Car Forums  

Go Back   Car Forums > General Discussions > General Chat
FAQ Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-27-2005, 09:24 PM   #1
Pythias
CF Extraordinaire
 
Pythias's Avatar
 
Join Date: Jun 2005
Location: Ohio, U.S.
Posts: 1,831
Turbocharged/Supercharged Car

Is it possible? From what "someone" tells me anything is possible. If this is possible why is it not done much? Too much money? Too much stress on the engine? I just discovered twin-superchargers are possible so I must post about this.
__________________
"Though I drive through the valley of rice,I shall fear no turbo for torque art with me. Thy rod and piston, they comfort me."

"It is not the strong who will win, but the winner who is strong." -ROTK7
"You wrote "The World Doesn't Need A Savior" but everyday I hear people crying for one."
Pythias is offline   Reply With Quote
Old 10-27-2005, 09:34 PM   #2
fudge
let's fighting love
 
fudge's Avatar
 
Join Date: Dec 2004
Posts: 1,003
From Club4ag:
Quote:

Turbocharged 4A-GZE. (Twin charged, HKS)

Using turbo as well as a supercharger, it is the most complex form of 4A-G, it is really expensive and resource hogging to setup, however, once correctly built, it gives the engine massive torque curves and allows you to use very large turbine to really trash the chassis. An impressive piping layouts allow even the owner to get confused which way the air travels... A common horsepower figures in the 350+ with unequalled torque characteristics.

Recent batch of new generation turbochargers are replacing these complex setups as boost lag become less apparent and higher peak boost becomes more stable and immediate. Quickly the twin-charger setup is becoming "low-tech" despite of it's complexities.
This'll answer all those questions.
__________________
fudge is offline   Reply With Quote
Old 10-27-2005, 09:40 PM   #3
Pythias
CF Extraordinaire
 
Pythias's Avatar
 
Join Date: Jun 2005
Location: Ohio, U.S.
Posts: 1,831
Quote:
Originally Posted by fudge
From Club4ag:

This'll answer all those questions.

Thank you very much

I have one other question though on twin supercharged engines. How exactly does it work? Do they kick in at different times from eachother or all at once for just one very powerfuly supercharger kick?
__________________
"Though I drive through the valley of rice,I shall fear no turbo for torque art with me. Thy rod and piston, they comfort me."

"It is not the strong who will win, but the winner who is strong." -ROTK7
"You wrote "The World Doesn't Need A Savior" but everyday I hear people crying for one."
Pythias is offline   Reply With Quote
Old 10-28-2005, 03:35 AM   #4
Bino
Written Off
 
Join Date: Mar 2005
Location: Phoenix, Oregon, USA
Posts: 844
Well, what was posted was a supercharged and turbocharged motor... which is not the same as a twin supercharged motor. All twin supercharged (no turbos) motors I've seen (disclaimer) run in parallel, meaning they're the same size supercharger, they run at the same speeds, and provide the same boost to the intake manifold. But, since you have two of them, you've doubled the volume of air being crammed into the motor relative to a single supercharger.

There are a couple ways to do the supercharged and turbocharged motor. You can either have the supercharger setup to provide boost down low, and then when the motor begins flowing enough air to spool the turbo, the supercharger is cut out of the airflow equation and the turbocharger takes over the boosting duties.

The more common setup (since most people don't setup clutches on the pulley of their superchargers) is to run the turbocharger (compressed air coming from the turbo) through the supercharger, which in turn additionally compresses the air from the turbocharger. In this way you're not really working either unit very hard, you can run your supercharger at what would normally be about 6psi, and run your turbo at 15 psi or so (you can run them at whatever you want, but this is my example). But, when the turbocharger spools, that 15psi is running through the supercharger now. Both devices run on a delta-pressure system. So, the supercharger isn't really working much harder to compress the 15psi from the turbocharger than it is to compress ambient air. But, the air to the intake manifold has now been compressed to about 27psi... and you've got the supercharger giving you some boost in the low range... good times indeed.
__________________
Build 'em Light and Wind 'em Tight.
Bino is offline   Reply With Quote
Old 10-28-2005, 03:53 AM   #5
Pythias
CF Extraordinaire
 
Pythias's Avatar
 
Join Date: Jun 2005
Location: Ohio, U.S.
Posts: 1,831
Quote:
Originally Posted by Bino
Well, what was posted was a supercharged and turbocharged motor... which is not the same as a twin supercharged motor. All twin supercharged (no turbos) motors I've seen (disclaimer) run in parallel, meaning they're the same size supercharger, they run at the same speeds, and provide the same boost to the intake manifold. But, since you have two of them, you've doubled the volume of air being crammed into the motor relative to a single supercharger.

There are a couple ways to do the supercharged and turbocharged motor. You can either have the supercharger setup to provide boost down low, and then when the motor begins flowing enough air to spool the turbo, the supercharger is cut out of the airflow equation and the turbocharger takes over the boosting duties.

The more common setup (since most people don't setup clutches on the pulley of their superchargers) is to run the turbocharger (compressed air coming from the turbo) through the supercharger, which in turn additionally compresses the air from the turbocharger. In this way you're not really working either unit very hard, you can run your supercharger at what would normally be about 6psi, and run your turbo at 15 psi or so (you can run them at whatever you want, but this is my example). But, when the turbocharger spools, that 15psi is running through the supercharger now. Both devices run on a delta-pressure system. So, the supercharger isn't really working much harder to compress the 15psi from the turbocharger than it is to compress ambient air. But, the air to the intake manifold has now been compressed to about 27psi... and you've got the supercharger giving you some boost in the low range... good times indeed.

Yes I know that was a pic of a diff motor but I was wonderin about the twin supercharged motors. I see and thanks for the info.
__________________
"Though I drive through the valley of rice,I shall fear no turbo for torque art with me. Thy rod and piston, they comfort me."

"It is not the strong who will win, but the winner who is strong." -ROTK7
"You wrote "The World Doesn't Need A Savior" but everyday I hear people crying for one."
Pythias is offline   Reply With Quote
Old 10-29-2005, 12:41 AM   #6
Bino
Written Off
 
Join Date: Mar 2005
Location: Phoenix, Oregon, USA
Posts: 844
Quote:
Originally Posted by Bino
Both devices run on a delta-pressure system.

I was eating lunch today and realized I worded this incorrectly (the numbers were calculated correctly), turbochargers/superchargers work on a pressure ratio system, not a delta pressure system.
__________________
Build 'em Light and Wind 'em Tight.
Bino is offline   Reply With Quote
Old 01-18-2006, 04:41 AM   #7
Pythias
CF Extraordinaire
 
Pythias's Avatar
 
Join Date: Jun 2005
Location: Ohio, U.S.
Posts: 1,831
I decided to bring this thread back up because I had a few other questions.

Based off what you said Bino, would it not be true a properly tuned Supercharger/Turbocharger would be more effective than a Twin-Turbocharger setup?

Also is it true the the atmospheric pressure in this kind of engine must be very low for this setup? (A friend said that)

And he also said You will be bound to blow something for sure because it will be impossible to keep a Super/Turbo engine cooled, he claims it would be bound to overheat?

And, you might even have to use premium with a high octane additive just to run it properly?

Also superchargers are more parasitic because of the hp needed to run it off the belts, so are they creating newer better superchargers that aren't as parasitic?

Just as well what would be the advantage to a twin-supercharger setup seeing as how they are parasitic?

Thanks
__________________
"Though I drive through the valley of rice,I shall fear no turbo for torque art with me. Thy rod and piston, they comfort me."

"It is not the strong who will win, but the winner who is strong." -ROTK7
"You wrote "The World Doesn't Need A Savior" but everyday I hear people crying for one."

Last edited by Pythias : 01-18-2006 at 04:43 AM.
Pythias is offline   Reply With Quote
Old 01-18-2006, 05:25 PM   #8
vwhobo
CF's Anal Orifice
 
vwhobo's Avatar
 
Join Date: Feb 2003
Location: Redneck Hell
Posts: 8,630
Quote:
Originally Posted by Bino
Well, what was posted was a supercharged and turbocharged motor... which is not the same as a twin supercharged motor. All twin supercharged (no turbos) motors I've seen (disclaimer) run in parallel, meaning they're the same size supercharger, they run at the same speeds, and provide the same boost to the intake manifold. But, since you have two of them, you've doubled the volume of air being crammed into the motor relative to a single supercharger.
Ummm, no. Something that is so obvious and still seems to always be overlooked is this. Superchargers, whether they're mechanically or exhaust driven, do not in and of themselves create pressure (boost). All they do is create additional airflow. When the airflow is channeled into the intake manifold and meets a restriction, then you have pressure. Notice that the most important word in this explanation is restriction. Without restriction, you have no pressure. Got it?

Now let's try an example. Let's say you have two pieces of pipe hooked up to a water pump. Let's also say that at an operating pressure of 25psi, both pipes will flow 10gpm each. Now remember, the pump only creates flow until there is a restriction (the pipe). And no matter what the source of the flow and pressure, at 25psi, each pipe can only flow 10gpm. Flow and pressure go hand in hand.

Now, take one of those pieces of pipe and move it over to another identical water pump. Turn both pumps on and what will you have? At a pressure of 25psi, you'll have a flow of 10gpm from each one of the pipes. Bottom line is if everyone is paying attention, that it doesn't matter if you have 20 superchargers attached to an engine, for any particualr engine you can only have X airflow for Y pressure.
__________________
Thanks for the pic, jedimario.

"Everybody believes in something and everybody, by virtue of the fact that they believe in something, use that something to support their own existence."
Frank Vincent Zappa, 1940-1993

vwhobo is offline   Reply With Quote
Old 01-18-2006, 05:32 PM   #9
Bino
Written Off
 
Join Date: Mar 2005
Location: Phoenix, Oregon, USA
Posts: 844
Quote:
Originally Posted by Pythias
I decided to bring this thread back up because I had a few other questions.

Based off what you said Bino, would it not be true a properly tuned Supercharger/Turbocharger would be more effective than a Twin-Turbocharger setup?

"More effective" is a very vague statement. A Sequential Twin Turbo system has its benefits. Generally (disclaimer), however, they require a very complicated mess of vacuum actuators and exhaust cutouts, etc (look up the TT setup on an RX7). The Supercharger/Turbocharger setup will provide boost at a low RPM as well as a sufficient top end due to the turbocharger. They're both fairly complex systems (why you don't see them very much), and most people really just need one supercharger or one turbocharger.

Quote:
Originally Posted by Pythias
Also is it true the the atmospheric pressure in this kind of engine must be very low for this setup? (A friend said that)

Your friend needs a lesson in common sense. Atmospheric pressure is... atmospheric pressure, it's the pressure of the air around you, which is about 14.7psi at sea level. The engine does not actually have an effect on the universe around you.

Quote:
Originally Posted by Pythias
And he also said You will be bound to blow something for sure because it will be impossible to keep a Super/Turbo engine cooled, he claims it would be bound to overheat?

The engine will have a great deal of additional stress from the added intake pressure. But, this is true for all forced induction systems. If your engine isn't built properly it will blow, but that's true for an N/A motor just as much as it is for a boosted motor. You can't take a stock Honda D15 motor and expect to pour 25psi into it. You have to upgrade the engine according to what you're going to do to it. Same thing with the cooling system. You have to expect to upgrade the radiator and probably add an oil cooler.

Quote:
Originally Posted by Pythias
And, you might even have to use premium with a high octane additive just to run it properly?

Yes, generally because of the cylinder pressures that develop with a forced induction system (or just a high C/R N/A system for that matter), premium fuel is required to prevent detonation or pre-ignition. My Eclipse requires premium fuel right off the show room floor, just like Corvette's, V8 Camaro's, probably S2000's, etc.

Quote:
Originally Posted by Pythias
Also superchargers are more parasitic because of the hp needed to run it off the belts, so are they creating newer better superchargers that aren't as parasitic?

Well, superchargers are getting more and more efficient, but you're never going to get away from the parasitic loss. The loss is just more than made up for by the additional power from the supercharger (it's a slightly tough concept). If the supercharger gives you 100 additional hp at the wheels of your vehicle, but requires (X) hp to operate, then the supercharger has actually added 100+(X) hp to your engine. But, you have a nice linear power band and an additional 100HP at the wheels, who cares about the parasitic losses.

Quote:
Originally Posted by Pythias
Just as well what would be the advantage to a twin-supercharger setup seeing as how they are parasitic?

Thanks

Same advantages as any of the others, if you want forced induction you just need to decide when/how you want the power. There's a salt flats race semi that runs two roots superchargers and four turbos on its diesel engine. He's just looking for as much boost as he can. A lot of times it boils down to packaging, it's much easier to package a turbo than it is to package a supercharger, and turbo's are generally easier for the grass-roots modifier to route a charge-air-cooler system.

They're not a whole lot different. People generally setup a supercharger for lower end torque and a turbocharger for higher end torque (higher HP). Plus, a turbo can be had off eBay for $25up, a supercharger is always much more expensive (I'm sure there are isolated cases that are otherwise).
__________________
Build 'em Light and Wind 'em Tight.

Last edited by Bino : 01-18-2006 at 07:47 PM.
Bino is offline   Reply With Quote
Old 01-18-2006, 05:35 PM   #10
Bino
Written Off
 
Join Date: Mar 2005
Location: Phoenix, Oregon, USA
Posts: 844
Quote:
Originally Posted by vwhobo
Ummm, no. Something that is so obvious and still seems to always be overlooked is this. Superchargers, whether they're mechanically or exhaust driven, do not in and of themselves create pressure (boost). All they do is create additional airflow. When the airflow is channeled into the intake manifold and meets a restriction, then you have pressure. Notice that the most important word in this explanation is restriction. Without restriction, you have no pressure. Got it?

Now let's try an example. Let's say you have two pieces of pipe hooked up to a water pump. Let's also say that at an operating pressure of 25psi, both pipes will flow 10gpm each. Now remember, the pump only creates flow until there is a restriction (the pipe). And no matter what the source of the flow and pressure, at 25psi, each pipe can only flow 10gpm. Flow and pressure go hand in hand.

Now, take one of those pieces of pipe and move it over to another identical water pump. Turn both pumps on and what will you have? At a pressure of 25psi, you'll have a flow of 10gpm from each one of the pipes. Bottom line is if everyone is paying attention, that it doesn't matter if you have 20 superchargers attached to an engine, for any particualr engine you can only have X airflow for Y pressure.

Yes, I thought something didn't seem quite right about that. But I couldn't quite put my finger on it at the time. Thank you.
__________________
Build 'em Light and Wind 'em Tight.

Last edited by Bino : 01-18-2006 at 05:38 PM.
Bino is offline   Reply With Quote
Old 01-18-2006, 09:18 PM   #11
Pythias
CF Extraordinaire
 
Pythias's Avatar
 
Join Date: Jun 2005
Location: Ohio, U.S.
Posts: 1,831
Thank you, you have answered all my questions perfectly.
__________________
"Though I drive through the valley of rice,I shall fear no turbo for torque art with me. Thy rod and piston, they comfort me."

"It is not the strong who will win, but the winner who is strong." -ROTK7
"You wrote "The World Doesn't Need A Savior" but everyday I hear people crying for one."
Pythias is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Forum Jump



All times are GMT +1. The time now is 02:17 PM.

Powered by vBulletin Version 3.5.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2002 - 2011 Car Forums. All rights reserved.