Hi guys, this is my first post, I am a long time follower of LS1TECH, and happy to of finally joined the LS1 family! Now to my question; I have 13 inch slotted rotors on the front my car, which feel to me like they are warped (obvious pulsating). I know that there are shops that still do machining of rotors, but is it possible to machine slotted rotors? I don't feel like dropping the cash to replace them if it isn't necessary.

 

they are machineable yes as long as there is a minimum spec stamp on the rotor that states the mimimum safe thickness allowed

 

Machining a rotor is only a short-term solution. Once a rotor has built these hot spots on the friction surface - not actual warping - it will happen again. Also, thinning out the rotor face reduces material and alters its thermal properties - making them more likely to "warp" again.

IMO, I would only machine the rotors if you can look into buying another set in the future. I would also suggest buying new pads when you machine the rotors and have you personally bed them in, not the shop. That way you know it's done correctly. Sometimes the cost of machining the rotors is the cost of a decent set of blank front rotors. I say buy those and then save up and get another set of slotted and keep the blanks as backups or AutoX rotors. That's what I would do.

- Kevin

 

I agree

 

That makes a lot of sense. Would I also be wise to choose another type of rotor so that this doesn't happen again? They were warped when I bought the car, it just seems to me that it should take a lot of effort to ruin them when they are a "upgraded" rotor.

 

It's a common misconception. I see it on forums all day long where people buy rotors and pads at a great deal and think they're upgrading when they really aren't. They're going to a reduced quality rotor with holes and slots in it. They look cool and they aren't pulsating like the factory brakes were, so they must be better, right? Talk to me in 20,000 miles...30,000 or 40,000. But, to be honest, street use isn't very abusive on rotors and these parts tend to work well for most street drivers. But I think brakes are a part NOBODY should go cheap on. It's a part that literally prevents you from dying and killing other people every time you drive. LOL

The only way to truly upgrade your rotors is to go with a company that uses a high grade of iron in its rotors. And trust me, you're not getting that with cheap-o eBay rotors and the like. haha Then the bed-in process for the pads if very important because it writes the story of how the pad material will apply itself to the friction surface from that point forward. An improper bed-in procedure can lead to irregular application of the pad material, which is what you're feeling when your brakes are pulsating - hot spots.

My rule of thumb for buying brake products is that if the company is well respected in the racing community, they make a good product. They run DBA off-the-shelf rotors in the V8 Supercar series. F1 cars run Brembos (albeit carbon/carbon), and Porsches win every weekend with StopTech. The big names keep their reputation by retaining a high level of quality and excellent metallurgy. That's why they cost more money. If you're on a budget, IMO I think the best rotors you can get are from Brembo, PowerSlot (same as StopTech now), and DBA.

So the only true way to prevent it is to pony up and get a set of rotors from one of the big boys. Damn...that was a novel, sorry. haha

- Kevin

 

Story or not, that is exactly what I wanted to see, thank you very much for sharing your knowledge. I won't be going cheap with the rotors I choose.

 

I also wanted to add that I will be replacing the pads as well, but wanted to ask; how do I perform the "bed-in" process?

 

I would recommend replacing the rotors if they are "warped" for the cost of new ones these days! You should use a high quality rotor that conforms to SAE specs for chemistry and hardness and do not use rotors that contain secondary scrap. Secondary scrap contains rogue elements such as tungsten, vanadium, etc. that contribute to carbide formations in the rotor. These carbides weaken the rotor and can cause stress risers and eventual cracking. Brakemotive's Kinetic brand rotors are manufactured by Powerstop! The castings are made from primary scrap and charcoal pig-iron without residual contamination from secondary scrap metals.