With the introduction of the 2015 Mustang’s S550 platform, the venerable ponycar finally joined the 21st Century with the integration of an all-new independent rear suspension platform design. The development of the suspension system was years in the making, but the true test of the design came once the vehicles hit the street and the legendary Mustang aftermarket was able to sink its teeth into the design.
Developing aftermarket suspension parts to work well on the track isn’t as simple as taking a stock component, identifying potential shortcomings, and reproducing the part out of more-robust materials. Instead, the research process requires careful application of physics principles, stringent material selection, and many hours of on-track testing; the end goal is to create products to withstand the abuse enthusiasts regularly heap upon them.
That’s where Kelly Aiken comes into the picture. As one of the suspension gurus at BMR Suspension, Aiken’s day gig involves providing solutions to Mustang enthusiasts to help improve their on-track performance. Aiken jumped on the purchase of this Deep Impact Blue machine virtually as soon as the vehicles hit the market, and has taken the car to a level that is difficult to comprehend – especially once the amazingly-basic parts list is considered.
The Details Behind The Insanity
The vehicle seen here is a rolling testbed for BMR Suspension, and Aiken has been a driving force in the company’s research process to create parts for this all-new platform. In conjunction with BMR’s founder and lead development engineer, Brett Rockey, Aiken has assisted in the development of suspension parts that have helped to propel this Mustang to single-digit elapsed times, with a best pass of 8.99 at 154 mph to date.
There’s not much to the car – at least not visible to the naked eye. But there are plenty of items that have been sourced from a variety of sponsors who came on board to help Aiken, in the process working with him to develop and test their own parts for the S550.
“The car has a JLT Performance cold-air intake on it, which is interesting because they don’t make one for this configuration. Jay (Tucker, proprietor of JLT) set me up with a kit that I had to modify to make it work with the supercharger inlet location and body of the car,” says Aiken.
“Over a year ago when we started building the car, we had to develop a number of parts. For example, we built the fuel system here in-house using common-sense principles and existing parts, because everyone we talked to couldn’t assure us that their parts would work. They hadn’t been able to test anything on the new chassis before we started modifying this car.”
There are so many stock parts on this car it’s shocking to realize just how quick it is – and how good the factory Ford parts really are. That’s not to say that Aiken hasn’t been challenged, because he has. During every step of the build process, he’s discovered which stock parts can handle the power, and which ones require replacement to run at this level.
The Go-Fast Parts
The engine was built by Matt Kesatie at Kesatie Motorsports using many stock components – the block, crankshaft, cylinder heads, and even the camshafts are stock right down to the Ford part numbers emblazoned upon them. Improvements were made through the use of a set of Manley Performance H-beam connecting rods equipped with ARP2000 fasteners, and a set of Mahle pistons out of the Cobra Jet program. An ATI Performance Super Damper was hung on the nose of the crankshaft with a pulley configuration to drive the supercharger, and that’s it for the long-block modification list. Every other part in the engine is Ford OEM-spec.
So where does the extra power come from? Atop the engine sits a VMP Tuning Gen 2 TVS supercharger system pumping out 21-plus pounds of boost pressure. Aiken is pushing the supercharger to its limits; with a smaller pulley the compressor would likely become inefficient and potentially lose power.
Exhaust is removed from the engine thanks to a set of Borla long-tube headers that run through a Magnaflow Competition exhaust system. Safety is handled by a six-point bolt-in roll bar from Watson Engineering, while Aiken dons a helmet and gloves from Racequip, a driving suit from G-Force, and slips behind a harness from RJS.
Another area where Aiken discovered some issues with regard to performance lies within the OE differential housing; it’s in this area that the car has received a serious upgrade in the form of a Strange Engineering Pro HD aluminum 9-inch Ford housing. In order to harness the power, Aiken upgraded the underpinnings with a G-Force Engineering 9-inch IRS system that features the Strange chunk. Although these components are not inexpensive, they’re what’s required to stand up to the power of the car and provide peace of mind when the hammer is dropped on the starting line.
Remember where we mentioned that the car is a rolling testbed for BMR Suspension? The company’s full line of S550 suspension parts has been developed thanks to the use of this car and the torture-testing performed by Aiken during the car’s lifetime.
The front suspension modifications are simple – just a set of BMR’s S550 drag springs. But since the rear suspension is a complete departure from the Mustang’s solid live axle of days gone by, it required a complete rework to stand up to the car’s power level. The company’s drag springs, Delrin cradle bushings, billet aluminum differential bushings, billet vertical links, adjustable toe links, upper camber links, and lower control arm bearing upgrade combine with the Viking Crusader shocks to control the rear suspension under power.
Put simply, it seems like their research has been successful. How does a 1.29 60-foot time sound? Aiken says it rides surprisingly well on the road; there isn’t much noise transmission into the cabin due to the stiffer bushings, and it’s actually quieter than it was with the stock Super 8.8 differential housing. Ford’s 8.8-inch gear design doesn’t hold up well to such hard launches.
Yet another impressive feat is that this car not only runs the number, but does so on 305/45/17 drag radial tires from Mickey Thompson, wrapping a lightweight set of Billet Specialties Street Lite wheels. Aerospace Components brakes at all four corners reduce unsprung weight and bring the car back to earth after a dragstrip run.
So far the engine has taken the beating he’s heaped upon it, although it hasn’t been without challenges. For example, at least year’s NMRA World Finals in Bowling Green, Aiken attempted to put a small shot of nitrous oxide through the engine on top of the boost already provided by the blower.
“I’ve put this thing through some serious abuse, running it super-lean just trying to get it to run hard. I was spraying the car with a 50-shot at Bowling Green last year when it was already out of fuel and I didn’t know it because the datalogger wasn’t working. I managed to log the last pass, and after looking at the air/fuel ratios it should have just blown itself into pieces. It just keeps on ticking,” says Aiken.
He’s just about out of fuel pump again, as he’s taken the current system to its limits to run the number. It currently consists of GT500 pumps, a VMP plug-and-play fuel pump booster, and a set of Injector Dynamics ID1300 fuel injectors.
“These GT500 pumps flow almost 300 liters per hour each; I didn’t have to put the pump booster on it until it was making over 800 horsepower to the tire on E85 fuel,” Aiken explains. “I don’t even know what it makes now, but Justin at VMP is real interested to see what it makes. His wife Rebecca’s car makes 905 horsepower, and that’s the highest anyone’s recorded on the chassis dyno with this blower system. He thinks this car makes a decent amount of power more than his.”
That said, right after our photoshoot he was planning to pull the engine out of the car in preparation for a brand-new bullet from Livernois Motorsports. The new engine will sport a number of as-yet-unseen modifications and tricks designed to improve the performance of the car even further, although Aiken remains humble when discussing the potential of the new combination.
“We’re going to be testing some different superchargers on the dyno that flow different rates; some ported designs, lower manifold modifications, things like that,” says Aiken.
“We’ll be on the dyno all day long, trying to figure out what makes the best power. The new engine will be way too much engine for the blower, but there are some prototype products we want to make sure are set up correctly. We want to make sure that the air path from the air filter to the intake ports is as efficient as possible so we can make the most power. We’d like to see 1,050 horsepower at the tire with this combination.”
One of the secrets to the performance has been unlocked by tuner Ken Bjonnes of Palm Beach Dyno. Bjonnes has been working with Aiken on this project since day one and has seen it progress to its current state – all with the OEM engine management system, and no actual dyno tuning sessions.
“Kelly’s car is a perfect example of how far remote tuning has actually come. 8 second passes used to require a trailer and a whole crew, let alone countless hours on the dyno. We did this with the internet and some street logs,” explains Bjonnes.
In fact, just prior to our photoshoot at the recent NMRA Spring Break Shootout in Bradenton, Florida, Aiken had driven the car – fully loaded with parts for display – from his home up the Florida coast. It’s a 90-mile one-way trip; Aiken also used the car to commute back-and-forth to his hotel all weekend, then back home after our shoot.
Amazingly, the transmission and torque converter on this car remain 100 percent stock, exactly as-delivered by Ford. Bjonnes worked to refine the performance of the transmission, and his expertise shows in the performance of the car. Although there might be a bit of performance to be found with a more aggressive torque converter design, Aiken still drives this car regularly and doesn’t want to wreck the drivability side of the equation.
This Mustang is truly the ultimate street car; docile and comfortable enough to drop the kids off at school in the morning, then hit the dragstrip in the afternoon to blast off elapsed times that are unheard-of for a street car, and still be home in time to pick the kids up. Technology is amazing!