This LS-Swapped RX-7 Proves That Horsepower Can Cure Boredom


This LS-Swapped RX-7 Proves That Horsepower Can Cure Boredom


While his father's interest in all things Mopar ensured that Gaven Holley grew up around cool cars, the Mannford, Oklahoma-based CAD designer tells us that his early interests gravitated more toward imports and the drift scene. “There’s a family picture of me at two years old sitting the driver’s seat of a four-speed Challenger, and he actually got me a 1969 Dodge Dart to work on as a project when I was really little. I dig Mopars, but I’ve always been more into old school drifting stuff and Japanese cars in general. I was really into Initial D for a time, so I got obsessed with the Toyota Corolla AE86. I wanted to get one of those for my first car, but I couldn’t afford it, so I bought a Mazda RX-7 instead.”

That purchase led to several rotary-powered projects for Holley that included another first-gen RX-7 as well as a REPU pickup. “I really love the engine’s character and its connection to motorsports,” Holley says. “They’re just so wild and loud. I really loved that truck, but that project got expensive really fast. It was a pretty rowdy build and it would regularly let fuel get into the oil. I like to drive my stuff as often as possible, so I had to change the oil constantly, and it was also kind of a pain to track down parts for it.”

Gavin Holley RX-7 LSFT22 Left Front

In early 2021 Holley started hunting another project that would be a little easier to live with, and that search led him to an 1985 Mazda RX-7 that was offered up through a Facebook group for rotary engine fanatics. Relatively stock and in decent shape, the car was outfitted with the same intake, carb, and header setup as Holley’s first RX-7 was, so he knew that it would be easy to work on. He quickly snatched up the coupe, but it wasn’t long before he was itching for a bit more oomph.

“Eventually I just got a little bored with it,” he says. “Even with the bolt-ons, that engine probably made about 115 horsepower on a good day. The initial plan was to hop up the rotary – I wasn’t really into the idea of doing an LS swap on a rotary car. But it was just way too slow for me, and at a certain point I just couldn’t handle it anymore.”

Gavin Holley RX-7 LSFT22 Carburetors

He recalled taking a trip in the RX-7 to Tail of the Dragon, a famous 11-mile stretch of mountain road that runs along the state line between North Carolina and Tennessee, which helped reshape his priorities. “I was hesitant to drive it on that road,” he says. “In the back of my head I was always worried that if something broke, I’d just be stuck because it’s not easy to find parts for those engines. I also love autocross, so I found myself wanting to put together something that would be a little more reliable for that kind of stuff. But more than anything else, I wanted to make it more fun to drive.”

After doing a bit of research, Holley found Granny Speed Shop, a company that at one time specialized in RX-7 V8 swaps. He purchased a swap kit from them, and after a bit of Facebook Marketplace scouring, he found a 6.0-liter LQ4 with ported and polished heads and a Brian Tooley Racing cam.

Gavin Holley RX-7 LSFT22 Interior

“At the beginning of the project I was planning to do a pretty stock LS swap with this,” he explains. “But with this healthy LQ4 now involved, I realized that I didn’t want to do some basic, single-carb intake. So when I found the Holley Hi-Ram, I knew that was the one. The idea was kind of inspired by the Aussie burnout cars – I wanted it to be kind of over the top, and I knew that the runner design would help the motor out a lot. Me and three of my friends were helping me install it at my house, and when we got it on the car we just lost our minds over how tall it was and how crazy it looked.” A pair of 450 CFM carburetors sit on top of the towering power plant. The combination makes about 450hp by Holley’s estimation and is backed by a Tremec T-56 six-speed manual transmission with a Hurst shifter. BC coilovers and Racing Beat sway bars give the car its stance and improve its handling prowess.

Completed this past February, Holley hasn’t let any dust gather on this head-turning RX-7. “I took it to Hallett [Motor Racing Circuit] and it did really well – it’s fast! But it definitely could use bigger brakes now.” He also took the RX-7 down to LS Fest Texas in June, where the Mazda turned a lot of heads on the autocross course as well as the burnout pit. “The car was a riot on the autocross, and it stayed cool despite the high temperatures. I hadn’t planned on doing the burnout contest, but I figured you only get to go to your first LS Fest once – might as well do it right, you know? But the coolest thing that happened at LS Fest was that Josh Mazerolle of Vague Industries actually gave me his winnings from the burnout contest. I think he was just really stoked to see a kid competing with their car at the event, and helping to keep the hobby alive. I was speechless.”

Gavin Holley RX-7 LSFT22 Front Wheel Detail

Holley has done a few cosmetic upgrades to the RX-7 since LS Fest and continues to put it through the paces while also regularly attending local car shows, but he admits that he’s at a crossroads with the project. “I’ve been toying with selling the car. I love it, but I also have this Ford Courier truck with a C5 Corvette chassis that I want to build, too. That thing will be really fun when I get it finished. But I don’t know what the plan is yet.”

Meantime, the RX-7 is still making a strong case for sticking around, and if it does, he’s got a few upgrades in mind for the future. “I’d like to put an 8.8 rear end in it,” he says. “I want to be able to run it hard on a prepped drag strip without worrying about destroying the factory rear end that’s in it now. It has run a 12.9 @ 117 mph with an easy launch, so I think there’s a lot more in it. There’s a subframe upgrade for the car that I’m considering as well, but it’s all still kind of up in the air. All I know is that right now it’s fast and fun to drive.”

Gavin Holley RX-7 LSFT22 Head-On


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