which are better?

[pimpingurz]

which ones are better?

Raybestos PG+ Brake Pads OR Raybestos Quiet Stop Brake Pads (ceramic)?

this is for a J30 93. i recently bought 4 new slotted rotors for $230 and planning to get pads with shims so the darn squealing would stop. so annoying, i also hear grinding but the pads are good. past owner put craps on there.

[Q45tech]

Neither, after trying dozens of brands in our business [to try to save owners money while increasing our margins] we had to reluctantly return to absolutely nothing but factory pads [for all Infiniti and Lexus] and factory shim kits/wear sensors.............although we do give the owner the option of 3 different rotors - factory, brembo, and powerstop drilled.

Nothing compares to the factory pads for all around goodness in the varying conditions the cars experience...cold winters/hot summers and light mountain driving and bumper to bumper traffic in long commutes..........especially quietness all the way from brand new to worn out.

[maccj73]

I've been wondering about that too. I just did my brakes a couple of months ago because they were squeaking so bad I just KNEW they needed it. Once I tore them apart they all had over half life left. I still went and turned the rotors and installed new pads. Then what? 3 days later squeaking again!!!!! That's the worst thing to me.....every back yard/home garage wannabe mechanic looks at you cross-eyed like you're too stupid to know your brakes need replacing, when you know that you just did it!!!!

[fxjackso]

Again the lack of logic of the aftermarket- if it was easy to increase performance at equal cost, or if equal performance was available at much lower cost, wouldn't the factory engineers have used those alternatives?

The first thing any cut rate brake place does is use lower quality pads, and the second is to throw out the shims. How else can they do the job in 30 minutes from when you drive in?

From a confirmed user of OEM pads, and complete OEM shim kits all around. Never a squeak!

[Highway Q45]

I had to replace front "performance" pads the PO had installed due to constant squeaking, grinding noises, accelerated wear, and heavy dusting. The OEM's pads and shim kit are so much better and the sensors actually work as designed. The OEM's are very well made and you can see the difference in more uniform grain size compared to aftermarket. They do cost more but I think they'll save on rotor wear in the long run. Once they are properly bedded they seem to modulate much better at higher speeds. YMMV

[juiceman]

Use factory

Put on high quality pads available at Discount Auto and wihtin 2 weeks they were squeeling away. Di not replace shims at that time so I ordered the dealer pads from scottsdale and the shim kits. No problems or squeels to date

[dougs98Q45]

Same for me- replaced aftermarket w/ factory and squeals stopped.

[szh]

After reading all the old posts on the topic, I went with OEM pads too when I had the the Irotor.com rotors installed. The Irotors folks wanted me to switch to another brand (I forget the name), but I decided not to.

The results are fine! No squealing at all of any kind. Just good braking performance.

Z

[Q45tech]

I keep pointing out that in test done on 1998, 2000, 2002, and 2,003 Crown Vic police cars [same weight, RWD and quality brakes with dual front pistons and single rear a clone of the Q and J designs] comparing about a dozen different brands-The oem Ford performed BEST better than anything they could buy. Same with the Impala Police version and GM pads because the pad compounds were designed for the car!

The factories have the test equipment and spend the money picking brake compounds.After all, all compounds cost with a dollar or two of each other.Walnut/cashew shell oil, metal dust, carbon fibers, scrap metal, kevlar, secret formula................not much exotic here!..........Titanium hum bug, if they could get away with Plutonium they would........actually depleted Uranium would work well -very dense.

Unfortunately by the time you do a factory markup, regional warehouse markup, and a local dealer doubling you get to $80 per axle for pads that cost them $20 just like most pads you buy at discount stores.

Pretty cheap [$80] for something that lasts 40,000 miles.

Aftermaket makes one price grade of compound to fit all cars, they don't discriminate, only the metal backing plates are copies of oem design.

Which oem compound was designed for a Q/J NONE WERE....now aftermarket German pads use BMW like compounds because that what people in Germany drive but how many drive 745 or 750 most drive light 325/328.

All about the weight of the car the brake compound is trying to stop and I can assure you that engineers don't think 4300 pound rear wheel drive cars are common enough to consider spending money to design for..............what is the average weight car on the road today 3300-3500 pounds.

In the testing of Police cars NAPA [two grades] were the worst, Bendix and Hawk had some dogs too.

Only the Metal Master are up to stuff for the [Q/J] fronts but the groaning and noise must be put up with to gain the extra 10% ultra hot performance.......and you must be prepared for the decrease cold performance.

[eQlipse]

I'll be replacing brakes soon as well. Thinking about the cross-drilled from Irotors or Mastergrade.

2 Questions:

What is a shim kit & its function?

The rotors from Mastergrade indicate they are Brembo or Bradi's. Are the rotors from Irotors Brembo or Bradi as well?

[Q45tech]

The shim kit is there to dampen vibration [which is the cause of brake noise and to insulate the caliper piston from heat from the pads.Each shim kit is tuned [slots, thickness, and shape] differently for different pads and calipers and rotors.

Obviously only the oem [Akebono] has the expertise, since they actually measure the sound the brakes make on the exact car.

It amazes me that DIY don't understand or care about the results.....takes a few ugly loud brake jobs to learn oem is always best unless you are trying to FAVOR ultra hot response then noise doesn't matter at the track.

What people go thru to try and save $40-$50.

[Q451990]

The rotors from Mastergrade indicate they are Brembo or Bradi's. Are the rotors from Irotors Brembo or Bradi as well?

That's what they told me on the phone...

Heath

[pimpingurz]

I'll be replacing brakes soon as well. Thinking about the cross-drilled from Irotors or Mastergrade.

The rotors from Mastergrade indicate they are Brembo or Bradi's. Are the rotors from Irotors Brembo or Bradi as well?

i bought rotors from Mastergrade havn't had time to install them yet. they upgraded my order to zinc plated for free.

[szh]

Are the rotors from Irotors Brembo or Bradi as well?

The Irotors rotors I got for my Q were Bradi - cross-drilled and slotted by CNC machines by Irotors. However, it is my understanding that they also can provide Brmbo upon request for essentially the same price.

In the month of June, they are doing Zinc plating for free. Mine wee not, since I bought a while back.

Z

[Q45tech]

A few companies make all the rotors [in various grades] in US then they are labeled to reflect the marketing company. Obviously other countries with non union and lower cost are available.http://goldenharvest.en.alibaba.com/group/0.htmlPouring molten iron into a form is kind of an art...........it is the quality of this iron and how it is cooled and treated that makes the start of a quality rotor.

" Hayes Lemmerz International, Inc. (NYSE: HAZ) announced today that it has been awarded contracts from Nissan Motor Manufacturing Corporation USA to supply brake rotors for its Altima passenger car, and brake drums for its Frontier pick-up truck.

The brake components are being manufactured at the Hayes Lemmerz manufacturing facility in Monterrey, Mexico. Product shipments are being supplied to Nissan's Smyrna, Tenn. assembly plant. The contract is expected to result in approximately $10 million in annual sales"

"To put racing car capabilities in context, a high-performance road car will record a braking force of about 1G during extreme braking, but in Formula One the deceleration forces can be in the order of 3.5G. That's enough to bring a driver close to blacking out, to distort his eyeballs (and consequently blur his vision), and to increase his effective body weight to 270kg"

A Q might reach 0.92G with the correct tires! Taking 129 feet to stop vs 60 feet to stop from 60 mph for the Formula car.

[Jeff Williams]

I can testify to the fact that factory pads are the way to go. I went through every pad manufacturer Auto Zone had for my '95 Maxima, before I got my moeny, and bought the pads at the dealership. I would replace the brakes, then a few days later the noise would come back. They were for my wife's car, so the brakes had to be perfect. Ironically, the factoy pads were $2 cheaper than the high performance pads from Bendix.

[Q45tech]

There is nothing magical about pad material every competitor buys some of the other's pads to test compounds.And the chemists are constantly test various materials to try for an edge..........but they don't test the pads on cars they build them for...........way too expensive.

Only the oem are tested on THE EXACT car!...........now Metal Masters /Stillen branded have been tested on so many Nissan 300zxtt/SER/Q etc that the downsides are know..........why many aftermarket rotor companies suggest them...........kind of aftermarket performance standard against which other pads can be compared. MM are not racing pads just have a little higher fade point [approximately 200F higher than oem] but they are tricky in cold climates whereas the oem are decent.

What most don't consider is that pads are designed to work in narrow ranges and if you raise the pads and do correct rotor cooling you will fry the rotors quickly.

Even using MM on my Q front and oem rears dramatically changes the wear warp rates on the rears as the MM attack bite is different so I am using more rear braking during slow or non agressive stops.......thus the rears wear and warp faster than with oem front pads.........balanced action!

I do a lot of mountain driving thus the MM are worth the downsides.

[Q45tech]

http://mvainc.com/case/case-brake.html"Examination by PLM and SEM determined the overall composition of the product to be a pulped Kevlar®, iron powder and ribbons, calcium fluoride, silicon carbide and copper, with traces of sulfides and calcium carbonate. To analyze the distribution of these constituents the microscopist used fluorescence microscopy to determine the volume percentage of the pulped Kevlar®. The image was digitized and analyzed to reveal the volume percentage of Kevlar®. "

http://www.ducatigarage.netfir....html

Pads are not heated above 650F in lab testing yet many exceed 1100F in real world on car testing testing.

[Q45tech]

http://www.racerpartswholesale.com/pf2. ... esign.html

http://www.cyberclassrooms.net....htmlhttp://girltech.cs.rice.edu/Pa....html

[eQlipse]

I wonder would this be an option?

BRAKE CONVERSION

[Jeff Williams]

I like the disclaimer "The 12.5” Brake Conversion kit is not intended for street use. Use this product at your own risk." That always makes me feel comfortable.

[eQlipse]

Then what's the point!

[Q45tech]

The problem is that Q are heavier than 300zx tt and the difference in weight translates upward [percentagewise] by a factor of 4 in foot pounds.Remember 4300 pounds times 88 feet per second [60 mph].But the VR4 was a heavy car at 3,800 pounds due to 4 wheel drive

A Q creates/needs 920,400 ft/lbs stopping from 80 mph vs a lighter G35 or 300zx only 750,000.

">From the Puhn book, page 11.

Kinetic Energy of a moving carK (ft-lbs) = Wc x S^2/29.9

Wc = Weight of car in lbsS = Speed of car in Mph

Average Temperature Rise of Rotors (not calipers) Avg Temp Rise (F) = Kc/77.8 x Wb

Kc = Kinectic Energy change (from speed change when braking) Wb = Weight of all four rotors

1988 E28 M5s weigh around 3500 lbs and have 56 lb total rotor weight. The 300x30mm vented front rotors weigh 19 lbs each and the 283x10mm solid rear rotors are 9 lbs each.

For a 40 mph stop (40 mph to 0 mph)Kc = 3500 x 40^2 / 29.9 = 187,291 ft-lb Avg Temp Rise = 187,291/77.8 x 56 = 43 degrees F

For a 80 mph stop (80 mph to 0 mph)Kc = 3500 x 80^2 / 29.9 = 749,164 ft-lb Avg Temp Rise = 749,164/77.8 x 56 = 172 degrees F

For 120 mph to 40 mph brake (80 mph change) Kc = (3500 x 120^2 /29.9) - (3500 x 40^2 /29.9) = 1,498,328 ft-lb Avg Temp Rise = 1,498,328/77.8 x 56 = 344 degrees F "

A single 80 mph stop probably only raises the Q rotor/pads by 210-230F above ambient.

[Q45tech]

See why the oem pads are set to provide optimum friction at 120+ 30+ 230F= 380-450F --- what one would get in summer highway driving in an 80 mph panic stop...........multiple braking pursuit type driving from 100 mph to 60 back to 100 back to 60 half a dozen times would easily build up to 1000F.

By the way from the previous equation you can see that changing the total rotor weight by 1 pound would only change the rotor temperature by about 2% worst case ..........8F.........so much for trued rotors warping faster because of weight loss!

Instead of 19 pound rotors one would need 25 pound front /15 pound rear rotors to make much of a difference...........25 pounds in total more rotor weight would decrease the temperature by 44%.................but 1 pound each [x4] heavier would drop temps by 40F probably noticable........a 10% reduction???

[Q45tech]

With drilled front rotors hopefully the air flow in/out of the rotor is slightly improved more than the mass loss raises the temperature.....they may get a few degrees warmer immediately but cool faster for repeat stops.

Lexus has some tremendous cooling ducts forcing air towards the rotors similar but larger than those found on 300zxtt.

[maxnix]

So is there any possibility of adapting the LS rotors and calipers to the first generation Q45? I recall that a popular upgrade for the Soarer (SC400) is the brakes from a turbo Supra.

Who has the Turbo Supra on the board? Maybe a quick inspection would give a clue.

[Q45tech]

So you can calculate oem Q are 17.0front and 11.25 rear totalling 56.5 pounds of rotor weight.So you can calculate oem Q are 17.0 front and 11.25 rear totalling 56.5 pounds of rotor weight.

This is approximately the same rotor weight as the 1988 BMW M5 which weighed 3500 pounds. So to have a proportional mass increase they would need to weigh a total of 66.25 pounds or 9.75 pounds more~~~2.5 pounds more each.

The J30 [and 97-01Q] rear rotors do weigh 1.0 pounds more each than those on the 90-96Q.

Hope this helps you decide what you would need to really upgrade the Q brakes.

[PalmerWMD]

Thank you tech!

Fred..:bowdown:

[szh]

Hmmm ... I wish I had known to weigh my Bradi rotors (cross-drilled and slotted by Irotors) before installation.

Oh, well, maybe when I take them off, I can weigh them. Athough there will be some wear and tear, I suppose, but surely not one pound worth!

So far, they seem to be working fine with the OEM pads - I now have about 500 miles on them.

Z

[diamondj30]

lots to choose from.i use porterfield r4s pads-and rotors.no prob for me.yet to make them fade.been on car since 98.never a squeak.must use shims.check out-porterfield-brakes.com.if your worried about price,disreguard.