Traxxas Slayer Setup & Tuning Guide


The Traxxas Slayer® is one fast truck. The TRX® 3.3 Racing Engine could even be called "too powerful" in certain situations, but that's the way Traxxas owners like it. With so much power available, prepping the Slayer for the track requires attention to detail, as setup is crucial. Though the Slayer and Revo share the same chassis configuration and suspension design, their wheelbase and track width dimensions vary considerably. The Slayer's CG and roll center are higher, and special attention to specific areas is required. In this article, I'll explain what each setup feature is for and walk you through any modifications needed using my personal race Slayer. Let's get to it.

Firmer Damping

The Slayer responds quite well to suspension settings that are firmer than the box-stock setup. Firming up the shocks with more aggressive damping and spring rates will provide a noticeable difference. The Slayer's stock shocks are excellent, but for absolute peak performance, I use the optional PTFE-coated, hard anodized GTR™ shock absorbers (#5460X). The hard anodized GTR shocks are the same dampers that I use on my Revo, and they are known for delivering consistent damping and long-lasting performance.

Pistons

I switched out the stock pistons for the Revo variable rate piston set (#5461). Before installing the pistons, I chose a set of four-hole pistons that can be drilled out to 1.2mm. Any of the variable rate Revo pistons can be used, since stock Revo pistons are all spec'd with holes that are smaller than 1.2mm.

Drill all four holes in each shock piston with a 1.2mm (#56 or 3/64") drill bit before assembling the shock shafts. Always use proper safety gear with operating power tools. When assembling the shock shafts, pay special attention not to overtighten the valves on the pistons.

Shock Fluid / Springs

The valves are installed on top of the piston, just as they are on my Revo race truck. This increases damping on the compression stroke while allowing less damping on rebound. Faster rebound rates get the tires back to the surface quickly, keeping the truck in control with better jump and bump handling without sacrificing smooth transition. I highly recommend these pistons for the Slayer. A good base setup for this damper set is 40wt shock oil up front and 45wt in the rear shocks. After filling the shocks with fluid, I finish the shocks off by installing the springs. Up front, I really like the "double black" spring set (#5941). They stiffen up the front end, which helps keep the front from dipping going into the corners.

Out back, the double purple set does the trick, keeping the rear end off the ground and providing ample support for level jump flights.

Parts and setups used in this section
Part NumberPart Name
#5460XShocks: PTFE-coated, hard-anodized GTR
#5461Pistons: Revo variable rate, valve on top, (all holes drilled out to 1.2mm, #56, or 3/64")
 Shock oil: Front – 40wt/ Rear – 45wt
#5941
#5942
Springs: Front - double black (#5941, 2.0 rate)/ Rear - double purple (#5942, 2.3 rate)
#5460A - blue assembled
#5467A - blue bodies
#5460R - red assembled
#5467R - red bodies
Colored anodized shock bodies

Rockers

Just like the Revo, I generally keep the P2 rockers on my truck and use the sway bars for adjusting response. The P3 rockers (#5359) are recommended for situations where the track surface is very smooth. The truck will respond very well, but will get out of shape more easily in the rough sections.

Pushrod Location

The front position is fixed, so there are no alternative positions up front. However, you can adjust the length of the pushrod, but I haven't found any "must do" setup tips concerning pushrod length. The stock travel is a good balance for the track in most conditions. Shortening the front pushrods to reduce travel slightly up front can be beneficial on smooth tracks. There are two lower pushrod mounting options on the rear arms, inner or outer. The inner offers a significant amount of extra down travel, which isn't needed in most race conditions. I use the outer holes for a base setting. Also, I installed PTFE-coated aluminum hollow balls to all of the rod ends on the vehicle. These provide much smoother operation and save over a full ounce of unsprung weight.

Sway Bars

The Slayer sway bar set (#5998) is probably the most important change you can make to your suspension. The sway bar kit allows you to push the Slayer harder around the track without fear of traction rolling. It really flattens the handling of the truck and is handy for tuning steering and response.

Parts and setups used in this section
Part
Rocker arms: P2 all around
Lightweight aluminum pushrods (#5918X)
Pushrod location: front - fixed / rear - outer
Aluminum hollow balls (#5355X) – replaces all steel hollow balls; lightweight, smoother action
Sway bars (#5998) – front (mounted midway down) / rear (fixed)

Wheel Angle/ Suspension Geometry

Suspension geometries such as caster, camber, toe, track width, roll centers and bump steer change the characteristic of the chassis, not only as the truck enters or exits a turns but also as the suspension compresses and extends in and out of corners, squats during acceleration, and dives under heavy braking and over bumps and jumps. Pay close attention to these settings as they can cause your truck to handle erratically if not set properly.

Camber

"Camber" refers to the angle of the tires relative to the track surface, as viewed head-on. Instead of being perpendicular to the ground (zero camber), the tires will lean toward the chassis (negative camber) or away from it (positive camber). Negative camber is the rule in racing, but pay attention to exactly how much angle you're dialing in. While cornering, the outside tires are doing most of the work. The contact patch changes as the weight shifts to the outside causing the chassis to "roll". As the chassis rolls, the outside edges of the outside tires dig in and the inside edges of the outside tires lift up. This reduces the contact patch of the tires while the outside edge is prone to grabbing ruts and surface imperfections. This condition will cause the chassis to dart left or right and possibly traction roll from catching a deep rut. Negative camber counteracts this effect and helps maintain a larger contact patch through the entire corner. Be careful not to go too far. Too much negative camber can have equally detrimental effects as too little. Make sure that the left and right sides of the truck are set equally. Mismatched camber settings will cause the truck to react differently while turning.

Front Camber = -2.0 degFront Camber = -2.0 degRear Camber = -2.5 degRear Camber = -2.5 deg

Toe Angle

Toe angle refers to the angle of the wheels as viewed from above. If the front edges of the tires point toward each other, this is referred to as toe-in. If they point outward, then it's called toe-out. Front and rear toe settings yield different handling characteristics and should be set independently from one another.

The front toe setting directly affects the response of the chassis as it enters and exits a corner. It also changes the way the chassis rotates through a corner, and how well the chassis tracks in a straight line. Generally, setting the front wheels perfectly straight (zero toe) is a safe solution and a good starting point for your setup. I generally use a little bit of toe-out up front to initiate corners a little more effectively. This increases steering sensitivity and improves overall steering through the corner. Toe-in can reduce sensitivity and help keep the front end planted, when this characteristic is needed. I usually don't recommend toe-in as an option as improved steering is usually a welcomed change.

The rear toe setting directly affects how well the rear tires hook up under acceleration and also how well the rear end rotates through a corner. Basically, the more the rear wheels are toed in, the more bite they'll provide and the more the chassis will want to drive in a straight line. This is good for loose and slick conditions. However, the chassis will not rotate easily in the corners, causing the car to understeer or "push". Dial in enough rear toe-in to accelerate out of the corners without spinning out easily, but don't go so far that the chassis is fighting every corner. It's hard to be fast with a chassis that pushes excessively. It's also important to note that when using a center differential, rear toe settings will change. The center differential improves rear traction, so using less rear toe-in is advisable.

Parts and setups used in this section
Part/Setup
Front Toe = +0.5 deg toe-out
Rear Toe = +3.0 deg toe-in (solid shaft transmission)
+2.0 deg toe-in (center differential)
Camber = front: -2.0deg / rear: -2.5deg
Toe (links - #5938R) = front: +0.5 out / rear: +3.0deg in

Caster

This is the angle of the hub carrier as viewed from the side of the truck.If you visualize a line through the upper and lower pivot balls, you can see how this line leans toward the rear of the chassis. This is the caster angle. This setting affects steering as the truck enters and exits a corner. Positive caster describes the top of the front hub carrier being swept back toward the rear. This makes the wheels lean back as they are steered left to right. Think of this as extra camber for when the wheels are turned left or right. It also has other effects, but part of what positive caster does is it exaggerates the angle of the front wheels so that the leading edges of the tires are lifted to help scrub ruts and imperfections on the surface. This resists traction rolling when diving into a high speed or high bite corner.

Positive caster also changes the inside tire's location in relation to the outside tire. More positive caster drops the inside tire further down as the wheels are turned and actually raises the outside tire. Though the changes are small, they are very effective in creating a more aggressive pivot point with the inside tire. This effect forces the inside tire to dig and allow the outside tire to rotate around more easily under acceleration. The opposite effect occurs when entering a corner.

The important thing to remember is more aggressive caster angles enhance on-throttle steering and detunes off-throttle steering. The opposite is true with less aggressive caster angles.

Parts and setups used in this section
Part/Setup
Caster = 3 clips forward / 1 clip rear

Track Width

Thanks to the pivot ball design of the Slayer's suspension system, track width is easily adjusted by threading the pivot balls in or out of the suspension arms. Be careful not to unscrew the pivot balls to where there are more than four threads showing. Any more than this can cause the pivots to pull out of the arms during a hard crash or rollover. However, turning the pivot balls out to where a two to three threads are showing will widen the stance of the Slayer by a few millimeters, which can greatly improve stability in the rough and in through corners.

Roll Centers

This adjustment is made by changing the position of the upper suspension arm pin location. There are two positions available. The upper position allows more chassis roll and basically eases the weight transition of the chassis. The lower positions "tighten" up the chassis and resist chassis roll, kind of like a sway bar. The result is faster weight transfer, which makes the chassis more responsive to input. Since the Slayer's track width is fairly narrow compared to its wheelbase, the chassis is inherently responsive. I recommend starting with the roll center pins in the upper holes. Only use the rear pin locations as a possible adjustment. I recommend not using the lower front roll center location, since it makes the front end a little twitchy. It will also take out a considerable amount of steering from the chassis. The rear is different. The lower pin position can actually be used when extra steering is needed. However, if you're already using the Slayer sway bar kit, I recommend leaving the rear pins in the upper location.

Parts and setups used in this section
Part/Setup
Roll Center = Front: upper / Rear: upper

Ride Height

Ride height is often overlooked, but is actually a very important aspect of setup. Ride height not only keeps the bottom of the chassis from dragging the ground, it also sets the vehicle's CG. The goal is to set the ride height as low as the track will allow. This means setting the ride height high enough so that the bottom of the chassis isn't digging or bucking off of the bumps and jumps. An important thing to remember is that when the rear of the truck bucks upward off of a jump causing it to nose dive, it's generally due to the ride height setting being too low. Higher ride height setting can also improve steering, as it allows more chassis roll, which in turn increases traction to the outside tires. A ride height setting that is too high will induce traction roll and hinder response.

Ride height – Front: Shafts level / Rear: Slightly above levelRide height – Front: Shafts level / Rear: Slightly above levelRide height – Front: Shafts level / Rear: Slightly above levelRide height – Front: Shafts level / Rear: Slightly above level

Bump Steer / Reactive Toe

Like the Revo, the outer toe linkage locations on the Slayer can be adjusted up or down to change the toe angle as the arms move up and down within the stroke of the suspension. A safe bet is to always locate the links such that there is no bump steer/ reactive toe. I recommend this for the rear end at all times. Reactive toe in the rear causes too many problems on and off throttle. The gain you get on throttle is not worth the side affect you get off throttle and vice versa. It's best to set the rear end with zero bump steer.

In certain situations, the front end can benefit from dialing in bump steer. However, I still recommend leaving this alone and finding the changes you need elsewhere. Set the front end for zero bump steer, as well. Remember that changes in caster setting will change bump steer. Refer to your Slayer manual for which linkage locations are recommended for each caster setting to eliminate bump steer.

Parts and setups used in this section
Part/Setup
Bump steer = Front: upper (caster = arms back) / Rear: middle
Caster = 3 clips forward / 1 clip rear
Track width = thread out pivot balls 2-3mm
Roll center = front: upper / rear upper
Ride height = front: shafts level / rear: above level
Bump steer = front: upper / rear: middle

Steering

To improve steering performance, there are a few modifications that can be performed to the steering components to increase steering throw. Check out the steps below to get your Slayer to turn on a dime.

Parts and setups used in this section
Part/Setup
Servo = high speed, high torque, digital, coreless
Servo arm = large, long throw
Steering mods = bell crank, pin retainer, bulkhead, pivot balls
Bell crank arm, aluminum = PL aluminum arm

Differentials

From the factory, the differentials are filled with 30K weight silicone diff fluid. This is a little heavy for racing applications. As with any setup parameter, a balance is needed. For best results, it's good to lighten up the diff fluid to improve control in rough track situations and to make chassis rotation much easier in the corners. Generally, lighter diff fluid improves steering and rotation while heavier fluids allow more power to be transmitted to the tires without excessive unloading of the wheels, also known as "diffing out."

The center differential (#5914) is a great option for improved traction under acceleration and through the rough. The center diff requires the installation of the rear brake kit (#5417). This allows you to adjust brake bias independently front to rear.

Parts and setups used in this section
Part/Setup
Front diff = 10K (#5135)
Rear diff = 7K
Center diff = 100K (#5914)
Rear brake kit (#5417)

Transmission

The Slayer is crazy fast, but 50+mph top speed isn't really needed on the track. Gearing down by switching to a larger spur gear and/or a smaller clutch bell gear can help keep the engine in the proper rpm range. The close-ratio two-speed gear set (#5383) is also important for giving the Slayer extra torque in second gear. It allows you to set an early shift point without sacrificing pull. I use the close-ratio set in my Revo, as well. I think it's the best change you can make to your transmission.

Parts and setups used in this section
Part/Setup
Clutch bell/ spur (#3955) = 15/40
Close-ratio (#5383) = smooth shift, early shift point
Lube silicone (#1647 or #2716) = long life, reduce friction

Engine/ Exhaust

Removing the EZ-Start® system from the engine will reduce rotating mass as well as static weight., and removes the drag of the EZ-Start's one-way bearing from the drivetrain. Check out my starter box conversion article here for instructions on converting a conventional starter box to start a Revo/ Slayer, but don't feel that you need to make this mod in a hurry; a properly race-prepped Slayer with an EZ-Start will be much faster on a track than a bump-start Slayer with a less than ideal setup.

Parts and setups used in this section
Part/Setup
Bump start conversion = frees up engine, quicker acceleration, no one-way bearing
Back plate (#5274R)
Starter pin removal/ crank replacement (#5219R)
40mm flywheel (#4142)
Starter box = starter box article

Additional tips

Spring mount header (#5340X) = longer header, more power, easier to work on
Throttle return spring (#4045) = lighter gauge spring, easier on servo, faster throttle response
Other Accessories
TRX accessory wheels (#5973A)
TRX Power Pack RX Battery (#3036)
M2C Engine Mount Brace (M2C part #sku 1020) = Strengthens engine mount
Vented brake disc (#5364X) = Eliminate brake fade, improved braking performance
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