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Turbocharge Vs Supercharge


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umm, whats better, a 2 metre piece of string or a 2.5 metre piece of string?

some might say 2.5 coz they like longer pieces of string. others might say 2 coz they may not need 2.5 metres.

it all comes down to the application of the vehicle and personal preference.

also have to consider the engine. under the given conditions that you intend to use the car, one form of forced induction may yeild better results than the other.

and i know you have a surpa, but its a very vague question, so youre not going to get the kind of responses your looking for.

Turbo = cheap and easy, lots of compromises though.

Supercharging = more difficult and expensive (few kits around) if done properly far better than a turbo though.

Now it is said you can get more power with a turbo, and it is probably true if you want to win horsepower heroes. But to get that power you will have minimal power band and bulk lag.

So you want a bit more streetable power, yes, but you still have to agonise over which turbine housing you want, the one with the big rush at the top end, or the other one with less lag.

Like I said, too many compromises.

Engineering yourself a good positive displacement supercharger setup is a lot of work, but you get it all.

There is also the myth about the power required to drive the supercharger, and turbos work with free energy.

Not true. The back pressure in the exhaust turbine will rob you of just as much power, even more if the turbo is a bad match.

When you put on the big a/r exhaust housing to make bulk power, it is the reduction in exhaust back pressure that gives you back the power that was always there in the first place. So turbos do not work on free energy.

If its properly set up a supercharger will kill a turbo. But some people expect that fitting a three hundred dollar blower is going to make more power than a good turbo. It will not.

A three hundred dollar turbo is not going to get you very far either.

...adding my $0.02...

in addition to the comments so far, Supercharging would give a more linear and predictable power delivery, being belt drive off the crank, unlike most larger turbochargers would give a sudden rush of power, as the turbo spools up, and wastegate opens to deliver full boost.

Depends on the purpose of the car, it's engine, and the practicality of both installs.

That RB26DETT with the twin high mounted turbos AND supercharger is INSANE! I would have though that all of that forced induction would have to create some sort of airflow bottleneck, surely...

Would this make it an RB26DETTS? :wave:

That picture is a fake...................

Some clown used photoshop or something similar, it cannot possibly work the way it is.

What stops the supercharger from blowing air back out through the turbos ?

The pipe from the supercharger meets the TWO turbo discharge pipes at a right angle. Why would they do that ? how are the pipes joined (just out of view)?

The supercharger rotates backwards. If the engine turns clockwise as viewed from the front, the supercharger would suck not blow. It is mounted upside down, the top rotor should be driven if it is supposed to work.

The drive belt is the standard airconditioner compressor drive belt. It would shred in two seconds if it had to drive a real supercharger. The photoshop clown has just replaced the aircon compressor with a picture of a supercharger.

This picture has been all over the web, and has sucked in lots of people. Clever eh !

Twincharging is great, I have done it myself, but that picture is still a fake.

Warpspeed, i still don't think that it's fake and been doctored in Photoshop. Here is another pic that i had downloaded quite some time ago. I did a search on Google, and here is the pic:

tas0021.JPG

I remember saving the pic from a homepage that had some pics he'd taken at the Tokyo Auto Salon 2000. It was showcasing a new line of superchargers that either Blitz or HKS or some other tuner was working on.

I can't see how the supercharger would be reversing air flow through the two turbos, because, with the twin turbos on their own, each turbo wouldn't be reversing air flow on eachother normally. This is what a blow off valve or pop-off valve (with a spring rate set to open at a certain pressure) is for. Only the engine can consume the air once the throttle bodies are wide open. But, my thought was that there'd be some serious surging problems. A RB26 head can only flow so many CFM.

A turbo will always produce more power as the boost can be wound up, whereas on the supercharger it's fixed and is quite low boost? Although turbos do have lag, which is a trade off for more power. Depends on the application, if u just want a little bit more power (no flexibility), then go the supercharger. If you want more flexibility and more power, but with lag...go the turbo. Also, I think there is a lot more support out there for turbos as opposed to superchargers.

umm it all depends on the type of car and type of engine.

For 4 and 6 i think turbo is better as it is cheaper and there are many kits around but for v8 it becames half-half;

Their are alot of sc around for v8 and alot of power can be made depending on the type "sleeper" or "root"

I ask this question on a america forum alittle while bak and i will post the comments for you. (corvette-fourm)

The Turbo is way to much custom work. You'll be better off spending your cash on a supercharger kit. IMHO
Turbos are great but from what i have read it seem like a lot of work and you have to contain the heat and then you have to think about a intercooler to handle that heat?
for stock engine or mild mods, and fore ease of installations, up to around 700 or so HP, the cent superchargers are hard to beat. the turbos are more expensive and no kit is available for the c4s yet so custom fabrication is needed. but if you really want some big HP and go wild, the twin turbo boogie is hard to beat.
Actually a ~1000HP centrifugal s/c setup is also relatively a "walk in the park" And you still have room for air conditioning.
Whats up,

"I was reading the procharge website and it said that the D-1 could pull 32PSI does this mean i can hook it up at 15PSI oF boost and get alot of power with no lag?"

No, running 15# of boost will require alot of supporting hardware, and a good tune and programing. 32 psi represents the max boost that the blower can make on what ever engine setup they wrere using mathmatically. Just because they say there charger is capable of 32#'s of boost on a stock LT1 dosent mean they have actually done it. Just shows you what it is capable of.

Kinda having a hard time saying what i mean.

Turbos are the ultamit imho, If your into wrenching. Instalation Is alot more difficult and can be a little more tricky to tune. Turbo lag is a thing of the past. A proper turbo setup for the street will have virtually no lag. There will always be some, but thats just the nature of the beast.

Ive heard good thing and bad things about procharger, do some reasearch on other sites and youll see what i mean. Theres no question there systems can make alot of power though.

Go with a sc if your just startingout and not into fabrication. Go with a turbo if you really want somthing exotic and dont mind the extra work.

Hope this helps a little,  

hope this helps

Originally posted by HRthirtyone

just get an electric supercharger.

hope this helps.  

lol

LOL

Looks like we are going off into all kind of tangents, hijacking this thread..

but, i read a magazine article or could have possibly been an autospeed online article about the "Turbo Zet electronic turbo" (i think thats what it's called). It retails for over $400, and this writer was trying his hardest to drop hints that this product was no better than a pair of 12V PC cooling fans that can be had for under $40. Talk about a scamm. Makes me wonder how many fools have bought one because they thought it was a budget "turbo" upgrade! LOL

Well maybe someone built it up as a dummy display engine for a car show. It would never actually run though. I can tell you that for an absolute certainty.

If you do a search under twincharge/twincharging, here, and at Performance Forum, you will find I have made many previous posts on this particular topic, I have built and driven my own twincharged 4WD Laser around for eighteen months. So I am in a position to know just a little bit about twincharging.

The supercharger definitely rotates the wrong way, it can never work. How do I know, LOOK AT THE PICTURE. The lower rotor turns clockwise as viewed from the front of the engine. Air trapped between the rotor and casing will go from right to left.

There is nothing to stop air blowing back out through the turbos either. Think about it !

In America unlike just about any other country on the planet, the majority of cars are V8s, probably of about five litres or more.

With these, low end torque is never a problem, they just do not like to rev. So a centrifugal blower is the ideal answer. It is also the best for Commodore V8s as well. Fitting twin turbos into a modern V8 engine bay can be very difficult indeed.

This does not mean that centrifugal blowers are better than turbos though. Just better for certain particular installations.

If you have a small four valve DOHC four cylinder engine that will rev its tits off, what you want is more torque, especially low end torque. A positive displacement supercharger will be best, and far easier to install on an inline engine as well.

Turbos are pretty good, but you decide, do you want good midrange, or strong top end ? Forget about tyre frying torque below 2000 RPM, it is not going to happen with a turbo.

It all depends on the type of engine and type of car. Twincharging is the best solution possible for a small engine. It is just too complicated and expensive for most people.

Lancia and Nissan have released factory twincharged cars by the way. So thy do exist. The Nissan March, and the Lancia rally cars each had a roots blower, and a turbo plus an intercooler. Do a Google if you are interested.

Warpspeed, i see your point. But after squinting at the pic again, the polished alloy pipe to the right of the supercharger (which everyone assumes to connect to the twin turbo outlet piping at a 90 degree) might actually be the supercharger inlet piping with the air inlet/filter piping out of view. The pipe to the left of the supercharger (near the block) which curves around to the top might be the supercharger outlet which isn't connected in this pic.

I haven't seen this supercharger before, so it is hard to figure out the way it is oriented. Even if this twincharging (triplecharging?!) setup was to work, there would have to be some sort of one-way check valve or vacuum diaphram which prevents the supercharger from blowing air back through the turbo outlets on low boost and low RPM. This is before there is enough exhaust backpressure coming from the exhaust manifolds to start spooling up the turbos and then merge with the flow of the supercharger (which would then run "out of puff" in the top end)

Another problem i can see with this setup is on RB26DETT's having twin AFM's which would cause all kinds of fueling problems if more or less air is being forced into the engine without the AFM's measuring it. That wouldn't be a problem if the management was switched to MAP based control from the inlet plenum.

If this setup actually worked this would make an otherwise very laggy twin turbo setup come onto boost very quickly from the instant boost creating nature of the supercharger. Creating instant exhaust backpressure to spool the turbos - NO LAG! (and no traction, i'd imagine too)

What you say is possible of course, but just having a pipe coming out of the supercharger into what looks like a blank aluminium cap on the end is not any sort of workable twincharge system.

It still looks like a very desirable dual turbo installation, onto which a supercharger has magically appeared. If it is a mock up, or a photoshop trick I cannot say.

After playing with these things myself, the only workable system is to place the turbo and supercharger in series. One way valves do not work.

I have never seen a working twincharge system on a car that had the turbo and supercharger operating in parallel, I cannot see how it is even possible.

The reason being that a centrifugal compressor requires flow before it can generate any pressure. Air is accelerated through the impeller. If flow is zero there is nothing to accelerate. That is why all compressor maps have a surge line.

Below a certain flow, operation becomes violently unstable. You cannot just fit a flap valve that stays shut until a certain boost is reached and then open it. The turbo would be destroyed very quickly that way, either from overspeeding, or the violent pulsations would kill the bearings. The noise it would make would be pretty objectionable as well.

By placing the turbo in series there is always airflow through the compressor housing, even below boost threshold. The two boosts just add. The wastegate can be set to the final required boost level, so the turbo makes up the difference, controlled by the wastegate in the normal way.

It is simple and very effective, and it is how all these systems work. That picture is total BS, sorry.

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