Dyno Test Results
Before our final session was to begin on the rollers, the factory fuel pump was replaced with a Walbro 255lph pump. The installation of this pump requires some serious modifications to the plastic housing that surrounds the unit and is considered very labor intensive. Luckily for us, HB Speed had the experience and knows how to tackle the installment in a short time period. With the newly installed Cobb downpipe in place, Buenas made use of the AcessPort and remapped the ECU with a more aggressive AVCS and timing map while turning up the boost to 20 psi. Buenas stays using an aftermarket downpipe allows him to tune more aggressively whereas using the factory downpipe would limit any tuners ability to properly extract horsepower. The Cobb downpipe along with tuning offered a significant horsepower and torque increase over our exhaust run. At lower rpm the dyno recorded a gain of 60 lb-ft of torque from 2,500 to 2,850 rpm. A consistent gain of 25 whp was seen from 2,500 rpm to 3,600 rpm, while the largest margin of gain was a whopping 27 whp and 45 lb-ft of torque at 3,250 rpm.
Conclusion
What began as a baseline dyno run of 223 whp and 250 ft-lb of torque was quickly revamped with our final run of 285 whp and 352 ft-lb of torque. A gain of 62 whp and 102 lb-ft of torque turned this '08 STI into a whole new rocketship. These were impressive numbers that were made possible with the help of proper tuning and someone knowledgeable to tune the new '08 STI. We can't stress enough how important tuning is when looking to create horsepower because our STI is living proof that this new breed of Subarus have definite power potential.
| PARTS | MSRP |
| Cobb Tuning AcessPort | $695.00 |
| Injen MR Series cold-air intake | $374.64 |
| GReddy SE (Spectrum Elite) exhaust | $669.00 |
| Cobb Tuning SS 3-inch catted downpipe | $595.00 |
| Walbro 255lph high-output fuel pump | $105.00 |
| MSRP TOTAL | $ 2,438.64 |
HB Speed
714.378.DYNO (3966)
www.hbspeed.com
Cobb Tuning
801.713.0035
www.cobbtuning.com
Injen Technology
909.839.0706
www.injen.com
GReddy Performance Products
949.588.8300
www.greddy.com
South Coast Subaru Performance
(Walbro pump)
714.689.2103
www.southcoastsubaru.com
| RESULTS |
| | BASELINE | COBB ACCESSPORT TUNED BASELINE STAGE 1 | INJEN MR COLD-AIR INTAKE | GREDDY SPECTRUM ELITE EXHAUST | COBB SS 3-INCH CATTED DOWNPIPE |
PEAK HP
| 223 @ 5,350 rpm | 257 @5,400 rpm | 270 @ 5,450 rpm | 274 @ 5,450 rpm | 285 @5,520 rpm |
PEAK TQ
| 250 @ 4,330 rpm | 277 @ 4,200 rpm | 293 @ 3,7500 rpm | 312 @ 3,750 rpm | 352 @ 5,520 rpm |
FINAL POWER
GAINS | Baseline | +34 WHP
+ 27 TQ | +13 WHP
+16 TQ | +4 WHP
+19 TQ | +11 WHP
+40 TQ |
Total Gains
+62 WHP
+102 TQ