Charles Quarton wrote:

The Powerdyne supercharger used on the E36 upgrades by both Dinan and ERT has suffered from occasional reliability problems. The internal belt that
drives the induction pulleys (and sometimes an internal bearing) has failed
in the E36 upgrades. The failure rate was aggravated by track use and particularly by high temperature days at the track. The same Powerdyne unit is used on Mustangs and has suffered track induced failures in that application too. Apparently, the failure rate of the internal belt or bearing is quite a bit lower for street use.

The Powerdyne unit as modified by Dinan, includes a cooling duct that supplies air to the formerly sealed chamber for the internal belt. I think
that there were also internal changes in the supercharger to improve the reliability.

(this is not a complete quote)

Acutally, I believe (correct me if I am wrong) that B&M, who makes superchargers under both the B&M name and the Powerdyne name, has redesigned their centrifugal Powerdyne unit under intense pressure from Dinan, ERT, and Turner to address the inertial belt failure problem. It seems that one side benefit to this design is that the supercharger is now much quieter. I have driven E36s with the old design, and I have have driven E36s with the new design (MINE! :) ) and the lack of supercharger whine in the new unit is phenomenal. In sum, I believe that the redesigned supercharger is not exclusive to Dinan, but in fact, is avaiable for all tuning companies to use.

Jason Leung 1992 325iK