2009 genesis brake rotors

[MADDMOE]

Does anyone know of anyone on line selling cross drill or slotted rotors for the 4.6 v8 hyundai genesis, thank u

 

[Sal Collaziano]

Moved into "Brake" discussion........

 

[Turn In Concepts]

Does anyone know of anyone on line selling cross drill or slotted rotors for the 4.6 v8 hyundai genesis, thank u

Get a hold of Ken at Knsbrakes.com as he has many sources of rotors that you may need.

As an aside, I personally would skip the cross drilled.

 

[scottdk]

Well I found these on Ebay. Would be interesting to know more info about the factory rotors and also these rotors......

http://cgi.ebay.com/ebaymotors/2009...r_Truck_Parts_Accessories?hash=item20aedcdca7

Would you consider a "performance" rotor, such as what's listed here? Why, or why not??

EDIT: Here is the link from the same company, but for the V6 brakes

http://cgi.ebay.com/ebaymotors/2009...r_Truck_Parts_Accessories?hash=item20aedcdecc

 

[scottdk]

I personally would skip the cross drilled.

Do you feel the slotted rotors are better? Or maybe neither??

 

[motorsportsauthority]

Wow...Thread resurrected. I'm pretty sure Stoptech makes them now.

 

[scottdk]

Wow...Thread resurrected. I'm pretty sure Stoptech makes them now.

Yeah, I happened to run into rotors on ebay when I was bored last night. I have a friend who is a firm believer to always stick with the Manufacters stock components and not use rotors such as the above. What are your thoughts??

 

[motorsportsauthority]

LOL. Stock components aren't generally the best. They are great considering the power and abilities of the average driver. If you are more aggressive or begin to mod the vehicle, then necessary upgrades are necessary.

That said, the best example I can give is of an Evo X that we have in the shop. The factory clutch was made by Exedy. It gave up after 3,000 miles of hard driving. We then got the Exedy Stage II aftermarket for it. Died after 2,500 miles. Now there's an ACT Stage II and 3,000 miles, it's still going strong.

I will say you do have to be careful on your aftermarket choices, Some parts can be poorly made, so stick with companies that have a proven track record or willing to back up their product. I usually don't recommend the drilled/slotted rotors on ebay even if it's a reputable brand. Most rotors undergo a specific process to keep their strength. Most of the rotors on ebay are solid rotors and then drilled at their (the ebay seller's) facilities. That actually weakens the rotors. I guess what you have to decided is what are you wanting it for? If it's for show, then it should last you ok without warping. I'm going to be auto-x'ing and going on the road courses just for fun. So I'll most likely buy some Stoptech's and cryogenically freeze them for added strength.

 

[scottdk]

LOL. Stock components aren't generally the best. They are great considering the power and abilities of the average driver. If you are more aggressive or begin to mod the vehicle, then necessary upgrades are necessary.

That said, the best example I can give is of an Evo X that we have in the shop. The factory clutch was made by Exedy. It gave up after 3,000 miles of hard driving. We then got the Exedy Stage II aftermarket for it. Died after 2,500 miles. Now there's an ACT Stage II and 3,000 miles, it's still going strong.

I will say you do have to be careful on your aftermarket choices, Some parts can be poorly made, so stick with companies that have a proven track record or willing to back up their product. I usually don't recommend the drilled/slotted rotors on ebay even if it's a reputable brand. Most rotors undergo a specific process to keep their strength. Most of the rotors on ebay are solid rotors and then drilled at their (the ebay seller's) facilities. That actually weakens the rotors. I guess what you have to decided is what are you wanting it for? If it's for show, then it should last you ok without warping. I'm going to be auto-x'ing and going on the road courses just for fun. So I'll most likely buy some Stoptech's and cryogenically freeze them for added strength.

THanks for the advice... I wouldn't buy any from Ebay, but I would be interested when the stock rotors are "done" and it's time for new ones. Years ago on my grand prix I bought a set of Powerstop crossdrilled rotors from Summit Racing and they were much better then the stock rotors...but with GM, that's not saying much

 

[Disaster]

You can find a lot of discussion on drilled rotors and the general consensus is, it is a bad idea because it weakens them. They also eat through brake pads faster.

http://www.girodisc.com/techinfo.htm

http://www.xtremesystems.org/forums/showthread.php?t=192422

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[Sayantsi]

Yes, slotted or drilled rotors are good on a track only for wicking heat at the expense of durability and brake friction. Unless you're tracking your sedan, stick with solid rotors for the best functionality. Add steel brake lines, use racing pads, and keep the fluid fresh.

If you're going for looks, I think there are better ways to spend the money. Like caliper painting or an aftermarket kit.

 

[scottdk]

Hmmmmm...I've used cross-drilled rotors for years and never had one problem. I also drove the rotors HARD. Many high end vehicles use slotted or cross drilled rotors factory and even without carbon brakes seem to hold up very well.

 

[Sayantsi]

I'm not sure which high end vehicles you're referring to, but most sports cars come with flat rotors. Drilled and slotted are typically found on race and track packages because that is where they are more useful, but they are not as strong. Slotting and drilling are compromises to help keep bakes cooler and effective when hot, at the expense or rotor durability. On a track, you'll burn through pads, fluid and rotors quickly, so they are considered disposable.

Regarding the OP's question, I don't know of any aftermarket, but I haven't looked. If they're on a Genesis for normal duty, I don't personally know how long they would last.

 

[motorsportsauthority]

The cracking as you see about is exactly what I was referring to. It's the process that they go about it. If the holes are drilled AFTER the strengthing process is done, then yes, they will definitely crack. If it's done prior to, then they will generally hold up. Like I said, I generally cryo freeze them when I get them just to be on the safe side. The holes/slots allow the heat to dissipate from the rotor quicker. If the proper manufacturing technique is used, they'll hold up. It seems a bit iffy why people would blame the drilled/slotted rotors as being a bad idea and then track cars have no problems?? They'll generally change them before they crack, but that's due to a significant amount of stress, heat, and wear...and still hold up.

Because of the slots/holes, you'll definitely get more pad wear. It's just the physics of it. Again, other than cosmetics or hard racing, I wouldn't do it because of pad wear. So it's a personal decision.

 

[STREETS]

Anyone found ceramic cross drilled for the Genny yet? lol
Having the TRACK COUPE's BREMBO rotors & calipers may be a good upgrade.

 

[scottdk]

Heck even the Grand Prix GXP comes with all 4 rotors cross drilled. I was surprised too Of course factory most cars do not come this way due to the pad wear already mentioned etc. I'm still interested, especially since the reviews of the brakes on the V8 are good, but I've noticed comments are made about brake fade in the Genesis, which other cars it was tested against didn't seem to have.

 

[Sayantsi]

Ha wow. Yet cars like the Corvette come with slab rotors (on some models)...

 

[mikec]

Cross-drilling and/or slotting of brake rotors is done to allow gasses to escape. When brake pads get HOT, some of the material in them (mostly the glue-like binder material) forms a hot, steam-like gas. This gas seeps out the face of the pad... i.e. the part of the brake pad that's supposed to be rubbing the brake rotor to make you stop. The gas ends up isolating the two parts - effectively your brake pad is hydroplaning on the rotor just like a tire hydroplaning over a water puddle at high speeds. Needless to say, if the pad isn't firmly pressing against the rotor it can't do much to stop the car.

Old drum brakes really suffered from this: drum brake shoes were trapped inside the drums (no air flow to vent the heat or gas) and the technology of the glue/binder material was pretty stone-age compared to today's brakes.

Disk brakes let some of the gas escape as the rotor turns; slotting or drilling the rotors gives the gas a much better escape path though. Note too that disk brake rotors today are "vented" which means they are two parallel disks connected by a webbing. That webbing is effectively a fan: it draws air from the center of the disks and expels it out the edge of the disk assembly to cool the disks. With drilled rotors, the brake pad gasses go into the drilled holes and into the fan area - the fan helps suck away the gasses.

Drilling/slotting rotors really helps if you run the brakes often and hard - i.e. track use typically. It reduces the brake pad's friction area slightly though since the pad can't grip the hole/slot. And, as others noted, when not done correctly drilling/slotting can weaken the rotor dangerously. Race cars replace brake parts after every race typically so rotor longevity isn't a concern; total braking performance for one race is the concern. Those brakes get HOT HOT HOT and need all the help they can to dump those gasses. Note too that the type of brake pads makes a huge difference on the gasses: "organic" pads tend to stop well but suffer a lot of brake fade because they get hot and have a lot of the binder to make a lot of gas. Semi-metallic uses a different binder and a harder friction material so they last longer... but that harder friction material wears the brake rotors faster. The latest is carbon brake setups... but that's big money.

mike c.

 

[GripperDon]

Many higher performance brakes have holes drilled through them. This is known as cross-drilling and was originally done in the 1960s on racing cars. Brake pads will outgas and under use may create boundary layer of gas between the pad and the disc that is detrimental to braking performance. Cross-drilling provides a place for the gas to escape. Although modern brake pads seldom suffer from outgassing problems, water residue may build up after a vehicle passes through water, and this can also impede braking performance. For this reason, and for heat dissipation purposes, cross drilling is still used on some braking components, but is not favored for racing or other hard use as the holes are a source of stress cracks under severe conditions.
Discs may also be slotted, where shallow channels are machined into the disc to aid in removing dust and gas. Slotting is the preferred method in most racing environments to remove gas, water, and de-glaze brake pads. Some discs are both drilled and slotted. Slotted discs are generally not used on standard vehicles because they quickly wear down brake pads; however, this removal of material is beneficial to race vehicles since it keeps the pads soft and avoids vitrification of their surfaces.


W.