Twin remote mount turbo?

I know many don't like the Idea of the remote mounted turbo, but it makes sense to me.

So my idea is this:

STS claims that moving the turbo to the rear has cooling benefits, less heat in the turbo, and such things as that.

Now, from my reading on their website I have gathered that the reason they want you to use alky injection over 5psi in the LS1 powered cars is becuase of heat, correct? Correct me if I'm wrong, but is that not the reason for the injection, that is to say, cooling the air charge down more?


Now, they also say that the run forward in the tubing acts like an intercooler because it's open to the air. Okay, good, so a single turbo can run 5psi on a LS1 car without alky or water injections.


Now, what do you say to this:

Get a true dual exhaust kit, two seperate runs to the back of the car. Then take two of the kits from STS (I know they wouldn't fit without fabbing something up, but put that aside for this example) And run them both, one on each side, at 5psi. Two seperate runs forward means you have twice the cooling. Then right before the throttle body or somewhere as you bring the tubing up to the throttle body you have your two air lines join.




Any comments?


If that wouldn't work, then why not get a custom intake manifold to basically have a pair of 4cyls on a common crank?


I also want to ask about taking a chevy 572 and turning it into an EFI engine and putting a turbo system on that as well. If that one would be done, I'd likely do that instead of this twin set-up on the LS1.


Feel free to blast holes in my ideas.

Besides not being a fan of the STS setup, that sounds fine. Don't give STS any money though, just buy your true dual system, buy a pair of t3 turbos, buy flanges for them, take it to a muffler shop and have them weld the flanges onto the exhaust where you want the turbos to sit. Then using silicon hose connectors and some straight and mandrel bends, run your intake piping. Or you could have that welded up too. Shouldn't cost you more than $700 if you know where to spend your money.

That's an interesting twist, I hadn't thought of that.

STS say their turbos are a weird size suited to remote mount. So how would I go about finding what that size is?

If you know how a turbocharger works you know a remote mounted turbocharger isn't the way to go.

The advantages STS claims are just bogus.

Fix yourself a real turbosystem instead, it's worth the extra work.

I have some thoughts on that. I read the older closed remote turbo thread and most of the people against them kept saying "They will work, just not as efficient as a normal system".

So taking that into it, saying heat is part of what drives a turbo and all of that jazz, I have to say something.

When you have your standard turbo system under the hood, you get lots of extra heat to deal with. Now I'm not saying heat is bad for a turbo, it's bad for the air charge and the components around it.

Now you'll say that an under the hood turbo mounted just off the exhaust manifold will work better-more efficient. But then consider this: You need an intercooler to keep KR from getting out of hand.

What's the normal pressure drop in an intercooler? I think it's somethign around 2-3psi, unless I'm not remembering correctly.

However, with the remote mount you get cooling on the run forward with no more then 3/4 psi boost drop.

So saying a standard turbo makes more boost at the same throttle on the same car as a remote mount, what could the difference be??

If it's more then 1-2psi then STS would not have gotten the GM design award. And the remote mount makes up for this lack of efficiency in the turbo, by having better efficiency in the cooling of the air charge.

That is my reasoning for trying the remote mount, because it makes logical sense. I don't want to start a big fight again like in that other topic from back in mid-2004, I was just pointing out that's my reasoning.

You believe that heat is required to make the turbo perform it's best, I don't. It's that simple. I'll take your advice, and I am looking into standard configurations for the LS1 turbo.

And speaking of that, I have a twin-turbo setup for a Commodore/GTO LS1 that I'm looking at. Any of you think it'll fit in a Camaro LS1?

When you have your standard turbo system under the hood, you get lots of extra heat to deal with. Now I'm not saying heat is bad for a turbo, it's bad for the air charge and the components around it.
The TURBINE section (what drives the compressor section) loves heat.
Heat is bad in the compressor side. If you have a heat problem with conponents close to the exhaust (turbine) housing, you just shield the sensitive items. Or duct air in.

Now you'll say that an under the hood turbo mounted just off the exhaust manifold will work better-more efficient. But then consider this: You need an intercooler to keep KR from getting out of hand..

The intercooler takes the heat out of the compressor side. 99% of the heat is put there unavoidably by the compressor itself. ALL compressors and blowers (Roots type) do this. Care has to be taken to keep the incoming air from being heated by local engine components. It's just basic engineering.

What's the normal pressure drop in an intercooler? I think it's somethign around 2-3psi, unless I'm not remembering correctly...
Intercoolers may take 1 to 1 1/2 PSI off. A well designed one will probably be less than 1 PSI.

If it's more then 1-2psi then STS would not have gotten the GM design award. And the remote mount makes up for this lack of efficiency in the turbo, by having better efficiency in the cooling of the air charge....
That's just the alcohol talking.

Okay, okay.....

Heat does drive the turbocharger. Consider that EGTs drop about 300F going through the turbine housing. That alone is energy being returned to the intake. Read in any basic science book and it will say that heat is energy. Hot air ballons for example.

You may get cooling benefits from the STS system(probably not a whole lot) but you will get some lag from having to pressurize all that piping.

STS has to size thier turbos differently to compensate for the lost energy(heat, noise, ect). They are probably much smaller turbine sizes. Size the compressor as you would a normal compressor, but you will have to toy with the exhaust size.

If SaabJohan says it isn't the way to go, it isn't the way to go. Simple as that.

Well then let me change my question: Do any of you think that this kit will be any good? I think it's still under development.

http://www.airpowersystems.com.au/ls1/ls1.htm

I was wondering if it could be made to fit a LS1 Camaro, maybe with some hammering and torching.

Heh heh heh, it certainly LOOKS like fun...
List of BS:
-Remote Turbos
-Electric Turbos
-That "Tornado" thing

Heh heh heh, it certainly LOOKS like fun...
List of BS:
-Remote Turbos
-Electric Turbos
-That "Tornado" thing

Remote turbos arent "BS", they just aren't nearly as good as a normal turbo setup. They essentially use exhaust pressure to work, which is created by the engine pumping out the exhaust. So basically it is powered by the crank... In my eyes, a remote turbo is basically a supercharger, although requiring slightly less power since there is some heat in the exhaust.

Remote turbos are good for newer camaros and such because of the lack of underhood room. Even the V6 has very little room.

That's the main reason I was looking at them. In my opinion I need to have the turbo in the back or under the engine bay, maybe tucked up with the tranny.

Don't have my car yet so i'll have to wait to see if it'll fit there.

That's the main reason I was looking at them. In my opinion I need to have the turbo in the back or under the engine bay, maybe tucked up with the tranny.

Don't have my car yet so i'll have to wait to see if it'll fit there.

Well, whatever you get, I hope it works out.
If it hasn't been mentioned yet, you might pick up a copy of "MAXIMUM BOOST" by Corky Bell. It may help you a bit in the selection of your turbo kit.

i like the idea of remote turbos, ive i had a v8 i would prolly use one. Just for their eas of use.

Well, whatever you get, I hope it works out.
If it hasn't been mentioned yet, you might pick up a copy of "MAXIMUM BOOST" by Corky Bell. It may help you a bit in the selection of your turbo kit.
I have that book its kinda outdated(printed in 1997 i think), but it covers basics.

I think you would benefit more from a single remote mount than a twin considering all of the energy lost on the way back.

I have that book its kinda outdated(printed in 1997 i think), but it covers basics.
Yeah............... It's 8 years old now.
Almost a classic!
Not trying to hijack this thread, but do you know of a newer / better book?

I still read Turbochargers by Hugh Macinnes. That book is from like 1983 but full of good info. Old info isn't necessarily bad info.

Anyone that thinks that a turbocharger is a pressure driven device, driven by exhaust pressure have not understood how a turbine works.

The specific work of a turbine, that is the amount of work per mass flow is the change in enthalpy of the turbine. That is the same as temperature difference multiplied with the specific heat of the gas (which can be said to be a constant). The power of a turbine is the specific work multiplied with the massflow per time unit.
To achieve a temperature difference an exapnsion needed. For turbine that means a expansion ratio aka turbine pressure ratio (which is always below 1). This expansion releases heat which can be converted by the turbine (a turbine in a turbocharger is at peak 60-80% efficient).

As a pressure ratio is needed the pressure must be higher before the turbine than after, this means that the pressure in the manifold must see pressures higher than atmoshperic when producing boost pressure.

That the crankshaft somehow should power the turbine is incorrect. When the exhaust valve opens the pressure is still way over atmospheric, and the temperature is high. The exhaust will flow out by itself, and it's the energy released now that will power the turbine. But, because of thhe higher pressure in the exhaust manifold there will be a pumping loss on the crankshaft as the piston will go against a pressure of perhaps 2-3 bar or even more instead of the normal 1 bar of pressure. Of course there will be a positive effect caused by the intake pressure during the intake phase and how this affects the engine (positive or negative) will depend on which pressure is the highest.
Note that also poor flowing exhaust valves among many thing also can cause increased pumping losses.

In a turbocharger the heat created in the compressor isn't caused by the heat in the turbine side which is infact effectivly isolated from the compressor section. The heat is caused by the compression itself and the inefficiency of the compressor. Most centrifugal compressors found on turbocharger are however very effective, air temperatures will be lower compared to a roots blower for example.

Air, like all other fluids will cause a pressure drop when flowing in a system. Anyone trying to claim that the long pipes on a remote turbocharger system is something haven't spent much thought on it. The long turbes will cause a restriction, just like an intercooler do. The pipes will also not have the cooling effect of an intercooler. Compare the surface area of the intercooler and compare it with the tubes, then compare the cooling air flow though the intercooler and compare it with the flow around the pipes.

Most people seems to think that heat radiation in the engine bay is a large problem with a turbocharged engine. Heat radiation can be solved just like it can with a natually aspiranted engine. Heat shields are an effective and cheap solution to this problem but auto manufacturers have gone longer. To reduce cold start emissions the catalyst must fast reach its operating temperature. So some cars have exhaust manifolds and pipes to the catalyst with two walls, one inner liner and one outer shell (almost like a gas turbine burner but without the cooling airflow).

With a turbocharged engine, power has rarely been the problem. The problem is to get maximum response from the turbocharger. This is done by using short pipes, preferbly separated pipes with twin scroll turbochargers which improve not only response but also reduces interference between the cylinders at the exhaust phase. The improvement in response is due to a higher pressure ratio is seen at the turbocharger faster, this is also with the help of the pressure pulses.

Several World War II fighters had turbo-superchargers mounted elsewhere than on the engine so it ain't new and it works!
http://www.animationlibrary.com/Animation11/Transportation/Planes/p-51_2.gif

Several World War II fighters had turbo-superchargers mounted elsewhere than on the engine so it ain't new and it works!
http://www.animationlibrary.com/Animation11/Transportation/Planes/p-51_2.gif
1. With airplanes transient response isn't a problem.

2. In the 1940:ies the turbines could not withstand high temperatures with the reliability needed in an airplane. Today we have much better materials, and higher temperatures = higher turbine performance (which is stated in NACA reports of the time).

3. The large and heavy turbocharger had to be placed in such a way that the balance of the airplane didn't change.

4. The airplanes didn't had any restrictive mufflers on the way to the turbocharger.

1. In combat aviation terms they had very fast responses to throttle input.
2. Planes rarely had failure of these components.
3. Most aircraft were built with the placement as a paramount concern during the design stage- they weren't after thought add-ons.
4. Yeah, I know and they sound fantastic!! If you get the chance at an air show you'll love to hear them!!
http://www.animationlibrary.com/Animation11/Transportation/Planes/spitfire.gif

1. There is some difference between aviation and automotive response. Airplane engines are also in comparison built for "constant" engine speed, and there's a big differece in turbocharger response when the engine is already at high speed.

2. Turbine inlet temperatures where in the region of 700-800 degC back then, today 900-1050 degC are used. The turbines used back then was also what I understand aircooled.

3. You still needs a good balance + an aerodynamic design of the plane. The turbochargers used was also quite large.