Slotted rotors: Which way is correct?

Post by **youngturk** » Wed Jul 21, 2004 9:33 am

I recently installed 30mm Brembo cross-drilled and slotted rotors on my '92 240SX. Here is how my installation looks. I have seen the slots pointing both directions. Is mine correct? Or does it matter?

Thanks.

Post by **DAEDALUS** » Wed Jul 21, 2004 9:33 am

I don't know if it matters, but, uh, which way is your car facing in that picture?

Post by **youngturk** » Wed Jul 21, 2004 9:33 am

That's a good question. The right side of the picture is the front of the car.

Post by **Nismo_Freak** » Wed Jul 21, 2004 9:33 am

It's correct.

Post by **Vkoslak** » Wed Jul 21, 2004 9:33 am

You could always switch them and see if it works better.

Hell, I'll let you use my jack when you come to pick up your new steering wheel. (Don't forget those extra locking lugnuts you have)

Post by **youngturk** » Wed Jul 21, 2004 9:33 am

Nismo_Freak: Thanks for the confirmation.

Vkoslak: Hey, aren't you supposed to be busy doing computer programming at work?

Man, I got busted by my own master mechanic. Vkoslak, I was just checking with the NICO crowd to CONFIRM that our installation was correct. No other motive was present.

Can I still pick up my steering wheel?

Post by **Vkoslak** » Wed Jul 21, 2004 9:33 am

Ya, I was just giving you a hard time. We did put them on the same way as we saw on a Mustang. The s15 steering wheel should be in today too. Tani is bugging me to get some locks for her pretty new wheels. Just give me or Tani a call when you want to come pick up your wheel.

Post by **Nismo_Freak** » Wed Jul 21, 2004 9:33 am

Vkoslak wrote:Ya, I was just giving you a hard time. We did put them on the same way as we saw on a Mustang. The s15 steering wheel should be in today too. Tani is bugging me to get some locks for her pretty new wheels. Just give me or Tani a call when you want to come pick up your wheel.

We are up to our eyeballs in front upper arms, you should purchase 5 sets to give away for christmas time haha.

Post by **Vkoslak** » Wed Jul 21, 2004 9:33 am

What I could really use, are some pillow ball mounts for shock absorbers, some linear springs, and a decent set of adjustable shocks for the s14. And tie-rods and tie-rod ends for s14.Front upper arms are for 300zx right? Right now the suspension on my z32 feels pretty darn good. I may get a set of those sub-frame spacers for my Z though. They worked great on the 240sx.

Post by **BuudWeizErr** » Wed Jul 21, 2004 9:33 am

i've heard people say that the other way is the 'correct' way, but i have mine like that, and have for over a year.

i've seen it both ways... so honestly.. does it even make a difference?

Post by **skydragoness** » Wed Jul 21, 2004 9:33 am

I bought a set of slotted rotors a couple years back and (i have slotted z brakes up front as of now) but i read the little install slip. And it said either way is fine, but with the slots facing opposite it gives more initial bite,and may squeak more (when breaking them in), and may increase pad wear. But that really depends on what kind of pads your'e running and how the car is driven I think.

my slotted rotors up front are opposite,doesn't feel any different than the other way around, IMO.

Post by **youngturk** » Wed Jul 21, 2004 9:33 am

Thanks guys for all your input. Based on what you all have said, I guess it is okay to keep mine as they are. I find it interesting that there is no standard way, but I guess that makes it more difficult to get it wrong.

Post by **hannibal** » Wed Jul 21, 2004 9:33 am

whats the point (advantage) of slotted rotors? That should help determine which way is 'more correct'.Ive noticed rotors mounted in both directions and always assumed the way youngturk has them was THE correct way.

Post by **BuudWeizErr** » Wed Jul 21, 2004 9:33 am

have you guys ever seen the rotors that are slotted straight up and down?

i think that proves that it really doesn't matter.

Post by **Dori Dori** » Wed Jul 21, 2004 9:33 am

IWannaS15 wrote:whats the point (advantage) of slotted rotors? That should help determine which way is 'more correct'.Ive noticed rotors mounted in both directions and always assumed the way youngturk has them was THE correct way.

The point is to deglaze the pads, vent gasses, and assist in cooling.

Post by **Vkoslak** » Wed Jul 21, 2004 9:33 am

glaze is for donuts. mmmmmmm donuts.

Post by **dreamsOfSkylines** » Wed Jul 21, 2004 9:33 am

Dori Dori wrote:The point is to deglaze the pads, vent gasses, and assist in cooling.

How do they help cooling? I thought it was mostly to prevent glazing and get the brake dust out. Is it true that almost all modern pads do not "gas out". How much shorter is the pads lifespan with slotted rotors?

Post by **hannibal** » Wed Jul 21, 2004 9:33 am

Well if its supposed to vent gases or assist in cooling, I would think direction in the pic above is better. It'd be hard to vent or cool with the vanes facing the other way*

*I assume you want to direct the heat/gases away from the center of the disc.

Post by **hannibal** » Wed Jul 21, 2004 9:33 am

ChunkiDori wrote:have you guys ever seen the rotors that are slotted straight up and down?

no???

Post by **youngturk** » Wed Jul 21, 2004 9:33 am

Here is how the rotors look on the 350Z S-Tune GT currently only being produced in Japan. The left side of the picture is the front of the car. Like I said above, I've seen it both directions.

Post by **14.5drift** » Wed Jul 21, 2004 9:33 am

Well they did it the wrong way

Post by **variable** » Wed Jul 21, 2004 9:33 am

14.5drift wrote:Well they did it the wrong way

Is this in response to youngturk's S-tune image above?

If so, what makes you say that? Please explain, because in the various Brembo FAQs out there given by the various brake parts dealers (interestingly I can't seem to find the same FAQ on Brembo's own site, are they making this up?), it mentions a particular direction for slotted Brembo brakes (which is what the brand the S-tune ones look to be). In particular: "Additionally, all of Brembo's slotted discs are directional as well, regardless of the vane geometry. The discs should be installed such that the end of the slot nearest the outer edge of the disc contacts the pad first." Presumably this applies to "forward rotation" of the disc.

Of course this isn't to say that slot direction matters at all for any brand of disc, it's just that for Brembo slotted discs, "forward slanting" (as in the S-tune pic) slots are the recommended configuration.

Post by **14.5drift** » Wed Jul 21, 2004 9:33 am

Well my brembo dealer says that it was the other way around. He said if they were the way shown in youngturks photo that it would wear down the pads much faster. I made it a point to ask him, as looking at the rotor I wanted to point the slot in the most aggressive way, but he said "no, that way encourage fast break down of break pad."

He was chinese, and those are his exact words in broken english

Post by **jdmsoarer** » Wed Jul 21, 2004 9:33 am

I'm a distributor of cd/slotted rotors also. Both directions are good. I recommend the one used in the above picture though. The reverse would help brake harder, but it is true that the pads will brake down alot quicker. I'm using it in reverse on my soarer right now and the pads have lasted me about 20k miles plus already.

Post by **Exar-Kun** » Wed Jul 21, 2004 9:33 am

14.5drift wrote:Well they did it the wrong way

and apparnetly you know more than many of the autocrossers and racers I've seen with it that way? any sloting(or drilling) will wear pads down quicker, but for the most part, I've seen them like the nismo s-tune pic above. I think it's been established in this thread that either way is satisfactory, unless the manufacturere MARKS THE ROTOR LEFT OR RIGHT, because of vaning in the rotor itself.

thank you.-chet

Post by **spitz7985** » Wed Jul 21, 2004 9:33 am

I think he was joking guys.

Post by **14.5drift** » Wed Jul 21, 2004 9:33 am

This is not a site for fun, only real serious stuff going on, lol

But yeah, now that Exar-Kun mentioned it I remember some thing about veining also, yeah, to keep the rotor cool, stuff like that

Post by **youngturk** » Wed Jul 21, 2004 9:33 am

Well I, too, couldn't find a Brembo FAQ at their home page, but a quick search on the internet yielded two websites that confirmed what Variable wrote above: my installation is incorrect. Here are the web sites:

http://www.buybrakes.com/brembo/faq.html#q28

http://www.autotoys.com/x/cust...t=838

One thing is for sure, they are both getting their information from the same source as Variable's source.

Since we can't get a confirmation from Brembo's web site, I will try switching the rotors to see what difference it will make. I'll let you guys know what effect, if any, it has.

Thanks for all your comments. Hopefully we will get to the bottom of this question eventually.

Post by **bob marley** » Wed Jul 21, 2004 9:33 am

[quote=" Exar-Kun [B..... I think it's been established in this thread that either way is satisfactory, unless the manufacturere MARKS THE ROTOR LEFT OR RIGHT, because of vaning in the rotor itself.

thank you.-chet [/quote]

This is what I have noticed on many cars an it's my belief too.

PS. Chet, I hate you because I've wasted too much of my life watching Naruto (greatest show ever) and it's your fault.

Post by **Exar-Kun** » Wed Jul 21, 2004 9:33 am

sharingan>you

I want one.dude, itachi is a bad-***....waaaaay bad-***.-chet

Slotted rotors: Which way is correct?

Slotted rotors: Which way is correct?

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