Zippers Performance

Welcome to Zippers

About ThunderMax

Take It to the Max! The History of ThunderMax 

Take It to the Max! The History of ThunderMax® 

#309-362 ThunderMax with AutoTuneToday, electronic fuel injection is considered to be the industry standard. Many companies have been advertising different types of post fuel controllers as performance solutions. However, one solution that has outpaced all others in true performance since the early days of factory fit EFI is the ThunderMax® EFI System. Engineered by Thunder Heart Performance (TN, USA) and developed by Zipper’s Performance Products (MD, USA), the ThunderMax® EFI system has changed the way consumers ride fuel injected Harleys.

Talking about Thunder Heart Performance and Zipper’s Performance Products working together on the ThunderMax®, Dan Fitzmaurice says: “Our alliance with Thunder Heart has allowed us to combine our aftermarket engine experience and performance tuning expertise with Thunder Heart’s engineering and manufacturing capability. Zipper’s decades of brand equity, revolving around our reputation for high quality, proven results, has helped us successfully market the ThunderMax® brand and turn it into a household name.”

Zipper’s Performance Products has been offering performance upgrades for Harley-Davidson® engines since 1978, when Dan Fitzmaurice first established the business in racing over 3 decades ago. The company specialized in strip-to-street performance, providing top-of-the-line machine shop services, eventually manufacturing many well-known brands such as Red Shift® Cams, Big Bore Kits, Muscle Engine Kits, ThunderJets® and other products.

Zipper’s Performance was the first aftermarket manufacturer to develop complete engine kits for the Twin Cam engine in 1999.  Each Zipper’s engine kit was sold with a carburetor and ignition, developed specifically for the engine package. These pre-engineered kits dramatically reduced the time and effort required for a dealer to install and achieve the same outstanding performance results for their customers.

The Zipper’s engine kit strategy was highly successful during that time. Pre-engineered kits were the secret to providing reliable performance.  Using many of the performance parts Zipper’s Performance made in-house, the company became the go-to source for quick repeatable results. However, Dan Fitzmaurice knew this would be short lived. The industry’s move to fuel injection signaled a significant new challenge. He knew in order to prosper Zipper’s Performance Products must rise to meet the new challenge.  

Zipper’s Performance Products has been known to partner with other industry leaders to gain perspective on new challenges. Thunder Heart Performance, Zipper’s future partner in fuel injection development, had previously developed the Comp Cams injection overdrive system in the mid-late 90’s. and were successfully supplying OEM electronics for the industry. When Zipper’s Performance Products and Thunder Heart Performance combined their expertise, they formed the perfect partnership for developing an advanced EFI performance module.

The official collaboration between Zipper’s Performance Products and Thunder Heart Performance was in full swing by 2003. The two companies began to work together on a prototype controller for the Delphi® based electronicA Trio of Happy ThunderMax Customers fuel injection systems found on Harley-Davidsons®. Testing began initially with the OE replacement module for the Delphi® based cycles. As the team developed initial beta modules, these were tested both in the lab and in the field. Many loyal Zippers’ Performance customers participated in the testing; conducting real-world evaluations with test motorcycles. The results were exciting.

By 2004, the product brand “ThunderMax®” was adopted.  Zipper’s Performance and Thunder Heart began marketing their EFI controller to the Harley-Davidson® aftermarket. For the next 3 years, the Zipper’s team canvassed rallies, trade shows, and special events while visiting dealers around the world to demonstrate this ground breaking technology.  For many service providers, the ThunderMax® seemed too good to be true, and, fearful of new technology, some dealers were slow to accept it. Naysayers were soon overrun by customers hungry for a product that outperformed all other options. In the end, it was the dedication of the ThunderMax® customers who turned many dealers into die-hard ThunderMax® ambassadors.

Zipper’s Performance and Thunder Heart Performance have created a truly premium performance solution for the EFI aftermarket, and are dedicated to its growth. The progress of ThunderMax® is carefully measured, while its functionality is expanded to exceed the customer’s highest expectations. ThunderMax® represents the finest in aftermarket EFI technology, offering dealers and their customers top of the line technology produced entirely in the U.S.A.

The product in question - the ThunderMax® EFI controller –is a true replacement EFI system that delivers outstanding results. Available for popular applications, and flexible enough for variable parts combinations, the ThunderMax® EFI system produces immediate results. ThunderMax® cures many of the persistent performance problems associated with the other aftermarket solutions. ThunderMax® users experience a dramatic increase in throttle response, improved drivability, stabilized engine temperatures, and eliminated exhaust popping on deceleration.

Perhaps the most widely discussed feature of the ThunderMax® system is the adjustable idle speed. ThunderMax® allows the idle to be adjusted low, while still providing a stable idle and helping to keep the engine cool in high-traffic areas. This feature has created a lot of buzz, even prompting many users to post and share videos on-line of their new motorcycle idling with the sought-after “potato-potato” sound.

The ThunderMax® should never be confused with less-advanced, low cost, and ineffective in-line signal modifiers, which many only richen the factory ECM injector pulse, or flash systems which attempt to integrate wide band tuning in the OEM circuit board that was never intended for this use. ThunderMax® with AutoTune is a complete and fully integrated replacement system for the OEM EFI module. ThunderMax® is built to perform with high speed data processors specifically designed for the unique wide band AutoTune feature. ThunderMax® AutoTune automatically tunes the engine at every combustion cycle, regardless of changes in ambient conditions, tuning for the engine actual operation of the motorcycle’s engine.  

Today’s riders want the flexibility to make performance changes on a whim – like adding air cleaner kits, aftermarket pipes or performance engine kits. From stock displacement to 131 CI engines, ThunderMax® high resolution base maps are dyno developed to provide immediate results for popular factory and aftermarket parts combinations. Custom map calibrations can be easily built and tailored through ThunderMax® software. ThunderMax® maps are so advanced that they work on multiple parts combinations, so the system can grow with the changes customers make to their bikes.

Zipper's Performance Products is proud of the daily testimonials received from ThunderMax® customers, which many boast about the outstanding results they experience which is a testament to all of the hard work put into this product.