About the SC14 Unit in general:
The SC14 is a Toyota built supercharger - but they will fit most any car. Why? Because they have the wonderful ability to spin either way and still make boost - Which is VITAL in this project, because the CA18 spins the opposite way to the 1G-GZE engines that the SC14 comes from. It is a roots-type positive displacement supercharger, meaning They were found on Toyota Supra’s from 85-89, a factory option on the 1G-GZE engines. See the black wires with a grey plug on the end in the picture above? That’s the wires for the magnetic clutch - That is, when wired to a switch in the cabin, you can turn the supercharger on and off at will - Nifty huh? Some people wire it to the throttle position sensor, only having it on at full throttle, and some people have it wired to both. Me? Haven’t decided yet, maybe to two switches, one to turn it on or off in the moment, and one to have it come on at full throttle or not to… Anyhow.
Will it fit in your engine bay? Dimensions and Details:
It is a roots type positive displacement supercharger.
On the Supra’s they run 0.7bar boost stock.
By changing pulley size more boost can be created, and the desired amount of boost selected with a boost controller or external wastegate.
The stock pulley on the crank of the supra is 145mm
They 1GGZE redlines to 7500 RPM
The SC14 is normally set up to rotate at 1.25 times the crank speed.
Oil lubricated using a specially formulated supercharger oil available from Toyota - 90 grade synthetic oil is almost identical, or normal oils can be used (the SC14 is quite robust) but don't blame me for damage, I did say they use a specific one.
Lets start with the pro’s and con’s stolen from here with lots of other good information on superchargers
The pros of using the roots type compressor include…
-positive displacement design makes matching engine airflow demands easy
-positive displacement design makes boost production possible at very low engine RPM
-simple operation provides nearly unmatched long term reliability
-simple integration of a bypass valve prevents most parasitic drag on motor when not boosting
-easy installation of an aftermarket design to most engines
The cons are few, but notable…
-thermal efficiency of this design is inherently lower than others
-large compressor design makes placement and/or drive assembly hard to fit in cramped engine bays
-heavy internal parts mean high parasitic losses when boosting
-large size and difficulty of placement can make it hard to add an intercooler
My translation of that stuff:
You can make lots of boost, very easily, at any RPM (no turbo lag, YAY!)
Its easy to fit, reliable and good potential for mods.
Downside is that it creates more heat, so an intercooler is required when running over 0.5bar boost. Its pretty big, so they wont fit all engine bays easily, and that its belt driven with heavy inside bits, so some of the power you gain from it is used to turn the blades inside it to create more boost and more power…. Fair enough say!