Event: 1/4 Mile Drag Racing (test and tune)
Location: Toronto Motorsports Park, Cayuga, Ontario (NHRA)
Ambient Temp: 61F
Elevation: 630
Weather: Cloudy, cool
Track and Conditions: zero track prep after rain (street wars / street tire night)
Tires: Hoosier DOT legal
Car: 1995 Subaru Impreza
Tuner: Mike @ Innovative Tuning
Builder: Innovative Tuning
Dyno Info: Mustang Dyno
Transmission: Stock 6 Speed
Gear: 4th
Peak HP: 403 whp
Peak Torque: 570 wtq
Baseline hp/tq for a stock 08+ STI on same dyno: 240whp
Target Boost: 28 tapering to 15
Target AFR: varies with boost
Fuel: pump E85
We have lots of Mitsu customers and I love Evos, but in the spring I decided I was tired of hearing that Evos can run a 9 second pass on a stock shortblock and Subarus can’t…so I broke that record with my road course Subaru.
Then Wednesday the VF48 (stock STI turbo) record was knocked down to 11.3 and I decided before someone else took away the right to say Evos can run 10s on stock turbo and Subarus can’t, I had one of my techs slap a VF48 on my 95 Impreza Thursday. On the dyno it made the same HP I made with my old rally car and a VF39, but with a lot more torque (570 ft lbs)! I didn’t spend much time on the tune, but I can probably get HP to hold better at high RPM if I try. The “charge pipe” I rigged to make this work is also pretty comical and I put nothing on the compressor inlet so it was sucking hot air off the top of the engine. There’s definitely room for improvement. I’ll let others find the limit.
As mentioned there was no track prep after the rain so the track wasn’t as good as it usually is, but I got the job done with a 10.97 followed by a 10.96.
This is the first VF48 (or any stock Subaru turbo from a North American car) in the tens and the quickest ever. To be clear this turbo is off a stage 2 car and it has not been ported or otherwise molested to enhance its performance.
This may also be the fastest trap speed for one of these turbos, but I’m not sure. Here’s my warmup pass timeslip. The launch stunk, but 100 mph at the 1/8 and 123.9 mph at the 1/4.
This video is the second 10 second pass, the 10.96 at 123 MPH. On this one I must have magically found a spot with grip because it seems it would have held more power on the launch.