JoeT
01-29-2004, 11:32 PM
Disclaimer: This is my personal opinion based on the experiences I went through with my car. I have all the records and data as well as dyno charts to suppliment these claims and are always willing to show them off upon request.
Also, the goals in this article maybe different from your goals, but I'm sure you'll follow similar methodologies to get where you want to go.
Speaking of goals, I mentioned it in the other articles, and I'll mention it here again. My car is used for autocross, therefore I want big torque as well as power out of the hole. Would I do things differently had I known what I know now? Nope.. I'm extatic with the results and I smile everytime I push the go pedal on my car.
Ok, now the quest for more power. In the previous article, I freed up the exhaust by adding headers and exhaust assembly. Now I need to further add to the mods in an attempt to flatten out the torque curve and increase the power output of my car for my intended application. At this point, the car felt wonderful with lots of grunt and go. It was actually baselined at 141 HP at the wheels at DPE (FWD)during the Dyno Days, and prior to the installation of the exhaust and headers it baselined at 121 hp, but the torque curves were fairly close to stock peaking at the same RPM.
Searcing for the right camshafts for the application proved harder than expected. I purchased a set of Cobb Tuning Mild cams from Lachute for "Big Bucks", and installed them in the car. Performance difference was not noticeable in my current state of mod.
Then I hunted down a company from VCR who designed camshafts for the SOHC Subaru engines, I installed those and the results were mixed. They freed up the breathing enough to produce the most power out of all the camshafts selected (yes there were more) but it was a constant battle with the CEL (misfire) because the idle was so rumbly.
What was needed was a compremise, something that would idle decently yet produce the appropriate torque curve that I needed for my sport. I consulted with a tuner that had links to Japan and he leveraged his connections and came up with a profile to test. We bought a set of blanks from a local parts supplier and proceded to have the cams ground according to the hybrid specifications. Results were fantastic.
Peak HP went up by approx 15 hp and over 26 hp at 6000 rpm, torque was increased by 10% across the board at all rpm ranges. No real drawbacks aside for the occasion CEL from the mildly lumpy idle, which was cured by raising the idle by 100 rpm.
It takes more than just lift and duration to create a profile that works best for the application, it's how much lift is created at which point in the cam and how long the intake and exhaust are kept opened, then there's the exhaust portion which has an overlap as well.
Now I had the NA power I was looking for, next step necessary, as shown by the dyno plot, was to smoothen out the intake to keep the engine pulling beyond redline.
As a matter of fact, the cams gave a strange sensation when driving at a constant throttle setting, as soon as you hit 3500 rpm, it's as if you pushed down on the accelerator another inch, the car would accelerate harder on it's own as the cams got into their efficiency range.
Note: These are the same cams that are currently in my car and they are Turbo Friendly, and they've been in for over 60000 Km...
Next Article: ECU Tuning, it's not the tool, it's the tuner! Make sure you know what to ask for, because you might just get it.
Enjoy!
Also, the goals in this article maybe different from your goals, but I'm sure you'll follow similar methodologies to get where you want to go.
Speaking of goals, I mentioned it in the other articles, and I'll mention it here again. My car is used for autocross, therefore I want big torque as well as power out of the hole. Would I do things differently had I known what I know now? Nope.. I'm extatic with the results and I smile everytime I push the go pedal on my car.
Ok, now the quest for more power. In the previous article, I freed up the exhaust by adding headers and exhaust assembly. Now I need to further add to the mods in an attempt to flatten out the torque curve and increase the power output of my car for my intended application. At this point, the car felt wonderful with lots of grunt and go. It was actually baselined at 141 HP at the wheels at DPE (FWD)during the Dyno Days, and prior to the installation of the exhaust and headers it baselined at 121 hp, but the torque curves were fairly close to stock peaking at the same RPM.
Searcing for the right camshafts for the application proved harder than expected. I purchased a set of Cobb Tuning Mild cams from Lachute for "Big Bucks", and installed them in the car. Performance difference was not noticeable in my current state of mod.
Then I hunted down a company from VCR who designed camshafts for the SOHC Subaru engines, I installed those and the results were mixed. They freed up the breathing enough to produce the most power out of all the camshafts selected (yes there were more) but it was a constant battle with the CEL (misfire) because the idle was so rumbly.
What was needed was a compremise, something that would idle decently yet produce the appropriate torque curve that I needed for my sport. I consulted with a tuner that had links to Japan and he leveraged his connections and came up with a profile to test. We bought a set of blanks from a local parts supplier and proceded to have the cams ground according to the hybrid specifications. Results were fantastic.
Peak HP went up by approx 15 hp and over 26 hp at 6000 rpm, torque was increased by 10% across the board at all rpm ranges. No real drawbacks aside for the occasion CEL from the mildly lumpy idle, which was cured by raising the idle by 100 rpm.
It takes more than just lift and duration to create a profile that works best for the application, it's how much lift is created at which point in the cam and how long the intake and exhaust are kept opened, then there's the exhaust portion which has an overlap as well.
Now I had the NA power I was looking for, next step necessary, as shown by the dyno plot, was to smoothen out the intake to keep the engine pulling beyond redline.
As a matter of fact, the cams gave a strange sensation when driving at a constant throttle setting, as soon as you hit 3500 rpm, it's as if you pushed down on the accelerator another inch, the car would accelerate harder on it's own as the cams got into their efficiency range.
Note: These are the same cams that are currently in my car and they are Turbo Friendly, and they've been in for over 60000 Km...
Next Article: ECU Tuning, it's not the tool, it's the tuner! Make sure you know what to ask for, because you might just get it.
Enjoy!