Option 3 - Big Disk Front Brake Upgrade Kit

LAST UPDATED: 12/1/08

NOTE: This kit is designed for racing use only. It is not for use on public roads, or on street registered vehicles. Read bottom of page for further details.

Complete kit designed for any rear wheel drive Gemini, models TX-TG.

This brake kit is for those who have Gemini race cars who need some serious stopping power. Perfect for any form of motor sport where high speeds are encountered. Supplied with semi-metallic brake pads with a higher temperature rating than standard OEM brake pads. This kit will dramatically improve braking performance and dramatically reduce brake fade.

For a description of brake fade and the performance of the standard braking system compared to ventilated disks, check out the Option 1 - 241mm Economy Ventilated Disk Kit for more info.

This is a complete kit consisting of all new components, designed to replace your original 239mm diameter, 10mm thick solid front rotors with brand new 280mm diameter 22mm thick ventilated units. Brand new big single piston floating calipers, new semi-metallic brake pads, new brake hoses and fitting kit with brand new parts are also included. Every part needed to fit this brake kit is included with comprehensive instructions to make installation a breeze.

The calipers used in these kits have been carefully selected to have a piston diameter comparable to that of the original Gemini calipers. Due to this, no master cylinder modifications or upgrades are required. The factory brake booster and master cylinder are a great combination with this kit, making it a truly bolt on set up. NOTE: Some conversions available from other suppliers using different calipers require a replacement 1" (piston diameter) master cylinder because the standard Gemini master cylinder does not supply enough fluid volume. My kit uses the standard master cylinder and has excellent pedal feel.

The combination of the size of the piston in the caliper, the diameter of the brake rotor, and the swept area of the pad, all add up to a level of brake retardation for the front of the vehicle that is higher than that of a standard Gemini. This means that when racing, it would be possible to run more "braking" at the rear to match the increase in braking at the front. This means that use of this Option 3 kit would be ideally suited to when a rear brake upgrade has also been performed, such as the fitment of rear disk brakes.

You also retain the original Gemini hub which means no changing of wheel stud patterns or offsets. You keep the original 4x100 stud pattern and can use alloy wheels made for a Gemini or similar, as long as they are at least 15" in diameter to clear the larger caliper. This also means that if you decide to sell you car, and want to keep the brake upgrade kit, you can simply unbolt it and install the factory disks and calipers easily.

The rotors used in this kits are 280mm diameter units, 22mm thick and are ventilated. The rotors are machined to bolt onto the original Gemini hub using new cone lock nuts and washers supplied. The photo below shows the standard solid Gemini rotor compared to a ventilated unit.

Also supplied are big single piston floating calipers and new semi-metallic brake pads to suit. The calipers are machined to bolt onto the original Gemini stub axle. The calipers are also finned, which increases the surface area available to help further dissipate the heat.

The semi-metallic pads provide a higher temperature operating range compared to normal OEM brake pads. This means that at the higher brake component temperatures experienced whilst racing, these pads continue to bite hard, and resist fading and surface glazing. Other lower spec pads can deteriorate when they get hot, as the bonding chemicals (glue) that holds the pads material together seeps out of the pad, and glazes the mating surface of the disk and pad. This leads to reduced braking torque, and also causes the annoying brake squeal many cars get.

Kit includes:

2 x new 280mm diameter ventilated rotors, machined to bolt onto original Gemini hub.

2 x new PBR single piston floating calipers, machined to bolt onto Gemini stub axle.

Full set of new brake semi-metallic pads.

8 x new cone lock nuts and washers to secure rotor to hub.

2 x new PBR brake hoses to connect Gemini brake line at inner guard to new caliper.

4 x new copper washers for banjo fittings for brake hoses and calipers.

2 x brake hose mounting bolts, nylocks and washers to secure new hoses to inner guard.

2 x steering stop packers that need to be welded to the lower control arm steering stop brackets.

Complete simple to follow fitting instructions that guide you through the installation.

Just follow the comprehensive instructions provided, fit the hardware to your car, bleed the brakes, and that's it!

The installation is literally a bolt in job, with the only tricky part being welding on the steering stop packers, however this is a very simple 10 minute job than anybody with a welder can do. If you don't have a welder, drop into your local exhaust shop and they can weld them on for you, probably cost less than $20. As with any other kit on the market that uses brakes of this size, the steering stop packers required will reduce your cars turning circle slightly. NOTE: a lot of brake kit suppliers do not include steering stop packers with their kits, and I know of several race cars that don't use them, but I like to include them for piece of mind.

I am asking $585 for everything included in the list above.

Email me at benw@ncable.net.au to discuss. Kit originates from Ballarat, VIC. but postage is not a problem to anywhere in Australia. I would need to know your post code before quoting postage costs.

NOTE: Slotted or cross drilled rotors will substantially increase the price of a kit. Slotted rotors appear to have a performance benefit in my opinion, however the price increase would be an extra $200 (approximately) for slotted, and an extra $300 for slotted and cross drilled.

The kit will require at least 15" diameter wheels. Some 14" wheels will fit, but I cannot guarantee it, and I am not prepared to send kits out and then have them sent back because your 14" wheels don't clear the larger caliper.

NOTE: This kit is designed for racing use only. It is not for use on public roads, or on street registered vehicles. I am offering this kit for people with Gemini race cars, the kit is not aimed at being "Engineer Approved" so I sell it for racing use only. The disks are re-drilled to suit the Gemini stud pattern and this is not technically allowed in some states. The steering stop packers required with the kit, as with any other kit on the market that uses brakes of this size, reduce the amount of steering angle that can be applied. These are not critical issues on a race car, but it can effect vehicle compliance with the standards for registration. Every state has different requirements, you should consult a local Engineer if your goal is to use this kit on a street registered car.

The following photos show the components of the kit.

The following photos show the 280mm "BIG" brake kit installed on a Gemini showing how it all fits together.

Disks behind 16" wheels - they fill up the space nicely!!

Disks behind 17" wheels below - they fill up the space nicely behind these too!!