WARNING: This product can expose you to chemicals that are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information, visit www.P65warnings.ca.gov.WHAT IS IT?
The XLR8 lightweight crank pulley for the Audi 3.0T platform is an overdrive pulley designed to increase boost on the factory Eaton supercharger. The pulley is a modular setup which features a 316 stainless steel crank hub which bolts to an T6061 Aluminum CNC machined outer ring, sized either 179mm, 183mm, 187mm or 196.5mm outer diameter.
All parts are designed and manufactured in the U.S. using the latest 3D product development software. We use only the finest U.S. produced materials from sources like Alcoa. The manufacturing processes follow strict quality control measures ensuring superior products that are attractive, durable, and most of all reliable. The pulleys are held to .001” tolerances, usually reserved for aircraft, medical, military and space manufacturing programs. All pulleys are CNC machined and 0 gram balanced.
This crank pulley allows you to overdrive the Eaton TVS1320 even further than the smaller supercharger pulley by essentially making it a dual pulley setup. The overdrive crank pulley, in combination with the smaller supercharger pulley, can increase boost significantly, resulting in large power gains. We have decided to make two sizes: 179 and 196.5 mm. The 179 mm basically is the same as running a smaller supercharger pulley. The 179 mm overdrive crank pulley
combined with most aftermarket supercharger pulleys equals the 196.5 mm crank pulley. The 196.5 mm crank pulley equals a 179 mm crank pulley and combined with a ~57.5 mm supercharger pulley. So if you don’t want to install a supercharger pulley just purchase our 196.5mm setup and achieve the same boost increase. If you want more than a dual pulley setup with a ~57.5mm Supercharger Pulley and our 179mm crank pulley kit, you can go up to a 183mm or 187mm Crank pulley.
Stock pulley sizing/ratio:
Stock crank pulley is 162mm.
Stock supercharger pulley is 63mm.
That is a ratio of 2.57.
Pulley Weight
- 179mm OD = 1 lb 14 oz
- 183mm OD - TBD
- 196.5mm OD = 2 lbs 3 oz
- Hub = 1 lb 1 oz
- Stock Pulley = 8 lbs 10 oz
WHY DID WE MAKE IT?
We made it for two basic reasons: performance and improvement. As many in the forum community are aware, gains are significant when combined with software, “Dual Pulley Software”. The boost increase will be the bulk of the gains, roughly 80% of the total. The diameter of the pulley will determine the boost increase and the gain from this increase. However, there will also be gains for just weight reduction, which will be highest during boost ramp up and will extend across the entire band. The rough formula we use is 3 HP & 3.5-4 ft/lb increase per lb. of weight reduced versus the stock pulley. Of course, all cars are different, software is different, all dynos are different, and temperature, elevation, and density play a role here as well.
We have been working with a manufacturer of lightweight crank pulleys for over a decade and there are significant improvements to be had over the stock crank pulley. The factory 3.0T Crank Pulley is two piece construction that is bonded together by rubber acting as an isolator. Our design improves upon the OE design by eliminating the failure-prone rubber isolator and substituting it with bolts to mate the two pieces rather than the bonded rubber. The failures we have seen consisted of the rubber bond breaking apart and separating . This generally is a slow failure process but can cause major damage to surrounding components if the failure occurs. Our pulley eliminates that chance of failure. See images of the 3.0T factory crank pulley below:
BUT YOUR PULLEY ISN’T A DAMPER!
By the nature of the factory crank pulleys mounting type it cannot be a damper. A damper must be interference fit to the crankshaft in order to be a true damper. Interference fit means a really tight press fit that has the effect of making the two parts like one. None of the engines we make pulleys for currently have a crank pulley that is interference fit.
Another interesting fact that exposes the gimmick that a damper is needed are the recent developments that have many engine families that have different outputs yet they use the same crank pulley part#. The crank pulley with elastomer was designed to reduce audible NVH and not to protect the engine.
The Continental site clearly talks about 80 dBA as the maximum noise level from under the hood, this goes to what many have been saying all along that all the power train components, including the crank pulley are designed with quietness in mind, not damping. Additional examples of reducing NVH are baffles, honeycombs and flow directors in the intake with an enclosed airbox, resonators and mufflers with multiple steps and flow diverters in the exhaust. The factories even add little rubberized damper weights on the chassis to control chassis resonance. Yet, we remove all of these as people who love to modify our vehicles. So at a 1,000 RPMs it is 2,570 RPM on the blower. So 2.57 at 7,000 Engine RPM you're at 17,900 RPM on the blower.
INSTALLATION
- Make sure the stock pulley has the two alignment holes in the 12 o’clock position
- Remove the belts then unbolt the crank pulley and remove.
- Disassemble the new pulley and install the stainless hub with the two alignment holes in the 12 o’clock position.
- When installing the stock bolts use blue Loc-Tite on the threads then torque to factory specs.
- Mount the aluminum pulley section onto the stainless hub, make sure the finger of the pulley sections is aligned with the engraving on the hub.
- This alignment is mandatory in order for the timing mark to in the right place.
- When installing the hub to pulley bolts use blue Loc-Tite.
- The hub to pulley bolts must be torqued in two steps.
- First tighten 22 ft/lbs in a star pattern to preload the bolt
- Then tighten to 44 ft/lbs also in a star pattern and torque twice.
- Reinstall the new belts and start the engine to check everything is aligned properly.
- Take the vehicle for a test drive and if everything is ok recheck the torque specs of the bolts now that all materials have reached full operating temperature.
