FULL THROTTLE PERFORMANCE - Your V-Twin Performance Specialists!

Release the Beast
A Mild-Mannered Screamin' Eagle 103 from Docile to Brute

I'm always on the look out for hidden horsepower, the kind you can let out with simple modifications. Even though the big-inch motors (113" and above) are exciting, I became interested in the Screamin' Eagle 103 when I did some tuning on one and saw the kind of numbers it put out stock.

Time: 3-4 hours
Goal: +10-12 hp

Parts
1 Complete set of Rinehart True Duals, with stepped headers & heat shields
1 Power Commander 111 USB
1 Doherty Air Pack

The Beginning
Straight to the Dyno room, and after hooking everything up, checking tire pressure and giving it a good warmup, I was ready for the first baseline Dyno run. Wow! 87.5 hp, 101.5 pounds torque. Two more passes of 88.2 and 88.8 gave me an easy 88 hp. Torque stayed close to the same, just like the Screamin' Eagle manual showed.

Old Off/New On
On the lift I removed the old exhaust. The Rineharts are first class in workmanship, fit, chrome, and clear installation instructions.

Once the exhaust was on, I moved to the air cleaner system. Easy to put on, breathes almost as good as no air cleaner at all and it looks great. The Doherty air cleaner sticks out just a little further than the stock one, and it will accept the stock cover. It's all billeted, and the two breathers can be routed off the bike or back into the air cleaner for a more legal application. The kit comes with two clear lines that look great before you start the motor. Afterwards they have a milky substance inside that detracts from the neat appearance. An easy change to black hoses looks much better, plus it can take the close hea6t of the exhaust much better. Everything fits rights and the built-in velocity stack really looks cool without the air cleaner. The design is really thought out and it works. I've made test runs with and without the air cleaner, both are very close to the same performance, up to 100", anyway.

Power Commander
Next the stock ECU was unplugged and a Power Commander 111 USB installed. This is very and easy to install on this bike. The only hard part is fitting and routing the wiring harness so there's no pressure on the plugin. In order for the harness connectors to stick to the bottom of the battery box, be sure to clean it with extra care. You'll need to bend or grind off the vent holes on the bottom of the box. Otherwise, you won't have a flat surface for the wiring connector in order to use the Velcro, and it becomes hard to get it to stay in place.

Dyno Results
Back to the Dyno. First run, 107.42 hp. My excitement level jumped a few notches as I started on the next run. Remember, the runs usually get stronger as the motor seals up tighter. The motor pulled smooth and strong, and I bumped the rev limiter again. 108.02 hp. The third run was 109.10 hp with 106.21 pounds of torque. The mighty Sreamin' Eagle 103 gained over 21 hp just by bolting on the right combination of parts. This works out to be 1.06 hp per cubic inch.

To put that in perspective, what would it take to get a stock 88" twin-cam up to 93.28 hp (88" x 1.06 hp per cubic inch)? Or how about a stock 95" up to 100.70 hp?

I didn't make the goal of 110 hp, but it came close. Every part we used did just what the manufacturer claimed, including Harley Davidson.


FULL THROTTLE PERFORMANCE: 56th E Exit off I-5. MAP 5212-A S. Washington St., Tacoma, WA 98409 253.472.7633 info@v-twinperformance.net
*Full Throttle Performance Tips & Tricks* Release the Beast A Mild-Mannered Screamin' Eagle 103 from Docile to Brute I'm always on the look out for hidden horsepower, the kind you can let out with simple modifications. Even though the big-inch motors (113" and above) are exciting, I became interested in the Screamin' Eagle 103 when I did some tuning on one and saw the kind of numbers it put out stock. Time: 3-4 hours Goal: +10-12 hp Parts 1 Complete set of Rinehart True Duals, with stepped headers & heat shields 1 Power Commander 111 USB 1 Doherty Air Pack The Beginning Straight to the Dyno room, and after hooking everything up, checking tire pressure and giving it a good warmup, I was ready for the first baseline Dyno run. Wow! 87.5 hp, 101.5 pounds torque. Two more passes of 88.2 and 88.8 gave me an easy 88 hp. Torque stayed close to the same, just like the Screamin' Eagle manual showed. Old Off/New On On the lift I removed the old exhaust. The Rineharts are first class in workmanship, fit, chrome, and clear installation instructions. Once the exhaust was on, I moved to the air cleaner system. Easy to put on, breathes almost as good as no air cleaner at all and it looks great. The Doherty air cleaner sticks out just a little further than the stock one, and it will accept the stock cover. It's all billeted, and the two breathers can be routed off the bike or back into the air cleaner for a more legal application. The kit comes with two clear lines that look great before you start the motor. Afterwards they have a milky substance inside that detracts from the neat appearance. An easy change to black hoses looks much better, plus it can take the close hea6t of the exhaust much better. Everything fits rights and the built-in velocity stack really looks cool without the air cleaner. The design is really thought out and it works. I've made test runs with and without the air cleaner, both are very close to the same performance, up to 100", anyway. Power Commander Next the stock ECU was unplugged and a Power Commander 111 USB installed. This is very and easy to install on this bike. The only hard part is fitting and routing the wiring harness so there's no pressure on the plugin. In order for the harness connectors to stick to the bottom of the battery box, be sure to clean it with extra care. You'll need to bend or grind off the vent holes on the bottom of the box. Otherwise, you won't have a flat surface for the wiring connector in order to use the Velcro, and it becomes hard to get it to stay in place. Dyno Results Back to the Dyno. First run, 107.42 hp. My excitement level jumped a few notches as I started on the next run. Remember, the runs usually get stronger as the motor seals up tighter. The motor pulled smooth and strong, and I bumped the rev limiter again. 108.02 hp. The third run was 109.10 hp with 106.21 pounds of torque. The mighty Sreamin' Eagle 103 gained over 21 hp just by bolting on the right combination of parts. This works out to be 1.06 hp per cubic inch. To put that in perspective, what would it take to get a stock 88" twin-cam up to 93.28 hp (88" x 1.06 hp per cubic inch)? Or how about a stock 95" up to 100.70 hp? I didn't make the goal of 110 hp, but it came close. Every part we used did just what the manufacturer claimed, including Harley Davidson.
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