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Cross-drilled brake better, vented cheaper

> So which way is the best to go....with
> vented rotors or cross drilled ones?
> -Travis 77z

Travis,
The cross-drilled reject heat better than the vented so they will have less fade than the vented - which have less fade than non-vented.
On your first panic stop you will probably see no difference between any of the rotor styles. It will become more apparent on successive stops or on high speed racing that has a lot of braking - like a road course.
If you aren't going to race the car - don't waste your money on the cross drilled. If you are - go for it. I'd wait until the vented were showing signs of fading during competition runs before I spent the bucks for the cross-drilled.
Phantom
 

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Re: Cross-drilled brake better, vented cheaper

I look at brakes in the following way, from worst to best.

1. Stock Drums
2. Finned Drums
3. Solid Rotor disc
4. Vented Rotor
5. Cross-drilled Solid Rotor
6. Cross-drilled Vented Rotor
7. Carbon Fiber Rotor

For the street, I would suggest a slotted vented rotor. This lets gas escape during hard panick stops, but the large mass of the rotor along with the vanes keeps it cooler for a longer period. The cross-drilling works great, but promotes rapid pad wear, and cracking. The slotting allows gas to escape without compromising the strength of the rotor.
Vented rotors stay cooler for 2 reasons, they have a larger mass, and airflow between the rotor surfaces. I'm looking into replacements for my stock solid rotors because they are warped now, although not severely. I just got the 1999 Wilwood catalog, and might try a set of these. They sell a hat to adapt a rotor to a Z spindle, but the rotor and caliper are still up in the air.
There is no kit available. You have to mix and match for the clearance you have with your rim, which will ultimately determine what caliper/rotor can be used. I'll post this as soon as I figure it out. I'm going to the junkyard during my 2 week vacation, and will try and get some measurements from there. I'm sure it will be cheaper than Arizona Z car, although I'm not sure how much. Probably around $700 for everything.
The hat is @$80 x 2 = $160
Rotors @$75 x 2 = $150
Calipers @$160 x 2 = $320
Pads @$50 x 1 = $50
 

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Discussion Starter #4
I've been researching that subject for quiet some time now and the best money/performance combination IMHO is: toyota calipers, semimetallic pads and 84-89 300zx front rotors they are vented and only need minor mods to fit( using stock hub). you can always cross drill them.
 

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> I've been researching that subject for quiet
> some time now and the best money/performance
> combination IMHO is: toyota calipers,
> semimetallic pads and 84-89 300zx front
> rotors they are vented and only need minor
> mods to fit( using stock hub). you can
> always cross drill them.

Travis,
Assuming you have to identical rotors, but one is cross drilled, here is what you will notice. One, the cross drilled breaks will seem to grab more, for the holes tend to keep the pads from glazing, so they bite harder. They may even brake better a few times. But as you repeatedly stop, and really heat up the rotors, the non-cross drilled rotors, with their more mass, will do a better job of rejecting the heat that your are dumping in copious amounts into them. The cross drilled will fail first, usually cracking around the holes, and over heating your breaks, causing either pad fade, or fluid boil.
But that is an absolute worst case scenario. You need to look at how your 240's brakes are doing now. Are they fading after a few spirited runs around the block? And what kind of fade is it? Is the pedal going to the floor,(brake fluid boiling, requires upgrading and flushing the fuild), or is the pedal hard, but just not doing anything,(pad fade, over-temp the pads, rendering them useless). Or do you just want the cool factor, ie hey man cool brakes!.
With that in mind, it will help you know what to do. As Stan put, my webpage has the vented rotor conversion that was posted by Stephan Moffet. He loves it, but remember, that adds unsprung weight, which is somewhat detrimental to handling. Obviously for the ultimate setup, go with the Willwoods, but thet is an $$$ option. Optimize your stock setup, then go from there.
-Bob Hanvey
 

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> So which way is the best to go....with
> vented rotors or cross drilled ones?
> -Travis 77z

If you ever AutoX that alone will put you in Prepared class. If you are not racing the car...what's the point of cross drilled rotors?

Ken
 

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Discussion Starter #7
> I've been researching that subject for quiet
> some time now and the best money/performance
> combination IMHO is: toyota calipers,
> semimetallic pads and 84-89 300zx front
> rotors they are vented and only need minor
> mods to fit( using stock hub). you can
> always cross drill them.
Thanks for posting the link to The Datsun Workshop, I've been considering the Toyota caliper conversion but the vented rotors would add another incentive. I was considering the drilled stock units from NOPI and others but I think the vented units would probably be better.
 
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