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Project Update - Project QuadSport Z400 ATV

Publish date: Jun 1, 2004
By: Dean Waters
Source: ATV at Off-Road.com

We are long overdue for a Project update, especially since we have been throwing a lot of dirt around with our Project LTZ400. This project has been tremendously successful to date and we are very pleased - yes, even with the availability of the newer competition machines, the YFZ450 and TRX450R. We have competed in numerous events and spent many hours of practice time on Project LTZ400. Two of those events have been long desert events - The BITD Parker 250 and the Terrible's Town 250. We FINISHED both races. Desert races are brutal on a quad and it's not uncommon for less than half of the teams to finish due to breakage, major or minor.Suspension

Project LTZ400 at the start of the Parker 250 Desert Race

The Holz long-travel A-arms and TCS shocks are working extremely well, including the rear shock which was completely reworked by TCS. This combination is allowing us a much more stable ride, so we can accomplish passes even on the rougher portions of the course. We are going to be working more on the rear suspension. We will be looking at changing the linkage, shock, and swingarm to get more travel in the rear of the LTZ400.

The DuraBlue rear axle is doing very well. We have had problems with other axles in the past with our hubs coming loose, especially with the long endurance events. NOT with the DuraBlue pin drive hubs on the Eliminator X-33 axle. We did have the axle nut back-off on us just slightly. We believe that it didn't get tightened down enough originally as it has stayed tight since we tightened it the second time. Body and Frame

Project LTZ400 at the WORCS Grand Prix in Goldendale, WA

The Clarke fuel tank has been overkill for the stock motor. (You do need to get a longer steering stem for clearance around the Clarke tank.) While the quick fill has been essential for getting out of the pits quickly on the long races, we have been getting such good fuel mileage that we probably could have had enough range for the events with the capacity of the stock tank. That said, we will be needing that extra capacity very soon as we bump the motor up to a Z450 with a Tudor's Performance kit.

(overkill part needs re-worded) Frame gusseting is pretty much mandatory for a competition LTZ400. After the first long event we discovered cracks in our frame near the upper shock mounts. The BARE gusset kit has solved that problem and the frame looks to be holding up well now. The PowerMadd handguards are working well and fit better than many of the handguards made for motorcycle applications and simply "made to work" on the ATV handlebars.

We have eliminated several pounds in the front of the LTZ400 by removing the stock headlights. In their place we have installed a lightweight screen. For the BITD Vegas to Reno race we will be installing a 3 light KC Hi Lite HID system made by SoCal Fab. Performance Reliability is critical for endurance races and to-date we have been running the stock motor. Where the courses have been tight and rough we have had all the quad we needed, but when the course is smoother and more open, we have definitely been at a disadvantage. We have absolutely lost positions on the race course because of it. The motor is the original 2003 motor with only a Dynojet kit in the carb, the Twin Air Power kit, and a Yoshimura / Suzuki slip-on exhaust. This combination has worked well and definitely provides a hit over a stock setup, but is not the hit we need to be truly competitive in the Expert Division.

Project LTZ400 at the finish line of the Terrible's Town 250 Desert Race - minus the seat.
(If anyone finds it, we'll pay to ship it back and send you an ORC t-shirt!)

The next big race for Project LTZ400 is the BITD "Vegas to Reno" race. This is the longest off-road race in the United States and covers over 500 miles. Since the course is longer, it is usually not quite as rough as some of the shorter races. This means we must have MORE power. To solve that problem our motor has been sent to Tudor's Performance in Corona, CA. Jeff has been building Suzuki ATV motors for years and we had great luck with the Honda 440EX that Jeff built for us some time ago. Jeff will be installing a 450 kit. Jeff builds some very wild LTZ's with 470 strokers but we decided to stay with the 450 for ultra reliability. Included will be Tudor's modified Hotcams. We will sacrifice some performance to keep the compression near stock, so that we can continue to run premium pump gas or a mixture of race and pump. Race gas can sometimes be difficult to get in the remote areas where we practice and race, so we have opted to keep the compression down. We will not get the performance that could be achieved with race gas but we are confident the we will get a significant enough power increase to be competitive. And over the long run we will save a little money on gas.

On the intake side of the new 450, we will be upgrading to an Edelbrock carb. We had great luck with this carb in the past and sure like the fact that we don't have jetting problems with changes in altitude. On our Honda 440EX we gained 2-3 HP over the stock carb by using the Edelbrock, and we like the endorsement that Johnson Motorsports has been using the Edelbrock carb on their Pro class Suzuki with great success.

Along with the carb we will also be switching to a 400EX air intake tube and a Pingry Racing aluminum air box that is made to accommodate the larger intake. The LTZ400 intake tube is much more restrictive than the 400EX intake tube and does not provide the kind of flow we are looking for. The Pingry box would also provide some extra strength since we had broken our stock airbox during a not-so-friendly get-off.

The long desert races have been an awesome testing ground for this Project and the sponsors products.

On the exhaust side of the motor, we will be installing a full Yoshimura system to replace the Yoshimura slip-on. This ought to do the trick in getting the air out the other side of the Tudors 450. Yoshimura has spent many hours of R&D on the Suzuki LTZ400 exhaust systems and we believe this is the best system out there for the Z400. That power does not do you any good unless you are getting all the power to the ground. We will be installing a new Tudor's Performance billet clutch basket and inside that a Barrnet Carbon Fiber clutch kit. The Barnett Carbon Fiber friction plates are extremely durable and heat tolerant and will not contaminate the oil.

To complete the performance upgrades, we will be using a Dyna programmable ignition so we get plenty of spark and have a performance curve to utilize the power the new 450 will make. The Dyna ignition offers increased spark, better starting, programmable rev limiter, and programmable ignition curves. Controls The Pro Taper bars on the Holz steering stem are working very well. We are utilizing the CR-HI Bend and find that to be very comfortable. We have installed a Motion Pro twist throttle to get rid of the thumb throttle. On the left side we have installed a Motion Pro adjustable clutch. This is working but the cable is a little on the long side and took every bit of adjustment to take up the slack. We have eliminated the stock lights/run/start cluster and replaced it with a Pingel start switch and have also added a Pingel billet kill switch. The Pingel switches are very nice, although a little spendy. The "idiot lights" have been moved into the front fender directly in front of the steering stem and that location has been working excellent.

The WORCS race provides a different environment for more testing of our Project Z400.

Tires and Wheels

We continue to use Kenda tires and Douglas wheels with great success. For the desert we have been using the 23" Kenda Claw up front and the 22" Kenda Knarly out back. Both are mounted on Douglas Ultimate Beadlocks. There is no question that the Douglas Ultimate is the best wheel for desert racing. No other wheel takes the abuse from the rocks like the Douglas Ultimate does with its rolled-edge design. For Grand Prix-style racing we are using the Kenda 20" Knarly for a little lower center of gravity where the terrain is not as rocky.

For Vegas to Reno will be adding Tire Balls to our setup front and rear. The Vegas to Reno race is always a challenge to have enough spare wheels and tires, and have them in the right locations with the right chase crew. While the Tire Balls are a little expensive, we figure they will easily pay for themselves in just this race by eliminating the need for as many extra spares. It can make a big difference in time on course also if we eliminate flats altogether, counting the time it takes to change one plus the time you lose riding 20+ miles on one.

Summary

The overall impact to the LTZ400 has been tremendous for competition, but not so much that the quad is not rideable for recreation. The ergonomics of the Z400 make it for a very comfortable ride, and having reverse is handy. It is not used that often but when it IS, you sure are glad it's there.

In our next update we will be able to report on the next round of improvements and how well they all help over 540 miles of desert terrain.

Suggestions, comments, products you would like to see tested and installed on Project Quadsport Z400? Please let us know via Email.

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