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Feature Article
Hot Rod Warrior
By Scooter Kizer
Copyright 2003 Motorcycle Street and Strip Magazine
In the world of aftermarket engine components and accessories, a new motorcycle is nothing more than a blank canvas.
Of course, the quality and size of the canvas directly affects the art. This canvas is the Yamaha Road Star Warrior,
which we are building into a street version of what competes in the AMA/Prostar’s popular Hot Rod Cruiser class.
For decades, the dragracing look has been popular with the late ’70s and ’80s Kawasaki Z, Suzuki GS, Honda CBX,
and Yamaha XS streetbikes up through all modern sportbikes. Dragbars and a lowered and lengthened chassis separate
the knee draggers from the straightliners.
Over the next several issues, we will transfer the already beautiful Warrior cruiser into a custom streetbike that
emulates the look of the newly crowned Hot Rod Cruiser championship bike of Patrick Racing Yamaha. I emphasis
“drag look;” although my love is dragracing, my passion is roadracing. Not that I’m good at it; I just get a bigger
thrill out of going fast through turns. It’s doubtful we will record lap times at a road course, but we might.
The goal is to build a high performance cruiser that HC champion Mark Underwood would feel comfortable taking down
the quarter mile and that Damon Buckmaster could also make laps around Road Atlanta on without grinding off the frame
rails or the exhaust pipe. (You might want to refer back to Volume 3, Issue 1, for an evaluation of the Warrior when
it was introduced.)
If you’re a talented mechanic who can create motorcycle art from scrap, God bless you. But this project is intended for
the average Joe. We will utilize only aftermarket products made specifically for the Warrior. I hate to admit it but,
though I come from a racing family, I never inherited the natural mechanical ability from the Kizer gene pool. Like most
shade tree mechanics, I can build anything with the right instructions. This project is no different; we will not utilize
any products for which we cannot easily explain the proper installation techniques. When it comes to internal, that’s right
(don’t panic), I said internal modifications, I will refer you to Yamaha’s excellent service manual that is so well written
that a child could follow it.
We started this project at the AMA/Prostar Schnitz Fall Nationals in Montgomery, Alabama, where Yamaha’s Patrick Racing Team
delivered our project Warrior. I sat down with Nigel Patrick, owner of Patrick Racing and Skip Dowling, owner of Orient
Express who also campaigns a team of four Hot Rod Cruisers, to help formulate a game plan. The “look” phase of this project
will include no less than ten aftermarket manufacturers, but the performance phase will be mostly a collaboration with the
cooperative efforts of Patrick and Orient. Although the two companies are fierce competitors on the dragstrip, taking the
#1 and #2 plates respectively, both also have a great deal of respect for each other and an admirable working relationship.
Duplicating our efforts is up to the reader, utilizing either Orient Express or Patrick Racing for performance needs.
Or, you could split the project up like I did because both guys are just too nice not to use. If it will be difficult for
you to decide whom to use, we have designed a simple dartboard for your convenience, or note that Orient is located on Long
Island, New York, and Patrick is located in Orange County, California. Both are quick to point out that the UPS man goes
everywhere from anywhere.
To find a baseline and track the progress of this project, we called upon Joe Marasco of Maximum Street Performance in Columbus,
Ohio, and his rider, former 600 SuperSport Champion, Keith “Shine” Dennis of Memphis, Tennessee, to do the track testing and
Dynojet dyno testing. Montgomery was only a two-day event and time allowed only one pass on the stock Warrior. But then,
with Keith Dennis at the controls, one pass was all we needed. Dennis ran a 12.39 at 104.95 mph, nearly duplicating the best
times of other magazine tests. All Prostar events are held at tracks within several hundred feet above sea level, so times
are real time without altitude correction factors. Motorcycle Consumer News reported 12.25 at 105.52 mph. We made a second
run in stock form at the next event, and Dennis recorded a 12.33 at 106.00 mph, so we will use the latter times as a baseline.
MSP Dyno testing at the Alabama Prostar event revealed our Warrior produced 77.5 rear-wheel horsepower. Dry weight of the bike
is 606 lbs. The engine’s stock configuration is a 1670cc push-rod V-twin with belt drive. For the sake of low maintenance, we
will utilize the stock wheelbase of 65.7 inches and the stock belt drive. This will limit the amount of obtainable horsepower
before shredding the belt. Prostar’s HC class has provided data from the inaugural 2001 season, showing that belts shred at
125hp under drag conditions. We will keep this project between 115 and 120hp to maintain our goal of a fast but friendly cruiser.
We will also maintain the Warrior’s “best in class” handling characteristics, keeping in mind our goal of a corner-friendly cruiser.
Several weeks after our run in Alabama, we brought the bike to the AMA/Prostar World Finals in Florida. As mentioned earlier,
Dennis ran 12.33 at 106.00 mph, at the class-required minimum weight of 800 lbs., including rider. With Dennis weighing only 140 lbs,
it took a full tank of gas to make weight. That night we made our first two aftermarket changes. The first thing a person does
to any model bike is toss the exhaust for more style, performance, and the all-important shedding of weight. Vance & Hines
suggested a V&H 2-into-1 Pro Pipe HS Exhaust System with a low-end torque baffle. The V&H engineers designed a beautiful
drag-style exhaust, with integrated heat shields, that features a collector heat-shield that retains the aggressive look of a
“handmade” race collector while offering protection from discoloration. When installing, make sure to attach the Y cover before
the exhaust tip. I didn’t and so the final cover alignment wasn’t perfect. The exhaust will have to be removed when I pull the
heads to ship to Patrick so I’ll install the exhaust correctly next time.
The second most important upgrade was adding a second brain. When adding aftermarket performance products, you need to be able to
have a programmable ECU for fuel-injected bikes. For this we used a Dynojet Power Commander III. The PCIII plugs into the stock
wiring harness and utilizes the bike’s stock ECU. Changes can be made to the fuel and ignition curves via the PCIII’s onboard
microprocessor. You can order a PCIII preprogrammed with a choice of several different settings, based on the modifications to
your bike. We got our unit from Orient pre-mapped for the V&H exhaust. The unit also comes complete with software and a cable that
allows changing between different maps or making adjustments to a map file from a laptop. Maps are supplied on a CD but can also be
downloaded from Dynojet’s website.
The typical stock bike has areas in the fuel curve that are far from optimal for performance. Dynojet reports that most are typically
70% optimized in stock condition and 60%-65% with minor performance modifications. After installation of the Power Commander with the
base map, you can expect to see 85%-95% optimization. In other words, you will be very disappointed with aftermarket add-ons if you don’t
install a Power Commander.
Installation is simple. And Yamaha makes it extra easy with stock quick-disconnect fuel lines for simple gas tank removal. For setting
the PCIII for the first time, the instructions say, “turn ignition on.” It should read, “turn ignition on and start engine.” Or you can
ask Orient for a Power Up adaptor, a $15 item for guys who don’t have a laptop or don’t want to ride their bike through the living room
to get to their PC. After following the set-up steps, the PCIII is set at lean and ready to ride. Or have your local Dynojet technician
map it. We review this option in the next article.
Installation of the exhaust and PCIII took less than two hours. For a limited budget, these two changes, along with the addition of an
air-filter kit, will drastically improve the bike’s performance and reduce weight. We chose not to replace the air cleaner yet due to
limited time for mapping prior to track runs. The air cleaner will be added prior to custom mapping.
With the V&H exhaust and Power Commander installed, we entered Dennis in the HC class. After one run at weight to legally qualify, we
decided to forgo the Prostar rules in favor of the project and cheated. The removal of the stock exhaust dropped the weight by 14 lbs.,
putting us under the legal weight with a half-full tank of fuel. Like that, Dennis ran 12.18 at 107.73 mph. New dyno runs showed an
increase to 84.1 hp, for a peak increase of 6.6 hp, but the mid-range saw the biggest gain. Not bad for a couple hours work. Giving the
bike the proper air will help the exhaust work to its potential.
Eliminations placed the bike in the ladder next to the HC winner from the Alabama event, Michael Ray of Patrick Racing. Although Dennis lost,
he ran a 12.08 at 107.66 mph. Patrick Racing left the race with the low elapsed time of 9.75 and high mph of 135.13. Don’t panic and hide
the checkbook, we have no plans to race competitively in HC. So with two changes, we shaved 3/10ths of a second off our quarter-mile time
and had a one and a half mile per hour increase, all for about an $800 investment.
Next we will perform the first of two “look phases” of the project in which we will lower the rear end, slap on a set of RC Component
Comp wheels, a box of goodies from Baron’s such as dragbars; trick, exposed front pulley; a lowering kit; Stealth air kit; a ton of chrome
from Yamaha Accessories; rear-set foot pegs from Orient; and a new clutch and cables from Barnett Performance Products. Then we will move back
into the final step of high performance by disassembling the top end, shipping it out for head work, and installing bigger pistons, cams,
lifters, clutch, and throttle bodies. In our final story, we will finish off the project with a custom seat and paint job to make the savviest
of the Daytona crowd jealous.
Resources
Baron’s 888.278.2819 www.baronscustom.com
Dynojet 702.920.8030 www.dynojet.com
Orient Express 800.645.6521 www.orientexpress.com
Patrick Racing 714.554.7070 www.patrickracingbillet.com
Thunder Manufacturing 602-269-5033 www.thundermfg.com
Vance & Hines 800.223.5952 www.vanceandhines.com
Future Sources
Yamaha; see your local dealer www.yamaha-motor.com
Barnett; to find dealer, see website www.barnettclutches.com
Photo Captions
1 [Keith Dennis & Scooter shot] The King of the quarter mile and the shade tree mechanic.
2 [Keith Dennis action shot] Keith Dennis en route to a 12.08 at 107.66mph.
3 [Close up of Power Commander] The Dynojet Power Commander fits neatly in the provided protective pouch and is concealed under the seat brace.
4 [Close up of wire connector] The Power Commander wiring loop (white connectors) snaps in-line to the stock ECU wiring harness.