What pads did you use?

I use the EBC yellows, great stopping power from the word go and only further improves as you get more heat into them, experienced zero fade too.

 

I used the Porterfields, but I am upgrading to the EBC Yellow Stuff. For all the rallying I do, I need solid brakes that can handle hours of twisty canyons.

 

Got mine in the UPS system finally.
Will update after I get them installed and bedded in

Ravi

 

ZMOOTHG I think you can use 80 grit sandpaper on your pads and take off the shiny part on the pad, take your car to a "Pro Cut" shop and re-bed your setup. This article from EBC explains why some get a good performance from brand new brakes and others don't.

https://ebcbrakes.com/articles/pro-cut-lathe/

Its a geometry/alignment chassis issue and this machine can help get the rotor tuned aligned to the chassis. This is not the same thing as turning a rotor. I didn't know there was a difference either. Turning a rotor is just removing material to make it flat to the rotor by itself, this process aligns the rotor surface to the chassis geometry of the car... It also helps bedding in the rotors a good 75% initially before you even do a bedding in process leaving only 25% to do by driving. It isn't expensive does not take but thousandths off and should be available at a brake shop near you. There is a dealer locator button in the link. That should fix your brakes. They explain that most "Warped" rotors are actually not warped at all, they are mis-aligned to the chassis. This is why turning them does not fix them long term. Pro Cut will fix permanently.

I have had excellent results with Extreme 6 DOT 5.1 fluid from www.TBMbrakes.com. It lasts waaaaaaaaaay longer than factory fluid, it doesn't absorb water, its dry boiling temp is 625deg, and is great price (12.95 a bottle) I put it in all my cars and trucks. It flat out stops the fade dead. Lasts forever and a day.

For those concerned in rotor life expectancy, one might consider a Cryogenic treating of the rotors. I did that to my vehicles for years and have not touched my brakes since 2012 on my 4Runner. I have moved across the US 7 times in two years (Contract work) and had this vehicle towing at or near the max capacity down 9000 ft mountain ranges in the rockies and over a hundred thousand miles on one set of rotors with absolutely no sign of wear. They look brand new still today. Fluid still looks new. Pads are at 20% after 6 years and 100K miles. I couldn't ask for more from brakes. I can't imagine I get that good of a result and you couldn't at the very least double the life of these pricey rotors with a inexpensive treatment. This also increases the thermal capacity of the rotors.

Article on Cryo Rotors:
https://www.frozenrotors.com/help-su...ake-rotor-faq/
http://stoptech.com/products/rotors/...treated-rotors
Vendor that does Cryo:http://nitrofreeze.com/services/conv.../brake-rotors/

Just a few inexpensive tips to increase the performance/dollar of a setup.
My $0.03

 

Is anyone else interested in buying a set of these? I'd be happy to arrange another group buy if there's enough interest.

We should be able to save roughly GBP 500 per set compared to buying them individually.

 

BJS - your link above for the fluid didn't work, here -- https://www.tbmbrakes.com/product/brake-fluid/

 

Since the factory rotors are expensive, ugly and heavy I guess the two reasonable choices for new rotors are these Wortecs or drilled $375 Ebay units. Oh course you get what you pay for, but for us guys that are not track racing, $2300?? for rotors is a lot. Tempted just the same.

Last night at PIR more people cared about the Demon and I was fine with that

 

 

I have a set of these lightweight 2 piece rotors installed on my car. I haven't put more than 8000kms (~5000miles) on them. Last year I had them on with the factory XFR-S Wheels, and probably put half the miles on with that setup, and this year I had switched over to a set of light weight forged wheels.

During normal driving where I do not exceed 120km/hr (75mph), I have no vibration during acceleration, coasting or braking.

During spirited driving, at speeds greater than 120km/hr (75mph), I have no vibration during acceleration, coasting, but during braking, the vibration gets more violent the faster I'm going, and I go to slam on the brakes.

I pulled my wheels off this weekend, and inspected everything brake related (rotors, pads, etc), while in place, and all seemed well, but this only happens at really high speeds, and only during braking, this typically would have had me look for warped rotors, or un-even wear on the pads, but based on my inspection this weekend, I turned up nothing.

Are there any other components that could cause this type of behavior (wheel shaking during braking only), perhaps wheel bearings?

I figured I would ask here, before I dig any deeper, I currently have the EBC Yellow Pads installed, but I do have a set of Porterfield 4S sitting on my shelf.

I can swap pads, and see if it's pad specific, but before I take out what appear to be perfectly healthy pads, and throw in another set, I want to be sure that it isn't something else, the rotors themselves, hence me asking on this forum, or perhaps something else in the wheel/ suspension setup.


Thanks

 

A warped rotor that causes steering wheel shake when climbing down from 120+mph can't be seen with the naked eye. You'll need to measure the rotors with a runout gauge to eliminate the rotors as a cause. I have found that when the rotors aren't suspect, the cause is a tire with separating cords.

 

Since you started to notice after changing the wheels, I would suspect the wheels, the tires as remounted on the wheels, or the wheels as mounted on the car. Could be as simple as an improperly balanced wheel, or even one of the weights fell off. Another possibility could be how the forged wheel seats on the hub. Factory wheels are bored to mount over a centering ring on the hub. If the forged wheel is missing this detail or if the bore was not machined to the precise size, you might have a wheel not perfectly centered on the hub.

All things to look at...

 

Something to consider- I had EBC RedStuff pads on a BMW a while back and had similar issues. I thought I had warped the rotors, but it turned out to be deposits from the pads onto the rotors that created smooth and rough areas which resulted in the pulsing and shaking when braking. Visually, the surface of the rotors had intermittent dark areas, which I assume were the deposits. After much research, I found that these pads needed bedding more than other pads, which I had not performed when installing the new pads.
I had the rotors resurfaced, and went out and aggressively bedded the pads and the issue went away.

To bed the pads:
Accelerate up to 80mph, then aggressively brake (without triggering ABS) down to 5mph, then repeat. Do this 5-6 times until the brakes are heated. When I finished smoke literally billowed out of the fenders.
It is important that you do not come to a complete stop, or at least that you do not hold your foot on the brake when stopped, or you can warp the rotors.

I ran EBS pads on my SRT8 as well, but I bedded them following the above procedure... never any issues.

 

Earlier this week I dropped off my XFR-S at the Jaguar dealer , and all they could tell me was it was the rotors, they never took off the wheels, they simply put it on a lift and spun each of the wheels, and they noticed that they would catch at a certain spot, as they turned them. They said the front two were very noticeable, the rears slightly less.

So I picked up a dial indicator, and a magnetic base, only to find out most of the front suspension on the Jag is Aluminum, so I had to get creative. Long story short, the runout on the left front rotor is 0.004" and the front right is 0.005". I will be doing the rears shortly. I have already mounted one of my stock rotors (with ~29,000kms or ~18,125miles), and the run out on the front left is 0.002". I'll finish doing the front right, and then move onto the back and report back.

For now its not looking good, I would think the front rotors are warped. I have already reached out to Paul (at Wortec).


Agreed, hence why I picked up a dial indicator and magnetic base.


This would be true if the vibration existed at all times, during acceleration, during coasting and during braking. I would be checking the tire/ wheel balance, and that the wheels were installed correctly. However, when the vibration occurs during braking only, its less to do with the wheels/ tires, and more to do with the brakes or possibly suspension.

Pads were properly bed in, the car drove fine for over 5000kms, and only in the last 2-3 weeks have I noticed this pulsation/ vibration. Based on my dial indicator readings on the front rotors, they appear to be warped, I would typically think anything greater than 0.003" is not good, but this will vary from manufacturer to manufacturer on what they specify is within acceptable spec.

 

Yikes! 0.03" is almost 1/32"... should be visible by the naked eye. I looked up allowable runout on a brake site and found this:
"The maximum allowable runout at the rotor friction surface is 0.002 inch (0.050 mm) as stated by most manufacturers."
...or less than 10% of what you are seeing.
Makes me wonder if these lightweight rotors can even be turned. Hate to think they would need to be replaced.

 

At least the hats won’t need to be replaced, just the discs. This, though, is a disappointing development.

 

My mistake... I was off in my readings by a factor of 1/10th. The gauge I was reading has a very confusing readout went back and edited my previous post to correct all the readouts.

I'll see what Paul at Wortec comes back with.


Finished up the rear end of the car, and the rear right was out by 0.005" and the rear left was out by 0.003+".

To avoid any confusion with how many decimal places, here are some links of my readings:

• Front Left
• Front Right
• Rear Right
• Rear Left

I went ahead and installed my stock rotors with ~29,000kms or ~18,125miles (and 0.002 run out), and sure enough all vibration issues are gone.

 

I'm having the same problem but my discs are just 2k km old (with new OEM pads). Is the consensus that I've not bedded them in enough or is there a chance the discs are warped?

 

Quick update on the Wortec Rotors...

Had to take them to a machine shop to have them skimmed. Paul presented me with two (2) options:

1. Re-install as is, and follow a bed in procedure, to remove any un-even pad material off of rotors.
2. Have rotors turned/ skimmed then re-install and follow bed in procedure.

I opted for option #2, just to be sure, and based on what the machine shop told me the rotors (on the right side only) really needed to be turned.

Rotors are installed, and I followed Paul's bed in procedure, will wait till tomorrow before re-driving the car. I also opted to switch from EBC yellow pads and installed brand new Porterfield 4S pads.

Will provide an update, once I have more time in the car, later next week.

 

I have been following this thread and was hoping to find out if the above problems are unique to a few or if others are also having warping issues. Are those having problems taking their cars to the track and working these brakes harder than street usage, or are people that use their cars on the street with average/spirited habits seeing these results? I want the lighter set up, they look like our brakes should look, and to me the price is within reason if they perform well and don't suffer premature problems that require re machining or replacement. Opinion, advice, further developments?

 

I use the brakes hard when I use them, but I haven’t tracked the car. No warping issues or even any fading.