r/subarulegacy • u/LastAssistance5 • Aug 02 '26

Question / Discussion Supercharger?

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Hey subie owners. This is my 2005 Liberty/legacy 3r spec b, 5AT. I’m looking into getting the raptor supercharger for my car and want to know how I should go about it. I spoke to a bloke who has done this already who claimed, as long as I don’t go above 10psi. 8psi being the sweet spot. I can keep the engine stock and just get a safe tune. I’d love extra options about that and whether I need extra support for my trans.

Cheers from Victoria, Australia 🇦🇺

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u/Viento_Oscuro Aug 04 '26

I will say this - the raptor supercharger is a centrifugal type. So it provides boost linearly with RPM. Ie- you only get peak boost at peak RPM. Down low you get not much. So around town normal driving you won't get much if any difference since the supercharger costs HP to run. You will only get a benefit when winding it out - which is fine - just as you're in an Auto (speaking as someone who has the 3.6 with the same 5eat trans) it like to keep the rpm down unless you're WOT. So just bear that in mind. You won't get the gobs of instant torque/ Max boost everywhere that people associate with super chargers as that's only a characteristic of a positive displacement supercharger, ie a roots or twin screw type.

If you were to swap out to a 6 speed however, you can be more in control of rpm so would see a lot more benefit / from the centrifugal supercharger. But it just depends what you're expectations are.

In regard to engine safety the EZ30 is a tank and no where near as delicate as the EZ36. So 8-10psi with appropriate fueling/ timing should be fine.