Track Test – AQ Motorsports 650hp Time Attack Subaru WRX STI
By Brian Jones, Photography by Joey Leh
With speeds exceeding World Challenge racecars, it comes as little surprise that time attack cars are popular with fans. For diehard Subaru nuts, the name JC Meynet may ring a bell or two.
The Street Tire Class champion in 2008, Meynet has been developing his 2006 Subaru Impreza WRX STI since it was his grocery getting, kid transporting daily driver.
After 30,000 miles of driving and commuting, Meynet’s STI began its long transformation into the caged, 650whp AQ Motorsports beast you see before your eyes.
We’ve come out to Willow Springs International Raceway in order to rig up our data system and put this STI to the test. And, like most track days in Southern California, it’s hot as hell when we arrive to the so-called “fastest track in the west”. Meynet has run as fast as a 1:24 previously but with the blazing sun affecting the track conditions, we don’t hold out hope that any records will be broken.
But, unlike an endurance road racing car, a time attack car only has to make one good lap. It doesn’t matter if your brakes give up the ghost after two laps or that your engine overheats after 10-minutes; all you need is one good lap.
Meynet’s AQ Motorsports EJ25 engine holds up just fine in the heat and it only takes two laps (one being the warm-up) for him to find his sweet spot. His best during our test session is a very quick 1:25, not too far off from his personal best.
A custom Griffin radiator and intercooler, along with plenty of ducting, help keep everything cool while on track. Starting with an EJ25 2.5-liter engine block, AQ Motorsports stroked the displacement out to 2.7-liters using a BC billet crankshaft, rods, and CP pistons.
Careful attention has been paid to the oiling system as well. A GT35 turbocharger produces the real power, about 650whp on E85 fuel, using an AEM EMS tuned by Church Automotive. An ACT six-puck clutch is used to hold the power.
Our data (see above) is referenced against our own Project Evo 9, which was equipped at the time with bolt-ons (320whp), JIC coilovers, Toyo R1R street tires, and a Voltex rear wing. After seeing the numbers, we have no doubts about the capability of the AQ engine to spit out horses. A whopping 20mph difference separates the two cars on each straight.
Meynet’s Subaru also shows its huge level of grip through Turn 1 and 2. Sticking out past the body of the car, Toyo R888 r-compound race tires measure 295mm wide.
Wrapped around 10.5-inch wide Enkei wheels, the tires work in conjunction with JRZ three-way adjustable dampers, Hyperco springs, and AQ Motorsports swaybars.
The difference in tire grip and understeer is noticeable as Meynet is able to carry 16 mph more average speed through Turn 2, a long right-hand sweeper, and much more average lateral-g through every low and mid-speed turn at Willow Springs.
The big difference comes in Turn 8, the fastest turn in the track and one saddled with bumps and dips. 650whp is difficult to put down at 150mph over bumps, especially with a loose suspension set up for rotation through the tighter turns.
The Subaru is equipped with a front splitter, flat bottom, and rear wing so large it could case spontaneous flight but Project Evo 9 is able to match its performance through Turn 8. We expect the car to pick up quite a bit of speed in Turn 8 once these issues are sorted out.
Through the cambered Turn 9 and onwards, Meynet’s Subaru time attack car is a rocket. Its recipe is a potent combination of grip, chassis stiffness, and horsepower.
After a 1.88 lateral-g spike, the mighty Subie shoots off to a 152mph top speed and a best time of 1:25.1.
That lap time is enough to sandwich Meynet in between two formula car records at Willow Springs and is only 1.3-seconds behind Tommy Kendall’s record in an IMSA GTU car. Seriously – that’s not too bad of a place to be.
2006 Subaru Impreza WRX STI
Engine: AQ Motorsports-built closed deck EJ25 motor, Brian Crower 2.7-liter stroker kit (BC crankshaft, rods, cams, +1mm valves, valve springs), CP custom 9.0:1 pistons, proprietary porting, OEM gaskets, ACL bearings, ARP fasteners, Moroso oil accumulator and high volume oil pan with baffling, Cosworth hi-flow oil pump, GT35 turbocharger, TiAL wastegate, OEM cast iron header, 3-inch straight dump exhaust, custom Griffin radiator and intercooler, AEM air filter with AQ Motorsports custom NACA inlet, Deatschwerks 1600cc/min fuel injectors, 1000 fuel pump with AQ Motorsports surge tank fed by Fuel-Safe 10-gallon fuel cell, AQ Motorsports recirculating oil surge/catch tank, and Hose Techniques silicone hoses.
Tuning: AEM EMS, tuning by Church Automotive, E85 fuel, and 650whp (Dynapack).
Drivetrain: ACT six-puck street clutch kit, Driveshaft Shop axles and aluminum one-piece driveshaft.
Suspension: JRZ three-way shocks, Hyperco springs (700lb/in front, 800lb/in rear), AQ Motorsports custom sway bars (23mm front, 29mm rear), AiM shock potentiometers, Ground Control front top plates, aligned and balanced by JC Meynet, Kaminari rear lateral links and roll/bump correction kit.
Brakes: Rotora big brake kit (six-piston front, four-piston rear) and CL brake pads.
Wheels: Enkei NT03+m, 18×10.5-inch
Tires: Toyo R888, 295/30R18
Exterior: Zero Sports bumpers and sills, Kaminari carbon fiber hood and trunk, AQ Motorsports modified fenders, flares, custom full flat bottom, and splitter, Password:JDM custom canards, Kognition wing and fully adjustable uprights, and Earl’s paint.
Interior: Bullet Fab custom multi-point roll cage, Sparco seat, harness, and fire suppression system, AQ Motorsports window net, AiM dash with multi-channel data acquisition, Motorola two-way radio, OEM dash, center console and window glass (per rules).
Contact
AQ Motorsports
www.aqmotorsports.com
Toyo Tires
www.toyotires.com
AEM
www.aempower.com
CP Pistons
www.cp-carrillo.com
JRZ North America
(310) 516-8081
650 is a lot of hp for a 2.6l. How much boost is run and how long does the engine last?
Awesome!
Love the new white look. 650whp must feel crazy. Power on oversteer?
Does AQ Motorsports sell those fender flares? How much do they cost?
LOL. I can only get up to 85mph on the back straight in my Jetta. Daily driver!
1.84g? I think I need to get some Viper sized Toyos too.
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This motor has held up very well. The closed deck and headstuds seem to be staying together under 30 or so psi. We’ll be changing out the headers and hotside to see if we can get a little more out of it in the near future.
we do not sell the fender flares, i think they’re meant for a nissan and we made them fit.
Those look like Datsun 240z flares.
Hey guys, thanks for the great write up OR and comments too!
Yes, 240SX flares with major “adjustments”…..
And yes, 650whp and 1.88 peak G’s is awesome! Wish everyone could expirience that.
The power itself doesnt change the balance or understeer as much as the chassis setup and aero balance does. All that extra power is great when balance is good but can actually slow you down if the basic balance is off. Fortunately, our great team has been doing an excellent job of making this car’s setup as good as possible, making my job much easier. But, it is still a monster to drive at it’s limits and I wouldn’t want it any other way….
JC
Great feature JC!