1984-1996 Corvette EGR Diagnosis


By Chris Petris

Exhaust Gas Recirculation (EGR) came about in 1975 when catalytic converters were introduced. The inert exhaust gas was used to quell the increased heat in the engine’s cylinders from the lean fuel mixtures required to keep the catalytic converters from melting down. EGR systems also helped eliminate spark knock from the increased combustion chamber temperatures. The feds were also pushing for a reduction of NOx nitrogen oxide emissions to reduce ground level ozone formation. The EGR system was an asset in many ways during the early years of emission control. As engine controls and development advanced, EGR has become obsolete for the majority of engine manufacturers. Unfortunately, there are many Corvettes on the road with EGR systems failing. (more…)

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Corvette Central C4 Cutaway Videos on YouTube

As we covered in an earlier post (“Why Cut Up a C4 Corvette?“), for the last few years, we had been discussing the possibilities of using a donor C4 for seminar and display purposes.

We knew that many owners had plenty of questions on how the C4′s were put together. Why not dissect one for science? Wrecked, salvaged and abandoned project C4s were for sale at almost every Corvette swap meet. Corvette Central’s 1988 Cutaway was found at Corvettes at Carlisle a few years ago. In cooperation with Chris Petris of Petris Enterprises in Scottsboro, AL, the C4 Cutaway Corvette became a reality, and has been making appearances at Corvette related events over the past two years.

We’ve assembled a collection of videos, hosted by Mr. Petris, covering a wide variety of common C4 ailments and remedies, troubleshooting, maintenance tips and more. Click here to access the YouTube directory page for the C4 Cutaway Corvette videos.


Enjoy and share with your fellow C4 Corvette owners.

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C5/C6 Corvette Suspension Tech: Coilovers vs. Leafs

What follows has been reprinted with permission from Corvette Online. Written by Clifton Klaverweiden.

Almost from the very start, the Corvette has been the performance flagship for Chevrolet, showcasing the best in power, handling, and overall performance General Motors has to offer. America’s Sports Car has evolved over the years to incorporate all sorts of new technologies – some, like the C4′s digital dash are best forgotten, while others, like the LS series of modern pushrod small block V8 engines, have shown that even ideas that have been around for a long time still have plenty to offer when given a high-tech makeover.

One piece of technology, the leaf spring, dates back to long before the first automobile, and yet the modern Corvette still makes use of this hardware, albeit in a very interesting and unique way. Is the transverse composite leaf spring suspension found in the C5 and C6 Corvette really holding these cars back, or can it get the job done on the street and at the track? Here, we’ll take a look at late model ‘Vette suspension upgrades from both sides – retaining the leaf springs, or switching to a coilover setup – to help you decide for yourself.

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C4-C6 Corvette Control Arm Urethane Bushing Installation Overview


Photos and article notes by Chris Petris


Over time, the original rubber control arm bushings on C4-C6 Corvettes will wear out and fail.  While some owners will want to stick with new rubber bushings as a replacement option, there is another option that has become almost second nature in recent years: urethane bushings.  These bushings offer two primary benefits: longer life and a firmer, more responsive feel behind the wheel.  While this is a task best suited for those with experience and access to a hydraulic press, it can be accomplished with a conventional vise.  Follow along as we remove the OEM bushings on a Corvette and replace them with urethane versions. (more…)

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C1 Corvette Battery Tray and Welding Risks on E-coated Parts

Pictured above on the right is Corvette Central’s Made in USA C1 battery tray (part #171301), along with a black coated tray that is a foreign made copy.  The black tray is a good reproduction, as well as an option if your top priority is saving $20.  However, readers should be aware that the black coating, known as “e-coating”, is not recommended by most professionals (including our own e-coater) as a “weld-through primer”.  In short, there are health risks associated with welding fumes.  To avoid this issue, it is recommended that the e-coating be blasted or ground back in the weld areas.  If your intention is to burn off the coating by welding, make sure the resulting fumes are directed away from you in a well-ventilated area. (more…)

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