The thing is though, they both add shit loads of power. So unless you're some millionaire competing at the top end of some national racing bracket that needs to squeeze every single possible horsepower physically possible out of your machine, then just go with whatever you like more or whatever would be easier\cheaper to go with.
>>14326923 >parasitic losses. BItch it gets me so mad that people still talk about this kind of bullshit.
The parasitic loss with a Supercharger its so fucking minimal, its like 5% or less of a powerloss, and since superchargers work with the same amount of force than a turbo with a lower RPM range it REALLY doesn't matter. Even turbos have some parasitic loss since the exhaust turbine its blocking the exhaust from leaving the car faster.
The only reason why you would seriously have to get a turbo instead of a supercharger would be because the turbos are way smaller, even tho they require more pipework
>>14326903 It's entirely situational. Turbo lag, heated bearings, pipework, and so forth versus superchargers sapping power from the engine to provide more power.
A turbo will end up with more power with the same level of boost. A supercharger will be lighter and simpler.
Then, of course, you get into different setups for the chargers. One big turbo versus screw-type supercharger, or twin turbos versus roots-type supercharger.
Of course, if you already have a big engine and a high exhaust velocity, a narrow rev range, and an even narrower power band with lots of gears to stay in it, a turbo wins every time. Which is why we have the turbodiesel being ubiquitous.
Now, the whole thing could be solved by an electrically-driven supercharger, run through batteries or capacitors. Charge up when you're not using 100% of the engine power, and then you CAN use 100% of the engine's power and get boost without the supercharger sapping power to provide the boost. Could even toggle it on and off at a whim, and it'd be even simpler to work on since there's way fewer moving parts.
honestly turbos get WAYYY to much hype for what they are...and the majority of superchagers are completely overkill for conventional settings. That being said I would say the centrifugal supercharger is king.
>>14327103 ur dumb. superchargers if positive displacement suck at high rpm. if you have a centrifugal then you have all the disadvantages of a turbo plus those of a supercharger. a turbo attains full boost far faster than a supercharger as its rotational speed isnt linearly tied to rpm. a turbo will always make more power than a similar supercharger except at low rpm. superchargers suck. and parasitic losses are real. a turbo extracts enegy from the exhaust which a supercharged car throws away. plus sc leaches power from the drivetrain. its inferior in principle and practice.
>>14328256 >a turbo attains full boost far faster than a supercharger as its rotational speed isnt linearly tied to rpm Except Turbos ARE tied to RPMs, and if you get a turbo-like supercharger you are a fucking retard and you deserve to get your engine blown off. Turbos has NEVER been able to make as much power as a supercharger, mostly due to their size, wich cant be increased too much, unlike superchargers. Parasitic losses are the ricers excuses to get a fucking turbo. Get fucking real, faggot, your "muh parasitic loss!" its just a fucking meme. Turbochargers stop the flow of the exhaust until they begin spooling up in the same way superchargers wont provide power until certain RPM.
There is nothing the turbo has against the supercharger.
In fact, if you have a small engine, you would be unable to carry a big turbo, since even at high RPMs your exhaust wouldn't be enough to spool the turbo up, while superchargers will always work no matter how small the engine is.
>>14327711 >Now, the whole thing could be solved by an electrically-driven supercharger, run through batteries or capacitors. Charge up when you're not using 100% of the engine power, and then you CAN use 100% of the engine's power and get boost without the supercharger sapping power to provide the boost. Could even toggle it on and off at a whim, and it'd be even simpler to work on since there's way fewer moving parts. Why isn't this a thing? Are batteries still too shitty?
>>14326903 >belt driven positive displacement supercharger loss of power from crank needs special brackets to help hold drive belt can be positioned closer to intake for less lags max boost point can be change by swapping pully sizes or useing cvt - can be clutched so as to deactivate generates good boost throughout rev range
>impeller driven turbine added back pressure requires to be mounted at a limited rage of angles due to oil return line captures and stores allot of heat and requires more vigorous cooling as a device it favours high rpm range and only really starts working after you have run out of torque given that its speed is not directly linked to the engine it can over speed and kasplod
>belt driven turbine limited aftermarket less power loss than a normal supercharger same boost delivery as impeller driven turbine but with better thermal efficiency combines the complexity of turbo and super charger with only some of the advantages of either
>>14326923 I'll just add to this that superchargers are directly linked to the drivetrain so while they are responsive they also spin at the same rpm as the engine despite load, which is bad for fuel economy. turbos on the other hand aren't directly linked, so while cruising at low engine speeds and not under a lot of load the turbo doesn't spin up and produce boost, which is good for fuel economy.
>>14329098 I am a mechanic, you giantic faglord. Parassitic power its only a fucking meme. Try driving a supercharged car yourself instead of basing your logic off from a taiwanese cartoon comic website.
>>14328986 >time for max cool carbureted draw though centrifugal supercharger air to air intercooler with water misting air cooled water jacket + triple cross flow radiator flywheel integral radiator fan because reasons waterless coolant sodium cooled desmodromic valves Methanol Water Injection nitrous oxide nitromethane novec 7000 evaporative cooling where possible pyrogel xt thermal insulated exhaust pipe
>>14329340 >"lol no supercharged engines for over 1000 hp lol" >i post 1000hp+ supercharged engines >posts links of turbocharged engines only making 600 hp
Are you just trying to prove me right at this point? if you cant pick both turbos and superchargers, superchargers have proven to be superior in every way, and modern lightweight parts only reduce parasitic power to the point in wich it almost has the same difference between timing chain to timing belt in crankshaft power reduction.
>>14326903 In a nutshell: >Turbo More efficient than belt driven superchargers, full boost pressure over the boost threshold >Centrifugal supercharger Highest peak horsepower, boost pressure increases linearly with RPM >Twin screw supercharger Maximum boost pressure at all RPMs, more efficient than Roots-type >Roots blower Maximum boost pressure at all RPMs, higher RPM limit than twin screw
Lag or throttle response is a function of throttled volume. You'll have incredibly fast throttle response on a turbocharged engine with ITBs, and have horrendous throttle response on a intercooled, supercharged engine with the throttle body in front of the supercharger.
Throttle lag is not equal to compressor lag. You may put ITB's on whatever you wish, but this will not overcome the key factor that is the ratio of mass in the compressor wheel versus that of the turbine wheel. This is the most important variable in turbocharger response.
No ITB rig or reduction in 'throttled volume' (which is not an engineering term) will overcome an exhaust housing with too great an aspect ratio. If you had a two litre motor and used the same compressor, say a T61 front end. Using the same turbine wheel, which do you think would be absolutely untenable to drive? An aspect ratio of .61 or 1.14? Even at 100% VE, a two litre petrol powerplant will not get shaft speed up anywhere near what is required before five thousand RPM with the 1.14, though I would hazard a guess that target boost would be reached by five thousand with an A/R of .61
A belt driven compressor does not automatically have the highest peak horsepower, that's an absolute fallacy.
Twin screw superchargers do not generate maximum boost at any revolution, were you high when you wrote this?
Roots blowers do NOT have a higher RPM limit than a twin screw, and cannot by definition of their function. A twin screw supercharger is a compressor, where a Roots blower is not. It is a positive displacement pump that builds 'boost' by trapping air in the intake tract. There is no compression happening here, and the process is extremely power hungry and generates a lot of heat. Further, the Roots design is an interference design where the lobes are in constant contact with the blower walls. Each lobe travels a greater distance with friction from the interference than the lobe of a Lisholm screw.
A Roots blower does not make maximum boost at any engine speed.
Why do people keep perpetuating absolute crap?
You do not know of which you speak. An afternoon with Corky Bell's 'Full Boost' is in order for you.
Why would a supercharger have poor response if the throttle body was placed before the lobes? The blower builds high levels of vacuum after the throttle body. The response is no better or worse than a naturally aspirated engine.
This truly tells all that not only have you no or little experience with blower combos, I would hazard another guess that you have never put your foot down on one. Response is similar, with face pulling torque to boot.
If you had thought a little more about what you had written, perhaps the thought that you cannot have the throttle body after the lobes of a Roots blower might have popped into the ol' grey matter?
It's an air pump, not a compressor. What happens to a positive displacement pump if the outlet is restricted or blocked?
The pump continues to turn, and continues to have easy access to air before the lobes that it can aspirate. It will force air into the space below the blower that is now restricted until it simply cannot force any more into that space, which is what a positive displacement pump will do.
You have an already inefficient air pump working at maximum capacity, generating insane amounts of heat and requiring similar amounts of power to rotate as if it were at wide open throttle.
Is this how you build engines to idle? Stay away from my shit.
>>14329776 >A belt driven compressor does not automatically have the highest peak horsepower, that's an absolute fallacy. Centrifugal compressors are significantly more efficient than positive displacement compressors, and at the very upper limit of tuning for peak power, the much smoother exhaust flow of a tubular header compared to the restriction of a turbo and wastegate makes quite a difference. The belt driven compressor will probably have less area under curve but will post marginally higher peak numbers.
>Twin screw superchargers do not generate maximum boost at any revolution >A Roots blower does not make maximum boost at any engine speed. They do. That's what positive displacement means. If it's geared for 6 PSI, it'll be making 6 PSI at idle and at redline, give or take some fluctuation.
>Roots blowers do NOT have a higher RPM limit than a twin screw, and cannot by definition of their function. A twin screw supercharger is a compressor, where a Roots blower is not. It is a positive displacement pump that builds 'boost' by trapping air in the intake tract. There is no compression happening here, and the process is extremely power hungry and generates a lot of heat. Further, the Roots design is an interference design where the lobes are in constant contact with the blower walls. Each lobe travels a greater distance with friction from the interference than the lobe of a Lisholm screw. One screw in a twin screw design turns at twice the input shaft speed. Obviously that gives it a rather limited operational range so it will have to be geared accordingly.
Positive Displacement does not mean what you just said. Take yourself outside and give yourself an uppercut, you could have spend ten seconds with Google and proved that yourself.
Positive Displacement means the pump displaces a set amount of air per revolution.
For example, if a PD pump is rated at 160 cubic inches, then the PD pump will move 160 cubic inches per revolution.
Does ANY engine you know have a set VE? Does your engine move the same amount of air at 600 RPM as 6000? Do you think the heat output of a Roots blower is linear?
Fuck me sideways!
Blah blah tubular headers. The front half of a turbocharger driven by Power Take Off will not automatically make more power than the front half of a turbocharger driven by a turbine. There are far too many engine and environmental variables to make the statement that one is always going to outperform the other.
A Lysholm screw with four lobes should have no functional issue at upwards of twenty thousand rpm. You must have some serious, serious overdrive to fuck this up.
>>14329900 >Does ANY engine you know have a set VE? Does your engine move the same amount of air at 600 RPM as 6000? That's not how VE works. VE is the amount of air moved per rotation. Yes, it changes with RPM, but you're not going to have 10x higher VE at 6000 RPM compared to 600.
>Blah blah tubular headers. The front half of a turbocharger driven by Power Take Off will not automatically make more power than the front half of a turbocharger driven by a turbine. There are far too many engine and environmental variables to make the statement that one is always going to outperform the other. The same compressor is going to have the same characteristics regardless of whether it's driven by a belt or a turbine. The difference is that the power loss from the belt is less than the power loss from the exhaust restriction.
Why are you regurgitating this rubbish? Again, can I recommend a nice afternoon with Full Boost? It's a good introduction to forced induction that may help clear some of your misconceptions.
I'm afraid my point is exactly how volumetric efficiency works. No, your Ve will not be ten times higher. But your consumption of air very well may be, and you are mad to think an air pump will scale it's delivery tenfold linearly.
And how did you come to the conclusion that a PTO will be less of a parasitic loss than an exhaust driven turbine? Are we really so wrong in our development of turbochargers and other turbines when really we just need large blowers? I am intrigued. And impressed, really, that you can speak such crap and not think to educate yourself.
The power used to drive the compressor via exhaust is measurably less than that used by PTO. Borg Warner have a wonderful white paper available from the EU site that sheds light on the factors of enthalpy that may assist you as well.
Wait a moment, what did you assert VE is? You mongoloid, VE is not how much air is moved per rotation. It is the ratio of air moved by the engine to the swept volume. This is true for internal combustion engines, piston compressors, any kind of plunger even.
Please, help yourself before you assume you can assist others.
You're actually a fucking moron. Big engines tend to have a V layout and hence its really impractical to go for a single turbo when twin turbos will both reduce lag for a given total system airflow and simplify plumbing. Nonetheless single turbo supra's have been making over 1000hp for years. Not that its the pinnacle of refinement & responsiveness since you're displacement limited but to say superchargers are inherently superior to turbos is wrong.
The amount of back-pressure a turbo generates is minimal and you even get an increase in thermal efficiency (provided your not running rich AFRs to keep the engine cool which most modern cars don't do) due to using exhaust heat that would be otherwise wasted.
Overall a well designed turbo system will be more efficient and make either more power or the same power with a smaller BSFC provided the base engine is identical.
Overall without taking cost & packaging issues into account the two best forms of forced induction are Twin screw s/c & Turbochargers.
>>14330336 >No, your Ve will not be ten times higher. But your consumption of air very well may be Your consumption of air will be ten times higher if your RPM is ten times higher, but the supercharger will be spinning ten times faster as well. VE is what matters here, and while it does change with RPM, the difference isn't big enough to warrant a mention in a one-sentence overview.
>>14330353 >Wait a moment, what did you assert VE is? You mongoloid, VE is not how much air is moved per rotation. It is the ratio of air moved by the engine to the swept volume. This is true for internal combustion engines, piston compressors, any kind of plunger even. I'm assuming we're not changing the displacement here. The nature of ratios is that if you hold one variable constant, you're effectively comparing the other variable to itself. At any given displacement, VE is just an arbitrary unit of airflow per rotation.
You're so desperate to prove me wrong that you're not bothering to read what I'm actually trying to say.
You do know a top fuel engine, while making 8000hp turns on 500 revolutions total before needing a total rebuild. It's not so much about about being a superior form of technology (not questioning the skills of the engine builders involved) but more about sacrificing durability for maximum power.
Also pro-stock engines are much more well developed and it's a lot harder to make a 2v Pushrod v8 make good power at 11,500 rpm.
Whooooooo, wait up again. The nature of a ratio is that if one is constant, you are comparing the other to itself?
good lord no, did you pass prevocational maths? There is no change in displacement relevant here. You are not comparing the net flow versus net flow as you state. You are comparing net flow versus swept volume.
This is laughable. Your VE may change up to fifty percent, perhaps more with forced induction.
You may exceed 100% volumetric efficiency with forced induction.
And yes, the blower is now turning ten fold. The increase in heat is exponential, it is now higher than tenfold. The increase in friction loss is exponential, it is now more than tenfold. Will the blower keep up?
Why do you assume you will not encounter negative returns? Do you know something the world's best do not?
>>14329688 Never said it was bud. A ford 461 stroker can put out over 800 crank. Chebby 572's can do over 950 crank. 680 cubes of bbc can easily do over 1100, as there have been 700+ cube motors developing over 1200 crank.
Turbos don't really have the lag issue they once did. Twin scrolls and vnt are not nearly as expensive as they once were either. What is expensive, or at least time consuming, is setting up a turbo system that will last 200,000 miles or more.
A turbo is a more efficient yet complex system, a supercharger is simpler.
>>14331857 >Well, fine, But i still think that S/cs can provide more power per size/weight than Turbos. guess what? most people aren't aiming to build a 5000hp single turbo setup so it doesn't fucking matter what happens at the extremes.
You think wrong. After all the text above, and your unimpeded access to the collected data and evidence floating around the ether within reach of a search engine, this is still the conclusion you have made.
Blowers are heavy, heavier than a turbocharger moving the same mass of air at the same density.
Blowers have a measurably higher power requirement to move the same mass and density of air. My own old little blower combo with a weiand 144 required eighty horsepower to move four hundred horsepower worth of air.
Blowers heat the air to a higher degree than turbochargers or centrifugal superchargers. Density reduces as a result. Not as much of an issue with a carburetted combo as the latent heat of vapourisation lowers charge air temp and increases density, but still most definitely an issue.
Blowers do not make use of potential energy in the exhaust stream. There is useful power to be extracted from enthalpy.
Centrifugal superchargers require more engine power from the PTO than the same compressor driven by enthalpy. Power loss is inherent in the belt PTO drive and more power again is lost in the overdrive needed to get shaft speed up.
Tl;dr A blower is not the choice for you if power to weight and power to bsfc are your goals.
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