For you guy that have the factory supercharger, or any for that matter. How many mpg does souping the car up, in this manner, shave shave of the stated 22/23 per city, 29 per highway etc. ?

 

The factory supercharger is not out yet... people have been waiting for it forever.. and it will most likely be fall or winter according to scion. Do a search on here and you will see what I mean.

As for the effects... it will degrade mileage, as any performance mod will. Scion is saying around 6 PSI or so... (still not written in stone, but 6 PSI and 60 bhp do match up calculation wise). So that is about 41% more air molecules... meaning 41% more fuel when in the highest boost range. These are just rough calculations... and the supercharger is not pushing max boost all the time. So I would say with normal driving, you are probably looking at losing around 5-6mpg... maybe more. But then again.. if you have a supercharger.. you arent going to be running it "normal" all the time

 

WOW, 5 to 6 miles.... That's crazy!

 

Like I said, it all depends on how much you push the car. At lower RPMs, you are producing less boost (and SC are more linear than turbos). So under normal, .ow rpm driving you will use less, but as RPM increases, so does usage. But a person wanting performance is not going to be too bothered by mileage. You have to pay for horsepower.

 

60 more hp, so i wonder if spending close to 4,000 on the supercharge when and if it comes out is worth taking ur car from 160hp to 220 hp??????

 

Well.... I have been told by numerous scion people (which seem to concur with most of the data people on here have heard) that it will be $2700 un-installed and around $3300 installed. Plus, it carries factory warranty, and if something breaks because of it, they are pretty much stuck warrantying whatever it is. If you buy a turbo kit with the same output, you are looking at pretty close to the same price (for a quality one) UNINSTALLED, and the kit probably carries no warranty after it is installed. Then, if your car is running badly due to the design of the turbo, scion will tell you tough!

Down the road, when I am looking at making it a more serious toy (when it is paid for and I have another daily driver to make a mid-range performance car out of) I will be putting it in the garage, tearing it down, then rebuild, forged internals, head and big ___ turbo.... but if they get the SC out any time soon... I think it is worth what you get for it. But we are all still guessing on the price and output... so it doesnt really matter.

 

Generally Supercharges can be turned on and off like an AC compressor.

 

i didn't know that... can u explain?

 

Superchargers work exactly like a turbo on the output side... the only difference is that they are belt driven as opposed to exhaust driven. They cannot be turned on and off like a compressor. A compressor is turned on and off via a clutch on the drive pulley. A supercharger does not have this option. If you turned it off, you would have a restriction on the intake side of the engine.

 

In addition, since there seems to be some confusion, I will add a few details.

A turbo is, as mentioned above, driven by exhaust gasses. This is more efficient than a supercharger in that it is using some of the "wasted" energy. However, it does create more backpressure, keeping it from being 100% efficient (which nothing is). A supercharger creates a parasitic drag by being turned off of the crankshaft. So, a turbo is more efficient.

Turbos experience what is called "lag". This is due to the time taken to spool up the turbo, meaning that it feels as if it "kicks in". This lag can be minimized with the proper size turbo (usually a smaller one) that spools up faster... but also reduces boost overall. So a proper balance is needed.

A supercharger is more linear... meaning it begins producing boost quickly, producing more with more rpm. Because of this, a car with supercharger will usually have better all around acceleration than a car with a turbo that produces the same boost (efficiency has to be taken into account too, so for matching overall systems, the supercharger will accelerate faster overall). However, the turbos produced today usually produce more boost per dollar than the supercharger.. so the turbo is usually a better idea.

The application has to be taken into account when choosing between the two.

So... there is a little more info on both

 

would there be a module you could get to control boost on a supercharger? I know you can on turbos and change the stages...Be cool if you could have a setup to run it nearly w/ no power then could adjust it to full power for when u want it....

 

no you can't the s/c is powered by the pulleys, You would have to literally get out of your car and change the pulleys/belts then you can run at a different PSI. Only turbo would allow you to raise and lower boost through an apexi avc-r or boost controller module.

 

I'm not familiar much with superchargers (or FI in general) in real life, only in theory. Theoretically, how would one increase the boost in a SC? By making the diameter of the pulley smaller at the supercharger, to increase the speed?

 

^^ that is exactly right

but after adding boost i would assume that you would reconfigure the ecu somehow

 

Of course it can be turned off with a clutch. Toyota did it on the 4AGZE. They used a bypass valve to allow air in when the compressor was shut off.

Here's some info on the system:

http://shell.deru.com/~sgn1/AW11/Scnotes.htm

 

I am more than willing to shell out $3300 for a reliable SC, installed.

 

a blower will aways be spinning and creating boost because it is physically connected via a belt. The bypass valve reverts air when you dont need the boost ie: idling. Eventhough no boost is reaching the engine there will always be parasidic lost in a supercharger system

 

Did you read a single damn word I said? It has a clutch so it can shut off the supercharger when its not needed. The bypass valve allows air to bypass the supercharger while its not spinning, and it also doubles as a boost control device, opening at 8psi to prevent boost spikes. It explains it all in detail on the website.

 

My TRD supercharger increases my mpg to 35mpg. It's pretty cool.

 

I thought the roots type such as the Eaton M45 used in the Mercedes C230 Kompressor was able to be turned off via a clutch. I didn't think Centrifugual type could use the same way