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2018 Challenger R/T Scat Pack
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Discussion Starter · #1 ·
My front rotors are warped and I need new ones. Any suggestions for a 18 Scat Pack?

Slotted, Cross-Drilled, slotted and cross drilled?

Brands?

I did some searching and couldn't find much that's helpful. I know cross-drilled saves on weight and can help with airflow but with heavier cars overheating of the rotor could be an issue because there is less material. Example: I put slotted and cross drilled rotors with ceramic pads on a 2000 Grand AM GT (3200lbs curb weight) and the braking power increased dramatically. I did the same on a 2000 Dakota SLT 4.7l and the braking power decreased a small amount (same brand/type rotors and pads). I'm pretty sure it had to do with the rotors running hotter on the truck, it might also have been from less surface area for the pad to contact, not 100% sure.

I would like rotors that are more durable than stock ones. I'm not looking to improve performance but don't want to lose any either. I know pads are a big part of the equation and I will have to replace them also so suggestions on those are welcome also.

Any one ever used slotted & cross-drilled rotors with ceramic brakes on a Scat Pack before? Would it be best to keep it just slotted with ceramic? Are semi-metallic known to be better for heavier cars like the Challenger?
 

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I don't know if you'd find anything more durable than factory Mopar rotors without spending considerably more money.

Drilled rotors have the potential to crack around the holes due to the way the metal expands and contracts with temperature. I'd stick with slotted.

Most guys seem pretty happy with the Powerstop Z26 pads. I haven't put mine on yet but apparently the stopping power is near that of the factory Brembo pad without all the dust. They are a carbon ceramic pad.

Another nice thing about Powerstop is that they come with all new hardware for your calipers (anti rattle clips and guide pins). Possible other brands might too, I only used factory and Powerstop.
 

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Discussion Starter · #3 ·
My issue with factory is the car has just 20K miles and the rotors are warped. I bought the car with just over 18K. I don't know if they were warped when I bought them and got worse since I've had it or if it happened in the few months I have had it. I do drive spirited often but am not hard on the brakes. I can't recall any time that I have had to do any excessive emergency braking.

I like the idea of carbon ceramic brakes. I read a few reviews of the Z26 pads and they were all good. I know one of the ways rotors get warped is from overheating and ceramic brakes should run cooler.
 

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I drive my car hard once a month when a group of us go driving and my rotors are in great shape (2016 Scat, 15.5k miles), and I have honked on those things from 130mph to 60mph when approaching corners and what not. I drive it hard enough that I put it up in my garage and pull the wheels off to inspect everything after each monthly drive. I was thoroughly impressed with how well the 4 piston Brembos did, though I decided to upgrade to the 6 pistons anyways.

Maybe somebody with more experience can chime in but I feel like, if you are warping factory rotors, you're going to warp the after market rotor as well (without spending tons of cash to upgrade). If you buy cheap rotors, you'll surely be disappointed.

Have you looked at your rotors to make sure they don't have material from the pads stuck to them? Sometimes the feel of a warped rotor is actually just a rotor that has material on it, causing it to be unbalanced. Have you taken them to a shop to see if they can turn them? The min thickness is 30 MM on the rotor, mine are measuring 32 MM right now, so plenty of room to turn them if you can find a shop that will.

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Discussion Starter · #5 ·
I don't like turning rotors, makes them less resistant to heat. Maybe in a not performance car.

I would spend money on good rotors if they proves better than stock, never said anything about buying cheap.
 

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The Bacon Hauler (‘12 Cop Charger)
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You might have just fallen victim to some pad etching on your rotors, giving the impression the rotors had become warped. They still have to be replaced, but the quality of the replacement is not a huge factor in recurrence of this issue. Driving habits/style is the largest contributing factor.

From Page 6 of this doc on brake judder:

“Whenever possible you should try not to come to a complete stop and leave your foot on the brake pedal when your discs are very hot. Of course it is no problem to leave the brakes applied at intersections etc. during normal urban driving because the brakes are not excessively hot under these conditions.

Discs will be very hot after heavy consecutive braking or a long brake application from high speed. Leaving the brake pads clamped to a very hot disc will lead to ‘pad etching’ or ‘pad welding’ in which friction material from the pads will be unevenly deposited on the disc surface at the point of contact. This can lead to DTV and will often be visible to the eye as the outline of a brake pad on the surface of the disc.

Bear in mind that when you stop the discs no longer have air flowing over them, which means that they will cool far slower than if you were moving! People who do track days need to pay particular attention to pad etching. DO NOT pull into the pits and stop with your foot on the brake pedal after a fast lap! This will lead to pad etching, among other problems. The reason that racecar drivers have cool down laps is to allow their brakes (and other components) to cool to more moderate temperatures before parking the vehicle.

So, if you have been indulging in some fast-road driving or have braked from high speed on a highway off-ramp it is not a bad idea to let your car roll back slightly (if there is no traffic behind you) or gently edge forwards rather than leaving the brakes applied at the intersection. Also, try to slow down and allow your brakes to cool slightly before arriving home and parking your car.”


Brake Judder.pdf
 
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Nuke nailed it.

Had this happen to me when I washed my VW Golf and didn't drive it afterwards to dry the brakes. Let it sit overnight then the next day got in the car and headed out. No real use the brakes until some few miles down the road I had to slam on the brakes to avoid a collision with a stop sign runner. I brought the car to a safe stop and without thinking left the brake pedal pressed down.

Afterwards during light braking the pedal had a pulsing to it. I found I could avoid this pulsing by just being a bit more aggressive with the brakes. Nothing extreme just avoid the real light application of the brakes whenever possible.

I was so successful that at around 150K miles when I put the car up for sale -- and yes it was on its original brakes: the more aggressive braking is actually less wearing on the brakes -- during the test drive by the prospective buyer during which of course like most drivers she very lightly applied the brakes from some distance away from the stop and she noticed the pulsing and said something about it. At first I wondered what she was referring to then I remembered. I had forgotten about it.

Tried to tell her and show her how to drive the car to avoid the problem but she was not happy. So I cut the price by $200 and she bought the car and was going to have her mechanic replace the brakes.
 

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Discussion Starter · #8 ·
Im gonna pull the wheels off and take a look before I replace anything. If it is just pad etching I might get them turned just enough to remove the etching. Turning rotors for that reason is okay IMO.

Will keep you all posted. Im on lockdown with a 3 month old so it might be a few days before I get to it.
 

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Discussion Starter · #9 ·
ALL my rotors look like this. Those are not scratches, it's brake pad deposited. I don't know what pads are on the car but they look fairly fresh in terms of wear and I'm thinking the previous owner put some cheap pads on sometime before he traded it. (Got the car used from a Dodge/Jeep Dealership.)

I'm gonna clean up these rotors and put some carbon ceramic pads on.

Alloy wheel Rim Wheel Tire Automotive wheel system
 

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How do you plan to clean them? Sandpaper?

I wish I was smarter about this but, I know guys used to run a specific type of pad for a short period of time to "clean" their rotors when this type of thing occurred. Anyone else know what I'm talking about?
 

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Discussion Starter · #11 ·
I don't beleive they can be "cleaned" per say. I have to get them turned I beleive. Just enough to make the surface smooth and flat again. It's not the same as getting them turned becasue they are warped, there is much less material removed. I've never had the issue of brake etching before so umm speculating some.

Question for the brake specialists; can slotted rotors be turned?
 

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I think wasp392 just cleaned his up good


A Guy
 

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Discussion Starter · #14 ·
While I'm sure that works, I know having those small scratches means less contact surface available for the pad. But I wonder if bedding the brakes would fill the scratches? My issue is I don't really have a place I can go to bed brakes. And there seems to be more traffic everywhere with this damn pandemic. I thought people were supposed to stay home.
 
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