SL-C Manual: Body Accessories

You can either contact a mobile auto glass fitting professional to fit your windshield or do it yourself. Many builders farm this part out, as the cost of failure is high. A replacement windshield, with shipping, can easily be over $1000. It’s often easier to let the professionals take the risk on your behalf.

However, fitting the windshield is really not that hard, and if done carefully with two people helping, it is easy to do in a home garage.

Note that the windshield is one piece that is best final-installed after the body is painted. You should go through the dry fitting process while the car is being built, but when you are satisfied that the windshield fit is good, store it away until after the car has been painted. This makes for much smoother paint edges, and a more professional appearance.

No matter when you decide to fit the windshield permanently, first dry-fit the windshield to the body opening to be sure the fit is perfect- you don’t want to discover a poor fit when your hands are full of a windshield with sticky edges.

If your car did not come with the windshield opening already cut out, now is the time to do so. Pay special attention to the edges, and the size of the lip (flange) on which the windshield will rest. Trim the body so that the flange on which the windshield will rest is not less than 1/2” wide, and not more than 3/4” wide. 

Note that too wide of a flange will typically force the windshield to flare out at the rear edges, and generally not fit. This is a common mistake, and the single biggest cause of complaints that “the windshield doesn’t fit”.

When you are done cutting the opening, smooth it out to hide cut marks, and consider painting the body edges with black paint.

If the fit isn’t perfect, or close to it – and it should be – consider building up or adjusting the body to fit. If it does not fit well, don’t try to force it; that is a recipe for a broken windshield.

Before fitting the windshield, you should check that the black borders are wide enough to conceal and cover the required areas. It is worth checking also that you cannot see behind the A pillar covers. If you can, one simple way to fix this is to make the black borders on the windshield wider at the ends where the windshield is closest to the window edges. This can be done by masking the inside border on the windshield and then spreading windshield silicone (or better yet, the black primer used to prepare the body for the urethane sealant) to cosmetically cover the border. The spreading can be performed using a small spatula or trowel, or your finger, if you are wearing gloves. In our experience you need to cover approximately 50mm from the windshield edge. This includes the existing black edge area and the dotted black area. But the best way to be sure is to fit the dash, then roughly install the a-pillar pieces. Then dry-fit the windshield. The areas that need to be covered with primer or black silicone will be obvious.

Once you know where the primer needs to be applied, use painters tape to define the edge and paint the primer on the back edge of the windshield. Let it dry and remove the tape.
The following photo shows the standard black windshield edge.

The following photo shows the wider windshield black edge created using black windshield silicone

Once you are happy with the overall fit of the windshield in the body opening, glue the windshield in place with special windshield silicone. You can use Sikaflex windshield silicone or similar from your local auto glass supplier. 3M also makes a great product called Window Weld which is used with a primer to promote adhesion to the glass and a painted surface.

To install the windshield, first prepare the windshield opening with the primer that came with your adhesive or sealant. Always mask the body around the windshield opening to avoid having to clean up errant primer and sealant: it’s very hard to remove after if cures, and messy when uncured.

You should mask the inside of the body opening, especially if you have left the dash in place while installing the windshield. Sealant can ooze out of the opening and contact the dash or other items on the top of the chassis, so mask to prevent any excess getting on them. Urethane is hard to clean up, and when cured, will bond the dash to the windshield where it leaked if you are not careful. This is a Bad Thing.

The edges of the windshield should be thoroughly cleaned with wax and grease remover or a similar product. If your sealant instructions say to do so, apply the primer to the inside of the windshield, as you did with the windshield opening in the body.

If you are installing the outside windshield trim (see below for more details) install it now and carefully trim the ends so that they are joined in such a way as to minimize or hide the seam. Put the seam at the bottom center of the windshield. Use sealant (in very small amounts) to hold it in place, and let it dry before proceeding

Allow the primer to dry according to the directions for your sealant.

Then apply a 3/8” diameter bead of sealant to the windshield flange on the body. Be careful to apply it evenly so that the bead is continuous and consistent. 

Now place the windshield carefully on the vehicle with the windshield in the center of the body windshield opening. The best way to do this is with both doors open so a person on each side of the car can hold their side of the windshield from both the inside and outside of the car, to help move it as needed to achieve a perfect fit.

There are special windshield handles with large suction cups that are used in automobile glass shops to install windshields. These are relatively inexpensive, and can be useful, but are not necessary, especially if you have a helper when you install the windshield.

You may find it useful to use small pieces of paint (stirrer) sticks to hold the windshield in place so it is perfectly centered in the opening. Use tape to hold the windshield in position until it is fully cured.

After the windshield has cured, you can then (optionally) neatly run a bead of silicone around where the windshield meets the body. This cosmetic step should not be attempted until the windshield bonding process is fully cured. This can be performed by masking both the body edge and the windshield edge so that you have a straight line on either side of the windshield to body recess. Run silicone into this recess and wipe to produce a smooth finish. It is best to remove the masking tape before the silicone starts to cure to keep a clean line.

An alternative to using sealant around the edges is to use a rubber trim piece around the entire edge of the windshield. This is more professional-looking because it avoids the appearance of smeared sealant. A molding that works is available from Spaenaur in Canada, as part number 825-229, or check with your local auto glass shop. The picture below shows such a trim piece around the windshield. If in doubt, try the trim before you commit to it because it needs to turn a sharp corner and must not bunch up there. 

It is advisable to dry-fit the trim on the windshield before you commit to it, as everything has a tolerance, and sometimes a better fit can be achieved without the trim.

If you elect to use the trim around the windshield edge, install it on the windshield before you install the windshield on the car. You can’t put it on after the windshield has been installed.

The SL-C kit comes with a powerful 2-speed wiper motor that should give years of reliable service. It is compact, direct-drive, and permanently lubricated. The wiper has a park feature that stores the wiper arm off to the side when activated, as with most production cars.

When connected to the standard chassis wiring harness, the wiper motor is controlled by the steering column switches. Because the “slow” setting on the wiper motor is very slow, and because the switches on the column are differential switches that the chassis harness doesn’t know how to handle, any of the wiper “on” modes will cause the wiper to move at the high speed setting. In effect, you have a one-speed wiper. You can use an automatic rain-sensing system as one builder has done to make use of the low-speed circuit on the motor, as such systems typically connect to both the low and high speed circuits.

Note that as with all parts on the car, production part numbers and sources may change over time. Your wiper motor may differ slightly in appearance, but the install process is essentially the same.

The picture below illustrates one possible location for the wiper shaft hole. This is correct for a car that parks the wiper on the right side of the vehicle, which is typical for a left-hand drive car, the theory being that when parked the wiper arm is parked out of the driver’s primary vision area.

The wiper motor shaft is secured into this hole and then the end of the wiper motor is mounted to stop the wiper motor from rotating. To fix the end of the wiper motor, fabricate a small bracket with a bolt epoxied on to mount to the existing 90-degree bracket on the motor, as shown in the following picture. 

Note the aluminum spacer on the main motor shaft to help bring the wiper arm closer to the body. You can adjust the thickness of the spacer to meet your needs. The spacer shown is ½” thick.

You should seal the hole through the body to stop water intrusion etc.

The locations for this hole are shown in the following pictures.

Note that this position requires a small notch to be cut in the chassis to fit the wiper motor as shown in the above pictures. If you don’t want a notch in the chassis, you can mount the wiper arm hole an inch or so higher. Mounting the motor higher will cause a long arm to touch the top of the body above the windshield, but this can be corrected with a shorter arm if necessary. Most of the cars from the factory are installed higher to avoid cutting the notch in the top of the chassis panel. If you do cut a hole for motor clearance, be sure to seal it so water, dust and unconditioned air do not enter the interior of the car.

Confirm that the wiper motor is set to a 110-degree sweep. The sweep can be adjusted internally in the motor by following the supplied instructions. Depending on the motor position and arm length, you may find that the 110-degree setting is not perfect for your car. The motor can actually be modified to have any sweep in the 60 to 110-degree range by drilling a new hole in the disc. Careful positioning and accurate drilling are required here, so do the math (it should be obvious how the relationships work) and drill very carefully. You may want to begin with a new disc and save the old one as a backup.

The side the arm parks on can also be changed by flipping the rotor disc inside the wiper motor so be sure it is set to park on the side you prefer. To test the parking, apply 12v to the motor to start the wiper motion and interrupt it in mid-sweep. Then apply power to the “park” terminal and the arm will move to the park position. If it is parking on the wrong side, open the motor and flip the disc, then re-test to be sure. Set the wiper arm so the park position is on the passenger side of the car. This permits the maximum view for the driver.

Note that the park position of the wiper may be further than the nominal sweep motion, so plan accordingly in your mounting. Maximizing the sweep without considering the park position will result in the arm parking on the body instead of the glass. This looks sloppy and may abrade the paint.

If you use the AFI arms, you may make up a hybrid wiper arm consisting of the AFI wiper arm part that attaches to the wiper shaft connected to a traditional automotive wiper arm for ease of blade replacement. It is an easy task to take the parts from both arms and combine them into one to achieve the best of both arms.

If you choose to install windshield washer nozzles drill a hole or holes in the body as required to mount them. The washer bottle can be located in the front chassis extension on the opposite side to the brake reservoirs. If you find that there is a space restriction in that area in your car, an alternative place is inside the cockpit inside of one of the interior kick panels. 

The kit does not come with a washer, so obtaining a pump, container and related parts is up to the builder, as well as making corresponding modifications to the chassis harness.

In this section, “clear plastic” refers to the hard-coated polycarbonate headlight covers, side windows and rear window.

Some builders will choose to use some sort of threaded fastener to attach the clear plastic and not rely on just double sided tape or other adhesive to affix the windows. However, many builders just use black adhesive to hold the plastic in and avoid the use of any screws or bolts. It’s up to you. The default factory installation is to use small 10-24 fasteners, about 1/2" long, threaded into the fiberglass flange.

You may want to remove and/or replace some of the clear plastic at some stage, so it is sensible to bond the clear plastic to ensure a weather type seal, but not bond it so well that it cannot be removed without damaging the body finish.

If using screws, you can just tap a thread into the fiberglass or use threaded inserts.
The screws can be placed only at the corners of each clear plastic part. For example, the side windows could use only three screws. The screws can be black coated so that they blend into the window once the edge is painted black. You can also use black nylon screws which cannot rust although they are weaker and more fragile than metal screws.

Photos below show a screw pattern using a minimum number of screws. 

It’s a good idea to use a very light silicone adhesive bead to weather proof the clear plastic against the body.

Also, you can paint the edges where the plastic covers overlap the body. Normal paint will flake off and disintegrate, so use a paint that is designed to be applied directly to polycarbonate or other plastics. Most of them use specific primers to help the paint adhere to the polycarbonate. One such paint is available from Jerry Bickel Race Cars.

Note that if you are using the race tail, and expect to use an aftermarket scoop to force air to a filter near the end of the car, you may not want to drill holes as shown above at the very tip of the rear window. In other words, if your intake approach is to use a 4” tube from the throttle body to a filter near the end of the car, you may need to trim the body to make the tube fit, and should allow for that.

If you are using the street tail, you will have to trim the rear window bottom area to fit the revised shape of the tail. For simplicity, there is only one rear window, and it perfectly fits the race tail- but needs to be trimmed at the bottom for the street tail.

Some of the pictures in this section show a black border around the edges of the windows and headlight covers. This can be accomplished in several ways. The simplest way is to use specific paint designed for edging on polycarbonate, as available from 5-star Bodies and others. Jerry Bickel Race Cars sells “Window Border Spray Paint” for this purpose- see the link above. The use of “regular” paint not designed for use on polycarbonate will usually result in peeling.

It’s also possible to have a vinyl sign shop create edging, and apply it. This may not be as permanent, but it can be applied, and peeled off if you decide later that a different width was preferable, etc.

Mirrors and Rear Vision

Two different types of side view mirrors are available from Superlite. The first mirror shown below is the “door mount” style and the second is the “hippo ear” style.

The door mount mirrors are mounted on the front edge of the door, just below the side window.
The mounting angle for the mirrors is best determined by the builder, with the normal driver in the car, in the seat, in position as used in operation. 

In most cases, the passenger side mirror will need to have the base trimmed on an angle so the mirror base is angled in toward the driver. Neglecting this will force an extreme angle on the passenger mirror glass that looks awkward, and will limit the amount of adjustment possible. When trimming the plastic base, first pull the wires up so grinding the exact angle is easier.

A good starting place is to locate the mirrors 40mm back from the front edge of the door. The 40mm measurement is taken from the front door edge to the front edge of the mirror base.

You will need to trim and fine tune the recess hole for the side light lens to fit. If you want the glass to be recessed further into the mirror housing, then you will need to trim the mounting ribs inside the mirror base and have the mirror glass ground down. The following photo shows what recessed mirror glass looks like.

The pictures below show the inside of the door area where the mirrors have been installed. This area should be covered with upholstery to hide the fittings, or small plastic caps may be used if frequent access is anticipated.

There is no interior rear view mirror since the rear bulkhead has no opening.

To improve rear vision, some builders use dedicated rear-view cameras and an LCD screen that shows a view from one or more rear-facing cameras. These are used in current GrandAm DP cars, which also benefit from better rearward vision. See the wiki for more details about rear view cameras.

If you have selected the “hippo ear” mirrors, the mounting is obvious- place them at the upper front corner of the door. If your doors haven’t been trimmed with these in mind, you may need to build up a small fiberglass piece and epoxy it to the door to replace the part that was trimmed off. If you have excess fiberglass in the mirror corner, trim it off, so that it matches the foot of the mirror. Failure to do this will obscure vision on these mirrors.

The first picture below shows the underside of the mirror mounted on the door. Note that the door – specifically the window opening- in this case was trimmed with these in mind as discussed above.

The second picture shows the driver mirror from the rear.

The next picture shows the mirrors mounted on a car in the head-on view.

Like the original mirrors, these have a clear plastic lens through which an LED assembly can be wired to show turn signals in the mirror. The lens and LED assembly are a standard part of the mirror.

Some builders modify the hippo ear mirrors in order to extend the trailing edge farther out to hide the edge of the mirror more completely. This can be done with fiberglass and bondo if desired. Not doing so will typically result in having the mirror glass extend beyond the mirror body edge.

With these mirrors painted black, they tend to blend into the daylight-opening of the windows, making them almost unnoticeable.

Street cars will benefit from the optional fender liners available from Superlite. These fender lines minimize the amount of debris on the chassis thrown up by tires. This reduces cleaning time, particularly after driving in the wet. They also reduce the risk of paint damage and starbursts from rocks hitting the underside of the fenders.

The fender liners require a bit of fettling for a perfect fit, so be prepared to take your time when installing them. They are designed for the race tail, and will need more extensive trimming if you have a street tail, especially the rear vertical pieces in the upper left of the picture below.

Also, as noted elsewhere, do not install these until after the body fitment is completely finished, as bonding them in will force the body to be more rigid and may make the body fitment difficult or impossible later.

The complete set consists of 10 panels as shown below:

The two long panels in the upper left of the photo are mounted in the rear, over the rear suspension as shown in this picture:

They are attached to the top of the tail as shown in this picture:

You will need to trim the panels to clear the suspension mounting hardware as shown in the pictures.

The rear side panel attaches to the rear tail light panel, as shown in this picture:

Trim as needed, and carefully bond the panel edge to the interior of the wheelwell opening.
Note that the molded-in access panel has been cut out for access to the tail lights. 

Replacement of bulbs is through the opening on each side. Save the panel when you cut it out, and bond in flanges from scrap so you can screw the access panel to the tail light panel, or make aluminum panels that can be attached to the panel.

The next step in the rear is to attach the forward liner. This piece has molded-in vents that should be opened with a Dremel. The purpose of these vents is to allow air to be pumped out of the wheelwell to reduce lift. You can leave them closed if you choose, but performance will be slightly improved if you open the vents by removing the excess fiberglass.

This piece is shown in the lower left of the beginning photo in this section.

It is installed in the picture below. You may need to make bracketry- see the example in the picture.

The front fender liners are a similar design.

To begin, loosely fit both front liners together to get a sense of how they fit on the nose. The large piece with the molded-in access flange mounts as shown in the picture below.
The upper curved piece bonds in as shown.

You will need to trim the panels to clear the suspension mounting hardware as shown in the pictures.

The rear side panel attaches to the rear tail light panel, as shown in this picture:

You will need to trim both pieces to get a perfect fit for your car. 
 
When bonding in panels, use a thickened fiberglass resin (i.e., fiberglass resin mixed with a thickening agent like milled fiberglass or microspheres) or one of the many commercially available bonding agents. 3M 8115 panel bonding adhesive works well, as do others.

As with the rear liners, there is an access panel for the headlights. Cut out the panel as you did with the rear liners, using the same approach to mounting. Alternatively, just cut out the hole and fabricate small aluminum panels of the right size to screw into the fender liners. The picture below shows a panel like this.

Here is a picture with the aluminum panel installed:

Once the panels are permanently fitted, you may want to coat the guards with bed liner or a similar protective coating to reduce wear from stones and debris, as well as reduce noise.

If you are using the track splitter with the front liners, the liners will need to be trimmed to fit over the tunnels.

The kit includes a Sparco fuel filler cap and neck. The builder is expected to connect this to the fuel inlet opening in the tank. The filler neck is 60 mm OD (a little more than 2.25 inches), and the tank inlet is 2” OD so this mismatch must be corrected. 

Several approaches have been implemented in different SL-Cs, including 

1. Custom fabricated tube of the right shape and with curves that connects the fuel neck to the tank.
2. A set of pre-molded hoses that are joined with a reducer in the middle
3. A single molded hose that is attached to a modified opening in the tank
4. A modified filler neck 

To install the filler cap and neck, cut a round hole in the body for the fuel filler cap on the passenger side of the car, using the existing body molding to guide the cut. Verify the position of the opening with the spider as well as the rear shell to be sure the openings are aligned. The hole should be 90 mm in diameter. Please confirm this with your filler cap before cutting. Fit the fuel filler cap with the fuel filler neck on the inside of the body. Depending on the thickness of your body, you may need to use longer screws.

To connect the tank to the filler tube using the two pre-molded hoses and a reducer, obtain an exhaust pipe reducer from your local auto parts store that reduces from 2.25” to 2”. Obtain two fuel-rated hoses with a 90-degree bend in them; one 2” ID and the other 2.25” ID. Cut them as needed to fit the reducer, and use good quality hose clamps to hold the connections together. 

Be sure not to use regular radiator hose as it is not rated for fuel, and may start to delaminate when exposed to fuel over time. You will notice this first as clogged fuel filters with black debris.

The single custom pipe approach is neater, but requires more work. A pipe needs to be fabricated with the right bends in it and either a reducer built in to accommodate the different pipe sizes, or the filler neck or tank opening need to be modified to fit. Connect the pipe with silicone hose and good quality hose clamps. Some of the pictures below show this approach.

You can use a single hose if you can find a pre-made hose that fits. The problem is that the hose needs to make bends in two directions, and if a hose that is slightly imperfect is forced, it will tend to collapse. We don’t know of any pre-molded hoses that will work, so if you do find one, let us know!

When the fuel filler is attached to the tank, the last step is to make an overflow connection to the filler or to an external vent can like a charcoal canister. This allows the tank to breathe when being filled. If you don’t do this (and it isn’t strictly necessary), you may find that the tank cannot be filled at the speed that fuel is usually dispensed without overflowing back over the car. The only option when this happens is to fill very slowly, or fill in spurts, allowing the tank to breathe between surges of fuel into the tank. 

To connect the tank vent to the filler neck, run a hose from the tank vent (the highest outlet on the tank) to a fitting that must be welded to the filler neck, just under the opening at the top of the neck. 
In the fourth photo you can see the small hose coming off the filler tube where the connections are made to fuel tank and carbon canister. 

Don’t forget to use the supplied cork gasket between the inside of the body and the filler neck. Failure to do so will cause leaks when driving or filling the tank.

Depending on your paint scheme, you may find that a different color fuel filler is preferred. In most cases, this means anodizing instead of painting or powder coating. The latter two processes add too much thickness to the parts, and fitment and sealing become problematic. Anodizing is available in many colors, though black is one that has been used with good results in the past.

Using a carbon canister lets the fuel system breathe as the fuel level changes, especially during fueling without creating a raw fuel smell in the garage. Suggested mounting locations for the carbon canister are on the rear of the engine firewall or between the body and the cabin area just behind the door opening as shown in the following photo. Carbon canisters can be purchased new anywhere, or obtained from local junk yards. One source that a few builders have used is the Standard Motor Products Vapor Canister, manufacturer part number CP1031, available from Amazon and other source like NAPA and Advance Auto. It is shown in the photo below. 

If you chose the race tail option, your car will come with a diffuser. The purpose of a diffuser is to channel air from the bottom of the car in such a way as to maximize downforce and reduce drag, so as to improve road holding. The street tail version does not have a separate diffuser; one is molded into the rear clip.

The race tail diffuser is typically loosely mounted onto the kit at the factory. For safety you should deburr the edges of the diffuser as soon as possible after delivery. Any eventual paint or powder coat finish will also be more durable with the edges deburred. 

Mesh over the body openings can greatly improve the function & appearance of your vehicle. The mesh can be of any material, but most builders prefer aluminum as it can be easily formed and attached to the body and does not rust. Plastic mesh is also available from the usual sources (e.g., McMaster- Carr) and comes in a wide range of patterns.

Recommended areas to apply mesh material are the rear side air intakes and the roof scoop. Other areas can be covered with mesh, but we will not cover them in this manual.

To start, make cardboard templates of the openings you want to cover. You will want the mesh to be larger than the openings so that you can fold the edges down onto the body. You can then just bond the mesh onto the body using silicone adhesive or 3M 8115. 

Whatever mesh you choose, be sure you understand the void ratio (i.e., how much of the total area is open compared to the area that is closed). This will help you select a mesh that has the performance characteristics you need. For example, a mesh or screen that has a 50% void ratio means that only 50% of the air hitting the screen will actually pass through. If you mount a cooler behind such mesh, only 50% of the nominal airflow you would see without a screen is actually going to get through to the cooler. Select your mesh carefully, with a clear understanding of what is behind it, and how much air it needs to function properly.