There's been a fair bit of bagging on this idea, but I reckon it's not bad at all. Anything which improves performance is a bonus, plus it has sleeper qualities ie you do it to a mx-5 and anyone looking under the bonnet doesn't know the difference As for the charge air piping that runs under the car, you could use it as a heat-sink - if you welded some stuff to it to increase it's surface area that is exposed to the passing air under the car If you were going to do it to an N/A zed then it wouldn't be a bad idea I think... and no need for muffler because the turbo reduces the output dB's - just run a longish bellmouth as your exhaust right off the turbine housing As for the arguments about cats before and after, well your turbine operates on pressure differential... if you cat is after the turbine, or before, shouldn't make much difference. And another thing to keep in mind, is that exhaust gases exit your cats a lot hotter than when they entered, which might mean more pressure available?
Ive posted a few posts about this in the past. Relating to a 350z sts rear mount and a z32 custom rear mount. Been done on the ford/holden scene, even been reviewed in some main magazines. Bottom line it works, depends on the setup to how well. The previous posts are right in saying there is lag due to a longer piping, but the long piping in the cool outside air acts to reduce temps and (low psi numbers) eliminates the need for an I/C so its not all together bad. Filling a 3-5l capacity fount mount would see similar lag results. On a high comp motor like the n/a z it has said to be very zippy and responsive, ide image just like a SC setup.
MaTTz Your right it does have merit, but I must re-iterate that it is not new school as a few LeMans LMPs did it in the 80s. There are a few thermal issues for road use, (ie: the turbine will see alot more flutuation in temp), but a good choice of turbine wheel should sort this. Same as the supply of vacuum, oil, and water. It is all really just engineering. As for the volume of air I think you might find that it would be closer to 10lt per side. Also did you take not where the air is drawing from on the photo. how often do you think that you will need to clean that air filter. As the saying goes though "horses for course". I would recommend that for the expense a Vortex or srew type charge woould be a "wiser" option. Or a CAPA kit.
Put a turbo designed for rear mount and put it up front and you'll see less boost too, the flow is the same only the air is more dense in the remote location. It just needs the correct turbine size to work efficiently. It should be cool enough at the rear to use a diesel variable vane turbo too.
I have considered this once the 8 is in. I think it definately has merit and in some cases is a lot easier and possibly cost effective compared with fitting a turbo or two in the engine bay. My main concern is the large distance to be travelled by the gas before it hits the turbine. The compressed side would be relatively direct, remember that a bend in a pipe is worth about 8m of straight pipe... Pressure drop would be minimal, but lag could be an issue if the sizing is wrong. I've seen it done, and I'm sure that others will do it again. I definately won't write it off. I have a feeling that the effeciancy would still be higher than a supercharger...
