In 2005 I formed Specialized Racing Products, LLC (SRP). Beginning the business with a simple offering-custom-fabricated low-temperature thermostats. I then broadened the product line to include underdrive pulleys, insulator plates, installation kits, chassis products, and more.
But the real challenge lay ahead. If I wanted to achieve substantial bolt-on horsepower, a supercharger seemed to be the logical answer. But how to design a supercharger system that would fit within the confines of the tight LT5 engine bay? I had entertained this idea since the day I purchased the car, but while blower installations had long been discussed on the various Corvette Web forums, my own conversations with knowledgeable ZR-1 enthusiasts confirmed that none had never been performed. The fact that no one had overcome this challenge was a big motivating factor for me.
After extensively researching various supercharger brands and models, I chose a Rotrex unit based on the following criteria: physical size, output (flow), step-up ratio, and oiling-system design (having a self-contained oil system was essential, as I didn't want to tap into the LT5's existing oil supply).
Thanks to a conservative 4...
Thanks to a conservative 4 psi of supercharged boost, the original "King of the Hill" can now perform on par with its C6 successor.
In January 2008, with a Rotrex supercharger head unit in hand, I set out to make my vision a reality. It quickly became evident, however, that many hurdles existed. First was the difficulty I'd face in establishing a drive pulley for the supercharger. Supercharger-drive pulleys are normally installed on the harmonic balancer and are an extension of the engine accessories' drive pulley. However, on the LT5, the rack-and-pinion unit resides directly in front of the balancer, and no room exists for an add-on pulley. Therefore, the supercharger needed to be driven inline with the engine accessories.
Second, the location most suitable for installing the head unit (the driver side) was where the power-steering pump's fluid reservoir and the traction-control adjuster assembly resided. As a result, we'd need to figure out a way to relocate these items. Third was the issue of interference caused by the AC lines and the left-side engine-coolant outlet tube. Overcoming this hurdle required the development of adapters, the fabrication of new lines, and the re-routing of the associated hoses.
Once the supercharger head unit was in place, we needed to figure out how to route and install the air filter and discharge hoses. Initially, we simply attached the filter directly to the supercharger head unit, but that positioned it directly above the driver-side exhaust manifold-not the best location for picking up cool, dense air. As for the discharge side, a collection of 90-degree aluminum pipes and silicone hoses was assembled as a temporary solution.
If the telltale whine of the...
If the telltale whine of the supercharger doesn't give the car away, a pair of personalized fender badges surely will.
The car was fired up for the first time in May 2008, albeit minus the remote intake system, the intercooler, and any fuel-management unit or ECU manipulation for fuel enrichment. We literally got the car running the night before leaving for Bowling Green to attend the annual C4/ZR-1 event. The idea was to show the ZR-1 community our work-in-progress prototype.
Once back from this trip, the next phase of the development got underway. It took an additional 12 months to work through what seemed to be the more complex elements of the build. These included the following:
* Designing and fabricating an intercooler
* Routing the discharge hoses
* Selecting the correct blow-off valve (based on the intercooler's output volume and displacement of air)
* Determining a remote location for the air-intake system
* Fabricating the air-intake system
* Relocating the battery to accommodate the new air-filter placement
* Selecting and installing a mechanical fuel-management unit
* Installing and calibrating a data-logging system to obtain real-time information on fuel enrichment, boost, inlet temperature, impeller rpm, engine rpm, fuel pressure, and so on