So, I have a 318 magnum, and want to run low-boost on it, about 5psi or so, looking at a GT35 or a T3/T4 hybrid single turbo maybe, but then I started looking at centrifugal superchargers, and that led me on a rabbit hole of weird Ebay stuff. Lo and behold I find the AMR500, a $100 500cc-per-revolution supercharger for KEI cars.

Now obviously one of those on a 1:1 gear ratio would not make boost, but they are supposedly rated up to ~18,000 rpm

So doing a bit of quick math if I used two of them with a ratio of 3.5:1, meaning at the 5100 rpm my automatic slushmachine likes to top out at the supercharger would be spinning at ~17850 to 18200 so riiiight at the top of what the AMR500 is rated at.

At 3.5:1 two 500cc superchargers will displace 3.5L of air per revolution, well over the "50% displacement rule" for superchargers.

Not including losses or volumetric efficiency (which I thiiink I would actually gain boost from because the engine doesn't perfectly suck in 5.2L of air every two revolutions) I would be seeing a pressure ratio of 7/5.2 == 1.346 giving me a boost of (14.5*1.346)-14.5 == 5.07

Am I missing something or is this just about the simplest and cheapest way to make ~5psi of boost?

 

There's also sc12 and sc14 superchargers they made for toyotas that displace 1200cc and 1400cc respectively, they're more expensive, but they might be better/less change of outright failure from the supercharger

 

Where are you going to put both of them and figuring out the mounting and belt placement/piping? Plus twice the drag to run them. I'd opt for twin turbos, Can't beat to sound when the spool up!

 

I thought about doing that I bought the manifolds off eBay! I honestly believe that hardest part is figuring out the intake

 

No, just need a duel air hat.

 

Didn't even know they made them

 

Turbo(s) require headers, crossover, exhaust AND intake work, and for the small amount of boost I want to make I'm not sure it's cost-effective. I was just wondering if the dual AMR500's would have any obvious issues working in this context, or if I had messed up the math somewhere.