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Discussion Starter #1
Hi guys, I just wanted to share some discoveries I made while working on a suitable front brake upgrade.

Firstly, I am doing this upgrade after successfully completing a 3s-gte conversion from an ST215 Caldina donor. The vehicle is now really quick but the stock brakes just can't fill the bill. In the process, I got to try the calipers of the Caldina and the mounting width is a perfect match with our Rav4. Funny thing is that the Caldina only uses a 275mm rotor but when you mount the Caldina Caliper on the Rav, you can put in a 315mm rotor without any problems. One thing that I have a problem with is that I have limited access to parts from models we don't have here in the Philippines. I have access to a rotor from a 96 Lexus LS400 which is 315mm in diameter and is 28mm thick but the the height of the hat is too tall (54mm) and will require that I put a 1/4 inch spacer between the hub and rotor which now completely covers the center lip and prevents my wheels from being hubcentric. This is not something I want to do. Our Rav has a hat height of only 46mm and the best match for it is from a Supra twin turbo which has a height of 49mm but I will now need to shave the diameter of the supra rotor because it rubs due to its 324mm diameter and also reduce the thickness from 30mm to 28mm. I was about to order a supra rotor when a new development came up.

I am now in possession of the calipers from a JDM Celica GT-Four and the 4-pot unit looks really massive and yet is super light due to its aluminum chassis. The bolt width is also perfect. I plan to use these now but have to make some minor modifications like tapping some threads into them. These units have clean bores while the Rav and Caldina have threaded bores. The nice thing with this particular calipers is that it will now allow me to use the Supra rotor without even shaving the diameter or thickness of the rotor. All these are easy to fix and I even have a larger diameter brake master on hand. My problem though is that I still have rear drums and the combination of GT-Four calipers up front and drums in the rear will make for some nasty nose diving behavior. I am now in the process of coming up with a rear disc solution but will post my questions to this in another thread. Thanks for reading.

Her
 

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Please keep us posted! I've got a pair of st205 4 pot calipers laying around as well, would be keen on a trouble free conversion. Should we be weary of tapping the soft aluminum of caliper? do you think a high tensile bolt/lock nut work better?
 

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Discussion Starter #5
Well, I finally finished my project and while I did not get to use the ST205 front calipers, I ended up with a decent setup nonetheless. Here are my discoveries.

1. You can use the ST205 caliper but you will need to tap threads into the knuckle mount. Don't tap threads into the ST205 calipers because they are mounted differently. The stock Rav4 caliper mounts on the outer side of the knuckle and it is the one with the threaded section.

2. When using the ST205 caliper, it will be mounted on the inner side of the knuckle which is why you will need to tap the holes on the knuckle itself. You will now end up using 2 bolts that are both slightly longer by 3/8 inch and also larger in diameter in order to fit the new threaded section of the knuckle. Before you do this, please consider this further requirement.

You will need brake rotors that are 330mm in diameter and it will need to be 30mm in thickness. The original Supra twin turbo rotor which is 324mm will still be a little small and part of the brake pad will extend past the rotor which is not an acceptable result. If you are in the U.S., this can be easily solved by using the rotor from a Lexus GS350 which is 30mm thick and 334mm in diameter. You will need to have this machined down to 330mm. The rotor of the GS350 also has the perfect hat height of 51mm. This will put the rotor right in the middle of the two pads without the need for refacing the rotor.

This will be a perfect fit. Here's the one slight problem. With a 330mm front rotor and a 4-piston calliper in front, you will need to replace your brake master cylinder with one from a '99 Lexus RX300 so that your pedal doesn't need to travel too long. The other problem, which convinced me to abandon this setup is that the brakes will be too front biased and will tend to make the nose dip everytime you step heavily on the pedal. We really need to get rear discs for this to be more balanced and then this will be one phenomenal brake system. I am already looking at the rear disc setup of the Rav4.2 and with a little creativity, it can be made to work.

HERE IS THE SETUP I ENDED UP WITH...

I ended up using the front calipers of the Toyota Caldina which are 2-piston instead of four. Because parts for a Lexus are harder to come by here in Manila, I had to get creative and look for alternative rotors that could be made to fit. I needed a 315mm rotor that was 28mm thick and had a hat height of 49mm. None of the Toyota models being sold here had that configuration. Fortunately, through much cross-referencing, I found that the 2014 Mazda CX-9 had a rotor that was 320mm in diameter but had the right hat height and the 5x114 bolt pattern. However, the centerbore was 70mm instead of the Toyota's 62mm. Fortunately I had a hub centric sleeve that was wide enough to cover the entire lip of the hub and so the hub fit was perfect all the way to keeping even my wheels hub centric. After having the rotor machined down to 315mm, the rest was history. I am now very happy with the brakes. The icing on the cake was that I did not even need to replace the brake master cylinder and pedal modulation was excellent. I'll post pictures shortly.

I haven't abandoned the idea of using the ST205 calipers but i'll switch to those only when I have solved the rear disc conversion. Thanks for reading.
 

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Thanks for the in depth reply! Once I get my rav on the road I may explore the st205 conversion, I have a st185 master cylinder handy so that might be appropriate to actuate them.. Currently swapping the rear disk set up from a 2000 model rav on to mine. Just wondering if I need to swap the brake bias valve as well, I assume- Yes.. ?
 

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Discussion Starter #9
Frontlever,

I would be interested to hear about your rear disk conversion using the 2000 Rav4 rear brake components. I have been planning to do it but have not had luck with finding a set from the yards here. I am optimistic that if the rear brake from a Rav4.2 works on our units, the swap to a full ST205 system will be quite straightforward. Good luck on your search and please keep us posted. Thanks.
 
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