Not only does swapping on...
Not only does swapping on a larger blower provide more efficiency to the current Lethal combination, but that extra .6 liters provides plenty of upside. Before moving to the bigger Whipple, we first wanted to see how some bolt-on mods could improve the performance of the 2.3-liter.
As we last left Lethal Performance's Grabber Blue test bed, the '11 Mustang GT had just made the leap from naturally aspirated bolt-ons to Ford Racing/Whipple's twin-screw supercharger. Obviously the Lethal crew doesn't stand still long when it comes to developing its project cars. As such it's no big surprise that they'd want to push the envelope beyond the level of the out-of-the-box kit.
It's obvious that the rotor...
It's obvious that the rotor pack in the 2.9-liter Whipple (left) requires a larger case, but the 2.9 also sports the high-flow Crusher inlet. Lethal also ordered a large selection of blower pulleys to step the big Whipple down to the same boost level as the 2.3.
"It's pretty simple. You can never have enough. At least, that's how I am" Lethal Performance's Jared Rosen explained. "For many, even a stock 5.0 GT is more than enough power. Add the FRPP/Whipple kit into the mix and you take care of another large group of people. Then there's the group such as ourselves where it just doesn't cut it. We need more. Whether by modifying the current setup with a larger intake or throttle body, adding more boost, or simply swapping on a larger compressor, we'll do what we need to in order to make more power and go faster."
It's not all madness and mayhem down there in South Florida-Lethal did decide to add a few bolt-ons to the FRPP/Whipple kit before stepping up to the larger Whipple 2.9-liter blower. First they added free-flowing induction, then a larger throttle body, to see what uncorking the inlet would. Of course, all along, they relied on Jon Lund to tune the car up with a more aggressive calibration.
Even in moving to the larger blower, the Lethal crew showed some restraint. They pullied the bigger blower up so it would only crank out the same 10 pounds that the 2.3. This was so we could examine the efficiency of the larger compressor at the same boost level, all in the name of science.
"For this combo and power level I'll be happy seeing mid-10s," Jared added. "Up until recent it's been warm and humid which really hurts us at the track however we're just starting to get some cooler weather down here which should help in reaching our goals."
Moving forward there are more mods in this car's future. In our next installments, we'll be opening up the exhaust, bolstering the suspension for the track, stepping up the boost, and strengthening the engine's internal parts for big power. Stay tuned as we ride this one out and see how loud a Coyote can howl.
On The Dyno
While stepping up to the larger Whipple CAI, Jon Lund also added a couple extra degrees of timing beyond what was in the relatively conservative FRPP tune. From there, Lethal added parts and Jon tuned the combo up to maximize performance while keeping the combination safe from damage.
Before swapping blowers, Lethal...
Before swapping blowers, Lethal wanted to explore the benefits of opening up the air path in front of the 2.3-liter Whipple. All positive-displacement blowers will benefit from as little restriction as possible on the inlet side.
"From our past experience with the '08-'09 FRPP/Whipple kits we know that the open filter element induction system would breathe better and make more power than the closed air box setup," Jared said. "So going to the less-restrictive Whipple GT500 123mm intake system, we knew we would benefit quite a bit which it did making an additional 21 rwhp over the intake that came with the system."
While the standard FRPP/Whipple...
While the standard FRPP/Whipple kit (PN M-6066-MGT23TD; $6,199) includes CARB-legal induction complete with a revised lid for the stock airbox. This lid not only integrates the stock box to GT500-style induction, but it includes the all important hydrocarbon trap to get the blessing of the emissions gods. In comparison, Whipple's 2010 GT500 Cold Air Intake with 123mm (PN MAF WP-SGTCA1; $598.49) provides an uninhibited air path.
"I had my mind set on a larger throttle body as we've seen how well GT500s respond with a larger throttle body. However, since the '11 GT kit runs much lower boost levels then the GT500s we were unsure what type of results we'd get," Jared added. "Since the FRPP/Whipple '11 5.0 supercharger kit uses the stock '07-'10 GT500 throttle body, we knew we could just swap it out for any other aftermarket GT500 throttle body. We added the L&M 66mm dual blade throttle body and made another pull. We were amazed to see that the addition of the throttle body alone picked up 33 rwhp. The car with the larger intake and throttle body turned into a complete beast."
Moving to the larger 2.9-liter Whipple obviously raised the beastliness of the combo to a new level. It also showed the larger compressor was more efficient at the same boost level.