It’s called belt wrap — ever heard of it? OK, it’s not really a secret. Chances are you might have heard of it if you’re a fan of high-horsepower supercharged builds. Better yet, maybe you’re all too familiar with it on your current project. If that’s the case, then you’re in the right place. Whipple Superchargers has been manufacturing twin-screw blowers for the better half of nearly thirty years, so they know a thing or two when it comes to optimizing belt wrap.
That’s why Whipple designed a new drive system aimed at maximum belt wrap on Coyote-powered Mustangs like our Boosted Coyote project. Of course, belt wrap is only one element of keeping your serpentine belt in place. If you like making big horsepower, eliminating belt slip while keeping modern amenities like factory air conditioning, you’d be hard pressed not to read on.
Whipple’s third-gen 2.9-liter twin-screw supercharger produces boost numbers well into the 30 psi range. Making this much boost, though, on a serpentine system requires a stout belt system.
Certainly it’s no secret that Coyotes love boost, a well-documented topic on our magazine. When north of four-digit horsepower figures, belt slip can become a concern.
“When a vehicle is making higher power numbers at increased blower speeds during high RPM, the longer the belt is, the more stretch occurs,” said Dustin Whipple, president of Whipple Superchargers. “This means you have a higher chance of belt slip.” He says the issue, at least on Whipple kits, is the tensioner. “During quick deceleration, the tensioner can begin to have trouble keeping up with ‘belt whip.’ With a heavy belt tension, the alternator bracket can fail, allowing it to bend inward and inevitably sending a serpentine belt packing,” Dustin shared.
Benefits of Whipple's Alternator Relocation Bracket Kit
Utilizes the factory alternator pulley for proper RPM range
Utilizes a shorter belt for less stretch and better grip
Retains factory air conditioning
Eliminates the need for grinding or cutting
Increases belt lifespan
Decreases belt-related issues
Increases alternator lifespan
Eliminate Belt Slip, The Right Way
To remedy this situation, for 2011-2019 Coyote-powered Mustangs running a Gen 2 to Gen 5 Whipple supercharger, Dustin recommends Whipple’s new Alternator Relocation Kit. It’s worth noting that Dustin says modern supercharger kits have come a long way. Previously, enthusiasts would consider deleting the factory A/C system in the vehicle to shorten the length of the belt to eliminate belt slip. Nowadays, Dustin tells us Mustang enthusiasts have modern options.
“In racing applications, some have removed the factory air conditioning,” he explained.
“This would allow someone to run the alternator behind the balancer and the supercharger pulley, which in turn would significantly shorten the belt length. A great example of this would be in a Mustang Cobra Jet application.
“The issue is, many of us don’t want to delete the factory air conditioning. In response to that, we developed a lightweight kit for our Whipple Gen 2 to Gen 5 kits that shifts the alternator forward, allowing it to use the factory spring-loaded tensioner and a small, 6-rib belt system in front of the blower pulley. This allows the air conditioning to stay on the back loop,” Dustin concluded.
For more information on how this kit can help your Whipple Coyote-powered Mustang, visit Whipple’s website here.