Brian’s Mustang: Keep It in the Family

Brian Navarra comes from good stock. His dad is a vintage racer with a penchant for Mustangs and he’s also the kind, trusting type, which is why he handed Brian the keys to his 67’ GT350 race car one seminal afternoon at Sonoma Raceway many years ago — back when it was known as Infineon.

“I probably wouldn’t have let my kid drive that car,” Brian said, laughing.

Fast forward a few years, and Brian had built his own ’66 Coupe into a no-frills track car. He quickly learned that his single-purpose car was on par with a few nicely sorted modern machines — so why build something so uncompromising and harsh if there wasn’t any speed to be gained from it? That was the thinking then, anyways.

Rather than spend months undoing all the unpleasant track-oriented modifications that worsened it as a street car, he decided to buy another ’66 and build a dual-duty track toy. Again, that was the plan, but having made a few more friends in the business and eager to try some new ideas, he ended up building another single-purpose machine without air conditioning.

However, he took this one much further in several key areas.

“It’s just on from 4,500 to 8,500,” Brian exclaimed.

At first, he aimed to race the car in a wheel-to-wheel setting, probably NASA American Iron Extreme. But as that class has fizzled into nothing over the last ten years, time trials caught his attention as it would be the most accommodating for an all-out build of this nature.

Taking his cue from the old IMSA GT Mustangs from the 1980s, he tubed the front end and added about as much structural support he could manage. “The number and size of the subframe reinforcements make the whole thing a lot like a box frame.”

It wasn’t just the IMSA cars’ rigidity which he tried to copy, but the motor as well. Back further in the body than the factory motor ever sat, Brian stuck an ex-NASCAR motor. Pieced together a Yates 358 with 13:1 compression.

Although the bottom end is basic small block architecture, it has race heads, port injection, and an Emtron KV8 ECU tuned by Nick Pavloski of Cohesion Motorsport to make a tick under 600 horsepower over a broad powerband.

To keep the powerplant lubricated once the anticipated suspension and tire upgrades were in place, he installed a five-stage Raceline dry sump system with an enormous NASCAR-grade Peterson tank.

It puts that power to the pavement via an HGT six-speed sequential and 335-section Hoosier A7s. Power application is impressive — in no small part improved by the three-link rear end. The full floater Ford 9” housing and DPI Platinum Torsen with 4.22 gears aid in turning traction into propulsion, too, provided Navarra rolls on the throttle out of slower corners somewhat cautiously.

Custom in-house 304 stainless stepped piping incorporates an oval x-pipe underneath the car and Borla XR1 mufflers.

The solid rear axle’s disappointing performance over curbs can be overlooked easily since its straightline performance is so strong. Plus, with the additions he’s made to the rear, he can adjust the rear over a fairly wide range to get the car to suit most settings well. “I added a Watts Link because it’s very tunable for longitudinal and lateral grip. If you’re able to make enough changes at the track, it’s easy enough to work around the solid axle’s shortcomings.”

To fit the 18x12.5” Signature wheels, Brian’s had to stretch the rear fenders to comfortably fit massive tire and wheel package. He ended up building his own front fenders with Eddie Venancio and an English wheel, which was wide enough to drape over his custom double wishbone front suspension.

Brian styled his suspension setup after a variety of race cars he’d studied over the years. “I had a pretty good idea of what I wanted. I still spent some time plotting the mounting points, but fabbing the arms and the uprights was easy enough."

Some things he decided to rely on a bigger company for. “I decided to go with a pre-made spindle from CorteX Racing because it was proven.”

AJ Hartman aero helps its high-speed stability.

For steering, he opted for Sweet Manufacturing’s power steering rack, then added double-adjustable JRi shocks at all four corners with weight jacker perches. Getting the balance right, despite having a hair too much heft over the front axle, was a priority. In fact, he moved the motor back towards the firewall by several inches. Now, his footwell’s noticeably hot by the third lap.

A MoTeC C125 dash and PDM keyboard conveys all necessary info.

Weighing just 3,150 pounds with driver, it has the legs on many cars at faster flowing tracks with (mostly) clean surfaces, but it still struggles administering power at Buttonwillow, say. The aero is admittedly a work in progress, with the completely unsealed front end, homemade splitter and airdam generating little downforce. AJ Hartman rear wing.

He plans for another engine with newer generation Yates parts and a promised 800 horsepower. It’s also somewhat lighter than the motor which currently sits in the Mustang by a notable eighty-five pounds, which should help him with his weight distribution aims. It’s sitting fifty-fifty at the moment, but if shifting the center of mass rearwards like a touring car’s might make all the difference with 33% more power. The more power you make, the more advantageous it is to have additional weight over the driven axle.

The short-term goals are refining the aero package, reducing weight, and continuing to tune the car to suit the driver. Long-term goals are bringing this rough but remarkably advanced Mustang up to carshow-standard levels polish and presentation. “I was kinda shocked when I brought it to Gridlife and realized how ratty it looks.”

No matter. He’s been focused on the right stuff for now. Paint and air conditioning can come later.