I've got an idea and hopefully someone can tell me why it won't work. So it's my understanding that the disadvantage with the vortech supercharger is that it puts out low boost at low rpms. So what if someone were to design a wastegate type blow off valve that would fit on the in intake charge pipe...which would allow full boost at a lower rpm and then bleed off the boost at higher rpms. Kinda like a wastegate for the intake charge.
vortech supercharger question
- Thread starter stealth512
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Too much stress on the charger and i dunno if ur car can handle full boost at idle...Not sure
I don't think it should have full boost at idle. I just think there should be a way to make it give boost more like turbo does. Too much stress on the charger..hmm..ok (like belts comming off cause there spinning faster, ect). Too much waste from being belt driven???
Maybe if u hooked up a electric thing that spins the charger at like 7000rpms when the engine reaches 3000rpms or somthing like that.
you're thinking about this wrong. It has low boost because it's a direct drive from the engine. Engine speed dictates charger speed. By the time you put on a pulley big enough to really spin it up, you'd have other issues. Want power down low? Go with a roots type SC.stealth512 said:
Maybe I've explained myself wrong. I have seen dynos on this. What I don't like is the almost 100HP difference from 6000rpm to 8000rpm, on some of the higher HP cars. It's this peaky right in the power band area that worries me.
I like the idea of this electric assisted supercharger that "YellowSi" brought up. As Mazda works on there hybrid electric turbocharger. And yes the supercharger is direct drive but is doesn't have to be. It have the ability to be both spun freely by the crank and electricity. But unfortuntally this idea is too complex an solution as it would probally require development on vortech's side.
I do beleve yes getting power down low might be difficult because of such a large pulley that would be required but imagine this...
Instead of the 8 psi pulley put in a 10 psi pulley, then 8 psi boost should occur at say 6500-7000rpm. Then a secondary BOV designed only to release a little bit of pressure will open maintaining the 8 psi boost till redline. Although this may only make a little difference imagine what this would do to the dyno graph. It would also probally make a really cool sound. To me it sounds like something simple and do able. I almost question why isn't this already done??
I like the idea of this electric assisted supercharger that "YellowSi" brought up. As Mazda works on there hybrid electric turbocharger. And yes the supercharger is direct drive but is doesn't have to be. It have the ability to be both spun freely by the crank and electricity. But unfortuntally this idea is too complex an solution as it would probally require development on vortech's side.
I do beleve yes getting power down low might be difficult because of such a large pulley that would be required but imagine this...
Instead of the 8 psi pulley put in a 10 psi pulley, then 8 psi boost should occur at say 6500-7000rpm. Then a secondary BOV designed only to release a little bit of pressure will open maintaining the 8 psi boost till redline. Although this may only make a little difference imagine what this would do to the dyno graph. It would also probally make a really cool sound. To me it sounds like something simple and do able. I almost question why isn't this already done??
this shoud answer your questions, unlike the very uneducated members who answerd s**t they have no idea about. its a writeup i did a little while ago, should give you a decent understanding. Yellowsi- please, do NOT answer tech questions that you have the correct answer to. your stupidity and ignorance is not welcome here, and is not helping the board out.
turbo- a turbo is a exhaust gas driven turbine, with the other end attached to a compressor. it uses a wastegate to regulate boost. one thing to note with turbines- they are built for a very specific rpm range where they are very efficient (meaning they produce a lot of pressure without making too much extra heat) and drop off quickly if not in their sweet spot- the center island on a compressor map. a PROPERLY sized turbo will offer you the most consistent power gains over the largest rpm range of any type of forced induction. with modern advances in aerodynamics, ball bearing center sections, etc, the "turbo lag" argument has gone the way of the dinosaur, except in situations where someone has purposely bought a turbo thats too large or wants to make unreal top end power at the expense of lag. because a turbo has a wastegate, the turbo can stay in its "sweet spot" rpm range for the longest time across the engine rpm band. turbos also do not have the parasitic loss associated with supercharger belt drives, but they do produce a small amount of backpressure.
roots type/positive displacment supercharger- this is your "classic" blower, which replaces the intake manifold. it consists of two interlocking "fans" which are more like semicircular lobes, that run at a constant pressure, and produce a constant flow of air (say the s/c has a pulley and set up for 7.35 psi, meaning the blower is forcing 1.5 times the normal air flow (.5 bar) of the n/a motor). these blowers usually have a bypass valve so they dont boost at idle. because the blower is not a turbine, it suffers from very poor efficency, at best, 60% (meaning 60% of the energy expended is used to pressurize the air, the rest is used to heat up the intake charge). they also suffer from the inability to use a normal intercooling system, further compounding the heat problem. the main advantage of a blower is ease of installation and tuning, espeically on a carburator. because all you have to do is replace the intake manifold, and use the new belt, install is easy. tuning is also much simpler because of the relatively constant boost pressure and predictable response.
vortech/centrithical (sp?)- this is, without a doubt, the poorest method of forced induction. it incorporates the worst of both worlds of the other two, along with almost none of the benefits. the vortech is the compressor side of a turbo, but is driven by a belt. remember now what i said about turbines- they are very, very picky about what rpm they operate at. on a vortech, the turbine is connected directly to the engine, so it has no way to get to its "sweet spot" until the engine achives sufficient revs (usually the last 1000 rpm or so of the engines rpm range). for the rest of the powerband, the voretch turbine is not spinning fast enough to achive much boost, and what boost it is producing is turbulent and overheated. there is NO way to make it not have either awful boost lag, or choke the motor on top end- the design itself prevents it from ever being efficient over a wide rpm range. vortech claims big hp numbers, which are usually correct- they simply use a huge compressor that gives massive top end hp, and reaches peak boost just before redline. on the street and the track however, this translates to a very poor feel, with the motor having no power for 90% of the rpm range, and then suddenly having massive power for the last 10%.
turbo- a turbo is a exhaust gas driven turbine, with the other end attached to a compressor. it uses a wastegate to regulate boost. one thing to note with turbines- they are built for a very specific rpm range where they are very efficient (meaning they produce a lot of pressure without making too much extra heat) and drop off quickly if not in their sweet spot- the center island on a compressor map. a PROPERLY sized turbo will offer you the most consistent power gains over the largest rpm range of any type of forced induction. with modern advances in aerodynamics, ball bearing center sections, etc, the "turbo lag" argument has gone the way of the dinosaur, except in situations where someone has purposely bought a turbo thats too large or wants to make unreal top end power at the expense of lag. because a turbo has a wastegate, the turbo can stay in its "sweet spot" rpm range for the longest time across the engine rpm band. turbos also do not have the parasitic loss associated with supercharger belt drives, but they do produce a small amount of backpressure.
roots type/positive displacment supercharger- this is your "classic" blower, which replaces the intake manifold. it consists of two interlocking "fans" which are more like semicircular lobes, that run at a constant pressure, and produce a constant flow of air (say the s/c has a pulley and set up for 7.35 psi, meaning the blower is forcing 1.5 times the normal air flow (.5 bar) of the n/a motor). these blowers usually have a bypass valve so they dont boost at idle. because the blower is not a turbine, it suffers from very poor efficency, at best, 60% (meaning 60% of the energy expended is used to pressurize the air, the rest is used to heat up the intake charge). they also suffer from the inability to use a normal intercooling system, further compounding the heat problem. the main advantage of a blower is ease of installation and tuning, espeically on a carburator. because all you have to do is replace the intake manifold, and use the new belt, install is easy. tuning is also much simpler because of the relatively constant boost pressure and predictable response.
vortech/centrithical (sp?)- this is, without a doubt, the poorest method of forced induction. it incorporates the worst of both worlds of the other two, along with almost none of the benefits. the vortech is the compressor side of a turbo, but is driven by a belt. remember now what i said about turbines- they are very, very picky about what rpm they operate at. on a vortech, the turbine is connected directly to the engine, so it has no way to get to its "sweet spot" until the engine achives sufficient revs (usually the last 1000 rpm or so of the engines rpm range). for the rest of the powerband, the voretch turbine is not spinning fast enough to achive much boost, and what boost it is producing is turbulent and overheated. there is NO way to make it not have either awful boost lag, or choke the motor on top end- the design itself prevents it from ever being efficient over a wide rpm range. vortech claims big hp numbers, which are usually correct- they simply use a huge compressor that gives massive top end hp, and reaches peak boost just before redline. on the street and the track however, this translates to a very poor feel, with the motor having no power for 90% of the rpm range, and then suddenly having massive power for the last 10%.
OMFG!!!!...i'm about to loose it. (don't mine me). I'm not trying to increase boost pressure with a BOV i'm trying to lower it. I'm increasing the pressure with the pulley and then bleeding it off with a BOV acting like a bypass. In an effort to widen the power band.Revolver said:
Now I do have a basic understanding of how the 3 charger systems work otherwise I wouldn't even be asking this question. But I like to create Bullshit idea's that sometimes work, which is why i'm asking this question.
Best answer I've got is from "handlebarsfsr" which I assume is turbines "are picky about what rpm they operate" at. I do disagree that the CFSC is the worst, it does have some good points. Such as the ability to run the water cooled aftercooler, quick response from the supercharger, and the ability to make power like stock (ironically also a problem). I will not disagree that it does come with disadvantages though...but this doesn't mean it's bad, it depends on your application....boost lag might be exactly what you want.
Turbochargers can run air-water intercoolers, CFSC do not have a quick response (they are not like a screw type blower), and it doesn't make power like a stock powerband (not a screw type blower CFSC make power very late in the rpm range).
As for the bleed off idea, why the hell would you want to loose any of the little amount of boost the CFSC is making? Doing that is not gonna widen the powerband, its gonna do the complete opposite. You want that Charger to spool up to high rotation speed as much as possible. However you will never get much from a CFSC because since it is a mechanical system, getting up to the speeds of a normal turbocharger would lead to the charger's gearbox failing.
As for the bleed off idea, why the hell would you want to loose any of the little amount of boost the CFSC is making? Doing that is not gonna widen the powerband, its gonna do the complete opposite. You want that Charger to spool up to high rotation speed as much as possible. However you will never get much from a CFSC because since it is a mechanical system, getting up to the speeds of a normal turbocharger would lead to the charger's gearbox failing.
I don't know why I even bother posting here. When I say that it makes power like stock...i'm talking about a b16 with a CFSC. Just enough power to get around low-mid rpm but a lot up top. It has a extremely linear power curve, and feels like having one crazy vtec cam. hmm..sound like a b16 characteristics to me but with more power.
Now to the why would you want to bleed off the boost question. I answer...why would you want to open the wastegate on a turbo charger. It's the same idea. Say your motor can't handle that much boost, so bleed it off. Yes it would probabally make more sence to just build the motor to handle the increased boost but what about a stock motor.
Now to the why would you want to bleed off the boost question. I answer...why would you want to open the wastegate on a turbo charger. It's the same idea. Say your motor can't handle that much boost, so bleed it off. Yes it would probabally make more sence to just build the motor to handle the increased boost but what about a stock motor.
You control boost by controlling the speed of the compressor wheel, not by bleeding of boost out the bov. The bov is there to stop compressor surge when the throttle plate is closed.
It sounds like your heart is set on this piece of s**t means of boost so by all means go ahead and waste away the money on it.
It sounds like your heart is set on this piece of s**t means of boost so by all means go ahead and waste away the money on it.
The power demand for an electric motor to run a supercharger would cause a parasitic loss at the alternator greater than the parasitic loss of just driving the supercharger off the crankshaft.stealth512 said:
Simple thermodynamics my man.
I was just thinking...You know what might work? Some sort of CVT drive for a supercharger. You could progressively alter the drive ratios on the supercharger to be on boost at lower rpms. Geared correctly, you could have X lbs of boost all the time!
The parasitic drain may be a factor as to why it won't work.
The parasitic drain may be a factor as to why it won't work.
simple "thermodynamics" hmm tell that to mazda, electric turbo assist:Beelzebubba said:
http://rotarynews.com/node/view/381
or this guy:
http://www.turbomagazine.com/tech/0406tur_knight/
Yeah that would just be crazy to have a CVT drive on there but it would probablly just make things worse relibility wise and parasitic drain wise.Beelzebubba said:I was just thinking...You know what might work? Some sort of CVT drive for a supercharger. You could progressively alter the drive ratios on the supercharger to be on boost at lower rpms. Geared correctly, you could have X lbs of boost all the time!
The parasitic drain may be a factor as to why it won't work.
I know what the BOV and speed of the compressor is suppose to do...but these are tuner tools, and as a tuner your always trying to modifiy things to do your bidding.Revolver said:
Now I'm not saying that the CFSC is the best type of boost, but just saying it's "s**t" is wrong. That's like saying a comptech supercharged S2000 is crap. I don't see them major issues on road courses...and there's nothing wrong with that in my book.
you might be able to use some sort of capacitive discharge just to spool up the turbo. Similar to how Honda's Hybrids electric assist work, but that's just unnecessary weight and complexity on a track carstealth512 said:
That guy is carrying around, count 'em, SIX extra batteries. Talk about a weight penalty. He would have done better if he had just gotten two big DC motors and hooked them up to direct drive the rear wheels. At least from a standing start anyway.stealth512 said: