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Discussion Starter #1
I have been reading about blowers and turbos and I'm really confused as to what to use where...I know their purpose is to draw in air but is there a differencce? what are the benefits of using one over the other? Or can you use both? ahhh....
I know it is a basic...newbie thing, but "I gotta know".
 

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I started your same quest with a book I found at Barnes & Noble on Turbos, superchargers, NOS and forced induction.
 

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Discussion Starter #3
any conclusions?
I will look up the book...Thanks !
 

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Maximum Boost
Turbochargers

They were both recommended to me when I wanted to start getting into turbos. I bought them and have glanced over both and they seem very good. Haven't read them cover to cover yet. AFAIK Turbos are more efficient than a blower since they run off exhaust gas and not the crank. Not sure why people are afraid of them, my guess is the extra plumbing.
 

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Blowers or super chargers use outside air forced into the cylinder and run off of an accessory belt.
Pro's) 1) No turbo lag ( see turbo cons) 2) Instant power. generally longer lasting. 3) Does not beat the hell out of your motor oil and coke it up
Cons) Uses an accessory belt so it consumes Horsy power all the time meaning poorer fuel mileage 2) Whine from the blower which some people do not like but I personally find it intoxicating

Turbo: Pro's 1) free horsepower as it runs off the exhaust you are already "wasting" and generally not until you want it to.. Means better MPG as it does not put a load on the motor and you generally get more concentrated power.

Cons) Turbo lag... This happens because the turbine must first spool up and spin at a very very high RPM (10's of thousands!) before it will produce any power and then depending upon where it is in the intake system, the time it takes that exhaust to get to the spool and then to get put back into the intake can induce serious lag, ie.. when you say GO , it says uhm... Hold on a sec and then WHOOOOOOOOOOSH! Can be a bit abrupt.

Turbos also need to cool down for about a minute before you shut off the engine otherwise, you will stave them of oil in a turbine turning many thousands of RPM. Oil quality is critical with a turbo as well as high octane fuel. Can be very hard on the internal components as well.

Hope this helps!
 

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I built an 8:1 460 to run a D1-X (Procharger) supercharger in my 67. Dynoed at 800+ HP on pump gas. But that's me.
 

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AFAIK Turbos are more efficient than a blower since they run off exhaust gas and not the crank. Not sure why people are afraid of them, my guess is the extra plumbing.
Thats an easy one....HEAT KILLS.

Supercharger should be more reliable... if you have the engine setup properly for it, and don't get stupid with overboosting.
 

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Blowers and Turbo Kits are not bolt-on dress-up kits for a V-6, so your confusion is nomal ;)

Randy (aka AboutToGetSlapped)
 

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NoLooking's definitions are a perfect, spot-on, Reader's Digest version of the facts.
Today's smaller turbos (housings and impellers) have helped the lag tremendously, but I doubt it will ever be completely remedied, due to its design. Water-based intercoolers (sort of the "radiator" for the turbo) have also greatly improved the cooling, and therefore the lifespan of the units.
As evidenced by recent GM and Ford "boosted" products, superchargers ("blowers") have become quite popular lately, over the turbocharger boom of the 80's - which were mostly used on smaller, underpowered (and often European) engines to "boost" their output - probably for a complex combination of the above mentioned reasons, and their adaptivity to larger (American iron) engine.
 

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Water-based intercoolers (sort of the "radiator" for the turbo) have also greatly improved the cooling, and therefore the lifespan of the units.
Ummm, no. Intercoolers lower the temperature of the air going to the engine. When air is compressed (ie, supercharged... whether by a turbo-supercharger or mechanically-driven supercharger) it heats up. Because hot air expands the heat is actually fighting against the specific goal of supercharging; which is to cram more air into the engine than would be naturally drawn/forced in by normal atmospheric pressure. So an intercooler (Air-to-air or air-to-water) is used to reduce the heat of the compressed air. An intercooler is NOT a turbo-radiator... Their function is to cool air, not the turbo unit.

- Gord
 

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Discussion Starter #13
Hey !!
I sat down with my 20 year old son...we had another one of our "car" talks. (he is studying high performance at UNO)
David explained that a turbo is placed on the exhaust side...it draws air into the engine. A blower or supercharger pushes air into the engine....did I understand him right?
Now I am off to read all the books you guys recommended. THANKS !! :)
 

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A supercharger is a supercharger. The difference we're talking about is whether the compressor (the part that forces air into the engine) is driven via a belt drive or via an exhaust turbine. The latter method is refered to as a turbocharger (actually shortened from Turbo-supercharger): Hot exhaust gases are routed through a turbine (same idea as a water wheel) spinning the turbine vanes at speeds between 30 and 100 THOUSAND rpm. The shaft that the turbine is mounted on passes through a sealed housing to where it is attached to another vaned wheel. This wheel is the compressor and as it spins it takes fresh air and forces it into the engine. The harder you work your engine the hotter the exhaust gasses get. The hotter the exhaust gets the faster the turbine spins. Because the turbine is directly coupled to the compressor, more air is forced into the engine (= "boost").

- Gord
 

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Water-based intercoolers (sort of the "radiator" for the turbo) have also greatly improved the cooling, and therefore the lifespan of the units.
Ummm, no. Intercoolers lower the temperature of the air going to the engine. When air is compressed (ie, supercharged... whether by a turbo-supercharger or mechanically-driven supercharger) it heats up. Because hot air expands the heat is actually fighting against the specific goal of supercharging; which is to cram more air into the engine than would be naturally drawn/forced in by normal atmospheric pressure. So an intercooler (Air-to-air or air-to-water) is used to reduce the heat of the compressed air. An intercooler is NOT a turbo-radiator... Their function is to cool air, not the turbo unit.

- Gord
Well, that'll teach me to over-simplify in the interest of clarifying for someone who has no knowledge or understanding of the subject (and is desperately trying to)!
I'm fully aware the intercooler is cooling the air, which due to the compression it is subjected to, heats up at an algebraic rate. However, technically speaking, do you really think that if you're cooling the air charge entering the housing, the housing itself, etc., won't be running cooler as well?? The coking problems of oil (solidified petroleum due to its cooking at extreme high temperature) in turbo housings is nearly a thing of the past due to the reduced temperatures created in part by improved intercooler design.
While your post was technically correct (and yes, mine was definitely and admittedly over-simplified), for this discussion, it seems to be knit-picking... ::
 

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Good questions and the replys show more education is needed. Spend some time with me, and I think I can help.

Re: Turbo lag , this can be a factor but it can be minimized by good design. I'm at full boost, 11 PSIG, by 2800 RPM. I'm at about 5 PSIG by 1800 RPM, load dependent. That sound like lag to you? The design goal is small turbos to build boost faster. Fine design concept for the street, not so good for the drags.

Re: Spercharger = instant boost is partly true. Better said, supercharger = instant LOWER boost. Superchargers are engine RPM dependent which means boost goes up with RPM and peak boost occurs at the upper end of the RPM band.

Re: Which is better? This is not a good question as too many evaluation factors apply. Which makes more power? Turbos, hand down. Ask yourself why a supercharger needs a 2" wide belt. Typical HP loss is around 75- 100 HP. Which is easier to install? Supercharges. Why? Superchargers follow along with the normal steps to build HP. Build a HP making engine, get tired, of the power, and add a supercharger. Turbos don't like all the things that make for a good NA engine, like cam overlap for example.

Re: Intercoolers- The idea, with either turbos ar superchargers, is to increase the air flow, (pounds/HR), through the engine. When air is compressed, it increases in temperature. As air heats up, it weighs less. So, density increases with pressure and decreases with temperature. The amount of temperature increase is effected by the compressor efficiency. Roots blowers are the worst as far as efficiency and they cannot be easily intercooled. Intercoolers go between the compressor and the engine so they don't cool the compressor as someone has said. Water cooled intercoolers are more complicated but don't heat soak like air to air intercoolers. Roots and Eaton style supercahrgers are difficult to intercool.

Re Turbo reliabilty - Watch the cool down cycle and they will last as long as the engine will.

Hope this helps!
 

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do you really think that if you're cooling the air charge entering the housing, the housing itself, etc., won't be running cooler as well??
An intercooler does not cool the charge entering the the turbocharger. It cools the charge after it has left the turbocharger. It's gotten the common name "intercooler" because of it's placement between the compressor and engine intake but, strictly speaking, they are more technically refered to as "aftercoolers".

- Gord
 

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do you really think that if you're cooling the air charge entering the housing, the housing itself, etc., won't be running cooler as well??
An intercooler does not cool the charge entering the the turbocharger. It cools the charge after it has left the turbocharger. It's gotten the common name "intercooler" because of it's placement between the compressor and engine intake but, strictly speaking, they are more technically refered to as "aftercoolers".

- Gord
I stand corrected! I mis-spoke on that sentence (that'll teach me to attempt to be erudite with enough NyQuil in me to anesthetize a horse). One thousand apologies! ::
However, in my defense of the previous "radiator" term, please see the following, as listed on WordIQ.com: ::

"An intercooler is essentially a radiator tuned for high flow rates and the increasing density of the charge as it cools. Most designs use ambient air for cooling, flowing through the radiator core, and often colocated with other radiators for oil or cooling fluid. An alternate design, often referred to as a charge cooler, uses water to cool the charge, then cools the water in a separate radiator. While heavier and more complex, charge coolers can often make arranging the engine much simpler.
Intercoolers need to be mounted so as to maximize air flow and promote efficient cooling. Cars such as Saab or Mitsubishi Lancer Evolution use front-mounted intercoolers mounted vertically near the front bumper, in line with the car's radiator. In contrast, cars such as the Subaru Impreza WRX mount the intercooler horizontally on top of the engine and use a hood scoop to force air over the intercooler. Some World Rally Championship cars use a reverse-induction setup, where air from ducts in the front bumper is forced up over a horizontally-mounted intercooler and then vented through ducts in the top of the hood."
 

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R100RT is right on. I'd be willing to bet my GN has less lag than a carbeurated car that bogs down when you jump on the gas. A combination of proper selection of torque converter, cam, intercooler, Turbo A/R, computer settings (TPS, IAC, VE, etc.) will greatly reduce or eliminate turbo lag. Can't be too much lag when the GN went 0-60 in 4.9 seconds and a 13.9 quarter back in '87 (bone stock) and was the fastest car produced that year. I've only improved on that a little :: Either way, turbo or supercharging is a great power adder.
 
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