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  #1  
Old 05-01-2001, 04:41 PM
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Lightbulb

I asked this question before with no replies. Most posts relating to better rotors centre on buying aftermarket rotors as a replacement for the Subaru items, which warp.

Again, like the rear wheel bearings, this is a case of Fuji under-engineering. My suggestion is a complete transplant of rotor and calipers from a similar car that has brakes which do not warp. You would need a donor of similar weight and power, that also had 16" rims so the diameter would be similar. The problem would be the hub, would need the same spacing for the 5 studs, and might need modifying to fit other make rotors to a Subie hub.

Can any of the technical people suggest if this is feasible? Martin Rieger?, Eddycat?, Subie_qa?

The cars I would suggest having good brakes would be the Lexus coupe [2.5, 3.0 or 4.0], same weight, same speed, no warping, or a Toyota Soarer, or possibly a Nissan 300 ZX or Nissan Skyline. Once you had done the conversion, you would have a ready supply of OE pads or discs, and be no longer troubled with warping and shudder.

{I know the thought of this is going to really get to Eddycat. Putting in non Subie parts is a sacrilege, even when the original parts are not worth a s**t }
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  #2  
Old 05-01-2001, 06:23 PM
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On the other side of the coin (not a debate, mind you, just another opinion), I've had my car for almost two years now. I bought it with 109K miles. It now has almost 153K. It had OE rotors and pads when I got it (no telling how much wear at that point). I had to replace the front pads (with OE) shortly after I bought it, so, you'd think there was considerable time on the rotors). In the, approximately, 50K miles I've put on the car, I've not experienced warped rotors. I've had the occassional hard stops, and God knows they certainly had the chance to warp while heading down the mountains in Snowshoe and in the Smokies. Of course, I feel safe in saying this, since there is not a meet any time soon and I would be in danger of brakes going out and taking 24 days to have them replaced . . . just in time to drive to the meet. So, all in all, despite the paranoia I had caught from others' brake stories, I'm more than satisfied (through my experiences) with the OE equipment. Albiet, I may be hearing one of my bearings "singing." Trouble is, I can't tell which one. Guess I'll have to wait for it to get worse -- it's a mere hum at this point.
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  #3  
Old 05-01-2001, 06:58 PM
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Another addition - My car's rotors look like trash. Very thin compared to a new set. Probably the original rotors. I put on pads at 100k when I bought it, and just put a new set on at 134k (they weren't needed quite yet but the rears were squeaking so I did both). My rotors do not thump at all - again, even after the trip down the mountain at the smokies meet. If I have to brake hard from 120-60 they become useless and thump like crazy until they cool down but they apparently do not suffer any long term damage from this (yet)

However-
The womans svx had new rotors put on at 80k, and they were turned again at 98k, They thumped like hell when we bought it at 100k. There were service records with complaints of thumping from the old owner. The pads were very thin when we bought it so I figured they were heating up which caused the thumping and put new OEM pads on (same exact ones I put on my car) and they still thump now after a few easy 55mph - 0 stops.

She also has had wheel bearing problems where my svx has had none.

Hmmm......
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  #4  
Old 05-01-2001, 11:05 PM
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Lightbulb Why do Brake Rotors warp?

Well I believe the causes and solutions to this "problem" have gotten out of hand, and I believe that I may be partially guilty for it.

You have to really analyze the situation, and get to the root of the problem. What causes rotors to warp? Well I Just replaced the front brake pads on my SVX, and inside the box of the new pads was a piece of paper with some information and guidelines for installation.

One thing that particularily caught my eye said something along these lines, "Be sure to properly and equally torque all lug nuts to manufacturer specification to prevent rotors from warping."

Having read that, do you really think that these Subaru rotors were "under-engineered?" Also are you aware that the Subaru Impreza WRC's of the early to mid 90's used the same exact rotors as the STOCK SVX(same dimension, different lug pattern). Sure the SVX weighs a great deal more, but the punishment subjected to those rotors during a rally must be the equivalent to, if not exceeding the abuse that even the most spirited SVX driver could put it through!

I believe that these (like probably many other) rotors, are just highly sensitive to a precise and proper installation. That's why you get reports of some guys braking on a set forever without problems, while others experience warping within weeks of installation. Attention to detail is KEY to every service rendered upon our SVXes!

Take note of that friends!
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Old 05-01-2001, 11:12 PM
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thumping

i just experienced some thumping for the first time today.....i got worried instaneously. i was doing about 80-85mph and came up on some guy doing 50 (a car merged and cut him off)....needless to say i had to slam on the brakes. anyway, they started thumping as i applied them. about a mile down the highway i took my exit and they were fine again. it was only about 71deg outside and i hadn't done any especially hard braking up to that point (i'd only been driving for about 2 miles.) is this the sort of thing the rest of you are experiencing?
thanks.
toby
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  #6  
Old 05-01-2001, 11:19 PM
tober76b
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thanks for the tip blondeman.
i'll check my lug torque when i get the chance.
i'd imagine that the damage is already done, but maybe that'll cure it.
i'll let everyone know if it does.
toby
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  #7  
Old 05-02-2001, 02:37 AM
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Quote:
Originally posted by svxistentialist

{I know the thought of this is going to really get to Eddycat. Putting in non Subie parts is a sacrilege, even when the original parts are not worth a s**t }
It's your car, so you can do with it as you like, but yes, I do not believe in anything but stock. As for the rotors being garbage, not so. I've worked around many different car makes over those many years, and there isn't one that won't warp rotors. The answer to why rotors warp, (other than heat) isn't over torquing the things, it's *uneven* torque on the wheels when you install them. You could crank 'em down to 300 ft lbs, but as long as you did it on all the lugs, you wouldn't have a problem.
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Old 05-02-2001, 02:14 PM
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After I warped the rotors that came on my SVX when I bought it I searched around the message boards for possible solutions to this problem. The torque applied to the lug nuts was the most common response I found. When I purchased the second (current) set of rotors I also bought a torque wrench and I use it every single time I tighten the lugs. Unfortunatly this did absolutely nothing for me as my current rotors are warped. I really have no idea why they are so easy to warp on some SVXs but not others. Maybe I brake harder than I think? I think I've only slammed on the brakes once or twice since I installed these rotors (never at 80mph), that must have been enough to do it. I'm not sure what you guys mean by "thumping". For me, when I apply my brakes (especially when exiting a freeway at 65 - 75mph) my whole steering wheel shakes badly. At slower speeds this doesn't happen but they are "uneven" as if I'm lightly changing the pressure applied to the brakes (which I'm not). If someone wants to offer me another suggestion (and save me $360 on ART rotors) I'm all ears
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  #9  
Old 05-03-2001, 01:16 AM
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Torqueing turkey

Quote:
Originally posted by eddycat2000


It's your car, so you can do with it as you like, but yes, I do not believe in anything but stock. As for the rotors being garbage, not so. I've worked around many different car makes over those many years, and there isn't one that won't warp rotors. The answer to why rotors warp, (other than heat) isn't over torquing the things, it's *uneven* torque on the wheels when you install them. You could crank 'em down to 300 ft lbs, but as long as you did it on all the lugs, you wouldn't have a problem.
Eric is coming up with the same excuse about torqueing the lug nuts. It's an obvious one, and I accept it may be valid. The same reason of improper care and fitment is put forward when replacement wheel bearings growl.

In both cases, this is not the total answer. For instance, why do the originals go off in the first place, rotors or bearings? Surely one could expect that Subaru-Who-Can-Do-No-Wrong would have qualified people making the original fitment using proper tools, care, grease and torque?

It is totally unreasonable to expect the driver of a car which can better 150 mph not to need to panic brake heavily at some point in the car's life in case the heat warps the rotors. It is worse than unreasonable, it is underengineering and defective quality control in an area that will lead to the car having unsafe brakes.

I appreciate the loyalty to Subaru here, but it is wrong to defend them in areas where their commitment to quality and safety for the people in their cars is under question due to the sheer number of failures.

And nobody has yet suggested if a brake assembley from another heavy, fast and non warping car might fit an SVX.

Joe
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