Very Cool Turbo Option

[JasonZ34]

Especially for us 3.4 people. It's a remote mount turbo system that puts the turbo farther in the exhaust closer to the muffler and brings the boost back to the engine. I'll post up the article later. Not like there is any room below my car but its a cool idea.

[SappySE107]

There is already a thread on this here I believe.

[sharkey]

im looking at doing the same thing on my car.

[dykz34]

I've seen it on a few F-Body cars... it's a cool idea though.

[pocket-rocket]

Yeah, I read up on it from the site that makes them. I didn't like the idea of all of the pipe being used as an intercooler. Nor did I like the thought of the pressure drop from blowing all of that air to the engine through all of that pipe. Cool idea though, I agree.

[sharkey]

the pressure drop is minimal, about 3/4psi when running 5 pounds boost, and about 2 when running high boost. its about the same as a large front mount intercooler.

and using the pipe for an intercooler isnt all that bad an idea. just because it doesnt have air flowing around it like a fmi doesnt mean it doesnt cool the charge down. and the sts system (the company that makes the ls1 setup) uses methanol or water injection to cool the intake charge.

i like is becaue its easy to build the kit. i have some ideas for oiling the turbo instead of running lines from the motor to the turbo, then back.

its feasable for a low boost setup, and i think can be done cheaper than a turbo under the hood. besides, i like the stealth factor of it. you can show people under your hood and all they see is the charger pipe, and likely will think its just a CAI.

[brian89gp]

Sure, it will work but it will never be as efficient as an underhood one. Pressure differential is what runs a turbo and the way to get pressure is hot expanding gasses. Put the turbo back there are you have some heat, but its mostly just exhaust flow spinning the turbine.

[sharkey]

taken from the faq on the sts turbo site

Doesn't heat create the velocity in the exhaust gasses to spool the turbo?
No, heat doesn't create velocity. Heat creates volume. If you look at any of the physics laws for gasses, you will find that pressure and volume and heat are related. PV=NRT is a popular one, The V isn't for velocity, it is for Volume.
The turbine housing is what creates the velocity. The scrolling design that reduces the volume of the exhaust chamber as it scrolls around causes the gasses to have to increase in velocity and pressure to maintain the same flow rate.

Hotter gasses have more volume, thus requiring a higher A/R which in effect means that it starts at say 3" and scrolls down to approximately 1". Lower temperature gasses are denser and have less volume, so they require a lower A/R housing which would start at the same 3" volume, as the turbine housings use standard flanges, and scroll down to say 3/4".

Now if you were to reverse the housings in application, the conventional turbo would spool up extremely quick, at say around 1500 rpm but would cause too much backpressure at higher rpms because the higher volume of gas couldn't squeeze through the 3/4" hole without requiring a lot of pressure to force it through. On the reverse side, the remote mounted turbo with its cooler denser gasses, wouldn't spool up till say around 4000 rpms but once spooled up would make efficient power because it doesn't require hardly any backpressure to push the lower volume of gas through the larger 1" hole.

and

Don't turbos have to be really hot to work properly?
Putting a torch to your turbo and getting it hot doesn't produce boost. What produces boost is airflow across the turbine which causes the turbine to spin. If turbochargers required very high temperatures to produce boost, Diesel trucks and Methanol Race cars wouldn't be able to run turbos. However, each of these "Low Exhaust Temperature" vehicles work very well with turbochargers when, like any turbo application, the turbocharger is sized correctly.
In a conventional, exhaust manifold mounted turbocharger system, the extra heat causes the air molecules to separate and the gas becomes "thinner" because of the extra space between the molecules. This extra space increases the volume of air but doesn't increase the mass of the air. Because the volume is higher, the velocity of the gas has to be higher to get it out in the same amount of time.

By mounting the turbo further downstream, the gasses do lose heat energy and velocity, however, there is just as much mass (the amount of air) coming out of the tailpipe as there is coming out of the heads. So you are driving the turbine with a "denser" gas charge. The same number of molecules per second are striking the turbine and flowing across the turbine at 1200F as there is at 1700F.

Front mounted turbos typically run an A/R ratio turbine housing about 2 sizes larger because the velocity is already in the gasses and the volume is so big that the turbine housing must be larger to not cause a major restriction in the exhaust system which would cause more backpressure. With the remote mounted turbo, the gasses have condensed and the volume is less, so a smaller A/R ratio turbine housing can be used which increases the velocity of the gasses while not causing any extra backpressure because the gas volume is smaller and denser.

Sizing is everything with turbos. There is more to sizing a turbo for an application than cubic inches, Volumetric Efficiency, and RPM ranges. A turbo must also be sized for the exhaust temperatures. A turbine housing sized for 1700F gasses would have lag if the gasses were 1200F. This is why turbo cars have lag when they are cold and not warmed up yet. Both systems work well if sized correctly.

[pocket-rocket]

Well to know the truth about their claims (they can claim anything you want, but I want proof), I would want to see dyno sheets of the same car with the same "appropriate" size turbo system to belive their system works just as fine as a conventional one.

[sharkey]

i have seen a 2002 firebird with the sts turbo setup on it. (this is what led me to this idea) it was a nice setup, and it freeking moved. he was running 6lb boost with the methanol injection, and it was just like any other tubo car.

the way i see it, if you want 10lb boost, as long as the turbo spools quickly and there isnt turbo lag, and you get 10lb boost, what is the differance if the turbo is mounted to the exaust manifold or the tailpipe???

[firechiken]

Exactly where is the methanol injected?

[sharkey]

its close to the turbo so it cools the charge down before it travels to the intake.