Just a quickie..

Just a quick update to let you avid readers.. (waits for applause.. hears nothing but tumbleweeds) know where we are at. In the last post we mentioned we were searching for a replacement crank pulley. The crank pulley from the 1MZ is what we decided to go with, and it should do the job quite nicely (see pic below). Originally i thought we might need to take a small skim out of the center hole so it would slot onto our timing belt pulley, however turns out its just about a perfect fit. The diameter is correct, the only problem is that there is a small notch in the pulley which slots over a ridge on the timing pulley. There is a notch on the 1MZ pulley already, except its just a bit small, so we just need to open that notch up a little and it should fit like a glove. We will then need to drill holes for the 4 bolts which attach it to the timing pulley.

We have also made up a bracket for the intercooler so we can mount it to the chassis. (See pic below). The intercooler is secured to the underside of the L bracket by two bolts, and also at the top via the extension arm. The beauty of the extension arm, is that we can attach a mount (to support the intercooler pipping) to the top quite easily.

Speaking of piping, progress has also been made in that department. We made a rough piping layout using 1 inch PVC with 45 and 90 degree connectors. We then took this to one of Adams mates (who has a business building aluminium boats) to make us some 50mm piping. (see pic below). We got him to make us the piping in sections so we can position them properly for final joining. We also got him to modify the existing SC outlet pipes we had so they would fit our situation. He cut the flange from the original outlet pipe, and welded the piping from the original inlet pipe at a 90 degree angle so our outlet pipe came up over the SC (see pic below). Due to a lack of space, there was no other direction we could go.

So much for a quickie.. turned out to be quite a long post.

   

Crankin’

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.