I’ve hinted about this in my previous two posts. Andy Hollis has raved about the results of installing one of these. Things like lightweight pulleys may give you back a horsepower or two. But when you only have 110 or so to the ground an extra one or two must make a big difference. Unlike the Prelude where the norm is to replace the P/S pump and alternator pulleys with lightweight aluminum versions that also spin the components slower the norm for the early Miatas is to replace the crank pulley with a lightened one. Unorthodox Racing is a leader in this area and is the brand that Andy used. Unfortunately right after he wrote his blog post Unorthodox decided to cancel production of this unit for 1.6L Miatas due to (presumably) slow sales. Doh!
After Unorthodox canceled the item I attempted to track one down via their distributors but no one had any in stock and most had taken the item out of there online catalogs a while ago. It was time to turn to eBay and the OBX brand. Several people had used the OBX and it worked fine but there were reports of having to alter the bolt hole pattern. Apparently some of them were drilled incorrectly. Oddly a few weeks after Unorthodox pulled the 1.6L pulley OBX pulleys for the 1.6L disappeared from eBay. OBX doesn’t sell direct, only through eBay so I couldn’t find a contact for them. I gave up on the idea except for keeping my eye out for a used one to pop up for sale.
Eric Simmons, a local competitor picked up a Miata to race in STS2 (he quickly changed his mind and is now in CSP 😆 ). He managed to find an outfit called ISC Racing which had a 1.6L Miata crank pulley on their website. A few posts on rr-ax.com and I found out ISC Racing was a reputable place and it was actually the OBX one that was modified to remove the P/S & A/C belt portion of the pulley for lower weight. Good and bad. Andy Hollis had done this to his. But I was planning on keeping my P/S. See my previous post on that. This issue weighed in on my decision to ditch the P/S. After that it was a no brainer to pick one of these up. I am excited to see how much it “wakes up the engine” after ll I’ve hard about it. Best of all since Eric is converting his car to CSP and will be installing a more powerful motor from a 99+ he offered to sell me his. Now all I have to do is find a manual rack.