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.

Justin's Moore's Mustang GT: Practicality Pays Dividends

In its earliest state, Justin had wrapped the Mustang in highlighter yellow.

Justin Moore figured this time around, he’d save himself a little misery. Exchange some sentimental attachment for peace of mind, keep your ass in the seat, and drive the wheels off it. What is it? “It’s a piece of expendable athletic equipment,” he declares. That’s the way he feels about his 2011 Mustang GT. Not quite the passion project his big STI was, this Ford has proven to him that there are other aims in motorsport outside of manifesting the vehicle he saw in his teenage dreams.

The Mustang wasn’t the first dependable track vehicle he bought. Prior to this, he’d been autocrossing a 987.1 Cayman S with a few minor tweaks. Though the two got along beautifully, the thought of an IMS failure or a big crash in the Porsche left him feeling a little tense. 

Rather than risk it, he sold the Porsche and consulted the knowledgeable Tony Rodriguez. “I wanted something that was fast, fairly cheap, fun, and fuss-free.” Basically, the costs had to be restricted to consumables for the platform to work. There were a few possibilities, but Tony and Justin agreed fairly quickly on the Mustang.

Most of the chassis modifications he’s chosen are second-hand, including the homemade splitter and the APR rear wing. 

Soon enough, there was a new car in his driveway. With Tony’s guidance, the put together a fairly lengthy list of modifications: big wheels and tires, a few aero pieces, and a set of pads. The S3 rules at the time limited the tire width, but he learned to drive around the resulting understeer and got on with getting regular seat time. 

Though the mechanical grip wasn’t really satisfactory, the combination of that and the aerodynamic download ended up ruining a motor. Oil starvation is never fun, but Justin didn’t sit with his head in his hands. Instead, he contacted Mark Luton and laid out a very basic plan for the replacement lump. 

For Phase 2, Justin shed the yellow wrap.

Justin calls it “Stock Engine-Plus,” but that doesn’t really paint much of a picture. MMR made sure that the motor could handle track abuse and lateral loading. Included in the parts list is an expanded oil pan, an Accusump, and all the ARP hardware to make the motor more resilient. Of course, a few bolt-on modifications and a tune by Ed Susman helped raise the power output to a respectable 480 horsepower at the rear wheels. It’s also held up to all the abuse Justin’s put it through in the past two years.

After the motor came back, the rules changed. Now the SpeedSF Challenge rules allowed wider tires and the option of slicks without a big points hit, so Justin moved on from his 285-width Nankang AR1s to a set of Hoosier A7s measuring 315, and the handling balance shifted dramatically. “I used to deal with the understeer, which made me angry. Now, it’s neutral, forgiving, and much faster. Wider tires were exactly what this car needed.”

Getting the handling balance right also required leaning the front tires in some—about 3.6 degrees of negative camber. There’s not much one can do to improve the solid rear axle in that respect, so he dropped the rear as much as he could without scraping. Along with a Watts Link and a soft enough setup has given him enough grip and predictability to get airborne and continue attacking.

This handling balance and reliability allowed Justin to grow along with the car. “It was never scary—and not just on the track. There wasn’t a need to ever worry about much, and so I could relax and focus on the driving side of things.”

That approach paid off. Currently, Justin’s leading the S3 Championship and hoping to secure the title. All he’s had to do is build a motor—not a meager expense, but still a simple fix. Well, there were the modifications he had to make to his air-oil separator, but that’d have to be classified as a minor annoyance rather than anything that could turn hair gray. The rest has been sweet and simple.

Times

• Thunderhill Cyclone: 1:57.465 (Speed SF record)

• Thunderhill Bypass: 1:56.494

• Thunderhill West: 1:20.610

• Buttonwillow 13CW: 1:54.516

• Laguna Seca: 1:36.938

Modifications

• ST Suspension coilovers

• Whiteline Watts link and front bar

• Forgestar wheels 18x12”

• Kooks long tube headers and x-pipe

• C and J intake

• custom air-oil separator

• custom hood vents

• Ford Performance crate motor with MMR-built bottom end.

• ARP hardware

• Ford Performance oil pump

• Accusump

• MMR baffled oil pan

• Ford Performance trans cooler

• 3.55 final drive and rear end fluid expansion reservoir

• lightweight radiator support subframe connector

• APR GTC300 rear wing

• Custom birch splitter

• Boss 302 lower front fascia for brake ducts

• Brembo Performance Package brakes

• DBA brake rotors

• Fidanza clutch assembly

• steel braided clutch lines

• Hawk DTC-60 brake pads

• Holley dual fuel pump upgrade

Seigo Ma's S2000: Grip and Reassurance

Photo credit: Jebin Huang

Seigo’s had a thing for lightweight Hondas since day one. His foray into track driving came through an RSX, and after about four years of that, he tried his hand at FR with an AP2 S2000.

With Gary Wong’s car in his reticle, Seigo started building this Silverstone Silver AP2 into a car that could run at the sharp end of S3. He began with a set of HKS Hipermax 4 SP coilovers, Stoptech ST40s at the front, and whatever inexpensive tires he could get his hands on. Cheap was the operative word with rubber choice; seat time was everything at this stage—especially if he wanted to get anywhere near Gary and his clean, measured, unruffled driving.

Photo credit: Jebin Huang

Despite it being his first FR, Seigo took to the S2000 quickly. Being an AP2, the rear is slightly more stable than its predecessor’s, but that doesn’t take away from the the accomplishment of adjusting so quickly to a very pointy car. Modeling his S2000 after Gary Wong’s car, he made some of the same changes to setup which help Gary drive quickly without taking in too many liberties.

After he grew tired of the silver paint, he applied a metallic green wrap to help his car stand apart.

He made sure the car remained stable and predictable at the rear so he could push comfortably. “The OS Giken differential, man! After I rode in Gary’s car, I saw how much better the car could exit corners. He’d just stand on it and the rear would take it,” Seigo said.

While the pumpkin was off, he changed the final drive to the “happy medium” 4.3. This was just enough to keep the motor out of its lackluster mid-range more of the time without the inviting constant shifting a 4.44 would require.

And if he was going to get a more stable rear, it only made sense he’d find more composure everywhere. The addition of a set of JRZ RS Pro 3-ways, found secondhand for a steal, he could hustle this car over rough spots, berms, and undulations like never before. “After the JRZs, the dorito at Thunderhill West was just afterthought,” he laughed.

Further improving the stability of Seigo’s S2000, he went for a little aero. “I didn’t want to spend thousands and wait months for a real one, so I got an Voltex Type II replica that I eventually replaced with a swanneck-style replica.” Now, the S2000, which he’d just recently wrapped a metallic green, had much more stick at the rear than most in its league.

To help the aero balance, Seigo added a trick Racebred Components front splitter—the pretty one with tunnels. These help produce more downforce than the traditional flat splitter. In theory, the tunnels work with the fender vents to help reduce front end lift.

By that stage, he’d addressed the main aims regarding balance and grip, arguably the most important traits with a track-focused S2000, so a few power adders were in order. The list was short: a Blacktrax tune, a 70mm Ballade exhaust, Mugen header, and an AFe Performance intake. The total output wasn’t much on paper, but 230 horsepower at the rear wheels in a 2,700-pound car with the right gearing is a surprisingly quick thing.

Still, horsepower was never its thing and will likely never be. “Power adders are expensive, so I’m just going to focus on weight reduction for now,” Seigo added.

Never feeling torque-limited has payoffs—namely in corners where the tires are thrust into the pavement. With a flat underbody extending all the way from the splitter to the Spoon replica diffuser, he’s able to take some quick corners without much concern. With Thunderhill’s Turn 8, it’s just a matter of turning in and staying flat—all at around 108 miles an hour.

“It’s so easy to drive at the limit now! It does exactly what you want it to do, and although it doesn’t have that much power, it can catch more powerful cars—even at Thunderhill East. They walk away in the second half of the track, but I can close the gap in from Turn 1 through 8, though they’re still a little faster in Turn 7.”

Eventually, he had to address one of the S2000’s few shortcomings. With a kit consisting of RX-8 rear calipers and Mustang vented rotors, he got rid of the overheating problem which plagues the stock rear solid rotors. While at it, he decided to upgrade the rear hubs to Karcepts. He’d seen the way Gary Wong’s hubs had given up at Thunderhill West and had no desire to experience that himself.

For now, the desire to put him in contention with Gary Wong and not damage his bank balance has given him one route to follow: weight reduction. With a lighter Shorai battery, APR carbon mirrors, and a carbon fiber hardtop, he‘s trimmed a good hundred pounds from the car, but it’s still about a hundred away from his target weight. He hasn’t committed to the idea of turning this car into a rough, amenity-free track scalpel, but with the indecisive way he’s been casually removing interior panels, it’s not hard to guess where he’ll be in a year.

. With a little dieting, there’s a chance he could give Gary a good fight.

Exterior:
-Fender Roll/Pull
-Replica Voltex Type 7.5 1700mm
-K1 Style Ducktail
-Alumalite flat floor
-Voltex Style Fender Flares
-Racebred Components Splitter with tunnels
-CR Style Lip
-Fender Vents
-Mugen Style Hardtop
-DF Style Side Skirt
-APR Mirrors
-OEM Hood with Trackspec Hood Louvers
Wheel/Tire: Titan 7 17x9.5 with 255/40/17 Advan A052

Interior:
-Momo Mod 78 330mm
-NRG Short Hub
-Worksbell Rapfix GTC
-Recaro RSGE Bride/Cusco Zeta III Sport C with Bride Rails
-CR Shift Knob
-Cusco 6 Point
-Hard Dog Roll Bar
-Innovate Oil Pressure/Temp with SOS Gauge Mount
-Shorai Scorpion Lightweight LiFePO4 Battery (2.75lb)

Suspension:
-Hard Race RCA w/ Camber Offset
-Spoon Gusset Plates
-Origin Fab Front Offset Bushings
-Random Mix of Hardrace/Ballade/ESM spherical bushings
-Megan 32mm Front Swaybar - 2 Position
-Hardrace 30mm Rear Swaybar - 2 Position

Brakes:
-Stoptech ST40
-Raybestos ST45 Front and ST43 Rear Pads
-Reilly Racing RX8 rear caliper conversion kit with Mustang GT Rotor
-Project Mu G-Four Fluid

Engine/Drivetrain
-Ballade 70mm Exhaust
-70mm TP
-Mugen AP2 Header
-AFE Takeda Intake with Oiled Filter
-Flashpro Tune by Blacktrax Performance
-Vibratechnics Fast Road Engine Mounts
-Moroso Baffle with Trap Doors
-Schmuck Built Coolant Reservoir/Catchcan Combo
-Koyo Radiator
-Spoon Clutch Disk/ Ballade 10lb Flywheel
-4.3 Final Gear
-OS Giken 1.5way LSD
-Road Runner Fuel Tank Baffle

Best Laptimes:
Thunderhill East Bypass: 1'58.2
Thunderhill West:1'22.0
Laguna Seca: 1'40.07
Sonoma: 1'47.8
Buttonwillow CW13 - 1'55.5