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Steve, aerodynamics with a V8 seem to pay good dividends. The fact that a Vette doesn't suffer from the gas guzzler tax says one thing. My friends Mark VIII that gets 26+ is another, and the car checks in at over 2 tons.


Fuel economy is a balance between aero, engine, and driver. Sometimes they come together, and other times they do not. The fact that a 500hp car can get as good if not better fuel economy than a Subaru means something though.

I didn't want to use the Corvette example as it's more specialized, but is a good example of a combination of decent aero and high gearing. Sure the engine can make 400 HP (and is not much heavier than some I4s), but that's under WOT. By lowering the amount of power needed on the highway through drag reduction, the engine can turn over on a whisper of fuel, being able to run as lean as they can get away with while a smaller engine is droning along at a higher rpm under heavier load, requiring more fuel on both counts. My Tigershark is a similar approach as the Corvette in that regard, but brought down to a level where a 4 cylinder should be able to run with about the same kind of relative efficiency.

The mileages of most small engine cars today is terribly unimpressive. Small cars are tall, short, stubby, and too heavy. It seems 36 mpg is about the realistic limit for a small hatchback in current form. I'm far more impressed with a 300 HP V6 brick that gets 27 or a 400 HP Corvette that gets close to 40 (as claimed by multiple people). Sure, you can probably get a Vette down to 10 mpg, but that's down to choice and when you want the power it's there. You don't need to access it very often anyway (probably tough to even find a place where you can). The Mini Cooper S I test drove when I bought my Mazda had 21 mpg listed as its average on the computer. Awful aero and too much weight force that anemic 1.6 to run off the supercharger nearly all the time. It was an unimpressive car on many levels, but that was the most shocking to me.

I intentionally didn't read past a few replies of the thread.

Take the random WRX. Tune it with your regular header of choice (non heat wrapped or ceramic coated). Note the rpm the turbo starts to spool and when it reaches peak boost. Now take those same headers and ceramic coat them. Now you will see that the spool has improved.

Heat is energy. The turbo is driven by high pressure exhaust. Cold gasses take less space than not gasses.

The placement of these turbos means a lot of energy is lost due to cooling ( contraction of the exhaust gas). The "turbo lag" by the longer intake is an issue but the same is true for trying to pressurize these extra long "headers"

These systems might feel good once they are spooled and give good numbers on the dyno but linear throttle response is important and many aspects of this system would make throttle response difficult to predict. If you tracked a car with this system (not drag racing) you'd probably get significantly faster times by riding the brakes at all times (to keep the system pressurized)

I used to work at a chevy dealership and this guy came in with a Z06 that had these turbos mounted on it. He had chains wrapped around them so nobody would steal them. I drove the car and noticed no more turbo lag than any other turbo car ive driven, what a fast car it was. Also we have to remeber that not all turbos have coolant lines, diesel trucks dont typically run coolant to thier turbos, and the cars that these are run on usually dont see a drop of rain or a gravel road in thier life.

Take the random WRX. Tune it with your regular header of choice (non heat wrapped or ceramic coated). Note the rpm the turbo starts to spool and when it reaches peak boost. Now take those same headers and ceramic coat them. Now you will see that the spool has improved.

Heat is energy. The turbo is driven by high pressure exhaust. Cold gasses take less space than not gasses.

The placement of these turbos means a lot of energy is lost due to cooling ( contraction of the exhaust gas). The "turbo lag" by the longer intake is an issue but the same is true for trying to pressurize these extra long "headers"

These systems might feel good once they are spooled and give good numbers on the dyno but linear throttle response is important and many aspects of this system would make throttle response difficult to predict. If you tracked a car with this system (not drag racing) you'd probably get significantly faster times by riding the brakes at all times (to keep the system pressurized)

Thank you

This was my point exactly,yes they make a difference but the idea seems like a band aid.For the cost,complexity,weight,and absence of putting turbo theory to work it seems that supercharging would be without question a far better option on this type of vehicle if hood space just cant be worked around,which is obviously why its way more common.

I do respect it from the point that they did take advantage of making something different that does in fact work.However, as much as you may want to defend the technology - there is a reason you wont find this system on any production car,or track car that is noteworthy.I have seen a really sweet rear turbo system one time i must admit,however the engine was also in the rear

That said i will give it one thing....must sound sweet .

Superchargers eat hp to run. Turbos don't. I would think the guys running these aren't lowering compression to work with them and these only provide small amounts of boost, or at least that's what I would do, so the lag shouldn't be very noticeable. Part of the appeal of this system is that it's simple to instal, so changing out pistons would go against the point. I would guess the power increase would be more linear than a hot cam coming into its rpm range and throttle response no different than stock depending on how they do the fueling and tuning.

Think slow spool from low revs but the stacks of power once you get that v8 humming with a few pounds of boost.
IMHO this would be awesome on a race track or a drag, with the huge resovar of pressure for the compressor it might actually work against lag once you are moving? I guess you would have to try one to know...