It was another late night tuning session last night for CP Racing/FI.com last night. Special thanks to Will (UnderPressure) from DynoDynamics for letting me borrow his dyno, as another car was parked on the shop dyno....and nobody felt like unstrapping it.
So Eric and I made about 30 passes on the dyno, dialing in the car for maximum power. The two man tuning arrangement really speeds up the tuning process. One person operates the dyno, and the other person operates the tuning software...both provide feedback...its perfect. Part throttle and lower boost were already dialed in during previous sessions. At times I feel like this car just lives on the dyno, as it's been subjected to over 200 various pulls on the Dyno Dynamics load based dyno.
From previous tuning sessions, and tuning Gman's car, the VQ with a free flowing exhuast can make about 550whp on pump gas at 12-13psi of boost pressure with a good safe tune. On my car, we've made 573whp on pump gas at 14psi of boost pressure.
But tonight was going to be special...no more games...no more experimenting with the limits of 93 octane fuel. So we increased the fuel pressure to 60 psi of differential pressure (vaccum line disconnected), then reconnected the vaccum line. We then proceeded to add a few gallons of C116 race fuel, for a net octane of about 100 (r+m/2) as the tank was roughly 1/3 full prior to introducing the race fuel. With some final EU tweaking, we were ready to make the pass.
The net result was 621whp/604trq at 16.5psi of boost pressure and 100 octane fuel.
Summary of engine modifications:
1) Arias 9.0:1 Pistons
2) Pauter ORds
3) JWT Cams/springs
4) Mildly Ported Heads
5) ATS Twin Disc Carbon (finally started slipping at these power levels...time for a triple or a heavier preassure plate)
6) AAM Spec Return Fuel System and Walbro 255
7) 550cc injectors (pushed beyond their limits....need to upgrade to 650cc)
8) 100 octane fuel
9) 16.5psi Boost Pressure
10) Greddy TT kit
11) eManage Ultimate ECU
After dyno tuning, we gave the car a thorough flogging on the street, monitoring all of the engine vitals. 3rd gear, 4th gear, and 5th gear pulls were all very impressive. 130mph comes up so quickly, and the car losses traction until about 95mph or so. Just nutty! Coolant temps never exceeded 205F and usually hovered in the 190-195 range.
One problem we encountered was an erratic boost controller...making it nearly impossible to dial in a perfect AF ratio....very close....but I think its time for an HKS EVC boost controller. It has a dedicated CPU for the stepper motor, and is extremely responsive and more stable than a traditional solenoid style boost controller.