Simply Extreme: This Rampaging Beast Is Surprisingly Uncomplicated

By Scott Lear
Jun 8, 2018 | Ford | Posted in Features | From the June 2009 issue | Never miss an article

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Complexity is a silent demon that lurks in every race car, waiting to thwart drivers at the worst possible moment. It lives in the tiers of ultra-impressive go-fast components and impossibly precise gizmos that are designed to bring track machines to the razor’s edge of absolute performance.

Unfortunately, the more finely honed this edge, the steeper the drop-off when something gets even a little bit out of whack. Drivers who wind their cars too tightly in the pursuit of performance have no one to blame but themselves when things come crashing down.

In many classes, the rules feature page after page of restrictions that prevent drivers from succumbing to this sinister urge to overcomplicate their race cars. NASA’s American Iron Extreme is absolutely not one of those classes.

In its simplest terms, an AIX car can be any 1960 or newer front-engine, rear-wheel-drive, American-made sedan that weighs at least 2700 pounds. Oh, and the power-to-weight ratio has to be less than 9.5 pounds per horsepower.

It’s important to pay careful attention to that last bit: less than 9.5 pounds per horsepower. A 2700-pound car with a hypothetical 1000 ponies equals 2.7 pounds per horsepower—hey, that’s less than 9.5 by a pretty good margin.

AIX is not a class for timid drivers. Need a performance benchmark? An uncorked NASCAR Sprint Cup racer has to lug around 4 pounds for each of its 850 horsepower.

California’s Ernesto Roco has been part of the American Iron series since its inception in 2001, and he moved up to the top-tier AIX class after four years. Ernesto’s 1998 Ford Mustang is frequently the fastest AIX car at any given track, but that doesn’t mean he’s cuckoo for horsepower. In fact, his reason for running in the nearly unrestricted AIX class is, almost paradoxically, based on budget restrictions rather than outright speed.

“The big reason I switched is I thought it was just as expensive to tune the car to an optimum horsepower-to-weight ratio as it was to just tune the car for maximum naturally aspirated horsepower,” he explains. “I wanted to let the creative juices flow and build the car faster, make it more fun to drive.”

Taking It Down a Notch

Ernesto didn’t always take such a measured approach to his Mustang. Like many pony car owners, he got hooked early and spent his share of resources on big power.

“I was in the service; I was 17 at the time,” he recalls. “I got involved with friends who were all into Mustangs. My first one came soon after that. It was a 1965, and I put all the bolt-on parts on it—four-barrel carbs, headers, all that.”

Ernesto’s Mustang saw the drag strip on occasion, but his primary competitive passion at the time was mountain bike racing. During a mountain biking trip near Laguna Seca, his eyes were opened to the world of road racing.

“I saw all these Mustangs and Corvettes running around the track—I never knew [that kind of racing] even existed,” he admits. “Looking back, I think that was the initial point where I knew: I’ve gotta do that.”

Ernesto bought his red SN95-chassis Ford Mustang Cobra off the dealer lot in 1998. Two months after the purchase, the modifications began: camber plates and new dampers. Just a few weeks later, he was at Buttonwillow Raceway for his first NASA HPDE. The power mods soon followed.

“I was just doing open track events, learning how to drive, modifying the car and blowing up a couple of engines,” he laughs. “I think I blew up at least three Modular motors,” he adds, referring to the stock 4.6-liter engines.

Ernesto grabbed hold of the wall before he fell too far down the bottomless horsepower well, however: “I went through a supercharging phase, the 600-horsepower phase that everybody goes through, that craving for more power. That turned me off so much that I think I’ve gone in the opposite direction.”

He admits that more power made the car harder to drive and led to broken parts. He then saw the appeal of a lower-output, easier-to-drive setup. At that point, he entered what he calls his naturally aspirated phase. “I’ve been there ever since,” he says.

When American Iron was born in 2001, Ernesto was there in his Mustang, surrounded by a complete interior and a simple bolt-in cage. He drove the car to the track on race weekends and competed, learning race craft and having a blast with others who were in the same boat. Ernesto and his car were a staple at AI events for the next several years.

Without gobs of power, he was forced to hone his driving talents in the search for speed. At the end of that first season, he decided to pull the interior, weld in a full cage, and turn his Mustang into a pure racer. In 2003, the drift away from complexity continued, and he replaced the fuel-injected 4.6-liter Mod engine in favor of a carbureted 302 block punched out to 331 cubic inches.

“I have the most simple car out there—four-speed, no cooling fans,” he laughs. “You look at the thing, and it’s got one wire going to the engine.”

Up the Ladder

For the 2005 season, Ernesto decided that fiddling with the car to target a particular power-to-weight ratio wasn’t as much fun as cutting loose. He made the jump from the American Iron class to AIX. “It was easier to just go fast and forget about the power-to-weight rule,” he declares.

His interest in weight reduction was comprehensive. The glass came out and Lexan went in. Carbon fiber panels replaced much of the factory steel.

After winning that year’s NASA SoCal AIX Regional Championship, he stripped the car down to the shell and, with the help of Troy Stacy at S&S Fabrications, media blasted and seam welded the entire chassis.

“I was actually surprised to find a lot of fatigue cracks in the unibody from the stress of all those years of open tracking with those big tires,” he recalls. “I’m glad that we took the car down to bare metal and seam welded it.”

The refurbishing also included an even more competitive powerplant, an aluminum Dart 363-cubic-inch V8 built by Ford Performance Solutions. Its 585 horsepower might seem monstrous at first blush, but in the world of American Iron Extreme it’s merely adequate. Ernesto admits that his engine budget is on par with his fellow competitors, but he feels that he’s spending his money differently.

“Say you’ve got 100 bucks. I put 90 of that towards making the engine light, reliable and easy to drive,” Ernesto explains. “A lot of people are making horsepower their first priority. I went through that phase, but I’m really convinced that you only need to put down as much horsepower as you need to drive the car at ten-tenths. If I had 900 horsepower, I don’t think I could drive at ten-tenths.”

Stripped of its extra bulk, the Mustang now tips the scales at an astonishing 2300 pounds wet, making it an effective weapon for events like our own Ultimate Track Car Challenge and the Redline Time Attack series. To meet the AIX minimum requirement of 2700 pounds, Ernesto must add nearly 200 pounds of ballast and accessories plus his own weight and a heavier battery.

Must Be Doing Something Right

Ernesto believes that much of his speed comes from the amount of time he’s spent determining how to set up his own car to suit his driving style. Learning the technical ropes has also helped to bring his budget in line.

“I have my own shock dyno, and I do my own setup,” he explains. “After paying people to do the work for me, I decided I’ve gotta learn this stuff. It’s not that I don’t trust anybody, but when it comes to safety and performance, I don’t trust anyone more than myself. I compete with a lot of guys who put more money into their cars. What little I have works and is set up right.”

Using his fairly basic dampers as an example, he continues, “It’s not an eight-way adjustable $10,000 shock—a lot of people [who have those] don’t even understand how they work or what their dyno graphs mean.”

Ernesto’s hard work paid off at the inaugural NASA Championships event at Mid-Ohio in 2006. He drove to an AIX victory nearly 25 seconds clear of second place, posting the second-fastest lap of the race with a 1:33.203.

At the 2007 championships, he was in position to become a repeat winner when his front bumper came loose and forced his retirement from the race. He had the fastest lap in AIX by almost 2 seconds that year, posting a 1:29.688 around Mid-Ohio.

The race was closer still at the 2008 NASA Championships, where Ernesto finished second to Paul Faessler’s turbocharged Mustang. “I got beat by a car that has 300 horsepower more than I have—and I congratulate him—but still, I think I could have won that event,” Ernesto says. “I still managed fastest lap of the day.”

Simple Doesn’t Mean Stagnant

Simplicity will always be an element of this Mustang, but that doesn’t mean Ernesto Roco is going to sit back, relax and wait for the wins to come his way. He says that the car is constantly evolving, and he doesn’t expect it will ever stop.

“I think the car has room for improvement,” he says. “I’ve had a lot of help from vendors—Hoosier Tire in particular has been a great partner. I’m just a regular guy, I don’t make a lot of money, but I’ve worked so hard getting help and sponsorship. I think I can safely say that I have the most sponsorship in AIX in the whole country, and that’s made it possible for me to focus what little resources I have to make the car better.”

Sometimes support deals are the catalyst for a change. For 2009, he secured sponsorship from Agent47 and recently switched over to their hardware. His first on-track shakedown with the new setup took place at Willow Springs, where he had previously set the AIX lap record. Just five laps in, he managed to best his old record time by two-tenths of a second.

Ernesto Roco is keeping his cards close to his chest, but his fellow AIX racers may find that he’s ready to turn up the wick a bit more for 2009. After all, the NASA Championships have moved to the long, flowing Miller Motorsports Park in Utah.

“I did recently acquire a turbo sponsor,” he grins, “but I’m not going to say more about that. I’d like to just show up and race.”

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View comments on the GRM forums
Driven5 SuperDork
4/2/18 3:08 p.m.

 ...I’m really convinced that you only need to put down as much horsepower as you need to drive the car at ten-tenths.

I know that the Mark Donohue "spin the tires at the end of the straightaway in high gear" philosophy is popular to banter about, but this is the truer answer.  It just so happened that for Mark Donohue, the two were one and the same...For the rest of us who do not operate on that plane of existence though, the unfortunate reality is that they are not.

It's great to see somebody so competitive in a big-power class outwardly recognize this concept in that context.

4/2/18 4:35 p.m.

A blast from the past! I followed Ernesto's meteoric rise up to and through his sponsorship with Agent 47. Then I saw his car for sale and apparently he stopped racing...? That was probably six or seven years ago now. There are / were some great videos of him racing his Agent 47 sponsored car on their site and on YouTube. Worth a look!

rjstanford New Reader
4/3/18 8:20 a.m.

Great build!  Reminds me a lot of a build thread I've been watching about Ryan's Miata - bone stock LFX, nicely prepped Miata, probably all of 300rwhp on E85, and setting track records.

ProDarwin PowerDork
4/3/18 9:13 a.m.

Oh, and the power-to-weight ratio has to be less than 9.5 pounds per horsepower.

It’s important to pay careful attention to that last bit: less than 9.5 pounds per horsepower. A 2700-pound car with a hypothetical 1000 ponies equals 2.7 pounds per horsepower—hey, that’s less than 9.5 by a pretty good margin.

A minimum horsepower limit?  That is confusing.

I think its a max hp of 9.5lb/horsepower.  So a 2700lb car can only have 284hp.

According to wikipedia:

 CMC, CMC-II, and AI classes have a power to weight limitation, while AIX is unrestricted.

mistanfo UltraDork
4/4/18 6:20 a.m.

No, AIX is unrestricted, but power to weight below 9.5hp/lb. drops you into AI.

nutherjrfan SuperDork
4/4/18 12:44 p.m.

A coupe is a sedan?  Anyhoo if I had to go to a road race this year I think this is a class I would want to see/feel/breathe and above all enjoy. smiley

Actually I spent two more seconds of brain power to think about sedan/coupe and now my brain kinda hurts. laugh 

A Rover P5B was a coupe.  A sedan can become a coupe or just a two door.  Can a coupe become a sedan?

Brief google search result.

Let's please not start on the infamous GRM liftback/hatchback wars of nearly a decade ago now. cheeky

Now off to search AIX.  Does it still exist?  I shall find out. yes

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