y2k_ta

iTrader: (80)

My question is more of a curiosity that anything else....

I've had Baer Eradispeed Rotors on my car for about two years, and I was wondering if they could ever be turned? I realize the slot will diminish somewhat after being turned, but the holes would always be there.

I don't think there are any problems with the rotors on my car yet, but just thinking about the future.

I have a slight vibration at 65 to 70 mph, and I believe part of it is due to a faulty driver's side rear shock as there is a very noticable sag on that corner of the car. I'm replacing them here in a week or two. I noticed the vibration after rotating my tires, so I could have a bad tire. From observation I can't find any bad spots or broken belts. Ok, I'm done.....

mitchntx

iTrader: (14)

http://frrax.com/rrforum/index.php?act=ST&f=2&t=753&

trackbird

iTrader: (4)

A sag would be a spring problem. Springs support the car, shocks just control the springs. A shock typically will not/can not cause a corner of a vehicle to sag (unless it is physically stuck in a position, but it would ride like it was mounted solid to the body and you'd know it for sure).

Also, usually, drilled rotors should (or any rotor) be ground at a machine shop. Like the multiple grinding pattern you find on new, high quality rotors.

y2k_ta

iTrader: (80)

Thank you for the advice guys.

So is a sagging spring a common problem for an f-body? Is there a slim chance that I'll be able to visually tell if the spring is bad? I can purchase take-offs from SLP for a very reasonable price. I just hate to buy a bunch of parts if they're not going to help. But then again I guess that's all a part of it....

trackbird

iTrader: (4)

It's not common, but it is possible. I'd unbolt the shock from the axle, push it all the way up to the body and then let it fully extend. If it feels just like the one on the non sagging side (and doesn't hang up anywhere during it's travel), it would have to be a spring problem or something is bent. I'd suspect springs before I'd think something is bent. They are inexpensive and easy to change. I'd probably start there.

y2k_ta

iTrader: (80)

I ordered a set of take-off springs from SLP today. My car has 108,000 miles on it, so anything is possible. While I've got everything apart it just makes sense to go ahead and swap out the springs too.

ta12sec

iTrader: (3)

If you picked up a vibration after roating your tires I would get them balanced if a unbalanced tire is on the rear its alot less noticeable then when you put it on the front. Yes you can turn drilled rotors (with a brake lathe) but after you cut the rotor you must use a drill to chamfer all the holes (takes forever).

y2k_ta

iTrader: (80)

I'll have the tires checked & rebalanced while I've got everything apart for the shocks & springs. One of my wheels does not have any weights on it, and that happened almost two years ago when I had the SLP take-off tires I got installed. Maybe it's taken this long to flair up?

That sounds like a lot of work for turning rotors. I'm not sure I have enough patience for that....

trackbird

iTrader: (4)

I had a bit on a brake lathe come loose and nearly destroy a flywheel I was trying to skim cut. It ran over the "gaps" on the standoffs for the bolts and hammered the cutting bit loose from the attachment. I agree that it could be done, but if the bit comes loose (like my experience) you may destroy the rotor. (Don't ask why I was turning a flywheel.....).

BADz2ATE

uh the point of cross drilled and slotted is to reduce glazing on the pads under hard stops, and to reduce heat on the rotor with the x-drilled. I dont see the need for any turning of the rotors, if you had spent that 800-1000 on those rotors, they should last forever IMO.

Mike

mitchntx

iTrader: (14)

trackbird

iTrader: (4)

I'm with Mitch.....

jRaskell

iTrader: (1)

^ If Mitch is laughing, and you're crying, how are you with Mitch? Are you laughing on the inside, or is Mitch crying on the inside?

PSU_Engineer

Purly speculation, but I think both are crying. Two years they have spent trying to educate the masses here that X-drilled do nothing for braking performance. What happens? Another person comes in proclaiming the merits of X-drilled rotors that they read on a website somewhere.

mitchntx

iTrader: (14)

1 at a time ... 1 at a time ...

jRaskell

iTrader: (1)

I'm always tempted to say let 'em believe what they want, but I realize that these beliefs inevitably propogate on to the uneducated, thus requiring a constant vigilance to educate the unedcated before they are infected.

y2k_ta

iTrader: (80)

What does crying have to do with my post???? I haven't even turned a wrench and busted a knuckle yet......

trackbird

iTrader: (4)

Yes.....

trackbird

iTrader: (4)

Ok. If I am trying to boil a pot of water with 2 gallons of water in it. It will take alot of heat to get all of that water up to boiling temperature. Right? Now, if I remove 1/2 the water, it will be easier to get that water to boil, there is less mass to absorb heat. Make sense?

Ok, If I take a 3 lb chunk of metal and a 5 lb chunk of metal and set them both over a small torch, which one do you think will heat up first? The lighter mass will see a more rapid temperature rise (it will get hotter, quicker).

Now, if I take a brake rotor that weighs 20 lbs and begin making "panic stops" with it, it's temperature will increase. Easy enough.

If I now take the same rotor, drill holes in it and it weighs 17 lbs and make the same "panic stop", would it not make sense (from the above examples) that the lighter rotor will end that stop with a higher temperature? Less mass to absorb heat will cause a more rapid temperature rise.

Many will say "cross drilled rotors cool better". Hmmm. If you really look at it, how much air do you think can blow through those little holes? Add the fact that they are spinning at a reasonably high speed and the cooling arguement becomes even less believeable. In fact, the holes could, in theory, disrupt the natural draw of air from the center of the rotor to the outside edge. That is the flow that actually cools the rotors.

Rotors were originally drilled to eliminate something known as "green fade". Green fade is kinda like playing air hocky (where the puck floats on a cushion of air from the table). A long time ago, pads were made with the best resins we could find. Many of those resins would produce gas when they got extremely hot (which would "cure" the glue, causing it to produce vapors). The vapors would get between the pad and the rotor and lift the pad away from the rotor. This caused the brakes to be very ineffective, even though they were not at the maximum temperature the pads were rated to handle (in many cases). The holes were drilled to allow that gas a place to escape. So, it is correct to say that rotors were cross drilled to eliminate fade, but not for the reasons you would think. The good news is that todays resins no longer suffer from these problem and the modern race pads are so good that this is no longer an issue. So, by cross drilling rotors, you will only manage to shorten the lifespan of that rotor (it now has less surface area to wear against the brake pad and will wear more quickly).

Baer racing told me, when I ordered my first kit from them, that drilled rotors will usually last 20% less than an equivalent solid rotor. This was why they always recommended solid rotors for extreme use. They have changed their stance on this since they learned that they could make a very large amount of money by selling "Eradispeeds" (they are pretty). I feel that they have gone from "supporting the racing community" to "making maximum money". And, I guess I can't blame them.....

Class dismissed.

Have fun!

Sorry, didn't mean to hijack your thread.....

y2k_ta

iTrader: (80)

No problem...those are very good points. I will say that for my needs, the Eradispeeds have held up way better than the factory rotors. I had warped rotors about every three months when using the factory pieces, but the Eradispeeds have been on the car for nearly two years now without any problems. Whether or not the holes and slots are beneficial really are unimportant to me when the product performs better and looks better than the originals.

Now I'm shopping for a decent spring compressor for when I swap out the shocks/springs. I've seen everything from $29.95 to $89.95.

Is there anything else related that I should consider replacing. I'm on a very limited budget, so if it's really beneficial for very little cash then I'm game....