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Gasoline Engine Turbocharger Concept.

  1. Oct 19, 2007 #1
    Conventional turbocharging is done from the manifolds. Or as close to as possible.

    In the last few years, a company (STSturbo) came out that designed a system for rear mounted turbos, that seems to work well.

    What I am ultimately trying to figure out is the most efficient way of turbocharging a gasoline engine.

    I came up with this idea.

    Normal pulse matched headers, going into a y exhaust setup (say 3 1/2") running to the back of the car, mking a u turn, then up to the front, where the turbo is mounted sideways (So the compressor inlet faces grille)

    Now plumb compressor straight into intercooler.

    Dump turbine exhaust behind front tire.

    Compressor inlet has filter on it poking into grille.


    1. Exhaust temps to turbo would be at atmospheric temp or close to. (Denser, pulse matched and you would not lose velocity, you would gain because of size of piping used?)

    2. Turbo would run 2x as cool as a conventional or rear mount.

    3. Oiling is easier to plumb.

    4. Turbine exhaust has little to no backpressure.

    This setup should make more power than either setup. (Traditional or rear mount)

    Questions I have are...

    1. Must the turbo have the heat element in it to function optimally?

    2. Would you need to have a smaller turbine housing with cool air pushing the turbine? or would a larger turbine housing work the same?

    3. Out of the 3 setups mentioned which would produce the greater amount of compressed air (boost)

    This is more for a personal project than anything. So any insight would be appreciated.
  2. jcsd
  3. Oct 19, 2007 #2
  4. Oct 22, 2007 #3


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    Any chance of some sketches? I'm finding it hard to picture your proposal.
  5. Oct 23, 2007 #4
    The problem with this, and with the STS kits, - and their general reasoning at least in their sales pitch- is that YES, the gas because denser... This does not mean it has more energy or capability to drive a turbine.

    I don't want to go too crazy, but both pressure and tempurature contribute to the energy content of a gas. The point of a turbine, is to pull that energy out of a gas and turn it into usable mechanical work, in this case to turn a compressor. Their logic is fundamentally flawed in that cooling the gasses does NOT drive the compressor better, in fact you are LOOSING energy which can be harnessed to do work, in the form of lost thermal energy. This is accompanied by a drop in pressure. Overall, this drop in energy hurts the maximum amount of energy available for the turbocharger. Now, here is where they get away with it: Turbocharger systems operate with a wastegate, which routes exhaust gasses around the turbine, because they are sized such that the available energy is more then what is required by the compressor to achieve a requested boost level. So, all that *really* gets hurt is the spool up time / lag, and they combat this by using smaller, more restrictive housings, which hurts overall system flow and thus power.

    It works ok, for a budget system. Their marketing is very decieving and well, pretty much incorrect, but a lot of people believe it anyways. I would definantly NOT take this system to the extreme by doubleing the distance to the turbocharger, in fact if one wanted to improve uppon the STS systems the first place I would start is with major insulation of the exhaust system on the way to the turbocharger in order to keep this energy in the system.

    FYI, on higher horsepower setups (I build turbo honda's and vw's in my spare time) we often see 30-50psi gauge pressure in the exhaust manifold before the turbocharger, at tempuratures up to 1700 degrees F... Drop that tempurature down to near ambient, and the pressure decrease this will come with, your going to have one VERY poor running turbocharger.
  6. Oct 24, 2007 #5
    study race car turbos they do it that way BECAUSE IT WORKS
    yes turbo's get HOT , cold gas has little energy = low power

    remember the big trade off in turbo's is drivability
    too slow a responce [called spool] makes a poor driving car

    I own and drive two turbo cars a gas volvo and a diesel M-B
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