The same principle is used in the hidden f-body kits they make for 4th gens. The turbo is just as efficient as a motor mount, and actually does not need an intercooler because of the length of the compressor tube. The air actually gets cooled more (on an f-body) through that long tube than an intercooler would, and you also do not lose any boost like with an intercooler. The turbo runs cooler as well since it is not subjected to engine heat, and it is out in the open. The downsides are rain and the amount of dirt the filter gets due to being behind the rear tire. The f-body kits come with a "sock" (like they run on dirtbikes) to protect the air filter from water and large debris, and you have to clean it like every oil change or something. The f-body kit is called and STS turbo kit, you can check them out online.
You'd think that with the length of that compressor pipe it would cause problems, but according to what I've read, once the pipe is pressurized it doesn't lose any pressure. The test cars they've run show something in the neighborhood of a tenth of a second or so difference in pressurization times between the STS turbo and an underhood with an intercooler. Turbos run 400 degrees cooler, and intake air temps are like 20% cooler than an intercooler-style turbo. Not to mention you now have significantly less underhood heat since the turbo isn't in there cooking everything.
The problem with that picture is the wire tie. That is NOT gonna last but about 1 second in the real world. That intake pipe would get so hot it would melt that wire tie, or the vibrations would break it. That looks like a mock-up installation and not what it will be when finished. The turbo would also melt the tail section because there is no heat shield. Good theory, and it will be interesting to see what it looks like when completed, but I wouldn't have those shoddy pics online advertising my product. And Lord knows you ain't riding that bike around town. You better get a 20 over swingarm to keep that sucker on the ground :lao
Q.) What type of tuning is needed with this setup?
A.) Most of our low boost (2-4 psi) turbo kit's are designed to run without the need for much additional tuning. However, we recommend that all bikes that have the turbo installed, also purchase a power commander to ensure the Air/Fuel mixtures are correct. We are also working on power commander mapping to help with your tuning needs. "
There is VERY little boost lag due to the length of the pipes. You have a defined amount of air in a distance with hard walls. The lag difference between that and one that is header mounted would be measured in tenths or hundredths of seconds. The boost lag is because of the turbos they use (too big for one thing and probably not dual ball bearing like the popular ones). That turbo is overkill for a bike. The one on a Nissan SR20DET isn't even that big, and those things can put like 250 to the wheels in a car which has a LOT more line loss than our bikes.
This is directly from the ststurbo.com website describing the advantages of a rear mount turbo kit for passenger vehicles:
Benefits of Remote Mounting
Ease of installation. STS turbo systems can be installed in about 8 hours with standard tools and average mechanical ability.
Performance Sound. The turbo acts as a muffler and sounds like an aftermarket performance muffler. Turbo spool and rushing air from the blow-off valve make a unique sound that will turn heads!
No need for major modifications to your vehicle. STS systems are designed to "bolt-on" to factory mounts.
Increased gas mileage. Unlike a belt driven supercharger, the turbo utilizes "wasted" energy leaving your tailpipe. Most of our customers get 1-3 mpg increase in gas mileage.
Lower underhood temperatures. No need to worry about melting wires, hoses, or other components.
Converts back to stock in about an hour.
More room under the hood. Future repair work or modifications will not require the expense of removing the turbo system to allow access to engine components.
Cooler oil to the turbo. Cool oil is better for both the turbo and engine.
Approximately 500F lower turbo temperatures. Eliminates the need for a turbo-timer, which allows the engine to run after the car is shut off in order to cool down the turbo and prevent oil and bearing damage.
Denser exhaust gasses drive the turbo turbine wheel more efficiently.
Built-in intercooling. Intake piping provides ~50% intercooler efficiency. There is no need for the expense, pressure drop, and installation problems associated with a front mounted intercooler.
Turbo is exposed to ambient air rather than underhood air. Allows for better cooling of turbo components.
No need for expensive headers, mufflers, or exhaust systems.
Turbo is closer to the tail pipe outlet. Provides a better pressure differential across the turbine wheel which promotes better flow across turbine.
Better weight transfer. Increases traction because the bulk of system is mounted in rear of vehicle rather than up front.
Also, Two Guys Garage on Speed did a turbo conversion on an LS1 car, and it was making boost at 3g's just as described on STS' site. There is no turbo lag, IF you use a correctly designed turbo. The turbo these guys are using is WAY too big for such a small displacement engine as a bike. That's why they have so much boost lag, it is NOT the length of the pipe.
The only thing I disagree with on the sts site is that you don't have to use a turbo timer. I would not take a chance on it. If I had a turbo anything, it would have a timer on it. 30 seconds of gas is a lot cheaper than a $1,000 turbo replacement.
first of all STS is crap. PERIOD. If turbos got better the further away from the motor then why have diesel trucks not done it yet?? My point is that this is just an easy way to mount a turbo not an effiecient way :cheers