Have you guys seen this?
http://www.STSturbo.com

You can look at it and say it won't work. In the end they have a 500+ RWHP LT1 camaro that says it does work. The only engine mods to the LT1 was the turbo kit, 8.5:1 pistons, and 1.6:1 rocker arms.

I emailed them about a kit for the Ls and HDs, he says they've considered it and may do it next year (isn't that always the case? )

If you look at their kits you wonder where the $3K goes... maybe someone could beat them to the punch. Think about it: Easy install, no other intake or exhaust mods, more HP then a KB.

 

Could we use both the turbo and the supercharger ??

 

You could, but since the turbo is much more effeicient (parasitically and adiabatically) you'd want to really turn down how fast the SC was spinning.
The math gets a little complicated, but the short answer is SC would be multiplying the boost (and the heat) the turbo was making.

 

i wander if turbo lag is affected by having it mounted further back in the exhaust system?

 

If you look at their FAQ, they claim that the air tubes are just a few feet longer than a turbo mounted under the hood with an intercooler.

I don't know, it may work, but I would still prefer the turbo under the hood close to the exhaust manifold where the exhaust gases are stronger. If you ever put your hand over a tailpipe while the engine is running, and then put your hand over the collector of open headers, you can see the velocity of exhaust is stronger at the header...especially since it is before cats and mufflers.

Also, mounting a turbo under the gas tank in the rear of the car...If you ever washed your car/truck, dried it, took it for a quick ride, and looked at the back of it, it is filthy. I wouldn't want the turbo to suck all of that filth/much in.

 

The same weight of air is passing through the headers as is passing out your tailpipe at the same rate. The weight of the air moving at a certain speed is what does the work. The same amount of molecules are availible to spin a turbo at the collectors as at the tailpipe, you just need to change the way you harness them.

It doesn't seem like it would work at first, but results don't lie.

Once you get past the fact that a turbo can perform equally well anywhere you put it as long as the system is sealed, you begin to wonder why you'd want to subject the turbo to the heat near the headers if it doesn't buy you anything.

 

Distance away from the exhaust valve does matter. Air is highly compressible. "Turbo lag" would be pretty noticable.

This idea is not efficient and is just asking for trouble from all the heat in an area that has not been designed for.

It's wrong. Dead wrong from an engineering standpoint.

WOT

 

The thermal expansion of the hot gases have more to do with turning the impellar than just the flow of the exhaust gas. This might work but i doubt its as efficient as a turbo mounted near the exhaust outlets. I work at an electric plant and our turbines are not insulated for looks.

http://www.turbochargedpower.com/Tur...r%20Theory.htm

 

Turbines are driven by differentials of pressure. We know by the ideal gas laws that with a given volume pressure goes up with heat. But pressure also goes up with an increase of molecules in a given volume.
If you restrict an exhaust pipe the pressure will be even across the pipe before the restriction. The temperature will vary, but the pressure will remain the same.
With a larger volume before the restriction it'll take more time to build that pressure, no one will argue with that, but relative to the ammount of air moving through the engine, this volume difference is minimal.

The system for the LT1 spools to full boost before 3000rpms... You can think about physics all day long, but if your end result says that it'll lag, the real world says otherwise.

 

I'm sure the system works, it just won't work as well as conventional setup. Hell, even those electric superchargers work, but what does that tell you?

I think I'd be more concerned with how the oil drains back into the motor, when the turbo is that low on the car. If anyone here has turbo experiance, they can tell you the slightest oil return restriction will blow out the turbo seals in a hurry.

 

Maybe it spools 1/10th of a second slower. The compressor is just as effeicient as a convential system. So really what we're talking about is probably a slightly slower spool up off the line and probably an unnoticable difference from a roll. Do these things counter balance:
Cheaper
Easier to install and uninstall
Turbo doesn't get as hot, no need for a turbo timer

No one would opt for this over a custom race built turbo system if you're looking to set records, but for the common driveway mechanic, seems like a good idea.

They use a pump. That is the one thing that worries me.

 

I don't believe it. Turbines are driven by changes in Enthalpy. Simple first law thermodynamics. For a control volume(i.e, a turbo with steady flow through it's inlets and outlets):

dE/dt=Q-W + dm/dt*hin - dm/dt*hout
where W=work(needed for the compressor)
Q= heat transfer from the turbo to outside
dm/dt = mass flow rate
hin/hout= enthalpys of gas streams
dE/dt = energy change with time =0 for steady state

What this boils down to is that the work produced(required to drive the compressor) is proportional to the difference in h's (in vs. out). For air (which can be considered an ideal gas), Enthalpy is proportional only to the temperature. By the time all that air has gotten back to the rear of the car, it has lost all of it's potential to do work. The only reason why a turbo works is that it is so close to the engine. Theoretically, that 1200 HP engine, as gorgeous as it is, would have been better off with two smaller turbos very close to the exhaust ports.

Good marketing though, showing the glowing red turbo and saying that you don't want it under your hood. Too bad it's those high temperatures that actually make the power.

What happened to that B.S flag smiley thing? Would have been great to have now..

Randy

 

So when I blow on a pinwheel, its the 5 or 10 degrees difference between the temperature of the air in my lungs to the temperature of the air outside that makes it spin? When its hotter then 98 degrees outside, does the wheel spin backward when I open my mouth near it?

 

Sublime, Nice armchair engineering there bud.. You gave it a decent stab..

Look it's basicly wrong from and efficiency and safety standpoint. It very well may function. I don't doubt it one bit. But having it that far from the exhaust valves is just not mathematiclly sound. I spent 6 years as a pump engineer and have delt with all 3 basic types. One has to understand & calculate the relationships of volume, velocity, slip, friction, and heat.


Even if we all agreed it's efficiency did'nt matter. You still have introduced a lot of heat in areas that were never meant to handle it. Not good for the longevity of all those parts & systems.

WOT

 

SonicL and desert...thanks for beating me to it. I work in a power plant that moves (ship) and I've studied thermodynamics. This is basically pi$$ poor engineering. I'm glad you guys pointed it out, cause I don't remember my formula's!!!! A turbo works mostly off thermodynamics. Not just a windmill. This system may work, but it is definatly not an efficiant design. Anyone who would go through the lengths of building this obviously does not understand turbo's and I would hesitate to buy for that reason alone!