Triumph Daytona 675 Project Bike - Goldenrod
Part 1: We Build Our Triumph Daytona 675 Test Bike Into A Mini Superbike
From the August, 2008 issue of Sport Rider
By Andrew Trevitt
Photography: Courtesy of Triumph, Riles & Nelson
The motley crew that put the...
The motley crew that put the project together, from left: Shop Foreman Michael Candreia drove parts, bikes and engines all over Los Angeles and was a big help at the track. Superfast WERA racer Chad Lewin piloted the bike at a WERA race at Buttonwillow and the AMA FX round at Infineon-the details of the races will be covered in part II of this story. Eric "E-Money" Nugent is both an artist and a terror with a Sawzall and built the Triumph in his garage. Our man Trevitt brought everything together and kept the other three from beating on each other. Is that a gray hair we see?
Triumph calls the paint color of our '07 Daytona 675 test bike "scorched yellow," but the metalflake finish reminds us of the famous mid-'60s land-speed-record-holder Goldenrod. Powered by four Chrysler V-8 engines, Goldenrod posted a 409.27-mph record run at Bonneville in 1965, and while we weren't setting goals that high for our project Triumph, we were hoping for some big numbers and a top-10 finish in an AMA Formula Xtreme race. Our bike does have one thing in common with the record-holding car aside from the color: Just as Goldenrod was built in the Summers Brothers' backyard Southern California garage, our FX Triumph came together in a tiny garage in the San Fernando valley and has never seen the inside of a brilliantly lit or fabulously equipped factory workshop.
The impetus for this project came from our Triumph contact, who offered up the full set of Daytona 675 racing-kit parts for use in a project bike. As usual our plans grew bigger by the day, and before long we had outlined the story: We'd build our '07 test bike into a racebike using the kit parts and enter it in an AMA Formula Xtreme race with a rider capable of a top-10 or even a top-five finish. By all accounts, the 675 is an almost perfect platform for the AMA's Formula Xtreme class. As one of the lightest middleweights in stock form, meeting the class weight limit would seem an easy task. And with the bike's displacement advantage it would be easier to get competitive horsepower from the engine without building a time bomb. The kit parts all fall within the FX rules, and the AMA recently opened up the class to allow 675cc triples along with the 600cc fours. The kit parts include all the usual go-fast goodies to form a solid base: cams, valves, a slipper clutch, an ECU and matching wiring harness, a lightweight AC generator and so on. Around the engine we'd build a killer chassis with 16.5-inch wheels and grippy slicks along with aftermarket suspension and brakes.
With its bodywork off, the...
With its bodywork off, the Triumph's minimalist package is evident. The finished bike scales in at 348 pounds with no fuel, 40 pounds less than the stock bike and two pounds under the minimum weight limit for the class. We didn't go to any extremes to save weight-the only titanium bits are the front-caliper bolts-and there are plenty of ways in which the bike could be made even lighter. Gripster Sport tank pads ($42) from TechSpec provide some much-needed grip on the Triumph's narrow tank. We used Sebimoto bodywork from Yoyodyne ($620 for the seat and fairing); the seat unit installed perfectly while the fairing required some work to mount. Kasey's Auto Body in Torrance, California, did a fantastic job on the stock-appearing paint job, and we topped it off with a Double Bubble windscreen from Zero Gravity ($90) and Factory Effex numbers.
Triumph's list of parts for the Daytona 675 is extensive and includes almost everything required to build a competitive motor. While most of the parts are manufactured in-house, some are outsourced, popular aftermarket bits.
|ITEM ||RETAIL PRICE |
|Arrow exhaust system ||$1699 |
|Intake and exhaust camshafts and sprockets ||$823 |
|Valves, valve springs, cam |
|chain and manual tensioner ||$987 |
|Intake trumpets ||$340 |
|Tall first-gear pair and HSG kit ||$731 |
|Rotor kit ||$899 |
|ECU and harness ||$649 |
|Cylinder-head gasket (0.65mm or 0.60mm) ||$76 |
|Carbon-fiber engine covers ||$178 |
|BMC air filter ||$79 |
|Manual idle kit ||$20 |
|STM slipper clutch ||$900 |
A 30-page manual details engine assembly, and we shipped everything off to Hypercycle and Carry Andrew (see sidebar on page 84) with instructions to install the parts exactly according to the instructions. Interestingly, the manual calls for a minimum squish height (the gap in the combustion chamber between the piston and cylinder head) of 0.6mm, and our stock engine with a stock head gasket was already tighter-we wouldn't be using any of the thinner kit gaskets. Other than this minor snag, the engine went together with little drama.
The $555 Beringer radial-pump...
The $555 Beringer radial-pump master cylinder is a beautiful piece machined from billet aluminum and features ball bearings at the lever pivot and to actuate the piston. This makes feel at the lever very smooth, but a minor tipover ended up breaking one of the tiny bearings and we had to replace it. We used Motul's RBF 600 synthetic DOT 4 brake fluid and didn't experience any fade problems. The steering damper is a V4 from GPR Stabilizer; the 20-position adjustable rotary unit ($495) attaches to the triple clamp and fuel tank mounts, safe from damage in most crashes. We installed a Yamaha R1 throttle tube to make the throttle throw shorter. Note also the custom brake lines and master-cylinder reservoir mounting. Aftermarket clip-ons from Driven USA ($180) are made from billet aluminum, are black-anodized and have removable tubes for easy crash repair.
The shorter (and stronger)-than-stock...
The shorter (and stronger)-than-stock Sebimoto subframe ($440) from Yoyodyne is made from aluminum tube and is more than two pounds lighter than the stock part. The stock battery had trouble turning over the engine after we added some compression, and eventually gave up. An R6 battery is just one inch wider and two pounds heavier but offers more than twice the cranking power; we slotted the battery box a bit wider, and the R6 battery slid right in. The Triumph kit manual calls for an external fuel-injection device to trim the kit ECU's map for various conditions or fuel, so we ordered up a Power Commander ($350) and quickshifter kit ($266). A Penske 8987 shock handles rear-suspension duties, offering adjustments for high- and low-speed compression damping, rebound damping, spring preload and ride height. The shock is very user-friendly, with easy access to the adjusters, and does not require a compressor to change the spring.
The stock fork was shipped...
The stock fork was shipped off to have GP Suspension's 25mm cartridges installed. While high-dollar aftermarket forks are allowed in the class, we were impressed with the cartridges in an earlier test and felt they'd be more than up to the task. The $1500 purchase price includes springs, oil and labor, making them an attractive option. The 16.5-inch front Marvic wheel is forged aluminum and wears a Pirelli Diablo Superbike slick. The front rotors are Axis-design ductile iron from BrakeTech ($350 each), cryogenically treated to reduce stress. The rotors' unique one-way carrier design allows them to be much lighter than a standard configuration. Beringer supplied a pair of its radial-mount, four-piston Aerotec calipers ($544 each); the two-piece units are machined from billet aluminum and have stainless steel pistons to prevent heat from transferring to the brake fluid. The stainless steel brake lines were custom-made by Orme Brothers to Nugent's specifications; the company offers a variety of configurations, fittings and colors with prices starting at $65 for a two-hose setup. While Beringer also makes rotors, the company doesn't list an application for the Triumph-the BrakeTech Axis rotors are slightly larger in diameter than the stock parts, and we had to shim the calipers to keep some clearance. The front fairing bracket is a $154 Sebimoto piece from Yoyodyne that is a quarter-pound lighter than the stock part.
While the engine was at Hypercycle, the rest of the chassis was dropped off at friend-of-SR Eric Nugent's garage, and our Geek made the phone calls and sent the e-mails to round up the necessary bits. Nugent built our last project racebike, an '04 Suzuki GSX-R600 that Corey Neuer raced in 2005 ("The FX Project," Jul. '05, and "Scared Straight," Aug. '05), and was a huge help in bringing this project to fruition. As expected, the availability of aftermarket parts for the 675 is not as extensive as it is for a typical Japanese middleweight, and in many cases the options for parts are severely limited. Still, we gathered up an impressive stash of speed parts for the bike, and all the companies we dealt with expressed enthusiasm for the project and the bike itself.
The kit camshafts have the...
The kit camshafts have the same lift as stock (as required by World Supersport and AMA Formula Xtreme rules) but more duration. Slotted camshafts allow timing to be changed, and a manual cam-chain tensioner replaces the stock hydraulic unit.
The kit wiring harness eliminates...
The kit wiring harness eliminates the extraneous street gear. Not only is the harness itself more than 1.5 pounds lighter than stock, it allows the ignition switch, left handlebar switch and other street-oriented bits to be jettisoned. The kit ECU raises redline by 1000 rpm and has provisions for a quickshifter to be wired in.
The valves included in the...
The valves included in the kit (the left of each pair shown here) are flat-faced to increase compression slightly. The stock valves are a two-piece design, while the kit parts appear to be one-piece. The heads on the kit valves are thinner and have a shallower dish, offsetting the additional weight of the flat faces-the kit valves are each about one gram lighter than the stock parts (22.5g versus 23.7g intake, 21.5g versus 22.3g exhaust).
Two thicknesses of head gaskets...
Two thicknesses of head gaskets are available in 0.5mm increments thinner than stock. We ended up using the stock head gasket to meet the kit manual's guidelines for squish clearance.
The kit valve springs (left)...
The kit valve springs (left) are shorter and made from a thicker wire than the stock springs (right). The ends are ground so as not to wear the retainers.
Halfway through the project...
Halfway through the project Triumph issued new springs (right) that appear to be made of a different material from the original kit bits (left).
With the engine complete and the chassis parts obtained, the bike came together in Nugent's garage, and we ventured to Auto Club Speedway (formerly California Speedway) in Fontana for a track day. Local club racer John Reeves volunteered to be the guinea pig and reported stable handling, good steering manners and power on par with a well-prepped supersport machine. We had just a couple of stumbling blocks during the day: The kit charging system only works at high rpm, and with the stock battery we needed to keep a charger hooked up when the bike wasn't being ridden. And fitting the switch for the quickshifter proved very difficult with the Woodcraft rearsets-there is barely enough room between the shift shaft and the frame. We eventually squeezed everything in, but our Power Commander was shipped with the wrong software to activate the quickshifter, requiring a call to Dynojet to obtain the right code.
It ain't pretty, but it works....
It ain't pretty, but it works. We were worried about running out of ride-height adjustment with the huge rear Pirelli slick, so we installed this lowering link from Adjustment Tech Racing ($280). There have been reports of the linkage bolts pulling out of the plates (with the expected consequences), so Nugent carved a second set from aluminum plate to add some support. The plates' unequal dimensions mean they can be oriented in different ways and used with a longer dogbone to subtly change the rear-suspension rate.
Woodcraft rearsets are the...
Woodcraft rearsets are the company's typical high-quality affair, with billet parts and three-piece pedals that make crash repair easy and cost-efficient. The 675 kit with GP shift retails for $399, and the footpegs and pedals are adjustable using this nifty pin arrangement (inset). What's not shown here is the Woodcraft setup for reverse shifting, which consists of a double linkage to put the rod through the frame in the original layout. The setup leaves no room for a quickshifter switch, and with the stock transmission internals (the kit parts smooth shifting substantially) it was impossible to make easy shifts. Nugent drilled a hole in the bracket to mount the stock shift pedal so we could run the rod and switch outside the frame.
The forged-magnesium Marvic...
The forged-magnesium Marvic rear wheel is six inches wide and allows the latest Pirelli 16.5-inch slicks to be fitted. Renthal supplied us with all our gearing needs. The company's front sprockets ($50) are CNC-machined from steel, case-hardened and drilled for lightness, while the rears ($83, available through T.A.W. Vehicle Concepts) are manufactured from 7075-T6 aluminum and hard-anodized. The RR4 chain ($175) is a high-strength, lightweight, 520 sealed-ring version intended for racing applications and is prestretched.
The lightweight AC generator...
The lightweight AC generator kit (left in both images) includes a heavy-duty cover and replaces the heavy outer-rotor design of the stock unit (right in both images) with an inner-rotor setup. The setup saves weight as well as drag on the motor but requires the engine to be spinning at high rpm to charge the battery.
This alternate gear cluster...
This alternate gear cluster has a higher ratio than the stock transmission, closing up the gearbox. The kit shift star seemed to make our bike shift more easily than our current test unit, but that may be just our two particular bikes rather than a difference of design.
Machined aluminum intake stacks...
Machined aluminum intake stacks are made of unequal lengths and replace the stock plastic parts of all one height, smoothing the power curve. The kit ECU has individual mapping for each cylinder to account for the offset. The stacks are shown here installed along with the BMC air filter supplied with the kit. After a tipover at dusty Buttonwillow, we replaced the filter with a K&N unit ($79). We also used K&N oil filters, which have a drilled nut welded on, making installation, removal and safety wiring a breeze.
Right after the track day our Triumph rep sent replacement valve springs to be installed before we rode the bike again, notifying us that the dealer teams had trouble in that area at Daytona. This gave us an opportunity to have the engine massaged for some more steam, though, and after talking with other builders more familiar with the Daytona we decided to have the head skimmed while it was off. Andrew had asked to perform this modification during the original build, citing plenty of clearance and more power, but-wanting to keep to the kit instructions as much as possible and looking for the most reliability-we declined. We realized after the track day that more steam would be required to run with the big boys, so 0.020 inch came off the head, boosting compression but keeping clearances well safe according to the manual.
The Arrow exhaust available...
The Arrow exhaust available from Triumph weighs less than 10 pounds. The stock unit, including the lights and license-plate holder hanging off the silencer, scaled in at 27 pounds.
The manual called for some...
The manual called for some machining of the exhaust port to match the Arrow exhaust pipe's spigots. Quite a lot of material needed to be removed.
The STM slipper clutch is...
The STM slipper clutch is a work of art and a necessary addition to the Triumph engine for racing.
With the engine returned and installed in the frame, local WERA and occasional AMA racer Chad Lewin was conned-er, enlisted to ride the bike at a Buttonwillow club race and then the Infineon Raceway round of the AMA series. Tune in next issue for the full details of our exploits.
After the original build didn't...
After the original build didn't result in the horsepower numbers we were hoping for, Andrew had the head ground to increase compression while the engine was apart to change the valve springs. Because the squish band is level with the head's surface, shaving the head doesn't affect squish clearance. We needed some rocket fuel to deal with the high compression, and VP set us up with U4.2 for WERA races, but the oxygenated fuel is not legal for AMA. For Infineon we used the tricker (and more expensive!) AMA-legal MRX01. The U4.2 costs $70 for a five-gallon pail, while the MRX01 costs $115.
Wild Hair Accessories imports...
Wild Hair Accessories imports these unique frame sliders ($165) from GSG-Moto. An aluminum plate attaches to the engine mounts, while the nylon protector mounts to the plate-no cutting of the bodywork is required. The company also offers axle protectors, but we were changing wheels so often-requiring the protectors to be removed each time-that we left them off. A crash at Buttonwillow bent the right-side frame slider plate dangerously close to the cylinder head, and the stress on the plate eventually led it to crack and break. Note the carbon-fiber engine covers, part of the Triumph kit, that attach to the stock covers with two-sided tape. The AMA's tech inspector at Infineon Raceway was reluctant to pass them, as they are not strictly engine covers but more an appearance piece. We used Motul's 300V 5W-40 double-ester synthetic oil in the engine, changing the oil and filter every two days of riding.
With the kit parts installed...
With the kit parts installed and before the cylinder head was shaved, we saw a healthy increase in peak power along with more overrev. This run is with VP's U4.2 fuel and is shown against the curve for our stock '08 test bike. As impressive as it is, 119 horsepower isn't enough to compete with the full-on FX bikes; other Triumph teams are reporting as much as 130 horsepower from their engines. We dropped our engine off at Hypercycle with a request for Carry Andrew to "work some magic," and he delivered: The rebuilt motor was much stronger. Unfortunately we didn't have a chance to get it on our dyno-we'll explain why in part II of the story.
Carry Andrew's Hypercycle
Longtime SR readers will be well familiar with Carry Andrew and his Hypercycle high-performance shop based in Van Nuys, California. As a crew chief and team owner, Andrew has worked with a long list of notable riders and claimed multiple AMA Supersport championships since Hypercycle was established in 1978. Along with the company's race-team efforts, Andrew has found time along the way to build a variety of wicked-fast sportbikes that have been featured in these pages, ranging from a 188-mph GSX-R600 to a totally streetable Bandit 1200S. More recently, the Kawasakis our editors have ridden in their "Riding With Legends" exploits have all been built in the Hypercycle shop.
Based on his extensive history working with a variety of different manufacturers, we entrusted Andrew with building our Triumph's engine even though he had never seen inside a motor from the Hinckley factory. And when the engine-built to the specs outlined in the kit manual-came back with a bit less power than we were hoping for, he knew exactly how to uncork more steam from the little three-cylinder mill, returning it in a decidedly peppier state of tune than the first iteration.
As busy as we keep him, the former AMA Superbike racer still finds time to ride and can often be found circulating either Willow Springs or Buttonwillow at one of Hypercycle's own track days.
Kasey's Auto Body