They say records are meant to be broken. But it takes a special kind of person to set a record just to break it themselves again later and become possibly the fastest stock bottom end LS of all time. Jon Capizzi, the mad scientist behind the world’s fastest stock bottom end 5.3, is just that kind of special—or crazy, depending on who you ask. You may remember when his L33-powered Fox body Mustang shattered the SBE 5.3 record with a blistering 7.81 at 173.61. Luckily for us, he showed up to LS Fest East and broke his own record yet again.
In case you’ve forgotten the car’s setup—we don’t blame you—here is a little refresher. The original setup was a junkyard-sourced L33 spinning a S485 from Forced Inductions Solutions. The snail was stuffing up to 36 pounds of boost through slightly worked over 799 casting heads. However, the record pass was made on 32 pounds of boost—above that, the car wasn’t making much more power, according to Capizzi. All of it is controlled by a Holley Dominator system which provides the pump E85 go-juice to the equation. To reiterate, Jon is doing all of this on pump E85!
When we last spoke with Jon, his previous L33 had just grenaded due to what Jon speculates was a bad tank of E85. That was enough to introduce a little knock into the equation, and at these power levels, that’s a recipe for disaster. The engine came apart and the Fox was done with its record attempts. Or so we thought.
Jon previously told us that he planned to replace the L33 with an L20 (a 4.8-liter LS) with which he planned to go even faster. But as we all know, plans change sometimes with a project car. Jon felt that the car could, and would, go even faster with a slightly different combination, so he headed to the local junkyard to pull another L33 from the heap.
This time around, however, Jon decided to go with a different turbocharger. He turned to the guys at Garrett for a massive 88mm, billet, GTX5518R snail. Just for reference, that turbo would be right at home on a 408, but it’s down right insane for a stock displacement 5.3—but that’s the name of the game when it comes to breaking records.
Jon handled the port work on a new set of 799 casting heads at his own shop, Capizzi Automotive, optimizing them from what he had learned the first time around. For the bumpstick, he turned to TJ Grimes at Baker Engineering for a bit of mechanical wizardry. You may remember TJ and Baker Engineering from both this record-breaking ride and David Adkins’ Impala, which just so happens to be the fastest and quickest LS-powered car in the world. Needless to say, the specs are top secret, but Baker Engineering is a huge factor in Jon’s success with the L33 powerplants.
With the car tuned and all of the kinks worked out, Jon headed for the largest gathering of LS gearheads in the world, LS Fest East. While we missed witnessing the pass first hand, Jon was running in the Grudge class all weekend long and actually managed to go 7.70s four separate times, the pinnacle of which was a 7.72 at 174.57—besting his previous record by nearly a full tenth of a second.
“I think it will go even quicker,” Jon said. “This weekend was the first time I have gone 4.xx seconds to the eighth-mile, and did it multiple times, with a best of 4.95 at 144 mph. My dad came to LS Fest with me and was a big help.”
Jon added that the phenomenal track prep and cool air temperatures really helped out as well, allowing him to make back-to-back record-breaking runs. Not only did he smash the stock bottom end 5.3 record, he did so repeatedly and with zero problems or breakages—even though he was shifting at 8,500 rpm and crossed the line at 8,100 rpm, all on stock pistons, rods, and even rockers. The 2,900 pound car pulled onto the trailer under its own power and is headed to Streetcar Takeover in St. Louis this weekend to find out if it can go even faster.
All things considered, we have to say that Jon’s setup is not only one of the fastest we have ever seen, it is the fastest stock bottom end LS in history in the quarter-mile. As of this writing, the fastest stock bottom end LS we’ve ever seen went 4.85 at 151 in the eighth. Know of one faster? Prove us wrong, but for now, this just may be the fastest stock bottom LS-powered vehicle in the world.