Pepmeier Engine Development

I have been a Corvette enthusiast since 1993, and a ZR-1 owner since 1999.  Recently, I have turned my hobby of more than 20 years into a business venture to offer unique engine solutions to the unique ZR-1 owner.

 

Modifying the LT5 has always been my passion.  As the second owner of 1991 #1145, I began modifying the car and took it to the chassis dyno within the first three months!  Custom EPROM "chip calibrations" were the first product to be developed.  There are approximately two-dozen LT5's running on these custom chips today.  That particular car later received a Haibeck 510 package and 4.10 gears.

 

In 2011, I designed and built the first and only 700 hp, 427 cubic inch naturally aspirated LT5.  The power was confirmed on both a Superflow engine dynamometer and multiple chassis dynos. That engine featured several custom-made parts, including the complete valvetrain (using .500" lift intake cams).

We have designed and sourced many custom LT5 components from all over the world, using top tier suppliers.  These niche companies from England, Germany, and the United States supply to the highest level of motorsports.

 

Our approach to engine design is highly analytical.  We have access to very high-end, OEM level 1-d engine simulation software.  Models have been developed which predict the LT5 power curve to within +/-1% on a 700 bhp engine.  We have also applied many parametric tools and formulas to inform certain aspects of the LT5 induction system.  Our design philosohy starts with the induction system, which dictates optimal tuning speeds.  From there, we specify the basic engine geometry to stay within accepted component stress levels.  Ultimately we optimize the gas exchange areas by selecting the right valve size, port velocity and camshaft profiles to maximize engine breathing.  Our first LT5 set a benchmark for specific output, at more than 13.0 bar Brake Mean Effective Pressure (BMEP).  We have development plans to take this to 15 bar or more.