Turbo or supercharger?

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Gik69
What is best turbos or superchargers? What gives the best power?

Turbo (high RPM at least) will give more power, some suffer a little lag (some more than others), however turbo boost comes on strong where the SC will not give as much peak gains it will increase boost progressively as rpm's rise and is a smoother increase.

So if your turbo gives too much power and upsets the chassis too much, an SC if available might make putting the power down easier, or less harsh.

This is just speaking to the SC's in the game, the IRL relationship is more complicated with so many more options.
 
Superchargers give the most power but unfortunatly they can only really be put on muscle cars, yes they can be put on other cars but turbo's are mainly for sports car, super cars etc :D
 
Both of those are wrong both in real life and in GT5?

Since there are only a couple of cars in which you can supercharge OR turbocharge a car, I'm not sure how you came to the conclusion that SC's make the most power. In real life, both a supercharger and a turbocharger are equally capable of putting up big horsepower numbers when tuned appropriately with the proper engine.

In terms of power as umadson is referencing. This is also incorrect since a supercharger is technically able to peak in the same way that a turbocharger is. While a supercharger technically provides more power at LOW RPM, there's nothing that is really limiting it at the top end any more than a turbo may be?

They're both simply compressors. One is related to the intake more so than the exhaust, but even this is oversimplifying.
 
And then there's cases where both can be applied, and some creative people even put them both on one engine.. Like this:





Twincharged Toyota engine test run.
Rotrex & Turbonetics GT-K550.
Hestec & M&W ignition.

1/4mile E.T 11,38s/203km/h (24.5-08 Pori wcsc)
New ET drive today 21.9-08 in Alastaro. 11,03s/208,13km/h 2,2bar boost
 
What is best turbos or superchargers? What gives the best power?

Turbochargers in every appilication. They have become very efficient in recent years. With almost no turbo lag in any part of the rev range. Turbos do require more engine bay room than a supercharger. Superchargers gain exponential amounts of friction as it increases rpms as it runs off the crank sapping hp. Turbos do as well from the exhaust heat but not at the rate of a supercharger. Hardly any automaker even makes a supercharged car from the factory for a reason.
 
Hardly any automaker even makes a supercharged car from the factory for a reason.

There are quite a few cars that come stock with a Super Charger. They aren't as common today, due to fuel mileage issues, where as stated above Super Chargers take power to make power. Turbo's are more efficient, but there are still cars today produced with Super Chargers, mostly American.
 
Turbochargers in every appilication. They have become very efficient in recent years. With almost no turbo lag in any part of the rev range. Turbos do require more engine bay room than a supercharger. Superchargers gain exponential amounts of friction as it increases rpms as it runs off the crank sapping hp. Turbos do as well from the exhaust heat but not at the rate of a supercharger. Hardly any automaker even makes a supercharged car from the factory for a reason.

Seriously... this is just 99% wrong.

1. While technology has certainly improved turbochargers in recent years, almost no turbo lag is still turbo lag. And when you're buying a car that comes with a stock turbo vs a car that comes stock turbo that you're adding a "better" turbo onto, you're going to have lag. Simple as that. It's physics. It doesn't change. Ever.

2. Turbos don't require more engine bay room than a supercharger, and superchargers don't require any more engine bay room than a turbocharger. You can have superchargers that look identical in size and shape to a turbocharger, in fact many radial flow superchargers are confused for turbochargers initially. Then on the other side of the coin you can have roots type superchargers that take up plenty of space.

3. A supercharger doesn't have any exponential friction issues that a turbocharger wouldn't have. It COULD have linear heat issues that a naturally aspirated engine wouldn't have without a supercharger being otherwise bolted to it, but thats it. In terms of exponential increases, both a turbocharger and supercharger increase air pressure at the square of the speed.

3.5. A turbo requires the engine to be producing exhaust gas volumes that are high enough to spin the turbine which then powers the compressor. Turbo's even at IDLE are STILL moving air, they just aren't doing it in any positive form for an engine. A supercharger on the other hand is belt (engine) driven in a method other than a compressible gas (mostly). This means that the engine can have a better low end response to the lag caused by a turbo.

4. You were correct that a supercharger requires horsepower to make horsepower, but wrong in assuming that a turbocharger doesn't do the same thing. If a turbine could be made to be frictionless and massless, then we'd have something. Otherwise... Physics. Doesn't change... yadda yadda.

5. The reason you see more TC cars than SC cars is simply due to the way people choose to drive. There ARE cars sold from the factory as supercharged for the record. But the primary reason for a turbo is to have a fuel efficient engine that can still have some go power when you give it the beans. Most people will hardly ever get their turbos in their Audis into a usable boost range (ok, well maybe the sill K03 turbo since it's the size of a peanut) so they'll never notice the extra fuel, but on a supercharger you'll always use it and need the fuel. Not to mention it whines and complains a lot more than a turbo on a "normal" car does.
 
The only two cars I've chosen supercharger over turbocharger (when I had the option) were the Caterham Fireblade and the Mazda Miata in endurance trim. Other than that, there is no reason to get anything besides a turbo.
 
Manufacturers do not fit their production cars with the best turbo technology available within given wheel and flow spec ranges. People can and do upgrade to turbos that both spin up quicker and flow more efficiently, and often there is options to go with larger wheels without sacrificing spool time, flow efficiency, or torque build.
 
Epic 'rolla
That was the sickest AE86 I have ever seen, thanks for that!


In game the High RPM Kit will make more BHP than a Supercharger, but not a lot more. Look at your power curve, if you don't have a lot of power low to mid range, get the SC, if you do get the TC.

In real life all turbo's experience turbo lag, unless you have a turbo boosting at idle, and if it did that you wouldn't get a good power boost out of it, unless you set up sequential turbochargers. Also The tech in SC's has stepped up quite a bit, where back in the 70s you were stuck with the Roots style SC, now you have Twin Screw SC's that produce more HP, and are more efficient. Because the SC's runs of the engine, you do get parasitic loose, but as a TC's is effectively creating a snag in your exhaust, it does to. Also the point were you really start making power with a SC depends on how large your SC pulley is, so you can make you SC really start building power at high RPMs, or boost low, it all depends on your pulley. If your worried about gas mileage, some SC pulleys come with clutches that only engage at higher RPMs, so you can still do your city driving without boosting. Toyota did this back in '86 with the MR2 SC. And if your worried about sound, small SC's don't make a ton of noise ('86 MR2 SC is pretty quite) just like cars with small TC's. The bigger they are the louder they are, just like TC's. SC's can do everything a TC can, you only have to know how to do it.
 
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oopssorryy
That was the sickest AE86 I have ever seen, thanks for that!

In game the High RPM Kit will make more BHP than a Supercharger, but not a lot more. Look at your power curve, if you don't have a lot of power low to mid range, get the SC, if you do get the TC.

In real life all turbo's experience turbo lag, unless you have a turbo boosting at idle, and if it did that you wouldn't get a good power boost out of it, unless you set up sequential turbochargers. Also The tech in SC's has stepped up quite a bit, where back in the 70s you were stuck with the Roots style SC, now you have Twin Screw SC's that produce more HP, and are more efficient. Because the SC's runs of the engine, you do get parasitic loose, but as a TC's is effectively creating a snag in your exhaust, it does to. Also the point were you really start making power with a SC depends on how large your SC pulley is, so you can make you SC really start building power at high RPMs, or boost low, it all depends on your pulley. If your worried about gas mileage, some SC pulleys come with clutches that only engage at higher RPMs, so you can still do your city driving without boosting. Toyota did this back in '86 with the MR2 SC. And if your worried about sound, small SC's don't make a ton of noise ('86 MR2 SC is pretty quite) just like cars with small TC's. The bigger they are the louder they are, just like TC's. SC's can do everything a TC can, you only have to know how to do it.

+1 great info, all good stuff. It's only too bad PD doesn't give us more options with boosting.
 
sick vid of hachi-roku have it all. best of all three worlds huh.
NA, Turbo & Supercharged xD
but owah ... 500+hp on Super Charge. I want that kind of power on the AE86 in GT5 lolz
 
+1 great info, all good stuff. It's only too bad PD doesn't give us more options with boosting.
Thanks! I wish PD gave up variable boost, based on what kit you by, and the option to Twin turbo, or Twin Charge using the SC and TC.I really think you should have the option to put in dish pistons in the engine tuning menu. You can't just slap a TC or SC on your car and run big boost threw it without changing your internals to match. And really, if you have the money you can get a TC or SC built for any engine. It's just like fully customizable transmissions, they cost a ton of money, but you can get one built just for you if the moneys right. So this "this part is not available for your car" is total BS. When you've got 20 million credits I pretty sure you can get one made!
 
Seriously... this is just 99% wrong.

1. While technology has certainly improved turbochargers in recent years, almost no turbo lag is still turbo lag. And when you're buying a car that comes with a stock turbo vs a car that comes stock turbo that you're adding a "better" turbo onto, you're going to have lag. Simple as that. It's physics. It doesn't change. Ever.

Apparently you haven't heard of VGT turbos and the recent blade designs? Lag is only a factor if you can't drive, aka don't shift properly. Anyone that complains about turbo lag just fails at driving.

2. Turbos don't require more engine bay room than a supercharger, and superchargers don't require any more engine bay room than a turbocharger. You can have superchargers that look identical in size and shape to a turbocharger, in fact many radial flow superchargers are confused for turbochargers initially. Then on the other side of the coin you can have roots type superchargers that take up plenty of space.

This is all subjective to the pure size of the forced induction being used, but it's generally a lot easier to squeak in a turbo or roots blower then its a centrfigual one.

3. A supercharger doesn't have any exponential friction issues that a turbocharger wouldn't have. It COULD have linear heat issues that a naturally aspirated engine wouldn't have without a supercharger being otherwise bolted to it, but thats it. In terms of exponential increases, both a turbocharger and supercharger increase air pressure at the square of the speed.

3.5. A turbo requires the engine to be producing exhaust gas volumes that are high enough to spin the turbine which then powers the compressor. Turbo's even at IDLE are STILL moving air, they just aren't doing it in any positive form for an engine. A supercharger on the other hand is belt (engine) driven in a method other than a compressible gas (mostly). This means that the engine can have a better low end response to the lag caused by a turbo.

No form of induction will ever produce positive pressure unless there is a load on the engine.

And just to throw this out there, even with roots style blowers, superchargers, and turbos; you need to pick the size appropriately. Even a roots style supercharger can have a lag, despite being driven by the engine. Although if you care about top end power, lag will never be the issue.

4. You were correct that a supercharger requires horsepower to make horsepower, but wrong in assuming that a turbocharger doesn't do the same thing. If a turbine could be made to be frictionless and massless, then we'd have something. Otherwise... Physics. Doesn't change... yadda yadda.

True. Takes power to make power, a turbo is just more efficient at it.

5. The reason you see more TC cars than SC cars is simply due to the way people choose to drive. There ARE cars sold from the factory as supercharged for the record. But the primary reason for a turbo is to have a fuel efficient engine that can still have some go power when you give it the beans. Most people will hardly ever get their turbos in their Audis into a usable boost range (ok, well maybe the sill K03 turbo since it's the size of a peanut) so they'll never notice the extra fuel, but on a supercharger you'll always use it and need the fuel. Not to mention it whines and complains a lot more than a turbo on a "normal" car does.

You can barely hear the whine on a stock supercharged car because they design the intake boxes to cancel out the noise, along with the supercharger itself. And again, with little to no load on the engine, it will not create boost.

Both systems improve fuel economy because there's an assist to help move air into the engine on light load.

Why are manufactures using turbochargers over superchargers, pure efficiency given size. Not to mention as said before, turbo lag doesn't really exist anymore. Couple that with direct injection and you have quite the efficient car at making power and saving you at the pump.

Supercharger will never, ever be as efficient as turbo.
 
Supercharger will never, ever be as efficient as turbo.

Shouldn't say that, as you don't know what going to happen in 20 years. Unless your magic, in which case could you grant me a wish?:dopey:

If anything a SC becomes more efficient the smaller, and higher revving the engine is. A small engine just doesn't produce enough exhaust to really get a turbo moving, or a least not one were any power can made. Were as because the SC runs off of the engine, the small, high revving engine, can produce more power. Put a clutch in your SC pulley and you have the gas mileage of a turbo, but in this case, more power. Think of a Honda CR-X, with the B16a, Supercharged! The only reason it hasn't been done is because turbo's are cheap and easy to pick up. If anything TC's are better suited to big V6's and V8's, because they usually don't rev up very high, but produce massive amounts of exhaust.

The only reason your seeing more turbos out there is because they are popular, not because they are better. When the American Muscle car fad died out, and the Japanese Tuner fad came in, TC's replaced SC's. Again SC's can do anything a TC can do it just takes a little know how.
 
Shouldn't say that, as you don't know what going to happen in 20 years. Unless your magic, in which case could you grant me a wish?:dopey:

Granted, I'll give you that.

If anything a SC becomes more efficient the smaller, and higher revving the engine is.

This is really depdenent on supercharger properly sized to engine size. Just go tell the KB Cobra guys that superchargers don't work efficiently for them.

A small engine just doesn't produce enough exhaust to really get a turbo moving, or a least not one were any power can made. Were as because the SC runs off of the engine, the small, high revving engine, can produce more power.

Superchargers have a maximum RPM they can spin. So higher revving engines require larger pullies to keep the supercharger happy, thus limiting boost down low.

And superchargers work a million times better if they can move exhaust gas efficiently. Go look at supercharger cam specs, and supercharged based headers. Exhaust is more critical on a supercharger then a turbocharger.

Put a clutch in your SC pulley and you have the gas mileage of a turbo, but in this case, more power.

A clutch would worsen gas mileage. Again, all forced induction is load based. No load equals no boost demanded, so forced induction then assists in putting air into the engine.

Think of a Honda CR-X, with the B16a, Supercharged! The only reason it hasn't been done is because turbo's are cheap and easy to pick up.

Superchargers have been done, with decent success, but the fact remains turbos just work better on those motors. Every setup you can imagine has been tried in the Honda world. They know the best ways to make power.

If anything TC's are better suited to big V6's and V8's, because they usually don't rev up very high, but produce massive amounts of exhaust.

Again wrong. Properly sized turbos for engine size helps everything. Turbos are suited for every engine, just like any forced induction and they all work well, but some work better then others.

The only reason your seeing more turbos out there is because they are popular, not because they are better. When the American Muscle car fad died out, and the Japanese Tuner fad came in, TC's replaced SC's. Again SC's can do anything a TC can do it just takes a little know how.

It's not true. You can't effectively run a supercharger that displaces more then the engine, thus limiting the amount of power you can make, at least with a decent power curve, and isn't that the sole advantage of the supercharger?

Turbos are popular because they flat out work better for producing power. I don't know how you could even argue the supercharger is a better power producer?

Have you ever compared compressor maps of all style superchargers to turbos?
 
How would a clutch make the gas mileage worse? If you not running boost AT ALL because the pulley isn't engaging the SC, how would your MPG drop? Yes a properly sized TC and SC make all the difference, but so does the engine your putting it on. The reason Honda's with TC's rev so high is so they can actually build exhaust to push said TC's. SC's are reliant on engine speed, TC's on exhaust, so in theory TC's should be more effective on larger engines that produce more exhaust and SC's on quick revving engines. Most cars still use the old Roots style SC which is horribly ineffective, instead of the Twin Screw, for cost reasons. If you were to take, lets say a 2.5 V6 that revs to 7.5, I bet you that the SC and TC applications would be about equal with the right amount of research and time put in. Again you can do anything with an SC that you can with a TC. The difference is that the TC is easier because it's been done before, were as the SC's haven't really been played with much in the tuner scene. If SC's are ever given the chance to catch up knowledge wise, then you'll see what I mean. Look at the Lotus Elise, it uses the Toyota 2ZZ-GE engine, with a Lotus built SC. Are you saying that Lotus was wrong in doing so? If TC's were really that much better than SC's I doubt that car manufacturers would still use them at all. It's all how you use the SC or TC that makes the difference.
 
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How would a clutch make the gas mileage worse? If you not running boost AT ALL because the pulley isn't engaging the SC, how would your MPG drop? Yes a properly sized TC and SC make all the difference, but so does the engine your putting it on. The reason Honda's with TC's rev so high is so they can actually build exhaust to push said TC's. SC's are reliant on engine speed, TC's on exhaust, so in theory TC's should be more effective on larger engines that produce more exhaust and SC's on quick revving engines. Most cars still use the old Roots style SC which is horribly ineffective, instead of the Twin Screw, for cost reasons. If you were to take, lets say a 2.5 V6 that revs to 7.5, I bet you that the SC and TC applications would be about equal with the right amount of research and time put in. Again you can do anything with an SC that you can with a TC. The difference is that the TC is easier because it's been done before, were as the SC's haven't really been played with much in the tuner scene. If SC's are ever given the chance to catch up knowledge wise, then you'll see what I mean. Look at the Lotus Elise, it uses the Toyota 2ZZ-GE engine, with a Lotus built SC. Are you saying that Lotus was wrong in doing so? If TC's were really that much better than SC's I doubt that car manufacturers would still use them at all. It's all how you use the SC or TC that makes the difference.

Ignorance is bliss with you. Even a twin screw is inefficient compared to a turbo. For example, my buddy has an 04 Cobra with 2.8 KB making 700 whp. That's the biggest blower the engine can handle efficiently. So whats the next step, twin 61mm turbos and 1000+ hp.

But you're right, superchargers are more efficient and can make more power.


Why don't you state a specific example, supporting you theory that superchargers are better? I'll be waiting.
 
Super Chargers are better because they make more noise, more of the time. Duh!
I was looking for a Mystichrome Termi for a while but changed my mind. They are nice though.
 
Apparently you haven't heard of VGT turbos and the recent blade designs? Lag is only a factor if you can't drive, aka don't shift properly. Anyone that complains about turbo lag just fails at driving.

So then... start explaining to me how a variable vane (or any turbine that can change it's aspect ratio) can have zero lag. Also, we're not talking at all, or even remotely about how good or bad a driver is, or how lag can be minimized by shifting properly. You're trying to defend the remark about lag.

This is all subjective to the pure size of the forced induction being used, but it's generally a lot easier to squeak in a turbo or roots blower then its a centrfigual one.

You're agreeing with me here, not saying I'm wrong, and then you suggest that we're both wrong when you say its subjective, but then list a specific type of charger. You're correct, as am I. It's subjective.

No form of induction will ever produce positive pressure unless there is a load on the engine.

And just to throw this out there, even with roots style blowers, superchargers, and turbos; you need to pick the size appropriately. Even a roots style supercharger can have a lag, despite being driven by the engine. Although if you care about top end power, lag will never be the issue.

I'm not really sure what your argument is here? Are you just arguing semantics? I think when I said "Turbo's even at IDLE are STILL moving air, they just aren't doing it in any positive form for an engine." you're thinking I'm suggesting something I'm not. I'm merely saying positive in terms of benefit. ie positively affecting the engine vs. negatively affecting the engine. Although, what you're saying is correct... I'm not sure why you were arguing with me?

True. Takes power to make power, a turbo is just more efficient at it.

This goes back to subjectivity. With modern "chargers" we're talking about single percentages in terms of efficiency differences. As for incorporating other things like the fact that SCs have parasitic drag and turbines use wasted potential energy. Maybe I can see your point. Maybe. But again, we're talking about miniscule amounts.

You can barely hear the whine on a stock supercharged car because they design the intake boxes to cancel out the noise, along with the supercharger itself. And again, with little to no load on the engine, it will not create boost.

Both systems improve fuel economy because there's an assist to help move air into the engine on light load.

Why are manufactures using turbochargers over superchargers, pure efficiency given size. Not to mention as said before, turbo lag doesn't really exist anymore. Couple that with direct injection and you have quite the efficient car at making power and saving you at the pump.

Supercharger will never, ever be as efficient as turbo.

Not really. The airbox thing is technically correct, but that doesn't discount the fact that a supercharger makes noise. Again though, this is subjective. You're totally wrong about the fuel economy though. Neither of them "improve" fuel economy as an engine still needs to maintain stoichiometrics, so the extra air needs to be met with extra fuel. What they DO do is improve the available power on an otherwise small and fuel efficient engine. And saying a supercharger will never be as efficient as a turbocharger is just wrong. Not only is there no way you could ever back that statement up, it's foolish to even say something like that?
 
Ignorance is bliss with you. Even a twin screw is inefficient compared to a turbo. For example, my buddy has an 04 Cobra with 2.8 KB making 700 whp. That's the biggest blower the engine can handle efficiently. So whats the next step, twin 61mm turbos and 1000+ hp.

But you're right, superchargers are more efficient and can make more power.


Why don't you state a specific example, supporting you theory that superchargers are better? I'll be waiting.
I never said that SC's are more efficient than TC's. The point I'm trying to get across, is you can do anything that a TC can do with a SC. I never said that that the TC can't do blah blah blah but a SC can. And on your buddies Cobra, your going for ONE SC too TWO TCs's, not exactly a good comparison.
 
So then... start explaining to me how a variable vane (or any turbine that can change it's aspect ratio) can have zero lag. Also, we're not talking at all, or even remotely about how good or bad a driver is, or how lag can be minimized by shifting properly. You're trying to defend the remark about lag.

I'm defending that remark because its a remark you made, period. Certain style superchargers also have lag. No system is perfect in all forms.


I'm not really sure what your argument is here? Are you just arguing semantics? I think when I said "Turbo's even at IDLE are STILL moving air, they just aren't doing it in any positive form for an engine." you're thinking I'm suggesting something I'm not. I'm merely saying positive in terms of benefit. ie positively affecting the engine vs. negatively affecting the engine. Although, what you're saying is correct... I'm not sure why you were arguing with me?

Sorry, but I cannot assume what you're trying to say. I think we were both on the same page, you just worded awkwardly. Superchargers and turbochargers both move air at idle, otherwise the engine would die, although most supercharger setups use a vacuum bypass solenoid, and some turbo systems due too. Just clearifing all points.

This goes back to subjectivity. With modern "chargers" we're talking about single percentages in terms of efficiency differences. As for incorporating other things like the fact that SCs have parasitic drag and turbines use wasted potential energy. Maybe I can see your point. Maybe. But again, we're talking about miniscule amounts.

Miniscule amounts? I think you are quite nieve there. Granted it depends on the type of supercharger you are talking about. An Eaton M112 for example can eat up almost 100 horsepower just to spin the rotors and compress the air. No turbo is going to take 100 horsepower to spin, although it comes down to how efficient the setup is.

Not really. The airbox thing is technically correct, but that doesn't discount the fact that a supercharger makes noise. Again though, this is subjective. You're totally wrong about the fuel economy though. Neither of them "improve" fuel economy as an engine still needs to maintain stoichiometrics, so the extra air needs to be met with extra fuel. What they DO do is improve the available power on an otherwise small and fuel efficient engine. And saying a supercharger will never be as efficient as a turbocharger is just wrong. Not only is there no way you could ever back that statement up, it's foolish to even say something like that?

With technology that is known about right now, there is no way to make a supercharger as efficient as a turbocharger, given compression method, heat generated, and parasitic drag. Explain to me how it could be more efficient then a turbocharger?

I'll have to eat my words, a touch here. Superchargers see no difference with fuel economy vs being N/A, when driven in normal conditions, which is 95% of the time out of boost.

Turbos do improve fuel economy when driven in normal conditions, which is 95% of the time out of boost.

Yes when being rumped on, it will eat more fuel. More air in = more fuel in. I'm talking every day driving.

oopssorryy
I never said that SC's are more efficient than TC's. The point I'm trying to get across, is you can do anything that a TC can do with a SC. I never said that that the TC can't do blah blah blah but a SC can. And on your buddies Cobra, your going for ONE SC too TWO TCs's, not exactly a good comparison.

Ok but a single 78mm turbo on there and it would again push further then what one supercharger would do. The only reason to go twin turbo, is because its much easier to setup on those cars.
 
Ignorance is bliss with you. Even a twin screw is inefficient compared to a turbo. For example, my buddy has an 04 Cobra with 2.8 KB making 700 whp. That's the biggest blower the engine can handle efficiently. So whats the next step, twin 61mm turbos and 1000+ hp.

But you're right, superchargers are more efficient and can make more power.


Why don't you state a specific example, supporting you theory that superchargers are better? I'll be waiting.

Since I have a little bit of experience in this area I thought I would wade in here and add my .02 e-cents... your mileage may vary though. This topic has gone way off what the original poster was after, but I digress...

articzap here is correct, a supercharger (in todays current world) is not as efficient as a turbocharger is. A supercharger requires a belt to drive the blower (unless its one of those trick direct drive race kits and even they are ran off the balancer) and as such it requires power to drive the compressor to produce more power. How much power it requires depends on the size of the blower... I know some of the Procharger race units several years ago took nearly 300 crank horsepower to spin the compressor. Power was made of course by driving the compressor but its still parasitic power nonetheless. A turbocharger on the other hand basically uses "free" exhaust energy to spin the turbine that in turn spins the compressor... there is no parasitic drag to speak of as the operation of a normal combustion engine is powering the turbo to in turn produce more power. Superchargers have came a long way over the years but they are still not as efficient as a turbocharger is. The pecking order of forced air compressors would go like this from least efficient to most efficient:

roots supercharger < screw supercharger < centrifugal supercharger < turbocharger

I saw someone mention (can't recall who) that even roots superchargers have lag... this is a false statement. A roots or twin screw supercharger has full boost as soon as the throttle hits the stop. There is no lag to speak of... the blower on my car will spit out 17 psi as soon as you mat the skinny pedal. It will even make 8 to 10 psi just "bliping" the throttle lightly... like any of the blowers mentioned they are load dependent to make boost but they roots/screw type blowers do it much, much faster. The drawback to this though is they have a relatively low RPM limit... 18,000 RPM is usually about the max a twin screw blower will spin and do it efficiently. Most of the centrifugal superchargers and turbochargers don't really get going until they're spinning at 75 to 80,000 RPM's... If you spend any amount of time looking at compressor maps for different blowers/turbos you will see what I'm talking about when they're in their efficiency range.

The rebuttal to this post was that it takes two turbos to make the same power as the supercharger on an 04 Cobra. This also is false... you can make the same power and more out of a single 76mm on a completely stock 03/04 Cobra motor as what a twin screw blower can and do it more efficiently. The purpose for twins as far as I know was that two smaller turbos can spool faster than one big one but with current technology you can get this same 76mm to spool just as fast as two 61's. The amount of power you can make with two 61's is more as you have the peak power output of the smaller turbo times the two turbos. You could do the same with one larger single... it just depends on which way you want to skin the cat for lack of a better term.

Oh and articzap a 2.8L is not the biggest blower for an 04 Cobra currently... Whipple makes a 4.0L kit for the car now. The next biggest is the 3.4L which is currently what is on my Cobra :sly: The 2.8L does make very good power though... I know of three people I talk with in various parts of the US that make over 700 to the tires with that blower as well.

This is just my thoughts on the matter :)



Shannon
 
I feel like there's a lot of semantics being argued here and they get intermixed into thinking that people are making wrong statements. I'd suggest that people refrain from referencing some specific vehicle (in this case, everyones cobra?) because its irrelevant and is only showing its a subjective argument.

Without exhaustively going through each of my previous statements, let me just hit a few points.

1. "Lag" is in most of these cases, the incorrect term. Lag is generally the difference in the time from when you want "boost" (or compressed air) entering the engine, and when you get a noticeable amount. In some instances, we're talking about compressed airflow positively benefiting the motor, and in others were talking about lag.

2. Don't be so quick to say that a turbocharger uses "wasted" potential energy. This energy is NOT free, and no energy is, this is the first law of thermodynamics for a reason. For the same reason why you'd rather have a 3" diameter exhaust over a 2" diameter exhaust, you'd rather have no turbine in your exhaust stream than have one. So a turbo DOES cause horsepower to be lost, and it DOES create heat that is bad for the car, and as such it DOES rob horsepower. There is simply no way around it. Superchargers ALSO do this, but they do it DIFFERENTLY, and in most (but not all) cases, a supercharger will eat up more power than a turbo.

3. When discussing the efficiency of a supercharger vs. a turbocharger, you're mentioning that a SC can NEVER be as efficient as a TC. What I'm trying to say is, there are superchargers that are within <5% differences in efficiency than a turbocharger. HOWEVER, when you really get into this, it's more of an apples and oranges argument rather than a forced induction argument since a supercharger is actually very different than a turbocharger in the way they handle their business and the problems they cause. That's why I say its a subjective argument.

4. I'm still going to bust you on the fuel economy. You have the idea 100% correct. More air in requires more fuel. Since a supercharger will always be generating more air, it requires more fuel. And what you're saying about a turbo giving you better fuel economy 95% of the time because the user will mostly be off boost... yes, but you have it backwards. Bolting a turbo onto a car from the factory or aftermarket will NEVER give better fuel economy. If you have a turbo on a 2.0L engine and it gets 20MPG without ever using boost, then get rid of the turbo and you'll still have a 2.0L engine getting 20MPG with no boost. The turbo makes a SMALL fuel efficient motor have MORE horsepower and SEEM more powerful. The 2.0L may be making 150hp by itself, but if you bolt a K03 onto it, it will be making 200HP. You see what I'm getting at? You're right, but it's backwards.

ALright... I gotta get outta here. Haha.

But as I said. Lag and Boost are terms being misconstrued here, and I think thats leading to much of the confusion.
 
Oh and articzap a 2.8L is not the biggest blower for an 04 Cobra currently... Whipple makes a 4.0L kit for the car now. The next biggest is the 3.4L which is currently what is on my Cobra :sly: The 2.8L does make very good power though... I know of three people I talk with in various parts of the US that make over 700 to the tires with that blower as well.

This is just my thoughts on the matter :)



Shannon

The closer the displacement of the blower gets to the displacement of the engine the more you'll notice supercharger lag. I know Kenne Bell has done extensive testing to show that their 2.8L blower was the largest blower that efficiently worked on the car. You can shove any size blower you want on there though. Just remember, as it gets larger it robs a lot more horsepower, so it'll be harder to get spinning to full boost as quickly. Most people don't experience supercharger lag because not many idiots are stupid enough to over blower a car.👍

EivlEvo
1. "Lag" is in most of these cases, the incorrect term. Lag is generally the difference in the time from when you want "boost" (or compressed air) entering the engine, and when you get a noticeable amount. In some instances, we're talking about compressed airflow positively benefiting the motor, and in others were talking about lag.

My definition of lag is this; the RPM span between when you place your foot to the floor to when you hit full boost. That is always what I have heard lag referred too. So in that sense, it does seem we are talking about two different types of lag.

EivlEvo
Bolting a turbo onto a car from the factory or aftermarket will NEVER give better fuel economy.

I don't get how this concept doesn't make sense to you. Maybe you have never turbo'd an N/A car before?

Let me draw it out for you. Lets say the N/A engine makes 75 hp at 2000 RPM. The now turbo'd motor can make 75hp at 1600 RPM. So if you are making the same power but don't need to spin the motor as fast, you'll use less fuel.

It's a hard concept for most to grasp, but its real.
 
2 pages of post and no one has answered his question lol. He is in the tuning forum asking which is better to use in game. So which is it??
 
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