Supercharged Camira..

Craig and Adam\’s attempt at adding an SC12 to a JE Camira wagon


Posted by superchargedcamira on April 5, 2007

Its been a while since we’ve last updated but rest assured we are working hard to soldier on! We are trying to tackle a crank pulley issue. Our current crank pulley has a triple V belt configuration but the supercharger has a 4pk rib type pulley. Our challenge is to either make a “franken-pulley” with a rib pulley (from some other car) connected to our existing crank pulley or get a custom aluminum one made (and do away with a harmonic balancer). Note: we also still need to run the alternator with a V belt.

Our trip to a few local wreckers searching for an existing crank pulley came up with mixed results. We found a crank pulley from a H22A engine (Honda) that had the right sized 4pk rib pulley for us to dissect but it wasnt for sale by itself (hmm a H22A into a Camira?! haha). We also found one that is almost 6 inches – shown below from a 1MZ engine (Toyota).

According to the calculations below, the size we are looking for is just over 6 inches (as opposed to our stock 5.7 inch pulley) to enable us to run a solid 7psi.

Here is the calculation we are using to determine our crank pulley size:

((((((engine capacity (in litres) * Max engine RPM) / 2) * ((Desired Boost level + 14.7) / 14.7)) / supercharger output (in litres)) / MAX engine RPM) * shaft pulley size (inches))

If we were to substitute our measurements into this equation we get this:

6.03 inches = ((((((2.0 * 6000) / 2) * ((7 + 14.7) / 14.7)) / 1.2) / 6000) * 4.9)

And here is the calculation for how fast the SC will spin:

(((((engine capacity (in litres) * MAX engine RPM) / 2) * ((Desired Boost level + 14.7) / 14.7))) / supercharger output (in litres))

If we were to substitute our measurements into this equation we get this:

7380 RPM = (((((2.0 * 6000) / 2) * ((7 + 14.7) / 14.7))) / 1.2)

According to internet literature it is commonly thought that as the SC12 supercharger RPMs approach 10,000 – the telfon on the rotors begins to melt. If we do a bit of playing around here with the calculations above, we could technically run 14psi of boost with a rediculous crank pulley size of 7.97 before we started to edge the 10,000 supercharger RPM limit! We have no intention of doing this… yet.

1MZ 1 1MZ 2 1MZ 3


2 Responses to “Crankin’”

  1. mat said

    OHH!!! that piping is rediculous.. couldn’t you get any mandril bends?? or even press bends.. hell even some 90/45 deg silicon joiners would have worked 1000 times better than that..

    but, good work anyway, i’ve been using your formulae for some other projects 🙂

  2. haha mat, yeah the piping was a bit rediculous.. but it was free 🙂 and cheap as possible was what we were aiming for.

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