883-to-1200: Part X, The Dyno Results
The Dyno results are in!Last night, August 24th, I was able to get my 'monster' dyno'd for the first time since the rebuild was completed back in April.
At 8,300 miles total and about 2,000 miles on the rebuild the technicians rolled it up the ramp onto the dyno machine. It was a rear wheel roller type machine with all the latest gadjetry. It had been delievered to San Diego Harley-Davidson in January of this year so its quite up to date and sophisticated. They told me it was a $40,000 investment on their part. It looked it to me.
OK! They made five runs and showed me the results of the the 1st and 5th run. Here are the best figures they recorded:
HP: 73.4 @ 5,900 RPM
TORQUE: 77.0 AT 3,800 RPM
Ask me if I'm smiling!
The HP curve is as smooth as glass right up to 5900 where it begins to fall off. The torque curve looks the same way. At 2,500 rpm its at the bottom of the chart. At 2,600 its at 60'-lbs. At 2,800 its at 70'-lbs and at 3,000 its at 73.5'-lbs. peaking at 77 ft-lbs., 800 rpm later.
The upgrade netted a 29.7 HP increase and a 44.2 ft-lbs increase over stock. That works out to costing around $61 per HP added. Not bad IMO. I'm sure I can get another 2 or 5 HP out of it by tighening my drive belt, fixing the dragging brake pads and throwing on a set of Nology HotWires and non-resistor plugs (smile naysayers).
Needless to say, I'm estatic about the gains I've realized and pleased with my choice of parts.
Oh, for comparison a *stock* 1200s puts out numbers in the high 60's at the rear wheel.
The only disappointment I've had 2,000 miles after the rebuild is I've noticed a small amount of oil leaking from the right rear corner of the rear jug's head gasket. Guess I didn't apply the hylomar well enough to the copper head gasket at that point or I didn't quite evenly torque the headbolts down on that jug, or maybe, the rubber o-ring for the dowel-to-gasket spacing didn't seat properly during assembly.
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Date this page last modified: 03/18/2005