Yet another car question from a guy who know's nothing about cars

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Yet another car question from a guy who know's nothing about cars

Postby Son of Samson » Tue Jul 27, 1999 10:52 am

Howdy.

I was wondering, overall, considering power, gas mileage, as well as wear and tear, which is better, turbocharging a car, or supercharging? Thanks for any info.

"Watch the tongue sweetheart, I've seen him lick his eyebrow clean"
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Re: Yet another car question from a guy who know's nothing about cars

Postby Mr. Know it all » Tue Jul 27, 1999 11:53 am

In Reply to: Yet another car question from a guy who know's nothing about cars posted by Son Of Samson on July 27, 1999 at 18:52:35:


Turbocharging is a very interesting concept: It works on the principle of hot exhaust gases; The exhaust pressure rushing out of the engine spins a rotary turbine located inside the turbocharger, which puses compressed air/fuel mix into the cylinders. since the air from the tailpipe is rather hot, the air/fuel mixture is passed from the turbocharger through a radiator called an "intercooler" before hitting the cylinders.The beauty of the Turbocharger is that it requires no HP from you cars engine to function.

Allow me to expand: The hot gases spin a turbine which is connected to an impeller that forces more air into the carburetor. Turbocharger also come with a "waste gate" which bleeds off excess pressure, pressure that could ruin your engine.

A blower is very similar, only it is always running and is hooked to the engines crankshaft to drive the impeller, rather than exhaust gases. As far as reliability, If you want to waste money, then by all means get some sort of turbo or supercharger, cause you will be spending lots of time in the shop fixing both. But if you must do this then, I would reccomend a Supercharger, rather than a Turbocharger.



Howdy.

: I was wondering, overall, considering power, gas mileage, as well as wear and tear, which is better, turbocharging a car, or supercharging? Thanks for any info.

: "Watch the tongue sweetheart, I've seen him lick his eyebrow clean"
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Thanks

Postby Son of Samson » Tue Jul 27, 1999 1:06 pm

In Reply to: Re: Yet another car question from a guy who know's nothing about cars posted by Mr. Know it All on July 27, 1999 at 19:53:13:


Thanks for the info Mr Know it All, I appretiate it.

: Turbocharging is a very interesting concept: It works on the principle of hot exhaust gases; The exhaust pressure rushing out of the engine spins a rotary turbine located inside the turbocharger, which puses compressed air/fuel mix into the cylinders. since the air from the tailpipe is rather hot, the air/fuel mixture is passed from the turbocharger through a radiator called an "intercooler" before hitting the cylinders.The beauty of the Turbocharger is that it requires no HP from you cars engine to function.

: Allow me to expand: The hot gases spin a turbine which is connected to an impeller that forces more air into the carburetor. Turbocharger also come with a "waste gate" which bleeds off excess pressure, pressure that could ruin your engine.

: A blower is very similar, only it is always running and is hooked to the engines crankshaft to drive the impeller, rather than exhaust gases. As far as reliability, If you want to waste money, then by all means get some sort of turbo or supercharger, cause you will be spending lots of time in the shop fixing both. But if you must do this then, I would reccomend a Supercharger, rather than a Turbocharger.

:

: Howdy.

: : I was wondering, overall, considering power, gas mileage, as well as wear and tear, which is better, turbocharging a car, or supercharging? Thanks for any info.

: : "Watch the tongue sweetheart, I've seen him lick his eyebrow clean"
Son of Samson
 
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Re: Yet another car question from a guy who know's nothing about cars

Postby TheDarkOne » Tue Jul 27, 1999 1:29 pm

In Reply to: Yet another car question from a guy who know's nothing about cars posted by Son Of Samson on July 27, 1999 at 18:52:35:


Why not add Nitous Oxide to your car, that way you can turn it on and off when you want. It's great fun for coming out of parking lots and toying with people trying to pass you on the freeway. Watch out that you don't snap your axels though.
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Re: Yet another car question from a guy who know's nothing about cars

Postby andre N » Tue Jul 27, 1999 1:30 pm

In Reply to: Re: Yet another car question from a guy who know's nothing about cars posted by Mr. Know it All on July 27, 1999 at 19:53:13:


I probably would not bother responding, but the tag-line of Mr. Know-it-all was too tempting.

CORRECTIONS

1) A turbocharger IS a supercharger. A supercharger is a device to pressurize the intake air. BELT-DRIVEN (I know or no CRANKSHAFT-DRIVEN) superchargers are called superchargers, exhaust-driven supercharger are also known as turbochargers.

2) The heat that is shed by an intercooler is does not come from the exhaust gas, it comes from the heat of compression (the heat that makes your bicycle pump get warm, or a shop air compressor heat up) that is why many supercharged motors also have intercoolers

3) I am not aware of any air/fuel mixtures running thru intercoolers, on all new cars, they will be running fuel injection (usually port) and no air fuel mixture will be passed so close to the turbo or thru pressurized tubes

4) While a turbocharger is an efficient way to boost the specific output of a vehicle (diesels are a good example) it is not correct to say they use no power. IE where do you think the power to compress a stream of gas from atmospheric to 1or 2 bar come from? The engine is supplying the motive force to produce the compression,granted, some of that is normally "wasted" is in the exhaust anyway, but it is not "free". The car must labor against the turbine, similar to a restrictive exhaust.

5) One benefit in a supercharged engine is the lack of "turbo lag" in a supercharged engine, as the "blower" is already at max speed, whereas a turboed car may requier several seconds to build boost (old Porsche 911 were notorious for that)

6)Lastly, properly maintained turbocharged and supercharged engines are not incredibly trouble-prone. I have friends with both with +100K miles with no problems, earlier turbos were prone due to oil "coking"( burning) if shut down after a long ride with no time to cool, modern cars use thermo-siphon oil or water-cooling to address this

7) If the writer of the original post is asking the best way to get more power out or a car, I agree that Suping of Turbing a car is dumb because you will need to lower the compresssion, requireing a engine rebuild--if you are going to that length, the normal route of high compression, and better heads will give you better bang-for-buck.
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Re: Yet another car question from a guy who know's nothing about cars

Postby TheDarkOne » Tue Jul 27, 1999 1:51 pm

In Reply to: Re: Yet another car question from a guy who know's nothing about cars posted by AN on July 27, 1999 at 21:30:55:


Man you know your stuff. I had a question though. In a supercharged engine, how much can you increase the cars output? With a turbo, you can have different levels of power (or different stages if you will). You can even rig a car so that the turbo gates stay open all the time right? How does that work with a supercharger? Do you just get a bigger supercharger or can you adjust the lever of a supercharger to change it's output?
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Re: Yet another car question from a guy who know's nothing about cars

Postby Fritz » Wed Jul 28, 1999 3:38 am

In Reply to: Re: Yet another car question from a guy who know's nothing about cars posted by AN on July 27, 1999 at 21:30:55:


Some companies offer kits that allow you to bolt superchargers to newer vehicles with minimal modifications.
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Re: Yet another car question from a guy who know's nothing about cars

Postby andre N » Wed Jul 28, 1999 8:40 am

In Reply to: Re: Yet another car question from a guy who know's nothing about cars posted by Fritz on July 28, 1999 at 11:38:28:


Absolutely, Paxton, Vortech, et al offer popular kits for belt-driven supes for the Ford 5.0. Typically, fuel system need to be improved to take advantage of the additional air. Larger throttle bodies are often used. And a engine management chip change is vital on most modern cars.
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Re: Yet another car question from a guy who know's nothing about cars

Postby andre N » Wed Jul 28, 1999 8:54 am

In Reply to: Re: Yet another car question from a guy who know's nothing about cars posted by TheDarkOne on July 27, 1999 at 21:51:24:


Thank you.

How much? That is a broad question, like so many complex systems, you just can't change one factor, and you need to quantify just what you are willing to give up: Drivability, reliability etc.

I would say ROUGHLY 30% power improvement w/o getting too radical.

Turbo gates? The gate is the pressure relief valve.

Works like this . Your are at idle, little gas moving past turbo, little inlet pressure. A fuel-injected suicide machine goes by driven by some skag and his floozie races by . You floor it, and take off. because the turbo has weight, it has inertia, so it takes a while for the turbo to "spool up" and deliver the boost that drives your HP up. So, finally there you are at speed. 1-2 bar of boost and you are approaching Anarchy road making full power and hanging on. Suddenly, Crawford hits the brakes and you get off the gas, while you stupid partner manages to hit a road sign with both barrels , you have snapped the throttle shut. Remember inertia, our old friend? Even though you have cut off the exhaust to the turbo, it is spinning at 20000 rpm (NOT RPMS--RPM MEANS REVOLUTIONS PER MINUTE, IT IS PLURAL AND DOES NOT NEED AN "S") and is still trying to stuff several hundred CFM of air into the engine that is now closed off. THAT is where the wastegate comes in...POP hISS, pressure relief.



Make sense?

Drive fast, take chances
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Supercharger for Chev Corvette/Holden Commodore 5.7 Gen3 V8

Postby Dave_H » Wed Jul 28, 1999 11:32 am

In Reply to: Re: Yet another car question from a guy who know's nothing about cars posted by AN on July 28, 1999 at 16:40:46:


: Absolutely, Paxton, Vortech, et al offer popular kits for belt-driven supes for the Ford 5.0. Typically, fuel system need to be improved to take advantage of the additional air. Larger throttle bodies are often used. And a engine management chip change is vital on most modern cars.

I did a search on a search engine I cant remember the other day on "supercharging" and found heaps of info including a commercial site which makes superchargers for the chev corvette 5.7ltr alloy v8 which gives (if I remember correctly) about 440 horsepower

this is serious shit folks.

I post this only because I believe that the corvette "alloy Gen 3 v8" (as it is referred to) is:

a) also used in 1999 series 2 holden commodores (australia)

b) the descendant of the iron chev 350 engine used in the 2 door holden monaro (which was the stolen black interceptor driven by the nightrider at the start of mad max 1)

any builders of replica nightrider interceptors might be interested in this info for power output.
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