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!

Monday, April 16, 2007

A Few More Bits Added

Getting closer and closer to track day. In my last post I went through my shopping list of goodies from Flatirons Tuning. After I got the Stage 2 up and running on the AccessPORT v2, the need for better handling and stopping became even more apparent. Luckily, I knew that was going to be the case and purchased a few things to remedy that situation.

First off I bought a Whiteline rear sway bar. This pretty piece is a 20mm two-way adjustable that replaces the laughable 16mm excuse for a bar. I also purchased some upgraded Whiteline endlinks as I have heard of many drivers breaking the stock toothpick-sized endlinks when driving aggressively. For those who may not be familiar to sway bar upgrades, the bar acts as a link from one side of the suspension to the other. Actually, they should be called anti-sway or anti-roll bars as they prevent the body from rolling excessively. The endlinks connect the sway bars to the body. Subaru builds the Legacy to be comfortable and so that the average Joe driver can drive like an idiot and get away with it. The stock swaybar size does not allow the rear end of the car to rotate out, even in hard cornering acceleration. This is to prevent average Joe driver from spinning the car and getting in a potentially serious accident due to his overactive right foot. Subaru put such a small bar in the rear of the car that under nearly any circumstance the car will understeer or "push". Once again, this is fine for Joe, not fine for the performance enthusiast. Adding this stiffer sway bar really helps the car to feel less like a milk truck and more like a touring sedan. A quick twitch of the steering wheel after it was installed and there was no question it improves the feel of the car. Install was a cinch, and I have not noticed any decrease in ride quality whatsoever. Highly recommended!

The next issue we needed to address was the braking system. Now the stock Legacy brakes are quite large (12.3" in the front, 11.3" in the rear) and have good clamping force from the dual piston calipers in the front and single pistons in the rear. For the type of driving that I do, mainly street driving, not very aggressive, I simply wanted to make the best use of what came on the car. I'm not interested in a $2000 15" cross drilled slotted big brake kit, because frankly I would never need that much braking power. I have to admit the big brake kits look cool though! After doing some research I decided to go with the Hawk HPS pads, a SS brake line kit from Goodridge, and a flush and refill with some ATE Super Blue high temp brake fluid. These parts will make my braking system tough enough to handle the upcoming track day, yet not be too aggressive for street use. The Legacy SS brake kit has 6 lines as the rear brake setup has two lines per wheel, and replaces the rubber lines with tougher stainless steel braided lines. These lines are guaranteed for life by Goodridge and are DOT certified. Replacing the stock lines improves brake pedal feel eliminating the mushy feel that can happen especially when the brakes get hot. Adding the Hawk pads gives me improved braking through a much larger heat range than the stock pads were ever designed to see, while not being overly loud, dusting too much or eating away my rotors too fast. These pads are used by most AutoX drivers that use their cars to get to work everyday and race them on the weekend. Upgrading the fluid helps keep the braking consistent as the heat in the brakes builds up like it will during track day. The stock DOT 3 fluid will actually boil under extreme heat and allow air to enter the brake lines greatly reducing braking efficiency. The ATE Super Blue fluid has a much higher wet and dry boiling point so it takes much more abuse then the regular brake fluid would. At this point the rotors were still in basically brand new shape, so I saw no reason at this point to replace them. When that time comes I will most likely go with a slotted rotor for even more heat dissipation. With the new brake components installed and properly broken in I can tell you that the difference in braking is significant. I feel much more connected to the brakes and they get me stopped quicker then the stock parts did. I now feel confident that my brake system can handle track day without becoming a safety issue.

Thanks again to Jon Cooley at Flatirons Tuning for his help! Support your local speed shops!

Stay tuned... in the next installment I will be taking the car to Super Rupair in Boulder to have it ProTuned by Harvey!