Option 1 - Economy Ventilated Front Disk Upgrade Kit

LAST UPDATED: 25/6/05

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

Bolt on front brake upgrade kit designed for any rear wheel drive Gemini, models TX-TG.  Perfect for weekend circuit racing, rallying, hill climbs, etc.  Will improve both braking performance and dramatically reduce brake fade. 

Although this particular kit is not designed as an "Engineer Approved" upgrade kit, it may also be ideal for when a brake upgrade is required if an engine is installed that is heavier or has more horsepower than the original.  Please consult a local Engineer if this is your intention.  The disks are re-drilled to suit the standard Gemini wheel hub and this is not technically allowed in some states such as Victoria, but this rule does not always seem to be followed too closely.  Every state has different requirements, you should consult a local Engineer if that is your goal.

If you intend to become more heavily involved in racing rather than the odd weekend stint, or if you have a high horsepower Gemini (200hp+ for example), check out my Option 2 - Performance Disk upgrade kit or my Option 3 - Big Disk upgrade kit.

This "Economy" kit is designed as a cheap and effective way to replace your existing solid front rotors with ventilated rotors, whilst retaining the factory twin piston calipers. Due to the use of the standard caliper, a change in brake bias is not an issue. Brake balance therefore remains as good as factory. This is a bolt on kit using brand new rotors, with all parts supplied. 

No master cylinder modifications or upgrades are required due to the use of the standard caliper, making it a truly bolt on set up.  You also use the original Gemini hub which means no changing of wheel stud patterns or offsets.  You keep the original 4x100 stud pattern and can use your standard steel Gemini wheels or aftermarket alloy wheels made for a Gemini or similar.  The use of any of my brake kits does not alter the way the wheels are mounted at all.

BRAKE FADE

Standard Gemini front solid rotors do a good job of pulling up the car at a set of traffic lights, but as soon as you attempt any form of performance orientated driving, you will notice that the standard brakes begin to fade.  This is due to the heat generated from the friction between the brake pad and the rotor.  The heat cannot be dissipated as quickly as it is generated and absorbed.  The result is a reduction in the amount of friction available between the pad and rotor, and it is this friction that actually does the braking.  Thus, reduced friction = reduced braking performance.  The more braking you do without ample time to allow the components to cool, the worse the performance gets.  You can push as hard as you like on the brake pedal, but the brakes simply cannot generate any more friction due to being overheated. 

This heat will travel too, overheating other components and damaging them or shortening their life.  This is especially the case with brake fluid, which can boil.  When a liquid boils, it is being converted to a gas.  Gas is compressible, whereas liquid is not.  So the normally solid brake pedal which is pushing on liquid brake fluid is now trying to push on a gas.  Instead of this gas working like a liquid, it compresses and the brake pedal can simply go to the floor, without barely actuating the vehicles brakes.  Definitely a scary feeling when approaching a corner after doing 200+ km/h down the strait.  After pumping the pedal several times, the gas compresses to a point where it starts operating the brake caliper pistons. 

This is especially the case if you have a Gemini with power levels higher than standard as you will approach corners with a higher vehicle speed, thus requiring the braking system to absorb and dissipate a higher level of heat than a slower car.  Also not only do you approach at higher speeds, you also navigate through corners more often because you are traveling faster around a race track for example.  This means there is less time between brake applications for the brake components to cool sufficiently for correct operation.

STANDARD ROTORS AND BRAKE UPGRADE

A solid rotor, as per the standard Gemini unit, is cooled by having air flowing over both the inside and outside of the disk surface as the vehicle is in motion.  A ventilated rotor has a pair of thinner disks cast together.  The benefit is that the air can flow over both outside surfaces, but also through the inside of the disks, giving effectively twice the number of surfaces for the cooling air to contact. Therefore, the ventilated rotor allows the heat absorbed by the brake componentry during braking, to be dissipated at a higher rate. This lowers component temperature, lengthens component life, and increases the assembly's resistance to brake fade. 

The standard Gemini rotors are 239mm in diameter, and 10mm thick.  With the calipers in the standard position, the pads only contact an area with a diameter of around 234-235mm.  This leaves an area at the extreme outer edge of the disk that is not utilised.  This is shown in the photo below.

 

ENTIRE ROTOR SURFACE IS

The installation is literally a bolt in job, with partial disassembly and some filing/grinding of the stock Gemini calipers required.  The caliper modification kits come with everything needed to fit the laser cut spacer plates to your calipers, and the rest of the kit allows the rotors to be mounted to the Gemini wheel hub easily.

Just follow the comprehensive fitting instructions provided, bolt the hardware on the vehicle, bleed the brakes, and that's it!  I provide instructions for both installation of the caliper and rotor to the vehicle, and easy to follow instructions on the caliper modification procedure, which is fairly simple, just takes a bit of time. 

The only thing this set up needs for operation is your original brake pads, or a new pair.  If buying a new pair, I can recommend Bendix Ultimate, they are an effective and economical pad, designed for higher temperature/performance use.

This brake kit fits behind standard Gemini 13" wheels.  So you won't need a bigger set of wheels to clear your brakes.  Also, there are some racing categories that only allow 13" or 14" wheels, which this brake kit would be ideal for.

I am asking $330 for everything included in the list above.   

Email me at benw@ncable.net.au to discuss.  Kits originate from Ballarat, VIC.  and are posted to anywhere in Australia or New Zealand.  I would need to know your post code before quoting postage costs, not the name of your city/town.

NOTE:  If you intend to ask for slotted or cross drilled rotors, the price is quite high!  The ball park would be an EXTRA $200 for a pair of slotted rotors, and an extra $300 for slotted and cross drilled.  That is extra, on top of the kit price.  Unless you are trying to keep your brake package within the confines of the standard wheels for that sleeper look, you will get better results from using the Option 2 - Performance Disk upgrade kit for the same amount of money.

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.  This is not a critical issue 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 some of the components in the kit, and the kit installed on a Gemini showing how it all fits together.  The red strip in the middle of the sample caliper highlights the laser cut caliper spacer sandwiched between the two halves of the stock caliper.