Installation Guide

It is important that you read this guide before you start the installation

Your rollcage kit has been designed and created in full compliance with the requirements of Motorsport NZ, in particular Schedule A of the National Sporting Code. It is designed to fit snugly inside the car so as to give protection against roof crush in the event of a rollover, without restricting access and egress unnecessarily.

When the rollcage has been properly installed, it will be able to be homologated by MSNZ for motorsport use.

The integrity of the rollcage is a function of the design and materials, but also importantly, the quality of the installation, especially the welding. This part is up to you!

On the Motorsport NZ website, we recommend you read:

• Appendix 2, Schedule A, Part 1, Article 4.6, and
• Appendix 2, Schedule A, Part 2, Article 5, and
• Guidelines for Safety Structure Homologation / Approval.

Bear in mind that most kits are designed to be floor-mounted, but some are sillmounted. It should be obvious on a trial fitting which one you have.

Notching of the tube ends is up to you. This enables you to have some choice as to where you mount some of the pieces, especially the location of the main hoop. Remember the old rule:

Don’t Cut The Tube Until You Have Measured It Twice !!!!

This guide is of necessity a generic one only. Please phone us if you need help!

Unpacking Your Kit
The main hoop pack usually contains the main hoop, the main diagonal brace, the harness bar, the two rear stays, and the floor reinforcing plates. Separate the pieces and note that each piece is named. The front laterals and the screen bar are in another pack, which may also hold other pieces if your kit is more than a basic one. Any side intrusion bars are usually in their own pack.

The Floor Plates
These plates are to be stitch-welded to the floor/side sill to provide a good base mount for the tubes of the rollcage. They must not be welded flat on the floor, so put a bend in them to go part way up the side sill. Make sure the majority of the plate surface is on the horizontal.

There are normally six plates with each 6-point kit. (Two for the main hoop, two for the front laterals, and two for the rear stays.) You may cut the rear stay ones in half if you wish, as they only have to be half the size of the main ones. Note that bolt-in kits also have extra plates for the cage feet.

Notching The Tubes
Most tubes will have to be notched to make a neat fit for welding to the other tube. If you don’t have a notcher, there are a couple of ways to do the job.
Start by holding the tube in position and marking the centreline of where the notch needs to be, top and bottom.

Method 1
Hold the tube in a vise, and cut a shallow “v” on the line about 8mm deep and 30mm wide.
Check that the “v” lines up with where you need the notch, then grind or file the “v” into a round curve shape to match the other tube. Keep shaping the notches until there is a good neat fit against the other tube. Remember if the tube is to be welded on at an angle, then one notch will be deeper than the other.
Notching this way is OK for MIG welding, but not usually for TIG, unless very neat.

Method 2
You can create a notch using a mitre saw. To notch a 38mm tube so it will fit onto another 38mm tube, set the saw at 32º, and cut a chamfer off both sides. To notch a 38mm tube to fit onto a 44.5mm tube set the saw at 25º. This method is best when the tube is to be attached at 90º, but not so good for angled attachment.

Now Follow The Steps Below.

Prepare the bodyshell
Make sure the car is sitting dead level, preferably on stands or on four tyres of the same size and profile, and pumped up hard. This will assist in holding the bodyshell square when you weld the cage in.
Disconnect the battery and ensure that any fuel lines etc are protected against sparks while welding in the car.
Remove seats, dash, trim etc.
Remove sound deadening where the floor plates are to be welded. Dry ice spread onto the seal works well to harden up the seal so it should chip off.

Front laterals
Hold one front lateral in place HARD UP AGAINST and slightly behind the A-pillar so that the centre section of the lateral is parallel with the A-pillar. The reason for mounting the lateral here is to minimise your vision loss when driving. Mark where the front footing will mount. Then mark where the top rear end reaches along the roofline. The main hoop must be located slightly forward of this place because you will lose a small amount of tube length when notching.
In some cars, there will be small lugs or brackets which may need removing or flattening to enable the laterals to fit snugly.

Main hoop
Mark the floor or sill where the hoop will sit. The hoop may be leaned back very slightly, especially to give the driver better helmet clearance. If you need to trim a bit off the bottom of the hoop, you should leave about 5mm between the roof and the top of the hoop, to avoid ending up with dents in the roof from body flex in your first event.

Floor plates
Bend the floor plates to closely follow the profile of the floor/sill that they will be welded to. Never attach the plates flat on the floor! The sill is the strongest part of the platform, and the vertical part of the plate should be welded to that. Leave the majority of the plates’ surface on the horizontal plane, as the cage legs will be welded onto that. DO NOT WELD THE FLOOR PLATES YET.

Welding the joints
Preferably ALL joints should be fully welded all the way around. But the main joints, where the front laterals meet the top corners of the main hoop, and the screen bar meets the top bend of the front laterals MUST be fully welded around.
Because there is usually not enough room for the welding torch to reach all the way round these joints, follow the procedure below

Remove the plates and the hoop and front laterals. Using a hole saw, make four holes under where the legs will sit. Refit the plates, hoop and laterals into place. Weld the notched underside of the laterals to the main hoop, and the notched underside of the screen bar to the laterals. The structure should now be fairly rigid. Then knock the plates out of the way, and allow the hoop and laterals to drop through the holes.
Weld over the tops of the four joints, then lift the structure back up and put the plates back under the legs. The plates can now be stitch-welded to the floor/sill, and the legs fully welded onto the plates.
Alternatively, you can make steel boxes to mount the four legs onto, in which case you don’t need to drill holes in the floor, because you can knock the boxes away to lower the cage down for welding over the tops of the joints.
The rest of the braces should now be able to be welded into place, BUT leave the side intrusion bars until last, so you don’t have to be climbing over them all the time.

Rear stays
Each one should be notched to mount against a top rear corner of the main hoop, with the lower end mounted onto an inner wheel arch, or the rear turret, or sometimes the rear floor area. The mounting plates should be stitch-welded onto the body.

Main diagonal brace
This brace should be installed between one top corner of the main hoop and the bottom of the main hoop on the other side of the car, or one top corner of the main hoop and the lower end of a rear stay on the other side of the car. The top end should be attached to the main hoop behind where the front lateral will meet later.

Harness bar
This should be mounted either between the rear stays, or between the vertical legs of the main hoop. It is important that the bar is installed so that the rear straps of the harness will pass over the shoulder of the driver and go straight to the bar in a slightly downward plane, without contacting the top or bottom of the seat holes. (This is so that in the event of an impact and the seat moves or breaks, the belts won’t become loose and cause injury to the driver).

Screen bar
This bar should be mounted between the top bends of the front laterals, close to the top of the windscreen. The bends should face up and forward. Make sure that the bar is a tight fit when tapped up into place.

Optional Extra Braces

Under-dash bar
This bar is mounted across the car between the front laterals beneath the steering column. You can mount the steering column and the dashboard to it.

Roof diagonal brace
This bar is usually curved upwards into the roof cavity and mounts between a top corner of the main hoop and the end of the screen bar on the opposite side of the car. If you are installing this bar, it should be tacked into position before dropping the cage through the floor, so you can weld the tops.

Transom
This should be mounted across the lower part of the main hoop legs, and may be attached to the top of the centre floor tunnel for extra rigidity

Front droppers
These should be mounted between the top bend of the front laterals where the screen bar is installed, and the base of the lateral on the same side. They may pass beside any intrusion bars, or pass through them by cutting, notching and welding them. Be careful to ensure there is adequate clearance near the steering wheel before welding the right side one in.

Front strut braces
These braces fit between the front strut tops and the front laterals inside the car. The top one is usually horizontal, and the lower one goes from the strut top down to the front lateral footing. They are normally quite a challenge to fit, as modern cars usually have bulky heaters, wiper mechanisms, fuse boxes etc in the way. Not all cars benefit from having them installed. It should be noted that it is no longer necessary to fit these braces for a Motorsport Authority Card.

Corner gussets
Tubular gussets are often fitted to reinforce the corners of the main hoop to front laterals, and screen bar to front laterals. They should be no longer than 300mm long unless they are 38.1mm rollcage tube. Any corner can be reinforced by small welded triangular steel plates however, and they do add real strength.

Side intrusion bars
Single intrusion bars should be mounted across the front door opening. The front end should be attached low down on the lateral, and the rear end higher up the main hoop, but no higher than halfway up the door opening.
Cross-type intrusion bars should be mounted the same, except that the second bar should be notched into the main bar and attached making a shallow “X” plan.
With bowtie intrusion bars, one is mounted with the ends attached to the footings of the main hoop and front lateral. The second bar is tipped upwards and positioned so that the centres of each bend are together. No notching is required at the meeting point.
Note that the bend is not in the centre of the tubes. Attach the longer ends to the main hoop, so the V point is more central in the door opening. The top bar can be rocked up or down to suit the driver before notching and welding into place.
With offset bowtie intrusion bars, the centre sections run parallel and against each other. You can’t tilt the upper bar with these.
Nascar-type intrusion bars have become very popular, and we offer several different designs. The lower straight bar is normally mounted horizontally, and the upper bar, which has a bend up at the rear, is mounted above it. We provide short upright pieces to form the traditional “ladder” in the door opening. There is a lot of notching work with these bars! We also make one-offs if you have a design you want

Lower rear braces
These bars mount between the upper stay rear mounts and the lower part of the main hoop, either down near the floor plate or behind where the upper side intrusion bars meet the hoop.

Other braces
If you have purchased other optional braces and need advice on fitting them, just phone us.

Homologation Process

Homologation
Download the application form T002A from the Motorsport NZ website (www.motorsport.org.nz) and read it. Use the information from our Tech Sheet to complete the sections regarding the tube specification and bends.

The welder/installer is the person who must sign the application form, not us.

Photos
As part of the MSNZ homologation process, you will need to take photos of various parts the rollcage installation. The photos are to show the weld quality and the blue heat penetration marks on the tubes. So DO NOT sand off the joints to make them look good! And DO NOT paint the cage until the process has been completed, in case MSNZ requires the cage to be inspected before they will grant homologation.

A hint here: Remember the staff in the MSNZ office have not seen your car, so the only information they have is what you send them. If any of your photos are not absolutely clear, they may have to ask you to take them again, or even get your local Technical Officer to actually inspect your rollcage installation, which costs money!

Log Book
For motorsport use, you will also need to apply for a MSNZ Log Book for the car. Download Form T001A for this.

Padding
Remember to attach padding to the rollcage as required in Schedule A of the MSNZ Manual.

Should you have any queries during any part of the installation, contact us. We are happy to assist where we can.