is steady across the board no matter how much boost you are running because as the boost goes up so does the end result of that 1%

<div class='quotetop'>QUOTE</div><div class='quotemain'> Turbos are much more efficient, as well...A supercharger is approx 40-50% efficient, while a turbo is 70% or more efficient</div>

Not all to true. The older style roots type blowers were 50-60% efficient were as all the newer designs have improved the efficiency of the Supercharger. The new superchargers are within 5-10% as efficient as the turbos. And the same rules apply to both the turbo and SC, You have to match the Turbo or SC to the size and air volume of the application (engine) if the unit is not matched properly to your engine then the efficiency of the turbo or supercharger drops drastically.

Then you also have to think about the heat produced by each unit. A turbo can only run X amount of boost until it is required that you apply an intercooler to bring the efficiently of the turbo back to respectable levels. From my experience the average amount of boost needed before the turbo needs an intercooler is ~7psi. this means tha tyou need to spend more $$$ to keep the turbo on par with the supercharger. Again with what I have personally seen, A supercharger can run up to about ( on average) 15psi until it needs any type of aftercooler/intercooler. (Take note that the stock psi for a grandprix GTP is ~12, for a ford lighting ~17psi, and a VW corrado was ~7psi and all of these applications can up the boost W/O needing any type of intercooler )

<div class='quotetop'>QUOTE</div><div class='quotemain'> There is almost no parasitic loss, except in the form of lower exhaust gas velocities until the turbo is spooled</div>

Well this is not all true… even when the turbo is producing boost there is still significant parasitic loss do to the turbo being in the way of the exhaust gasses trying to move out of the engine faster than the turbo is spinning. This is were you get you inefficiency from the turbo. If it did not have the problem then the turbo would be about 99% efficient and then their would be no need for any type of SC.

And as far as racing imports. Lag is a VERY bad thing. Yes if your car is FWD your weight transfer does suck, But it doesn’t’ matter if you have a SC or Turbo you will still spin off the line like mad if you can’t drive your car. People that race FWD also have a different type of suspension setup that RWD cars do. I know tha the 1G and 2G eclipse/Talon guys stiffen up their rear suspension and loosen the front to help them get off the line. Then if you are making some real power you can add wheelie bars out back to help control the weight transer on a FWD car.

ANY ONE here actually watch import drag racing? Then you know why all the turbo guys have their RPMS peaked before the tree drops right? To build up the boost, to overcome the turbo lag. People also use a shot of nitrous to help overcome this problem. And if you don’t spool up the turbos before your launch you better be making some serious power to overcome the humiliation that you will experience off the line…

As far as the application goes as long as the SC or turbo is matched properly they will both make comparable power to each other but the SC will end up being cheaper than the turbo….

[Auto-9]

This is what I was told by Hennessey and Lingenfelter when I asked them why they chose their respective methods of forced induction:

Supercharger - great on small displacement engines, improved technology now allows for almost 0 parasitic losses, simpler setup than a turbocharger thus easier to maintain, but tuning can be limited by the pulley.

Turbocharger - amazing on large displacement engines which suffer 0 turbolag, allows for incredible power gains, but it's more complex to set up.

Neither of them said heat was a factor because it's not a direct result of forced induction, but rather a result of air/fuel.

Well I'm not going to argue with lingenfelter, but remember, they are dealing with all-out drag cars. They build some of the fastest cars around, therefor they are also dealing with the 9-10 second 1/4 mile times.

A turbo will always produce more power than a supercharger, because of the efficiency. Yes, it is correct that a turbo does present parasitic loss because of the loss of exhaust gas velocity ("backpressure"), but still, it is many times more efficient than a supercharger. Remember that in 13 and 14 second import racing (which ALL aftermarket turbo'd cars, and cars with turbo upgrades, should be in), we still have time to play catch-up. We live on max hp numbers, because we make nothing for torque. We have plenty of "lag" already, in the fact that our motors generally don't get workin' until 3000-3500 RPMs.
If a supercharger presents more power loss than a turbo, it is less beneficial in a slower race than a turbo, which presents very very little power loss. Off the line power can be sacrificed for higher hp numbers, in this case.
10-second imports are impossible without some form of FI, so let's get that out of the way quick. 10-second imports would not be able to be created without FI. Just in case someone tries to argue for imports running fast quarter times (11-10 second range), that they should use a supercharger.
Lag is never 0, remember. It's like an automatic transmission, it takes time for the "fluid" (tranny fluid compared to exhaust gases) to transfer it's energy to the turbine, beginning it's spooling. It may be damn quick, but then you are either using a really small turbocharger, which will limit ultimate power, or using a multi-thousand dollar turbo, which makes its large compressor wheel extremely light. Still, no lag is ever 0.
Lag is the tradeoff for higher power numbers, and in a case where lag can actually work for you, the turbo is the obvious choice.

And RedGalant2k1 will be watching this thread, so any off topic posts will be deleted. Thanks.

[Jet Black]

<div class='quotetop'>QUOTE(Auto-9)</div><div class='quotemain'>Neither of them said heat was a factor because it's not a direct result of forced induction, but rather a result of air/fuel.</div>

Which isnt quite true. With increased pressure comes increased heat: General Gas Equation - P1V1/T1=P2V2/T2

So lets say you 5 atm, 10 L, and 40 degrees celsius of O2, and then you increase the pressure to 10 atm, the equation would be:

(5 atm)(10L)/(40+273.15 kelvin) = (10 atm)(10L)/(x kelvin)

x = 626.3 kelvin, and 353.15 degrees celsius.

[8ggalant]

<div class='quotetop'>QUOTE(Jet BLaK)</div><div class='quotemain'><div class='quotetop'>QUOTE(Auto-9)</div><div class='quotemain'>Neither of them said heat was a factor because it's not a direct result of forced induction, but rather a result of air/fuel.</div>

Which isnt quite true. With increased pressure comes increased heat: General Gas Equation - P1V1/T1=P2V2/T2

So lets say you 5 atm, 10 L, and 40 degrees celsius of O2, and then you increase the pressure to 10 atm, the equation would be:

(5 atm)(10L)/(40+273.15 kelvin) = (10 atm)(10L)/(x kelvin)

x = 626.3 kelvin, and 353.15 degrees celsius.</div>


huh :shock: ...sorry i had to post that..mods u can erase

<div class='quotetop'>QUOTE(Jet BLaK)</div><div class='quotemain'><div class='quotetop'>QUOTE(Auto-9)</div><div class='quotemain'>Neither of them said heat was a factor because it's not a direct result of forced induction, but rather a result of air/fuel.</div>

Which isnt quite true. With increased pressure comes increased heat: General Gas Equation - P1V1/T1=P2V2/T2

So lets say you 5 atm, 10 L, and 40 degrees celsius of O2, and then you increase the pressure to 10 atm, the equation would be:

(5 atm)(10L)/(40+273.15 kelvin) = (10 atm)(10L)/(x kelvin)

x = 626.3 kelvin, and 353.15 degrees celsius.</div>
true. PV=NRT right there. Volume stays the same, pressure increases, so temperature must increase as well. Add to this the added heat of a turbocharger's exhaust turbine housing being bolted onto the compressor wheel, and you have one hot mother. That is where air-to-air intercoolers come into play, and even liquid-to-air, which can be more than 100% efficient, meaning the intake temp charge is actually lower than the ambient air temperature.

[Jet Black]

<div class='quotetop'>QUOTE(8ggalant)</div><div class='quotemain'><div class='quotetop'>QUOTE(Jet BLaK)</div><div class='quotemain'><div class='quotetop'>QUOTE(Auto-9)</div><div class='quotemain'>Neither of them said heat was a factor because it's not a direct result of forced induction, but rather a result of air/fuel.</div>

Which isnt quite true. With increased pressure comes increased heat: General Gas Equation - P1V1/T1=P2V2/T2

So lets say you 5 atm, 10 L, and 40 degrees celsius of O2, and then you increase the pressure to 10 atm, the equation would be:

(5 atm)(10L)/(40+273.15 kelvin) = (10 atm)(10L)/(x kelvin)

x = 626.3 kelvin, and 353.15 degrees celsius.</div>

huh :shock: ...sorry i had to post that..mods u can erase</div>
P= pressure V=volume T=Temprature
lol, basicly by doubling the pressure your getting nearly 9 times the heat.

[Jet Black]

<div class='quotetop'>QUOTE(ScootinIntegra)</div><div class='quotemain'><div class='quotetop'>QUOTE(Jet BLaK)</div><div class='quotemain'><div class='quotetop'>QUOTE(Auto-9)</div><div class='quotemain'>Neither of them said heat was a factor because it's not a direct result of forced induction, but rather a result of air/fuel.</div>

Which isnt quite true. With increased pressure comes increased heat: General Gas Equation - P1V1/T1=P2V2/T2

So lets say you 5 atm, 10 L, and 40 degrees celsius of O2, and then you increase the pressure to 10 atm, the equation would be:

(5 atm)(10L)/(40+273.15 kelvin) = (10 atm)(10L)/(x kelvin)

x = 626.3 kelvin, and 353.15 degrees celsius.</div>
true. PV=NRT right there. Volume stays the same, pressure increases, so temperature must increase as well. Add to this the added heat of a turbocharger's exhaust turbine housing being bolted onto the compressor wheel, and you have one hot mother. That is where air-to-air intercoolers come into play, and even liquid-to-air, which can be more than 100% efficient, meaning the intake temp charge is actually lower than the ambient air temperature.</div>

So the intercooler actually can cool the air from some ungodly number (due to the heat of the turbine translating in to heat in the compressor, and pressure on top of that), to a more normal number? Damn that is effecient. But would it be even better to add an intercooler to a supercharger thats not pumping out hot gases, even if its not neccecary?

[00GTZ00]

<div class='quotetop'>QUOTE</div><div class='quotemain'>A turbo will always produce more power than a supercharger, because of the efficiency</div>

not true...

and if we are creating 10-12 sec imports that is not fast enough to see any "real" gains from one kit to another. and a 10-12 sec daily driver is MUCH more reasonable in a SC car. The up keep on a sc car is not nearly as much as the turbo. again I say that a SC car is much more reliable for a daily driver that is only in the 10-12 sec range

<div class='quotetop'>QUOTE</div><div class='quotemain'>We live on max hp numbers, because we make nothing for torque</div>
Correct, torque is a problem for small displacement cars. But also remember that HP is a measure of torque that is produced at any given RPM. So in a race if you do not have the torque to get you off the line then you will not win, no matter what. sooo if the 4 cyl cars do not have torque, you would want to correct this problem right?

Using a SC will give you that torque that you need/lack for every day driving, so that you do not have to rev to the moon to get your car moving.

The SC can be geared for hig end power, Just like the turbos can. Take the S2000 (very high reving engine) and the kit from comptech

<div class='quotetop'>QUOTE</div><div class='quotemain'>If you are looking to transform your S2000 the Comptech Aftercooled Supercharger kit is a great start! Utilizing the benifits of a centrifugal supercharger, designed to match the factory power characteristics of the high reving Honda 2.0L powerplant. The Comptech aftercooled Supercharger kit will add more power to your S2000 at the higher RPM's, keeping the car drivable in traffic & day-to-day driving, but throttle the engine to redline & you'll feel the burst of accelleration from the additional 90-100 horsepower at the rear wheels! Included in the kit is everythink you'll need to transform your S2000 into a Boxter killer. The kit includes the blower unit, airbox aftercooler, waterpump, all mounting brackets, fuel system upgrades (including an in tank Fuel Pump & Comptech FPR), all hoses & drive belt and the Comptech ESM unit. 340 horsepower at the crank! Utilizes a very efficient gear driven centrifugal supercharger and is a simple bolt on kit. Includes air box, fuel pump, regulator. CARB legal This kit is designed so that it can be removed without any modifications to the factory components. The kit has been certified to meet or exceed the C.A.R.B. emissions standards for all model year S2000's, making the kit smoggable in all 50-states</div>

now what I see here is a 340 hp S2000 that has been made to gain all the HP in the upper RPM range but at the same time giving the car better torque so that you do not have to rev to 9000 rpm to get through the traffic light...

[00GTZ00]

<div class='quotetop'>QUOTE</div><div class='quotemain'>Damn that is effecient. But would it be even better to add an intercooler to a supercharger thats not pumping out hot gases, even if its not neccecary?
</div>

The cooler the air the better the results

00GTZ00 is right about the daily driven power a supercharger presents, you don't have to wait for a turbo to spool to get that power. But honestly, how many of you are adding a form of FI to get better daily driving power? You guys are most likely adding FI to rip through the quarter mile, or mile, or whatever you're racing.

And a turbo will produce more power under the same airflow as a supercharger. Notice I said airflow, not boost. Boost is dependent on temperature and pressure. Higher boost can mean higher temperatures, while having lower airflow than a lower-boosted car with much colder intake temps. Airflow is what really affects the power of a car under FI.
Think of it this way...you can either have power:5 and loss (to drive the FI):1 or you can have power:5 and loss: 2. No matter what boost you run at, you will always lose more power in a supercharger vs. a turbocharger. Intercoolers work wonders.

The cooler the air, the less resistant to knocking, the more fuel you can add, and the more airflow you get. 8)

[00GTZ00]

<div class='quotetop'>QUOTE(ScootinIntegra)</div><div class='quotemain'> No matter what boost you run at, you will always lose more power in a supercharger vs. a turbocharger. Intercoolers work wonders.

The cooler the air, the less resistant to knocking, the more fuel you can add, and the more airflow you get. 8)</div>

yes but remember that you can allways run an itercooler/aftercooler on a SC setup. So if the SC creates LESS heat to begin with adding an intercooler to a SC will insrease the airflow even more....

<div class='quotetop'>QUOTE(00GTZ00)</div><div class='quotemain'><div class='quotetop'>QUOTE(ScootinIntegra)</div><div class='quotemain'> No matter what boost you run at, you will always lose more power in a supercharger vs. a turbocharger. Intercoolers work wonders.

The cooler the air, the less resistant to knocking, the more fuel you can add, and the more airflow you get. 8)</div>

yes but remember that you can allways run an itercooler/aftercooler on a SC setup. So if the SC creates LESS heat to begin with adding an intercooler to a SC will insrease the airflow even more....</div>
but this increase in airflow will be offset by the drag of the pulley. The more boost you run with an SC, the more power you lose as an effect of that increased boost (due to the smaller pulley). The more boost you run in a turbo, the more power you get, with no added drag on the system.

[00GTZ00]

That drag though stays at ~1% of the total output of the SC power. So if the SC is making 100 hp it will take 10hp to run the pully, 200 hp it will take 20 hp etc etc. not a bad offset in my book...what % of hp does the turbo rob from the engine? it is in the way of the exaust flow yaknow..and creating all that extra stress on the exaust manifold and head or heads..

and the Vortech V5 G-trim has to be a pretty efficiant SC to turn a 210 crank hp V6 (eclipse GTS) into a 350+ crank hp monster

<div class='quotetop'>QUOTE</div><div class='quotemain'>This kit has produced 350.11 horsepower and 346.25 foot-pounds of torque at the flywheel on a 5SPD and 308.75 and 277.12 foot-pounds of torque on an automatic sport Trans on 93 octane gas. While retaining stock-like drivability. So basically Your driving around a 280 Wheel Horse Power car with 277Lb/ft, which is comparable to a C5 Vette and better than a new BMW M3.
</div>

or a 180-205 WHEEL HP 4 cyl car at only 5psi
<div class='quotetop'>QUOTE</div><div class='quotemain'>To date our customers have produced as a bolt on modification on stock internals and rated at the drive wheel, these horse power figures:



205.5WHP GS 5SPD at only 5-6psi



188.1WHP ES Galant Automatic at only 5psi</div>

* all quotes from rippmods

Plus the SC offers a VERY impressive package, Ease of install and tuning VS a turbo. And for the everyday driver that is what counts. I personally want a car that I can drive everyday, Install the whole kit myself woithout have to make trips to every garage in my area to get shit fixed.