Eliminate Belt Slip NOW!!! | VMP Atlas and Claw Adjustable Idler Bracket Inspection
The performance of a supercharged car hinges on one simple aspect of the boost building mechanism, the ability to spin the blower. If you can’t turn the rotors (or impeller) at the desired RPM you’re leaving power on the table. Belt slip is the thief-in-the-night of that mechanical system. Everything else can be perfect, but if the belt is slipping on the pulleys you’re not going to see the horsepower you’d expect. With the goal of ensuring that pony makes it to the pavement, the crew at VMP Performance set out to develop a series of products designed for blower car owners to get the most out of their supercharger setups.
“With force induction, it’s easier on the entire system to extract all the performance possible with a given pulley setup than it is to just keep pulleying-down to chase more power.”, said Justin Starkey, owner of VMP Performance. This philosophy led VMP to produce several combinations of Coyote FEAD (Front Engine Accessory Drive) components, centered around their proprietary Atlas adjustable idler bracket. Check out this video detailing the installation and function of the kit:
The Atlas bracket is fully adjustable and increases belt wrap on supercharger pulley on Coyote engines. The adjustability allows it to work with basically every commonly available blower pulley size. Increasing belt wrap increases grip, which decreases the likelihood of belt slip. The unfortunate truth about belt slip is that once it occurs the first time, it will become easier for it to occur each subsequent time. This is because the rubber in the belt will begin to harden and “glaze” as it is essentially polished against the pulleys. This is why preventing belt slip before it starts is so important, and the VMP Atlas Bracket is one step towards ensuring your FEAD system is functioning optimally.
However, for some more aggressive setups (often with larger supercharger rotor packs and smaller blower pulleys) you may need to go a little farther. That’s when moving from a 6-Rib belt setup to an 8 or 10-Rib system may be appropriate. VMP has designed their Atlas Bracket to be modular and upgradeable, so you can run whichever rib count fits your goals. VMP sells every component you need to run the size belt you need, including upgraded tensioners and wider A/C clutch pulleys.
This gives you a good look at the billet Atlas Bracket, and the adjustment slot that allows you to customize the amount of wrap you get based on your supercharger pulley size.
All you have to do is loosen the pulley bolt and slide it up or down in the slot, then tighten down the bolt.
The VMP crew didn’t just stop with the Coyote V8, for Shelby GT500 owners they have created a bolt-on bracket they call The Predator Claw (also featured in the video above). The Claw bracket pulls double duty, because it increases belt wrap on both the crank and supercharger pulleys on 5.2L Predator engines. This bracket bolts entirely to the engine’s front structure, so it can be used with aftermarket superchargers.
(Sidebar :: It’s almost as if VMP designed the Predator Claw Bracket to work with an upcoming 3100 TVS Supercharger Upgrade…)
Again, VMP has also developed a host of FEAD upgrade options (including a 10-Rib setup centered around an ATI balancer) for the 5.2L Predator powered GT500 (and potentially the F-150 Raptor R in the future). When combined with VMP’s Griptec supercharger pulleys, this system virtually eliminates the possibility of belt slip. This is due in no small part to Griptec’s proprietary pulley rib surface which not only gives the belt more traction against the pulley, if also keeps the belt cooler. Given their effectiveness, I would definitely make sure I was running a Griptec pulley in conjunction with either the VMP Atlas or Predator Claw bracket.
The Predator Claw Bracket is a bit more complicated than the Atlas unit.
The Claw shares the same billet construction and bolt-on installation as the Atlas.
The Claw has an additional provision to increase belt wrap on the crank pulley.
Upgradeability is the name of the game here. The Claw system is ready for you to step up to a 10-Rib setup.
Increasing belt wrap and belt/pulley interface surface area are not new concepts. Many of us ran auxiliary idler brackets on SVT Lightnings and Terminators long before the Coyote V8 was even on the drawing board. However, VMP is one of the few companies that have taken the time to engineer and develop such complete solutions to the belt slip issue for the Ford Powered community. Modularity and upgradeability are the hallmarks of the Atlas and Claw based systems. VMP took great effort to make sure nearly every 5.0/5.2 PD blower owner has a FEAD solution to fit their supercharged needs and budget. Check out the full line of parts for yourself:
The construction and finish on all of VMP's FEAD components are top-notch.
This Coyote FEAD displays nearly all the good stuff, including an 8-Rib belt conversion.
This display has been to SEMA and PRI this year, and it may be coming to a race or show near you. It's a great way to show off some very nice performance products.