Rotors...

[Guest ladyz]

 

i might be picking a set of these rotors for my z. but i have a quick question... would it be a good idea to mix match them or would it be better and safer to use all 4 same designs?

 

i was thinking about getting the power cross for my front and Stream Cross for my rears.. any suggestions?

 

Thanks

-Mark

[bjhines]

Those look really cool.

 

But they do nothing for your braking performance on the street or track. In fact they will make humming noises when you come to a hard stop because of the pretty little partterns on them.

[DavyZ]

would it be a good idea to mix match them or would it be better and safer to use all 4 same designs?

 

Thanks

-Mark

 

I doubt it will make any difference if you use different designs front to rear. If I ruined just one of my front rotors, I would replace them both in front at the same time, not just one. Same style, regardless. Differences in design front to rear should make little difference.

 

Davy

[johnc]

Cute rotor names.

[JMortensen]

But they do nothing for your braking performance on the street or track. In fact they will make humming noises when you come to a hard stop because of the pretty little partterns on them.

Cross drilling reduces weight but hurts the ability of the rotor to absorb heat. Reducing weight will improve braking performance. Cross drilled solid rotors, especially in the rear of a Z, do indeed make a whirring or buzzing noise as the air expands in the hole but is trapped by the brake pad and then is released when the rotor turns. It never really bothered me when I ran them. I actually thought it was kind of cool sounding. Like a baseball card in your spokes for grownups....

 

Slotting supposedly provides a path for gases to escape between the rotor and the pad. I haven't used them myself but I know lots of people who have and you see them on race cars on TV all the time. It seems like pro racer types wouldn't use them if they did nothing...

 

I think both do something. The question is do you want or need them to do the something that they do? If you have stock rotors you probably don't want to cross drill them, although if you're racing you might want them slotted. If you have vented rotors you probably don't need either, although if you have huge 13" brakes on a 2300 lb car you could probably justify cross drilling to reduce the effect of the heavier rotor and reduce the mass out at the end of the rotating lever which is the rotor.

 

For 99% of people, they buy them for style and drive around on the street thinking it looks cool. If you're one of those, get whichever style tickles your fancy. If you want different front and rear it won't make the slightest bit of difference.

[Evan Purple240zt]

Not sure if this applies here, but I have seen pictures on the net of cheap rotors that have cracked between the crossdrilled holes.

 

Evan

[Guest ladyz]

cool thanks for the help everyone. yeah the z is my daily driver im not going to be doing track or anything. i am going to replace all 4 of my rotors. i think im definately going to get the power cross in the fronts and stream cross in my rears. have to email the guy tomorrow. Thanks! once i get them in i'll post some images and how they perform on my z... anyone know how to break in rotors on a fresh install with new pads? thanks!

-Mark

[Guest TeamNissan]

All that sound advice and your still going that rt? Say it aint so lol.

[MrFancypants]

Dude... you have to get the Extreme Cross ones... they go to 11.

 

 

 

- Greg -

[Evan Purple240zt]

Why didn't you just make 10 as loud as 11?

 

But, it goes to 11....

[Pop N Wood]

If you call they may sell you their cross dress model.

 

They don't list it in their catalog. You have to ask.

[capt_furious]

Not sure if this applies here, but I have seen pictures on the net of cheap rotors that have cracked between the crossdrilled holes.

 

That's been the primary reason I've heard for cross drilled rotors being a bad idea(besides the fact that they don't help much).

 

...the McLaren F1 has 'em, so does the Carrera GT(carbon!), so they must be good for something...

 

Slotted rotors are likely a different story. Probably much tougher to crack.

[Evan Purple240zt]

Oh, I am sure you would not crack a set of high end rotors.

 

Its the ones that are inexpensive I would be weary of.

 

Evan

[Flexicoker]

Expensive sports cars have cross drilled rotors for the way it looks. Real, modern, RACE cars don't have cross drilled rotors. Most are just grooved.

[Guest TeamNissan]

Saying they do it JUST for looks I think maybe too far, I'm sure there are physics involved just like everything else. MOST race cars don't use them though your right. I can only assume any performance gain is out weighed by the durability of a solid vented rotor. All be it made of some insane material or combination......

 

Just because exotic materials and huge surface area equal great breaking doesn't mean they manufacturers can afford to implement them even on higher end sports cars. So they look for cheaper ways to achieve gains. Then smaller companies poorly try and copy those ideas and here we are lol.

[jerryb]

Just curious what makes you choose one design for the front and another for the rear. What is the criteria for this decision?

[LS1 240Z]

are these suppose to be vented direct replacement rotors.. or what..

[Savage42]

I talked at length with guys at Brembo and Wilwood about the different designs. Bottom line is that slots are a good thing, as mentioned before, that it lets the hot gas between the pad and rotor escape and helps keep the pad surface clean, helping increase braking and cutting down on brake fade.

 

Cross drilling is only done for looks, as people pay to have them that way, even though they dojn't add anything over slots. In extreme cases, they stress crack around the holes and can cause premature rotor failure. (in their own words) So, I went with the GT slotted rotors with my Wilwood setup and most of the race cars I've driven are only slotted. I've run all my cars hard for over 15 years of autocross, hillclimbs and track days and have had great results with just slotted. Just my .46 cents.

[bjhines]

I just don't get why people think they have to upgrade street brakes, other than the bling factor.

 

There is NO COMPARISON between the braking events for street vs track.

 

What are people doing to require "performance" brake parts on their street car? Give me a break, you stomp the middle pedal to stop. Don't hit it too hard or you will skid the tires. The tires are the limiting factor on the street. How are you EVER going to improve on the braking system aside from keeping it in working order.

 

I will give myself an answer to that q.:

The factory brake system can gain an improved feel and reduced maintenance costs by changing to more modern rear disk brakes. The "feel" I am talking about is not related to initial grip or anything that could be changed by pad choices. I am talking about the "2-step feel" of the factory disk and drum combination. Getting rid of those drums gets rid of the pedal action required to overcome the rear shoe retraction springs. If you don't feel this 2-step action on factory S-30s then you don't have enough experience with sports car brakes(so don't bother upgrading).

The bias of the brake system will change depending on how you go about switching to rear disks, so that is not just as easy as bolting on the rear disk related parts. You really have to rework the entire brake system and make good pad choices for that to ACTUALLY improve the overall braking performance.

 

This still has nothing to do with cross drilled or slotted brake disks.

This has nothing to do with performance brake pads.

 

I think the ideas for streetable-track pad compounds is a folly. No doubt they are better at high temps than cheapo organics, but THEY ARE NOT RACE PADS.

The race pads simply don't fade. The race pads will fry your rotors before they quit gripping.

The trackable street pads(ex. Ferodo DS2500) DO FADE. They tend to fade just as I need to transition into the turn under trail brail braking situations. It is much harder to modulate when you are constantly applying more pressure to maintain braking force.

 

If some of these people actually attended an HPDE they would quickly understand that these "performance-street" brake parts are a scam(like washer nozzel lights).

[Guest TeamNissan]

Washer nozzel lights are a scam? damn......... lol