Beyond the Supernatural

Mark Delashmit’s ’94 Callaway makes a half a ton of fun

Andy Bolig - June 30, 2014 09:48 AM


Finding room for all the necessary piping and turbos wasn’t easy. As you can see, everything does fit under the hood, but just barely.


The quality of NRE’s work stands out with all the shiny lines and strategic placement of parts.


The interior still features all the creature comforts. Bill Boudreau at ZF Doc in Cave Creek, Arizona, did the ZF transmission and shifter upgrades and the leather-wrapped steering wheel is signed by Reeves Callaway himself.


Mark and his wife Erin at their wedding.


The three Delashmit Callaways.


Ed Wright, Tom Nelson and Scott Carpenter combined forces to make Mark’s car beyond super. Mark appreciates all the hard work that went into this creation.


The Blowerworks alcohol injection system keeps detonation at bay and this custom cover from Blowerworks makes the install look factory.


Reeves Callaway and former Corvette Chief Engineer Dave McLellan give their approval of Mark’s car in front of the National Corvette Museum in Bowling Green, Kentucky. They further sealed their approval with signatures under the hood.

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Corvettes have been assembled by mere mortals in Bowling Green, Kentucky, since 1981. To make this super-streetable ’94 churn out over 1,000hp, its builders needed to go even further than the Supernatural.


Mark’s C4 began its ascension to a higher power in much the same way as many other performance-minded C4s. It first worked its way up to the hallowed grounds of Callaway Cars in Old Lyme, Connecticut, for one of their Supernatural packages. Callaway began their relationship with Corvettes during the earlier B2K package, boosting the L98 engine’s performance through a pair of turbochargers. When the LT1 engine found its way under the hood of Corvettes in ’92, Callaway decided to rely on natural aspiration to get the job done and termed their newer performance package as Supernatural.

Available between 1992 and 1996, the Supernatural series output constantly evolved. Introduced as a Supernatural 400, designating 400 horsepower, it grew to become the 425, 435, 440, and finally the 450 models for LT1-based cars and the 475 or 490 being offered for the LT5 models.

Mark’s ’94 had the LT1 and as such, was treated to the common core of components contained within the Supernatural engine package. During the conversion, Mark’s Corvette was treated to Callaway’s Aerobody modification, which necessitated a complete re-paint of the entire car. Likewise, the interior was craftily treated to leather accents like the leather-wrapped steering wheel, hand signed by Reeves Callaway himself. To keep the additional power at bay, Callaway also installed their upgraded Brembo brake package and wheels, as well as a coilover suspension and Speedster center exhaust.

For most enthusiasts, the additional performance would be more than enough to satisfy, but Mark knew there was more to be had in the performance universe and shunned the flat-earth mentality to plunge over the horsepower event horizon. He soon found out why many were content within the confines of an assembled package.

One of the reasons that most folks don’t attempt to cram more performance under the hood of a Corvette is because there isn’t much more room to do so! When looking for a place to position power-adders, it seems that every square inch of room is already full of sensors, hoses, lines or wires to either keep the engine running or the riders safe. There just isn’t much more room to make them happier.

That’s where the higher learning of those in the know can cross the chasm between mere mortals and monumental performance. Mark and his Corvette made the journey from his home near Dallas, Texas, to Nelson Supercars in Chatsworth, California, for a transformation of epic proportions, yet compact enough to fit under the C4’s hood.

Tom Nelson of Nelson Racing Engines is well known for his works of art that not only look great, but also perform exceedingly well. That’s the reason that Mark entrusted his Corvette to the craftsmen at Nelson’s shop. Even with all of their knowledge and technology, they’ll be the first to tell you that squeezing in copious amounts of power under that low-slung hood is NOT an easy task. Finding a place to put items like turbos is easy. The hard part is when you try and figure out how to run all the necessary hoses and ductwork to actually be able to USE them.

The team at Nelson persevered and found the necessary space to install a set of 67mm, ball-bearing Turbonetics turbochargers and all the necessary plumbing. Of course, the factory LT engine wouldn’t hold up for very long trying to keep up with those turbos, so NRE assembled an LT4 with turbo-happy parts such as a Callies forged 3.75-inch crank, six-inch Oliver rods and JE forged pistons. Steel main caps were installed to keep the rotating assembly from rolling out from under the car and the entire bottom end was sealed up with a Canton seven-quart oil pan.

By the time NRE had finished the installation, they had successfully found room for not only the turbos, but also a set of wastegates, Tial blow-off valves, an air-to-air intercooler and a Blowerworks alcohol injection system to help keep detonation at bay. Custom stainless hard lines were bent up for all vacuum, oil and fuel delivery chores, and to keep the spark appropriately timed, an MSD 6BTM was implemented.

When it came time to prove the potential of this new creature, none other than Ed Wright of Fastchip in Tulsa, Oklahoma, flew out to Los Angeles for tuning. He was commissioned with the task of keeping the air and fuel in proper ratio all through the engine’s range and when the rollers were done, had successfully coaxed 1,000 horsepower out of this relatively stock looking C4! Tom Nelson has seen these types of numbers before but what really impressed him was the drivability that the car still exhibited.

With horsepower reaching other worldly proportions, the fact that the car still has all of its real-world characteristics is simply divine. Nelson Racing Engines even highlights the car on their website and has a video of Mark’s first drive after the transformation. It’s safe to say that Nelson has made a believer out of him.

With all of the changes, one might ask what the future has in store for the little white Corvette. Mark is quick to point out that whatever it is, he’ll be right there to witness it. You see, while Mark and his wife Erin may enjoy the car now, the memories that the car contains are much more powerful than its engine. Being true enthusiasts, they were married in this car. It makes a nice addition to their other Corvettes, a 1991 B2K and a 1996 Aerobody Collector’s Edition. This gives the Delashmit family a refreshing choice. Sometimes it’s nice to get a little boost and sometimes, you look forward to something Supernatural. But then, there are those times, where you might just want to go further than that!