installation instructions

718 gt4 splitter

required tools & hardware

*DBJ is not responsible for damage to you or your vehicle by installing our products. Avoid improper installations that can lead to damage by using a professional for all installations.*

Tools required

Torx T20, Torx T25, 4mm Allen, 10mm Socket

Included Hardware

(24) M6x15, (16) M6x25, (16) M6x30, (6) M6x40, (7) #8 x 1.5" screws

(26) M6 nuts, (6) M6 clip nuts.

(52) M6 washers, (29) Oversized washers

install diffusers

Preassemble the splitter by installing the two front diffusers. Take (12) M6x15mm screws, (12) M6 nuts and (24) M6 washers and install them as shown to the left for each diffuser scoop. Use 1 washer below each nut and 1 below each screw.

remove the front undertray

The front undertray must be removed first for the installation. Using a Torx T25 socket, remove the necessary screws around the tray. Once removed the underbody section should look like the right. The fender lining in each wheel does not need to be trimmed as the diffuser will fit right underneath.

install m6 clip nuts

With the under tray removed, it is time to install the (6) M6 clip nuts. In the image to the left, you can see the center 2 positions that need the clip nut.

In the image to the right, the positions of 2 more M6 clip nuts are shown. In total there are (6) M6 clip nuts to be installed.

install main mounting brackets

Carrying most of the splitter load will be (4) sets main brackets. The top parts of the bracket has 8 tapped threads and the bottoms just have through holes. These brackets are designed to clamp onto the aluminum bar as seen in the picture below.

Using (4) M6x30 screws, attach the bracket sets in each of the bottom 4 locations. Before tightening these clamps, Use a leveler to make sure they are all flat and roughly centered on the aluminum rod. For the first fitment it may take a little bit of back and forth with the splitter to make sure all the holes line up properly but there is a decent amount of room for error. Once these brackets are in their proper positions, tighten the screws.

install end mounting brackets

These 2 mounting brackets are to be installed on the each of the ends of the metal "pipe" that runs down the front of the car. This "pipe" is hollow and is the main support beam for the splitter weight. The round ends are inserted into the main support beam and used as additional fastener points for the splitter board. 

install steel wire supports

Included is a steel wire kit. This steel wire kit is meant to add additional support for the center metal pipe that sustains all of the front splitter load. Now that a larger splitter has been added, the loads have increased to the extent that the OEM steel wire is no longer sufficient at high speeds. As in the photo to the left, you can install additional cables to spread the load across multiple steel wires. We recommend adding 2 in the center and 1 on each side closer to the headlights area. Be sure to loop it around the crash beam as this is a strong structure capable of bearing the load.

Install the splitter

Once the brackets are secured, and in the right position, it is time to install the splitter onto the car. Start by lifting the splitter into place and using a couple of M6x25 screws to hold the splitter up. There are (4) screws for each main bracket for a total of (16) screws. For each screw use one of the oversized washers. Like all installations, it is recommended to not tighten down all screws until the all of the screws are in position. Although not shown in this picture, use M6x25 screws to secure the splitter to the end mounting brackets on both sides. Once the splitter is held up by a few screws, it is time to install the rest of the fasteners on the main brackets. Next, the positions circled in green require a #8 x 1.5" screw. The #8 x 1.5" screws use a T20 Torx bit. Finally, use (6) M6x40 screws in the other 6 locations highlighted in red that are not part of the main mounting bracket holes. There should be some play in the position of the splitter since the screw holes are all slots. Position the splitter as desired and tighten down all of the screws. The further the splitter extends outwards, the more downforce will be generated in the front.

Do not over torque the (6) M6x40 screws. These should just be hand tight as they are only meant to keep the splitter sealed to the bumper.