This Underdog Bites Back: Modified Mazdaspeed6

By Staff Writer
May 9, 2020 | Mazda, Mazdaspeed6 | Posted in Columns | From the June 2019 issue | Never miss an article

story by devin altieri


It’s all about the Mazdas for Clint Griest and Johanna Foege. The pair that met through the Mazda community now teams up to take on the pony cars in the SCCA’s formidable E Street Prepared autocross class in the most unlikely of machines: a 2006 Mazdaspeed6.

Despite the model’s lack of aftermarket support, Clint has turned the turbocharged, all-wheel-drive challenger into a serious class contender and has no plans of stopping until he drives the Mazdaspeed6 to an SCCA national title.

But Clint’s autocross story didn’t start in a Mazda. It began in a Mercedes-Benz.

I had gotten out of the Marine Corps in ’08, in the middle of ’08, and some friends back home, which was central Illinois, asked me to come out to a local autocross with the Champaign County Sports Car Club,” he recalls.

I went out, rode in some cars, and thought, ‘I should probably do this.’ At the time, I had a Mercedes-Benz C230 sedan. I took it out for a couple autocrosses and just got hooked on it.”

After autocrossing the Benz for a year, Clint jumped ship, hopping into a Mazdaspeed3 instead. “I had met some really great people over the four years that I had the ’Speed3. It’s a really great community,” he recalls. “In 2013, I would meet my now-fiancée because of the Mazda community, so a lot of good things have come out of that.”

That same year, Clint purchased the Mazdaspeed6–initially for drag racing. After modifying it and fitting R-compound tires, he learned that the SCCA would place his mid-size sedan alongside traditional, rear-drive pony cars in the E Street Prepared class.

It Takes Two

That fiancée is Johanna Foege, current co-driver and winner of the 2018 Mazda-funded Wendi Allen Scholarship, a program that supports women in the SCCA. An active participant in the autocrossing community, Johanna drove the Mazdaspeed6 to third place at the Tire Rack SCCA Solo Nationals in the E Street Prepared Ladies class in both 2017 and 2018.

“I asked her to co-drive for the first time in 2014. I moved to Southern Illinois in 2013 and she moved down in 2014, and we started autocrossing together pretty regularly,” Clint says about Johanna. “She’s been a big part of the development with driver feedback and working on the car, going out and measuring stuff with me when it’s 30 degrees outside, and just generally supporting me and my crazy habits.

“We travel with [the ’Speed6] nearly every weekend. We take the dog with us. A lot of our summer activities revolve around autocrossing and working on the car when we break it–which is pretty often.”

Over the five-plus years they’ve been mending and modifying their machine, the pair has braved plenty of trips out into the cold to wrench on it. Thanks to the Mazdaspeed6’s limited production status–only about 10,000 cars were built during a two-year production run–Clint and Johanna have largely been on their own in creating and fitting suitable aftermarket mods.

“I decided I really wanted to autocross it and started looking around, and they don’t even make suspension for this car!” Clint recalls. “So I thought, ‘What am I going to do now?’”

The first order of business: piecing together some Bilstein shocks and turning them into coil-overs. With the help of Fat Cat Motorsports, damper revalving and further suspension work came next, and suddenly the mostly stock Mazdaspeed6 had become a project car that Clint is fine-tuning to this day.

Joy and Pain

“I’m a mechanical engineer,” Clint explains. “I like to take the analytical approach to everything, so we started measuring everything on the car.”

And when Clint says everything, he means absolutely everything. No stone–or bolt–was left unturned in his quest to get the Mazdaspeed6’s setup down to a science.

“We took all the stock springs, stock sway bars, stock bump stops–we measured their rates. We measured all the suspension components, motion ratios, suspension geometry, bumpsteer curves, put it all on paper, and bounced it off of some pretty standard calculations to really figure out what we were up against and what we could do to make the car better,” he explains.

Clint’s thoroughness paid off, as he can now make multiple changes to the car at the same time. Using formulas and calculations from his rigorous measurements, the car will “be 98 percent of where we want to be without ever testing it,” he says.

It took him five years to get to know the car inside and out, but it seems to have paid off. In 2017, Clint finished 13th at Solo Nationals. In 2018? Fourth.

Between 2017 and 2018, Clint also made three major changes to improve the car’s performance. The first was new tires.

“If you decide to go Street Prepared, you’re all in and you chop fenders. There’s pretty much no question about that,” he explains. “In 2015 I chopped the fenders and ran a 275 Hoosier A6, and that’s when we really dove into the deep end of things.”

A 285mm-wide tire followed in 2017, still the smallest tire found on a nationally competitive E Street Prepared car at the time. But for Clint, it wasn’t enough.

“There was really no choice at that point,” he continues. “I said, ‘We’ve got to go bigger this year.’ I took the 315 and another set of wheels I thought might fit, stuck the 315 under the car, and thought, ‘Man, this is really easy.’

“So I picked up a 335 and found that we could stuff a 335 under the car front and rear.”

After Clint shoehorned the 335mm-wide tire into the Mazda, he started looking at the suspension. “With the added grip, there was going to be more roll, more camber loss,” he explains, so he decided to increase both the spring rate and the shock valving.

“I got that with Fat Cat Motorsports,” he continues. “Shaikh, the owner of Fat Cat, we bounced some ideas off each other and we ended up deciding on rates and a setup on the dampers with all of his new technologies.”

Those new technologies included Shaikh’s heavy blow-off damping and ripple reducer, the latter of which increases traction by “smoothing out the background jitter,” Clint describes. The new shock absorbers were the car’s second major change for the 2018 season.

The third addressed a very specific issue caused by the Mazdaspeed6’s open front differential. “As grip has gone up over the years,” Clint explains, “we have experienced front-inside tire spin coming out of corners. The car makes a boatload of low-end torque, so as we’re hammering out of corners, the stock front diff in the car was open and it would spin up the inside-front–even though it was all-wheel drive.”

This was a tricky problem for Clint, as many aftermarket companies were asking several thousand dollars just to conceptualize a fix. Luckily, he discovered a solution close to home.

“I found a guy in Illinois that specializes in gear trains,” Clint recalls. “I happened to be working in Illinois when I found him, and he happened to be in the same city that I was working in.

“I call him up, I said, ‘Hey, I have this really strange diff. I know you’ve done some limited-slip things in the past. Would you be interested?’

“He said he thought they could do that, and I asked him if I could come to his shop right that minute and drop off a differential with him.”

So, in February of 2018, Clint tore down his nearly brand-new transmission and rebuilt it with the new Torsen differential. The results, he says, are incredible: “We are able to come out of corners, before the apex, full throttle, and we aren’t penalized with a ton of understeer. We’re putting the power down earlier than we ever have been and we’re not getting that front wheelspin anymore.”
That trifecta of changes helped power Clint to a fourth-place finish at Nationals in 2018. He was leading after a wet first day; the second day’s drying conditions might have reduced the Mazda’s advantage of all-wheel grip, though.

Keep It Going Now

What’s on the horizon for the Mazdaspeed6 in 2019? Fewer changes, for one.

Clint and Johanna ended 2018 incredibly happy with the car’s performance and don’t have any major work planned. Clint knows he’ll have a few bushings and alignment changes to address, but with a wedding to plan and a house to buy, the pair will have less time to spend on the car this season.

However, the two are looking to improve themselves in 2019: Driver development is in the plans. The goal? “Make reality the same as expectation, every single run,” Clint says. “I know that I can drive the car at 99.9 percent of the limit; it’s just a matter of doing it every single time, first run. That’s always my mindset. Looking back at Nationals 2018, I didn’t have that the second day and it shows.”

And although he’s considering a move to a rear-wheel drive car in the future, Clint still has plenty to prove in the Mazdaspeed6 first.

“It’s given me an opportunity to really explore some engineering that I wanted to get into anyway,” he says. “It’s just been an outlet for my engineering–and some creativity in there, too, by being the unique, weird car that it is.

“I’m really looking for the National title in the car, so I’ve got a couple more years with it.”

Join Free Join our community to easily find more Mazda and Mazdaspeed6 articles.
View comments on the GRM forums
NickD PowerDork
8/15/19 9:49 a.m.

Saw this thing in action. Evil, evil, evil machine. 

MazdaFace Dork
8/16/19 9:26 a.m.

Amazing work. Beautiful machine. Almost enough to make me want to keep my ms6. Almost 

Our Preferred Partners