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200.mph 11-27-2018 11:11 PM

use it to strip paint lol. i have a use for dot 5 fluid but 3 and 4 wont work for i use it for

wannawankel 11-28-2018 07:38 AM

Walmart has brake fluid in both DOT 3 and DOT 4 for ~ $4 / 946 mL - the cheapest around and more than enough to replace/clean the reservoir --> bleed brakes --> top off the system. In general the DOT3 and DOT4 bottles breathe enough that an unopened container will pickup moisture over the 1-2 year stated shelf life. New fluid is so cheap you're better off buying new and using it right away than chancing issues with NOS fluid.

Steve Dallas 11-28-2018 07:55 AM


Originally Posted by Chrishoky (Post 4875965)
Thanks! What can I do with the old stuff? My local auto place only takes used oil.

Definitely do not use that old brake fluid. It is absolutely full of water.

For street driving, it doesn't much matter whether you use DOT 3 or DOT 4, and for the record, they are compatible and can be mixed in a pinch if needed.

As for where to dispose of old brake fluid, Firestone service centers take it in my area. I discovered that by Googling something like "brake fluid drop-off location" or something like that. No one wants to take brake fluid, because unlike motor oil, they have to pay to have it taken away.


BARNETT89 01-14-2019 12:01 PM

Great post and sticky..

The only info I disagree with is on the drilled and slotted rotors. It is much past my imperical knowledge but there must be an advantage to drilled rotors as high powered, high priced super cars have drilled rotors. I know they use carbon ceramic rotors so its not comparing apples to apples but i'm sure they have done the R&D to prove them to be beneficial and installing them on their cars.

IamFodi 01-14-2019 12:59 PM


Originally Posted by BARNETT89 (Post 4878937)
Great post and sticky..

The only info I disagree with is on the drilled and slotted rotors. It is much past my imperical knowledge but there must be an advantage to drilled rotors as high powered, high priced super cars have drilled rotors. I know they use carbon ceramic rotors so its not comparing apples to apples but i'm sure they have done the R&D to prove them to be beneficial and installing them on their cars.

Good call. Wish more people understood this.

AFAIK the main benefit is better cooling.

There's also some very slight weight reduction, for whatever that's worth; e.g., for the Brembo BBK for the RX-8, you can get drilled or slotted rotors, and the drilled rotors weigh about 0.4 lbs (~3.5%) less per Brembo.

I've also seen a study that suggested that holes can slightly improve high-speed braking vs. blanks, though I don't know if that applies in all cases.

Loki 01-14-2019 01:25 PM


Originally Posted by BARNETT89 (Post 4878937)
Great post and sticky..

The only info I disagree with is on the drilled and slotted rotors. It is much past my imperical knowledge but there must be an advantage to drilled rotors as high powered, high priced super cars have drilled rotors. I know they use carbon ceramic rotors so its not comparing apples to apples but i'm sure they have done the R&D to prove them to be beneficial and installing them on their cars.

They are beneficial: they look hot and sell for a premium!


UnknownJinX 01-14-2019 01:34 PM


Originally Posted by IamFodi (Post 4878942)
Good call. Wish more people understood this.

AFAIK the main benefit is better cooling.

There's also some very slight weight reduction, for whatever that's worth; e.g., for the Brembo BBK for the RX-8, you can get drilled or slotted rotors, and the drilled rotors weigh about 0.4 lbs (~3.5%) less per Brembo.

I've also seen a study that suggested that holes can slightly improve high-speed braking vs. blanks, though I don't know if that applies in all cases.

But don't the holes also multiply the mechanical stress and make them more prone to cracking? I would think this makes them a bit unreliable for track use.

For street use, well the benefits are not really worth it and you won't see much of a performance difference.

wankelbolt 01-14-2019 02:19 PM


Originally Posted by BARNETT89 (Post 4878937)
The only info I disagree with is on the drilled and slotted rotors. It is much past my imperical knowledge but there must be an advantage to drilled rotors as high powered, high priced super cars have drilled rotors. I know they use carbon ceramic rotors so its not comparing apples to apples but i'm sure they have done the R&D to prove them to be beneficial and installing them on their cars.

https://cimg3.ibsrv.net/gimg/www.rx8...23e48c7c23.jpg :D:

Supercars are more a slave to fashion than ordinary cars. They have to look like supercars.

Drilled rotors are useless, but even Porsche has admitted they put them on their cars because most people who buy very expensive cars don't know shit about cars and expect "racy" looking brake rotors (can't find the quote right now). (Plus, Porsche gets to sell them rotors more often when they crack.) Drilled rotors are left-over from the 1950-60's when brake pads sucked. They would out-gas when they got hot, and that would reduce braking. Shitty old brake pads farted. So they drilled holes in the rotors to let the farts out. Brake pads haven't been that way for 50+ years.

Now, let's hear from some professionals that make brake systems:

Stoptech:

]Which is better, slotted or drilled rotors?

StopTech provides rotors slotted, drilled or plain. For most performance applications slotted is the preferred choice. Slotting helps wipe away debris from between the pad and rotor as well as increasing the "bite" characteristics of the pad. A drilled rotor provides the same type of benefit, but is more susceptible to cracking under severe usage. Many customers prefer the look of a drilled rotor and for street and occasional light duty track use they will work fine. For more severe applications, we recommend slotted rotors.
Baer Brakes:

What are the benefits to Crossdrilling, Slotting, and Zinc-Washing my rotors?

In years past, cross drilling and/or Slotting the rotor for racing purposes was beneficial by providing a way to expel the gasses created when the bonding agents employed to manufacture the pads...However, with today’s race pad technology, ‘outgassing’ is no longer much of a concern...Slotted surfaces are what Baer recommends for track only use. Slotted only rotors are offered as an option for any of Baer’s offerings.
And let's here from the motorsports experts at Grassroots Motorsports:

Cross drilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the '40s and 50s, not a whole lot. Rotors were first drilled because early brake pad materials gave off gasses when heated to racing temperatures, a process known as "gassing out." ...It was an effective solution, but today's friction materials do not exhibit the some gassing out phenomenon as the early pads. Contrary to popular belief, they don't lower temperatures. (In fact, by removing weight from the rotor, they can actually cause temperatures to increase a little.) These holes create stress risers that allow the rotor to crack sooner, and make a mess of brake pads--sort of like a cheese grater rubbing against them at every stop. Want more evidence? Look at NASCAR or F1. You would think that if drilling holes in the rotor was the hot ticket, these teams would be doing it...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?)


Originally Posted by Loki (Post 4878943)
They are beneficial: they look hot and sell for a premium!

Bullseye!

IamFodi 01-14-2019 03:07 PM


Originally Posted by UnknownJinX (Post 4878945)
But don't the holes also multiply the mechanical stress and make them more prone to cracking? I would think this makes them a bit unreliable for track use.

I was responding to a question about the benefits, not the downsides. ;)

But if we want to talk about the cracking: Yes, of course they're more prone to cracking. To be fair, though, that's not the real question.

The real question is whether cracks will take the rotor out of service before wear does, and that depends on the quality of the rotor. For most drilled rotors, especially the cheap ones that most people here (and on GRM for that matter) will be looking at, yes, there's a significant risk that cracks will make the rotor unusable before it's worn out. But the OE rotors used by BMW, Mercedes-Benz, Porsche, etc. -- and rotors of comparable quality (rare and expensive) -- will most likely wear out before they develop cracks worth worrying about. On some of them, the holes are actually cast in, not drilled after the rotor is made. That's a major contributor to durability.

Yes, track use makes cracks more likely. But it also speeds up wear, so the equation is still the same.

Another thing that'll crack even the highest quality drilled rotors is abuse with extreme heat cycles. But that treatment is just as likely to warp any rotor, so it's hard to say a drilled rotor of comparable quality is at a meaningful disadvantage there.

My E90 M3 seems to be on its original factory drilled rotors. Just ticked over 83k miles. No cracking to speak of, even with the fronts nearing their minimum thickness.



Originally Posted by UnknownJinX (Post 4878945)
For street use, well the benefits are not really worth it and you won't see much of a performance difference.

With extremely rare exceptions, this is correct.

Loki 01-15-2019 04:52 PM

I just watched a review of a Cayenne Turbo and guess what: drilled carbon ceramic brakes. For all those times you see a Cayenne in your run group ;)

It's all for show.

wankelbolt 01-15-2019 05:32 PM

"No one in this world, so far as I know ... has ever lost money by underestimating the intelligence of the great masses of the plain people." - H. L. Mencken

Since Speed Holes [1] make cars faster, I fully expect the Cayenne to kick any Formula 1 car's ass. 'Cause F1 ain't got em, Yo! :cool:

https://cimg8.ibsrv.net/gimg/www.rx8...54ae004cd8.jpg


[1] Speed Holes! :D: :D: :D:
https://youtu.be/whnms4CLJys?t=41s
https://www.youtube.com/watch?v=G3ja6Hn8ps4

https://cimg9.ibsrv.net/gimg/www.rx8...7fc80756df.gif

UnknownJinX 01-15-2019 05:35 PM


Originally Posted by Loki (Post 4879027)
I just watched a review of a Cayenne Turbo and guess what: drilled carbon ceramic brakes. For all those times you see a Cayenne in your run group ;)

It's all for show.

I mean, can SUVs even participate in motorsport events?

IIRC my local Autocross event said that the vehicle height cannot exceed its width. Naturally not an issue for cars, but this basically means no SUV or pickup trucks can participate.

IamFodi 01-15-2019 06:26 PM


Originally Posted by wankelbolt (Post 4879029)
"No one in this world, so far as I know ... has ever lost money by underestimating the intelligence of the great masses of the plain people." - H. L. Mencken

Since Speed Holes [1] make cars faster, I fully expect the Cayenne to kick any Formula 1 car's ass. 'Cause F1 ain't got em, Yo! :cool:

https://cimg8.ibsrv.net/gimg/www.rx8...54ae004cd8.jpg

F1 cars also don't have cooling fans. Are those just for show, too?

Loki 01-15-2019 07:53 PM


Originally Posted by UnknownJinX (Post 4879030)
I mean, can SUVs even participate in motorsport events?

IIRC my local Autocross event said that the vehicle height cannot exceed its width. Naturally not an issue for cars, but this basically means no SUV or pickup trucks can participate.

I've met a Jeep Cherokee SRT something on track. I was surprisingly agile, but it was hard to take it seriously. It was a small lapping organization rather than a racing org.

wankelbolt 01-15-2019 08:52 PM


Originally Posted by IamFodi (Post 4879032)
F1 cars also don't have cooling fans. Are those just for show, too?

That's... what?

Are you trying to refute that brake Speed Holes are pointless by saying cooling fans make a car faster too?
So F1 should add fans and drill Speed Holes to go faster? :dunno:

Or are you saying that F1 is fast, and because they lack fans that must mean no fans is faster?
So by that logic you/re helping my point because F1 is fast and F1 brakes have no Speed Holes. Ergo, Speed Holes make cars slower. :D: :beer05:



IamFodi 01-16-2019 04:25 AM


Originally Posted by wankelbolt (Post 4879050)
That's... what?

Are you trying to refute that brake Speed Holes are pointless by saying cooling fans make a car faster too?
So F1 should add fans and drill Speed Holes to go faster? :dunno:

Or are you saying that F1 is fast, and because they lack fans that must mean no fans is faster?
So by that logic you/re helping my point because F1 is fast and F1 brakes have no Speed Holes. Ergo, Speed Holes make cars slower. :D: :beer05:

Take a breath. Everything's okay. I promise. ;)

My point here was that F1 cars have their own set of constraints, so what's best for them isn't always what's best for street cars or anything else.

I think you're drastically overestimating how much people like drilled rotors here. The original question was "there has to be some benefit, right?" The answer to that is yes, there are some potential benefits. Not that there are no downsides (there are). Not that drilled is always better (it isn't). Not that all performance applications should have drilled rotors (they shouldn't). Just that there are more than zero potential upsides.

Then there was a comment about cracking at the holes, and I said that problem doesn't affect all rotors. Not that the problem doesn't exist (it does). Not that it's not worth worrying about (it is). Just that it isn't an issue for some. Not all; not a majority; not a big minority; just some.

I promise, that's all that's happening here.

Steve Dallas 01-19-2019 08:29 PM


Originally Posted by wankelbolt (Post 4838275)
How do you know when it needs to be changed? Do you have a scientific test, or get it tested? Or do you just guess based on time and use?

For the record, I just guess based on time, use, research, and experience. I'm at 76000 miles, thousands of those on-track at speed, and still using the original factory calipers with no leaks or failures of any kind. Never used anything more sophisticated than Catrol LMA or Valvoline Synthetic.

I couldn't help but necro-quote this.

It depends on the layout of the track. My favorite configuration at my home track is very hard on brakes. CoTA and Eagle's Canyon Raceway are even worse. As a result, I'm on my 4th caliper rebuild, due to overheating seals to the point of fluid leakage

Speaking of calipers... If you purchase Cardone Ultra Mordaza de Primera Calidad, you receive rebuilt calipers that are nicely powdercoated in satin gray. Rockauto sells them inexpensively. With a 10% off coupon, I just bought a set of 4 for $360 - $120 core = $240. Not bad. And they aren't ricer red.

I take it these are re-manufactured in Mexico:
https://cimg5.ibsrv.net/gimg/www.rx8...483ef8d65f.jpg

NOT RED:
https://cimg6.ibsrv.net/gimg/www.rx8...e27af7177a.jpg

This is what happens after 6 years of track heat burns off the anti-rust coating:
https://cimg7.ibsrv.net/gimg/www.rx8...41dcc6a2bf.jpg

Much better. Hopefully, they hold up well.
https://cimg2.ibsrv.net/gimg/www.rx8...e8fe7078ff.jpg

SmuttyHutty 02-01-2020 01:38 AM

I'm going to revive this zombie thread/sticky with a simple thank you to the OP for the info regarding bedding in. I have a 2004 192 RX8 which has been meticulously cared for by the two previous owners. It only has 64k on the clock and runs sweet as a nut. It is a second car and up until a month ago I had covered about 700 miles in 4 months - it was mr weekend fun machine.

On a long drive back home I noticed a repetitive throbbing noise particularly when braking. The discs looked good - well, three of them. One front one was slightly marked and it turns out that I needed discs and pads on the front. I have no idea about costs for these things and paid £216 for parts and labour for them to be replaced. Anyway, the bedding in procedure is great. I live in the countryside so have little traffic around me and can go through the given routine. I will say that I had to google 'sparks from new brakes' when I got home as I did the routine last night and had a decent fireworks show which I assume was form both sides but I could certainly see from the driver's side.

Anyway, the brakes smell fab when they're hot - it takes me back to my motorbike days.

So, anyone who has a regular throbbing noise from their RX8 when driving ans particularly when braking - it might be the same issue as mine.

TeamRX8 02-01-2020 04:14 AM

Is it the same noise as before?

SmuttyHutty 02-01-2020 05:16 AM

Do you mean the throbbing noise when driving and the noise when braking? Pretty much, yes.

The noise when driving sounded like I was driving over a stud in the road spaced at regular intervals. When braking it was accentuated and really noticeable. My guess is that one/both front discs were bent or damaged? I am genuinely unsure of the exact reason. It is just noce to know it is fixed now.

TeamRX8 02-06-2020 07:32 PM

It could be wheel bearings or a tire issue is my thought

IamFodi 02-06-2020 07:51 PM


Originally Posted by IamFodi (Post 4878956)
My E90 M3 seems to be on its original factory drilled rotors. Just ticked over 83k miles. No cracking to speak of, even with the fronts nearing their minimum thickness.

FWIW, I ended up swapping those rotors out at over 95k total miles, which included some very hard running at the Tail of the Dragon. Zero visible cracking on any of them. Just reinforces the point that cracking is not at all a given with drilled rotors.

TeamRX8 02-06-2020 11:18 PM

C’mon man, TOD is not any comparison at all to a real track etc. situation. I cracked OE rotors doing hardcore autocrossing. :suspect:

SmuttyHutty 02-07-2020 01:22 AM

I'm still getting the thud thud thud noise from 52mph to 70+mph so am guessing it is a wheel balancing issue as well. Taking it to a tyre and exhaust place today to get checked.

UnknownJinX 02-07-2020 11:44 AM

From my experience, wheel bearing noise would get louder the faster you go, and you would notice a difference in volume and tune when you are turning.

A surefire way to find out is to get your wheels off the ground, spin them by your hand and listen to if the hub(front wheels) or the bearing(rear wheels) are making any noise inside.

If your wheels are out of balance then you would definitely feel it in the steering wheel.


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