"Some companies offer conversion kits that while performing well, are quite expensive, utilizing custom rotors, calipers and pads available only thru mail order or special sources. We offer affordable conversion brackets that require no special pieces; items available cheaply thru local boneyards or your local NAPA or Autozone - and thru discount internet suppliers such as RockAuto.com.
For example, 1982-92 GM F bodys (Camaro and Firebird) have different axle housings for rear disc and drum applications. We offer a simple conversion bracket for the drum housing, which utilises the 1979-85 E body (Cadillac Eldorado, Olds Toronado) calipers, rotors and combination valve."
Hi Q, If you clicked on the parts page, scroll down farther. They have front disc plates too.
Here's a description from their eBay ad:
"These precision laser-cut brackets use your existing stock front drum spindles to convert to disc brakes. No machining of your drum spindle is necessary; you do not even need to remove it from the vehicle. We use GM metric calipers and 4WD S-10 rotors (10-1/2", same as original disc) to accomplish this. You will need to machine down the drum hub diameter, and do some minor reworking of the metric caliper. Done properly, you can convert to disc for less than $300. Please measure your spindle to steering arm bolts; I must know whether you have 1/2" or 7/16" bolts."
Sounds cool, eh?
2nd question, if this is a reasonable conversion, and if my Firebird is 99% original, SHOULD I modify it?
whether or not you should modify is up to you. brakes are something you can easily swap back to stock if you ever want to.
i have seen these brackets before, and i would rather spend my money on GM style brackets, and buy a spindle, or machine down my drum spindle to fit them.
the reason for this is they are stronger, and beefier. when you apply your brakes, the caliper really would like to spin with the wheel, but the bracket keeps that from happening. with floating or sliding calipers, there is a certain amount of 'slap' as the caliper moves and hits the bracket when the brakes are applied. the OE brackets go across ~1/2 of the 'slap surface', consisting of 2 parts, an inside surface ~1/4" wide, and an outside surface ~1/2" wide. these aftermarket brackets are only 1/4" wide.
without this outer surface, the caliper will tend to twist slightly more compared to OE, while clamped to the rotor during braking. this can eventually lead to uneven pad wear, and bent caliper slide pins.
i have seen bent slide pins on OE brakes owned by people who apply their brakes very hard and frequently. i would not use these dinky things, though there is nothing really unsafe about uneven pad wear and slightly dragging brakes.., it's just undesireable.
you can machine down the drum spindle to fit OE brackets for very little, and pick up some brackets from a salvage yard, or buy some. i have seen them for as little as $80/pair. then you can use the proper rotor, and all other brake parts listed for a '69 firebird.
--------------------------------------------------------- most metric calipers are low-drag. i wonder what kind of "re-working" they speak of. low-drag calipers have a seal which is cut at more of an angle, and retracts the piston more. they require a step-bore (quick take up) master cyl, or a residual pressure valve to negate this effect, which would give a low pedal with a conventional master cyl.
SixStarved, I sent a copy of your post to Scarebird and they replied:
"My brackets are made of the same thickness and material as the originals; 3/16" mild steel. When you apply the brakes, the rotor itself keeps the caliper from twisting- lot of force there, much more than the force on the bracket. My brackets are in a flat plane- so are stronger than the originals. Also, my brackets have "flats" that engage fit the caliper, just as the stock one do- the pins are there only to slide upon as the pads wear. My brackets have the following advatages:
Lighter, cheaper, components much more readily available- and you do not have to remove your drum spindle from the vehicle.
disadvantages? not stock, less clamping power, though US brakeworks sells a caliper that remedies this, and some minor machine work required.
I am working on a high performance version of this, one that uses 12" rotors and WIlwood type multi piston calipers..."
they only have the inner plane. it is not centralized to the caliper, and can not be, as the caliper changes its center as the pads wear.
it happens on OE, and even more so with these. why would GM make theirs wider? lack of research to find out they could save $10 bucks on each of over 1 million vehicles?
you can actually see it happening first hand. this is not disputable.
the bracket keeps the caliper in a semi fixed position... not the rotor. that's just common sense. on a floating caliper, there is twist. i'm not saying the bracket twists. fixed calipers use a similar bracket, but they are in a fixed position, and cannot move. floating and sliding calipers move... a sliding caliper has a bracket almost all the way across, with a spring of some sort, depending on design, and there is very little twist. a floating caliper does not rely on its slide pins, or (duh) the rotor to keep it from moving. it relys soley on the bracket. the thinner, and less centralized the 'slap' surface is, the more it acts like a fulcrum, inducing twist. the lever action changes as the pads wear, and the caliper slides inward. there is not much, but there is some, except when the surface is dead center to the caliper.
i'm not saying this is a bad product. it is not as good as OE, and is not for those who abuse their brakes (most people do), and are concerened with optimum performance. they will work fine, but depending on how you use your brakes, you may experience uneven wear, premature wear, and you will want to replace the guide pins with every pad swap (which isn't a bad idea with OE parts either).
"slap surface' is my own defenition of the surface the caliper hits when it is thrown forward or backwards by the brakes applying. it really is vey slight. the twist i speak of is nearly negligable. i would still go with OE.
