cssnms

Has anyone tried out StopTech slotted rotors on their GX?

http://www.autoanything.com/brakes/77A2722A3405063.aspx

I am considering installing them on the front this spring along with new OEM pads, curious if anyone had any more success with these vs OEM rotors.

470SNC

I ran stoptechs on my FJ, really great rotors, pair them with some hawk pads for crazy stopping power

Dashome

Yes, except mine are cryo. Been going fine with about 1k miles since the swap. I started a thread since no recent discussions have been had, but maybe you hadn't seen it: https://www.clublexus.com/forums/gx-...endations.html

Dashome

I concur slotted rotors would not provide much (if any) benefit for street use. They happened to be the most cost effective option for cryo treated rotors based on pricing the day I ordered. The advantage to Cryo treated is to (hopefully) prevent the warp issue that caused me to prematurely replace the front brakes. To the OP's question, I wouldn't recommend the added expense of slotted rotors based on standard street use, unless you have cosmetic preferences or unspecified uses.

As for the cryo treated, since I bought the truck used my driving habits or the cryo treatment may be the reason for better results. Since I still have many miles to go, it is too soon to see if I will receive the benefit of no warping.

cssnms

Improved airflow/better cooling, reduced glazing on the rotor surface, which I am hoping will 'mitigate' uneven glazing/run-out. The StopTech slotted rotors also have differential vanes which in theory helps cooling.

They are only $114 so why not?!

My old Grand Cherokee was well known for having rotor run-out problems - I can't count how many OEM rotors I went through. Then I installed slotted rotors and I did not experience any more issues with run-out during the remaining time I owned my Jeep. I hope for the same experience with my GX.



James Walker, Jr.


Slotting

Slotting rotors, on the other hand, might be a consideration if your sanctioning body allows for it. Cutting thin slots across the face of the rotor can actually help to clean the face of the brake pads over time, helping to reduce the ‘glazing’ often found during high-speed use which can lower the coefficient of friction. While there may still be a small concern over creating stress risers in the face of the rotor, if the slots are shallow and cut properly, the trade-off appears to be worth the risk. (Have you looked at a NASCAR rotor lately?)

Interestingly enough, James Walker found NO benefit to the cryo treated rotors.

Too cool!

Last year we bought 4 rotors. Two were bone stock, and two were subjected to a process know as Cryogenically Treating – one of the high-tech buzzwords floating around the paddock. The rotors were run back-to-back on the same track on the same car on the same day with temperatures taken to make sure that they saw the same level of heat. Following the track session, the parts were removed and we had them literally dissected by a materials lab.

The testing conducted included surface hardness, grain structure analysis, density, and surface scanning with an electron microscope. Guess what – after seeing the heat of use, the rotors looked identical in every regard. This is not to say that there is not a benefit from treating other parts which see lower temperatures and/or have different material properties, but treating our rotors on our car showed no tangible benefits (note that it didn’t seem to hurt anything either). Come to your own conclusions, but in our case, we’ll pass.

Break upgrade Front Rotors

As with any thermal mass upgrade, the most important step is to select and install new front rotors. The stock 330i rotors measure 12.8 inches in diameter and 1.0 inch in thickness and are tucked underneath stock 18-inch diameter wheels. In theory, a pair of 14.0-inch diameter rotors would have fit inside the stock 18-inch diameter wheels, but since we wanted to run 17-inch diameter wheels at track days, we selected 13.1-inch rotors that are 1.3 inches thick.

To further improve rotor cooling, we chose friction discs with differential vanes to replace the straight-vaned stock parts. We also went with a two-piece design to reduce radial brake pad taper at elevated temperatures, with the added benefit of reduced rotational inertia. Finally, we chose to have the friction discs slotted. (Although the additional leading edges reduce brake pad life on the street, in this application their on-track performance benefits justify the compromise. Plus, the slots provide the desirable high-performance look, too!)


http://www.teamscr.com/29-james-walk...e-upgrade.html

Through scR motorsports consulting, James Walker, Jr. has developed an extensive portfolio of vehicle dynamics and hydraulic brake system courses that he delivers exclusively through SAE International. All seminars have undergone industry technical review, received SAE approval, and are sanctioned to award Continuing Education Units (CEUs) as authorized by the International Association for Continuing Education and Training.

Dashome

Good info, based on your experience. Just checked tirerack, and they are cheaper. FYI, the cryo are 126 there. Again, not sure if it is really necessary, but hopefully it prevents me from having to replace warped rotors well before their due date.

fastnoypi

for daily drivers, i've found continuous warping is usually caused by improper torquing of the wheels , poor hub preparation when putting on rotors, and sticking calipers.

fwiw, i believe a good set of vented solid rotors are best. More pad to rotor surface area. Centric is an oem rotor supplier and parent to Stoptech.

cssnms

Hmmm, I've been on this forum since 2008 and I have owned my GX since it was new, now going 110k miles, so I have seen and heard just about all of it. I've been a part of the many brake system debates.

The fact is, James Walker has forgotten more about brake systems then anyone on this forum knows combined. Write to and describe for James Walker Jr in your professional opinion why he doesn't know what he's talking about.

I am not going to debate the theoretical benefits with someone that is only speculating. If you 'think' there are no benefits, great, don't buy them, stick with blanks.

I understand the importance of cleaning hubs when installing rotors, and or pad materials and while yes that's all fine and dandy, that is not the underlying issue with the GX brake system.

And by the way, 'machining' rotors is about the worst advise. This only reduces the mass of the rotor and thus its' ability to absorb heat which will make it more prone to run-out. It will NEVER again perform at its optimal level not to mention reducing the life of the rotor, which for a brake system that has already demonstrated it is undersized for our trucks, this is NOT a good thing.

My post was an inquiry to see if anyone else has tried this particular rotor on their GX, so I am not sure why you felt compelled to offer up an unsolicited opinion, then continue to argue about the merits of slotting a rotor as-if you are qualified to speak on the subject. Anyway, thank you for input.

BTW, I am normally a proponent of OEM blanks for every day use, but in the case of the GX I believe the brake system IS undersized which is the primary reason for frequency of run-out, hence why I am looking to improve on the thermal dynamics of the system with a slotted rotor with direction fins. This is of course short of doing a big brake upgrade.


Now if anyone else has tried these rotors on their GX I would be interested to hear how durable they proved relative to your experience with your OEM blanks.

cssnms

Not yet. Next month I am going to pick up a front set and see how they how they fare.

ChimpanZed

FWIW: I just ordered a Hawk LTS Sector 27 Brake Kit which includes pads and drilled and slotted rotors. The price is right ($364.19 front and rear) and the reviews are positive. I'll let you guys know how it pans out.