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Some more Hawk pictures for your viewing pleasure. The group shots are from the 2000 RMHR (Rocky Mountain Hawk Ride)
This is at a lookout on Hwy 67 - mine is the Hawk in front (notice tailpack, TBR exhaust, F2 clip-ons. Don't notice the scratched and cracked bodywork, please.)
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Crazy Hawk riders (redundant, I know). Left to right, Val, Doug, Jason, Ben, and Royce. This is Pine Junction (Hwy 285
&
67) where I rode to meet them coming down from Denver. Really nice group - the ride on twisty 67 was great. Not too much traffic and everybody stuck together well (probably because I was in front going slow!)
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Another shot at the same place. I climbed on top of a boulder for this one: it is amazing what leathers and full body armor can do to bolster your confidence!
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At the lookout (like the top pic). That's me on the far left. Mom, pay no attention to the scuffed and scraped leathers.
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Here's a poor post-midnight picture of my custom crossover tube. The header is a early race TBR, the version with large diameter primaries that give it a flat spot in the midrange. This crossover tube is supposed to allow some of the pressure pulse to transmit from one primary to the other, softening the positive pulses reaching the exhaust valve, therefore lessening the soft/flat spot. Unfortunately, if it works, that means it also has to soften the negative pressure pulses at higher rpm that the tuned length is designed for (to increase hp). That said, I won't miss a few horsepower at 8000rpm like I would at 4000.
What you don't see are the anti-reverionary stubs that are welded in the primaries right at the flanges. They protrude into the primary about 1" and act like a one-way flow director. Think of a regular funnel vs a funnel with a big lip in it. It doesn't
prevent
reverse flow of exhaust gases with positive pressure pulses, but does
restrict
them. Basically, it allows a larger diameter header to act like a small one, helping mid-range and low-end.
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Yet another shoddy late-night pic. This is of the oxygen sensor I had a fitting welded on for. The O2 sensor generates a low voltage signal based on the amount of unused oxygen in the exhaust stream - an indirect measurement of the air-fuel ratio. I mounted an air-fuel ratiio gauge (see pic below) that converts this low voltage signal into little LEDs that are easy to understand (rich to lean). With all of the modifications and jetting, my carburetion is slightly rich at all throttle openings and loads. This is actually what I was going for, being at 6500ft and running to sea level once in a while and not wanting to run lean.
One thing I have noticed is the lag time in the gauge reading. I assume this is due to the distance of the sensor from the nice, hot exhaust port for good readings. I suppose I could install a heated element sensor, but I probably don't need to.
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Third and final out-of-focus and poorly lit picture. I drew a little arrow so you could see the gauge a little better. I promise to get better pics soon. I whipped up a bracket that mounts off the fork tube clamp bolt. I plan on making my own "gauge" that uses leds drilled into the aluminum gauge bracket between the tach and speedo sometime.
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Here will be the pictures of my Airbox lid that I modified by drilling several holes in with holesaws. Others have proven how restrictive the airbox lid is with countless dyno runs to back it up. I know from my VW flowbench experience that this can be very true, so I removed the restriction by increasing the amount of intake surface area. The only drawback to this is the increased intake noise. Personally, I enjoy the loud inhaling sound eminating from under the gas tank, but if you are sensitive to this, you might think twice about it. (Important point, I usually ride with earplugs in addition to the obligatory helmet, so it may seem even louder if you do not wear plugs - good idea to though, as cyclists' hearing loss is directly related to windnoise over several years).
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Here will be a pic of the factory and my custom filter. As I was doing my jetting and airbox mods, I cleaned the factory filter intending to reinstall it. Then I started looking a little more closely at it. It did not have very much filter surface area at all, and worse yet, on the back side was a sheet-steel plate between the filter material and back-fire screen with a series of widely-spaced holes drilled in it. This is not a high-flowing design condusive to making all potential horsepower. So, I got out the utility knives, side-cutters, tin-snips, mini-hacksaw and files and went to work.
I wanted to keep the back-fire screen for safety reasons and for filter material support, so I had to be a little careful cutting. I trimmed away the paper filter material and then proceeded to trim back the plastic, concentrating on the area above the carb mouths. After making the suitably scientific measurements (picture me holding my thumb up with one eye closed saying,"That looks about right") I destroyed a few extra performance filters for cars I had lying around, stealing their foam. After fitting and trimming the material to fit the newly opened sections, I put a bead of RTV silicone around the edges and placed the foam in. Presto-chango! Instant free-flow intake, for a cost of one old filter I already had, some time and some bulk foam I had lying around (you can buy it in bulk at cycle shops). I don't expect this modification to help much if you don't open up the airbox intake - that seems to be the bottle-neck.
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Hawk GT home page - mailing list, too!
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