Monday, April 23, 2007

Finally Tuned---Kind of

In the last installment I got some much needed suspension and braking help. The next step before track day is to make sure the car is running safely and with as much power as possible. Notice that I put safety first and power second. I could be making 1,000 horsepower and it wouldn't mean a thing if the car breaks down. I don't have the finance to be doing a full motor rebuild at this time, so I told my tuner that I wanted the most power the car could produce while keeping safe air fuel ratios (AFR's) at all RPM's and engine loads. This keeps the engine from detonating or knocking, and destroying itself. I have the COBB AccessPORT v2 installed and was running the 91 octane Stage 2 map from COBB. At the time I purchased the AccessPORT from Flatirons Tuning they were running a special with a discounted rate for ProTune dyno time. I jumped at the opportunity to have the COBB Stage 2 map tweaked for my personal car, again making sure things were nice and safe for track day.

I took the car to Super-Rupair in Boulder, CO for the tune. I have known Harvey for many years in the Subaru community and really trust him to do whats best for my car. The AWD DynoDynamics dynometer is really a nice piece of equipment, and much safer than doing wide open throttle pulls on public roadways. This particular dyno reads quite a bit lower than some of the others in the area, it's referred to as "the heartbreaker" mostly because Harvey uses a 1.15 correction factor(CF) instead of the higher CF that most places use. Dyno numbers by themselves are useless unless you have something to compare them to. For example a stock 2.0 L WRX puts down between 160-175 WHP as measured on this dyno. A stock STi puts down about 235-245 on this dyno. A stockLegacy GT dynos at around 200-210 on this dyno. I'm not really concerned with the numbers themselves, rather the increase I get from adding parts and tuning and the smoothness of the power curve.

Harvey worked with my busy schedule and even left a local car show early on a Saturday to get me tuned. I pulled up and got right on the dyno as scheduled. Jon from Flatirons Tuning came by as well to see what kind of numbers my Legacy put down. We don't have too many modified Legacys running around here so I didn't know what to expect. What we found surprised all of us including Harvey.

We got the Legacy all tied down and ready to go in about 1/2 hour. I'm an idiot and forgot my camera so I don't have any pictures, but such is life. The hood was opened slightly but we didn't put a fan directly on the intercooler, just in front of the car to simulate normal driving conditions. The first run netted 234 hp and 260 lb-ft torque. We were amazed! The most impressive thing however, was the AFRs through the powerband. They were damn near flat indicating that the tune from COBB was a perfect match for the items I had installed on the vehicle. Harvey was very surprised, he said that he very rarely sees a factory map like the COBB be dead on perfect like that one was. We did another 2 pulls to verify and make sure it wasn't some sort of fluke and on the last run it made 236 hp and 264 lb-ft torque. Basically, the car is putting down as much power as a STi in stock form.

I couldn't be happier. Since Harvey didn't do any tuning he was a great guy and just charged me for a baseline reading, leaving my ProTune for when I have added more goodies. I'll post up the dyno graphs as soon as I get them scanned in the computer. Now I know the car is nice and safe, not to mention very fast, I feel more and more excited for track day!

Stay tuned, next installment is going to cover my way-too-complicated-and-expensive-intercooler-sprayer! I also need to get those lowering springs on! Too much to do!

1 comment:

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