Erik, Fatty Fat Cat and I would like to offer some of our pseudoscience (UPGSS) in regard to our efforts to help eliminate alternator problems with the RB26 and similarly equipped engines.
The cars we build rarely have high output alternators but that is not the standard of the industry. Many shops install aftermarket alternators outputting anywhere from 135A to over 200A! This increase in shaft load is enough to push the alternator into a "stall" or "belt slip" condition where the system voltage becomes a violent graph similar to Richter Scale graphs in Los Angeles!
The OEM belt wrap is about 20±%. With our idler kit the belt wrap increases at least 15% (more with the LS alternator kits) This is NOT intended to be a "fix-all" for alternator belt slip issues across the board but it is definitely the solution for some who are experiencing belt slip/voltage falloff.
Higher current alternators, such as the LS based unit, on the market suffer from belt noise/squeal and inconsistent charging voltage due to belt slip. Our new idler kit aims to address part of the problem by giving the belt more wrap on the alternator.
*******Recommended belt size for the LS kit is a 4pk925, this is with a OEM RB26 water pump pulley. Your sizes may vary. *****
***With the OEM alternator the belt will NOT have to be changed. ****