OEM, Crossdrilled or slotted? With the winter coming up I need to replace the front rotors and pads. And on the rear just the pads. I have called my local volvo shop, ipd and another independant volvo mechanic and I have received from each conflicting info. One says use only oem, another use only cross drilled and the other only use the slotted. I'm looking for the best stopping power and not for the looks. Also just how hard is it to change the brakes? I don't have a V70 manual but how hard is it. I was quoted $180-$440 just to put the parts on. These prices were just labor rates, not the parts. Any help would be appreciated.

Bill in Denver

I've gotten the same mixed reviews. A local independant Volvo mechanic only likes OEM. Says that ANY aftermarket rotor he's put on has warped, slotted, drilled or NORMAL! I find it a little hard to believe that only OEM is trouble free. He even said that Brembo wasn't really all that good!?

IPD slotted, good, but expensive. Same as Euro Sport Tuning but $70 more. The crossed drilled Zimmermans were attractively priced, but almost too cheap ($52 ea. Front). Makes you wonder about thier quality. OEM, works well so far, but for the money, you can get slotted or even drilled and slotted.

Unless you get an upgrade kit, larger rotors, 4 to 6 piston calipers and such, you probably won't see much if any difference in stopping distance. My old car had slotted, and it "seemed" to brake better, but w/o a Road & Track style test, its all in the butt-meter.

I just ordered slotted for my 98 S70T5 from Euro Sport Tuning in Canada.

Oh by the way, if you've changed pads, changing rotors is just a few simple steps more!

Good Luck!

-Ananda

I just recently did front brakes, rotors and rear pads following

directions at:

http://volvospeed.com/bay13.htm

Easy job. Tricky part is really the grease since it is not

clear how much to apply and where. But, you will figure it out.

Took about 5 hours, taking my time.

Do not get cross drilled rotors for a street car. In fact, do not get them for a race car either. Most of the race cars that you see with "cross drilled" rotors, the holes in the rotors are cast in, not drilled. When the holes are drilled, they crack and the rotors are junk. Slotted (or cross drilled) will not give you any better stopping power or better cooling. The slots or holes are for gases that develop between the pad and the rotor during hard use (race track use). The gas escapes via the slot or holes and give the pad a better bite on the rotor (same idea as tread on a tire evacuating water). Unless you are really hard on your brakes and encounter brake fade, you should get OEM rotors.

I have a Porsche 911 track car with slotted rotors and a 2000 V70 R with OEM rotors. When my V70 rotors wear out, they will be replaced with OEM rotors since I don't drive it hard enough on the street to experience fade. My 911 on the other hard is almost only driven on the track, and the slotted rotors help, BUT, I have to clean the slots every few events. Then get packed with baked on brake dust and are not longer slots. Holes also fill in.

If you want better stopping power, buy better tires since that's the limiting factor. If you have sticky tires and are experiencing brake fade, try a more aggressive pad compound. They will most likely make more noise, but the bite on the rotor is amazing with some competition brake pads (Pagid Orange and Hawk Blue to name a couple.)

Stacy Janes

2000 V70 R

87 Porsche 911 (http://members.rennlist.com/sjanes)

Great advice, BUT, running a more aggressive, or higher coefficient friction, pad WILL produce more heat, and wear through the oe rotors MUCH faster. Should someone go for a more aggressive pad, don't expect the rotors to last nearly as long. And with the extra heat production, initial bite will improve, but fade will occur quicker to brake pedal application. And that's where aftermarket rotors come in.

It's just my opinion, but if you are going to go oe, stay ALL oe. If you want to go aftermarket, you'll probably have to experiment a while before you find the perfect combination for your car and driving style.

Sin,

I agree with the rotor wear part of your message, but not necessarily the fade part. Fade can be related to too much heat in the pad or the fluid or both, but it is better described at http://www.rennsportsystems.com/~porsche/2c.html than I would do here.

Basically, a competition level brake pad such as the Pagid Orange that I use on the 911 has a higher temperature operating range, so the pad can deal with the extra heat. Actually, the pad needs the heat as it does not work well when cold. I usually takes me a couple of laps to warm up the Pagid pads to within their operating range, but then the bite is excellent, and consistent for the entire run. If I use my stock pads at the track, they work on the first lap, but fad over the run as they get too hot. I would actually not recommend a competition level brake pad for regular street use since they would not get hot enough under most driving conditions to give 100% performance.

The problem is that since the competition pads can take more heat, the weak link in the system becomes the fluid, so a proper high performance fluid is necessary. This leads into your statement about staying all OEM. I agree with this unless the user has a specific problem to solve. The reason for this is that the brake system on your car was designed as a system, and just changing one area usually moves the problem to another area until you've changed almost everything.

I think that in this case, the original poster just wanted better stopping power for his car on the street, and for that, it's my opinion that the tires are the limiting factor in braking, so buy better tires.

Stacy Janes

I totally agree with what you just said. "Fade can be related to too much heat in the pad or the fluid or both." But, you left out the rotor. Imagine running a significantly higher coefficient brake pad on the oe system. If you are running the oe Micheilng Pilot HX's, tire grip is probably not the limiting factor. The first things you would notice are, MUCH better initial bite, but at hard braking from high speeds, you will glaze the rotors, even though the pads are well within their operating range.

With my Toyo Proxes T1-S 205/50/16 tires, and stainless steel braided brake lines, and otherwise stock brake system, and with my aggressive driving, I can tell you right now, my biggest problem is not with the tires, but with the coefficient between the oe pads and rotors. My next upgrade to the brakes will most likely be slotted rotors and higher coefficient pads. Being involved in the racing community, I have my apprehensions with cross-drilled rotors for a number of reasons, which are too long for me to list here.

I have to disagree about the rotor and "glazing". I've seen pads glaze due to too much heat, but the rotor is a smooth steel surface anyway. I've seen pads leave deposits on rotors, usually from improper bedding of the pads, but I've never heard of anyone at the track "glaze" a rotor. I can only speak from the experience that I have and that is that a pad compound with a higher operating range works better that a regular street pad over an entire 30-40 minute track session (for me anyway). I've never experienced the "MUCH better initial bite" and then fade that you describe, even at tracks like Watkins Glen where I am braking from speeds up to 135 mph, or Mosport where the compression after corner 4 generates some of the hardest braking forces I've ever experienced.

My comment about the tires being the limiting factor are related to the situation like:" if a driver is driving down the 401 at 100 mph (not the aggressive driving style that is causing your problem) and has to come to a complete stop as quickly as possible, the Michelin Pilot HX's will be the limiting factor with a V70 R's brakes." Even a 205 wide Hoosier would be a limiting factor unless there is something wrong with brakes on the car. If you can lock a tire or activate the ABS, then it's the tires that are giving up early. In your case, I would agree that fade and not tire grip is the problem.

When you say your next upgrade will be slotted rotors, will the rotor size change? If not, then all the new rotor will do for you over a new stock rotor is to help channel pad gasses (if the pad gets that hot). If you haven't looked at the site listed in my last post, I suggest you do as it contains good information on brake upgrades (even if it is for a Porsche).

Stacy Janes

Have you never seen a glazed rotor? It discolours, and needs to be resurfaced with a cross hatch.

The 401 at 100mph? That's some speeding going on there ain't it? Actually, at about 100km/h, should I need to brake to a complete stop as quickly as possible, I may be able to lock up causing the abs to kick in if I stab at the brakes at 100km/h, but after the first second or so, it's the brake fade as a result of heat production that becomes the limiting factor. So I disagree about the tires being the limiting factor.

And yes, I want the slots because I intend on using a high coefficient pad that will produce more heat, and in turn, gasses.

Maybe my rotors don't get hot enough to "glaze" as I've never had to have a rotor turned either. If you are developing heat like that, you need larger rotors. My 911 have larger brakes than my V70 R and also being a lot lighter, I never see temps that high.

The 100 mph on the 401 example was to illustrate typical driving that I think the person who started this post was concerned about, but that's a guess. I do not assume his is a race car like yours. I don't know what kind of Volvo you have, but if you experience brake fade after one stop from speed on a street tire (Toyo or not), then maybe your rotors have worn too thin, unless of course you are racing and doing multiple hard stops.

You will probably find that the pads will not be enough. Air ducts to the center of the rotor will help a lot for cooling the rotor, but if that doesn't work, you're probably looked at larger rotors and calipers.

You probably won't on a 911. But on an 850, when you are really running and gunning, you do. Once or twice, I've gotten them SO hot, that just touching the brake pedal caused the ABS to engage. It's fun when you get out of the car, with it still running, and you smell all these odd burning smells :)

I've thought about ducting, but I never really thought they were very efficient. Do they actually work? I'd imagine their effect is only noticeable at high speeds. Plus, while trying to work it out, I couldn't find a good path without quite a bit of modification for the ducting. And with no guaruntee of any effect, I didn't think it was worth it.

Don't get me wrong, I'd love to have larger rotors. But living in Toronto, I need to run winter tires. And I doubt I'd be able to find a 17" winter tire that will fit on an 850, especially one that is lowered.

Plus, being a student, I don't plan to go TOO insane on this 855T. I plan on keeping it another couple years, maybe till after my masters (4-6 years), then trade up.

Thanks felow brickbrd members for your input. Some of the problems discussed I have been through. While going from Denver to Winter Park Colorado its about a climb from 5,000 ft to 11,000 ft and back to 8,000 ft and the road is a real challenge. The brakes got so hot at the bottom that the abs was actually kicking in while braking and even when it kicked in the car didn't really slow down so I needed to downshift to a lower gear to help slow the car down for the last hairpin before the ski area. After that last experience I need to do something so before this winter starts I want to make sure that I have a better braking setup. Heck we have even glazed our rotors on our Expedition. Sounded terrible and scared my wife when she came to a stop.

Since this is my winter car I want to make sure it stops. My fun toy is a 65 mustang fastback with a supercharged 351 W in it running 12 seconds at sea level. Brakes are simple on that car, just get it to stop after a 1/4 blast. With the Volvo, Ive got to get it stopped many more times.

Thanks again,

Bill in Denver

I would try and go for slotted rotors if I were you. I would not use drilled rotors unless they were cast they way, but those can be very expensive. Here is a good article on slotted rotors upgrade for the project 850R that Swedespeed did:

Slotted Brake Upgrade

You can check this site for prices, they have a great selection and are pretty reasonable.

EuroSport Tuning