Z1 2-Piece Rear Rotors????

edconline · 04-22-2014, 10:25 PM

Quote:

Originally Posted by DEpointfive0

They are.

And slam1918 installed them wrong if I'm not mistaken

I believe them to be backwards as well. Based on their pictures on the site. The cooling vanes need to be angled towards the rear in order to evacuate heat from the rotor. If they were straight vaned I don't think it would matter which direction the slots ran, but they appear to be curved from the pics.

edconline · 04-22-2014, 09:52 PM

Oh boy, please tell me these are available without the cross drilling!

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DEpointfive0 · 04-22-2014, 09:58 PM

Quote:

Originally Posted by edconline

Oh boy, please tell me these are available without the cross drilling!

Sent from my iPhone using Tapatalk

Yep, slotted FTW. Ordered mine already

slam1918 · 04-22-2014, 10:11 PM

what's the beef with X drill??? I have an 04 Joe Gibbs Silverado with 175k miles Magnuson blower & Baer slotted X drilled rotors all around. I drove the crap out of it in the S. Florida heat & not a peep out of em. Changed pads @ 75k & didn't have to resurface the rotors.

DEpointfive0 · 04-22-2014, 10:15 PM

Quote:

Originally Posted by slam1918

what's the beef with X drill??? I have an 04 Joe Gibbs Silverado with 175k miles Magnuson blower & Baer slotted X drilled rotors all around. I drove the crap out of it in the S. Florida heat & not a peep out of em. Changed pads @ 75k & didn't have to resurface the rotors.

Drilled rotors are infinitely more prone to cracking. You probably won't crack them with any amount of aggressive street driving in any temp, but tracking would probably do it.

I get upset that if stress cracks occur the manufacturer is blamed... Which is BS...

Chuck33079 · 04-22-2014, 10:12 PM

They are much more prone to cracking than blank or slotted, especially with track use.

slam1918 · 04-23-2014, 05:07 AM

Funny Z1 tech told me on the phone cooling vanes in between the rotor surfaces go toward the front to scoop air and assist in cooling but I will triple check with them. Maybe if Z1 is peeking in on this site they can chime in. The pic is front & rear but thanks for pointing that out. I'll confirm today.

FPenvy · 04-23-2014, 07:40 AM

Quote:

Originally Posted by slam1918

Funny Z1 tech told me on the phone cooling vanes in between the rotor surfaces go toward the front to scoop air and assist in cooling but I will triple check with them. Maybe if Z1 is peeking in on this site they can chime in. The pic is front & rear but thanks for pointing that out. I'll confirm today.

i mean i could always just go look at my stock rotors and tell you which way they go lol

edconline · 04-23-2014, 07:36 AM

They may have said that however unless their rotor design defies conventional wisdom/practices re: curved vane rotors, I think it was bad information.

Installation:
MOTOR Magazine Article | MOTOR Information Systems
https://www.drt-sport.com/faq
How to properly install plain, slotted, or drilled brake rotors

Good discussion on it here:
Direction of rotation - RacingBrake Forums

Sh0velMan · 04-23-2014, 07:41 AM

A key point that may be being missed in those articles vs this discussion: It's internal vane orientation that matters, not the slots on the outside. So you gotta be sure the internal vanes are pointed the right direction.

LostSol · 04-23-2014, 07:42 AM

Quote:

Originally Posted by Sh0velMan

A key point that may be being missed in those articles vs this discussion: It's internal vane orientation that matters, not the slots on the outside. So you gotta be sure the internal vanes are pointed the right direction.

edconline · 04-23-2014, 08:36 AM

Quote:

Originally Posted by Sh0velMan

A key point that may be being missed in those articles vs this discussion: It's internal vane orientation that matters, not the slots on the outside. So you gotta be sure the internal vanes are pointed the right direction.

Those articles were reference internal vane orientation... The forum link was to the racing brake forum where they said exactly that, the slot on the outside doesn't matter but ALL CURVED INTERNAL VANES must run with the vane angled towards the rear for proper operation. I have a feeling they know a thing or two about brakes.
Right now his rotors are opposite to that. It just makes good sense when you think about it too, sucks air from the center of the rotor, through the hot rotor and out the edge away from it. If it 'was sucking air in' as apparently the Z1 tech suggested, it comes across the hot rotor to the inside and goes... Where?

Edit:
From the first link I posted:
"Rotors with curved vanes, however, are directional and must be positioned properly to achieve full heat dissipation. With curved vanes, the rotor must be mounted with the vanes angled rearward, which results in a centrifugal pumping action. This causes hot air to be pumped from the center area outward. "

From the second link:
"Rotors with straight or pillar vanes are non directional. Direction of cross drilled or slotted rotors can be installed on either side as long as the front and rear match.

A curved vane rotor is directional and must be installed as left and right. The vanes sweep backward from the inside running back toward the rear of the car."

Third link:
"Some higher performance cars come with "directional rotors", which have curved or tilted internal cooling vanes. These curved vanes pump more air through the rotors, resulting in improved cooling efficiency. Thus, there is a left and a right rotor. When the directional rotors are properly installed, these internal vanes should lean toward the back of the car - as shown in the diagram on the lower left."

Waiting for Z1 to chime in and explain why their curved vane rotors are apparently supposed to spin opposite to every other curved vane rotor on the market.

Quote:

Originally Posted by FPenvy

i mean i could always just go look at my stock rotors and tell you which way they go lol

That probably wouldn't help as IIRC the stock rotors are straight vane design.

Sh0velMan · 04-23-2014, 09:34 AM

Yes, I'm glad that you agree with me.

Quote:

Originally Posted by edconline

Those articles were reference internal vane orientation... The forum link was to the racing brake forum where they said exactly that, the slot on the outside doesn't matter but ALL CURVED INTERNAL VANES must run with the vane angled towards the rear for proper operation. I have a feeling they know a thing or two about brakes.
Right now his rotors are opposite to that. It just makes good sense when you think about it too, sucks air from the center of the rotor, through the hot rotor and out the edge away from it. If it 'was sucking air in' as apparently the Z1 tech suggested, it comes across the hot rotor to the inside and goes... Where?

Edit:
From the first link I posted:
"Rotors with curved vanes, however, are directional and must be positioned properly to achieve full heat dissipation. With curved vanes, the rotor must be mounted with the vanes angled rearward, which results in a centrifugal pumping action. This causes hot air to be pumped from the center area outward. "

From the second link:
"Rotors with straight or pillar vanes are non directional. Direction of cross drilled or slotted rotors can be installed on either side as long as the front and rear match.

A curved vane rotor is directional and must be installed as left and right. The vanes sweep backward from the inside running back toward the rear of the car."

Third link:
"Some higher performance cars come with "directional rotors", which have curved or tilted internal cooling vanes. These curved vanes pump more air through the rotors, resulting in improved cooling efficiency. Thus, there is a left and a right rotor. When the directional rotors are properly installed, these internal vanes should lean toward the back of the car - as shown in the diagram on the lower left."

Waiting for Z1 to chime in and explain why their curved vane rotors are apparently supposed to spin opposite to every other curved vane rotor on the market.

That probably wouldn't help as IIRC the stock rotors are straight vane design.

edconline · 04-23-2014, 09:38 AM

Quote:

Originally Posted by Sh0velMan

Yes, I'm glad that you agree with me.

LOL. I just re-read your post and was like

The 'May be being missed' was too much for me when I read it this morning, just came off an all night shift at the base and clearly wasn't reading right lol. All I thought was, dammit how are people not getting this yet lol.

Sh0velMan · 04-23-2014, 09:42 AM

Quote:

Originally Posted by edconline

LOL. I just re-read your post and was like

The 'May be being missed' was too much for me when I read it this morning, just came off an all night shift at the base and clearly wasn't reading right lol. All I thought was, dammit how are people not getting this yet lol.

04-22-2014, 09:52 PM	#2 (permalink)
edconline Track Member Join Date: Mar 2010 Location: Edmonton Posts: 855 Drives: 10' MB Z34 6MT T/S/N Rep Power: 23	Oh boy, please tell me these are available without the cross drilling! Sent from my iPhone using Tapatalk __________________ View Journal Audio Build

04-22-2014, 10:12 PM	#6 (permalink)
Chuck33079 A True Z Fanatic Join Date: Nov 2011 Location: Houston Posts: 12,265 Drives: 2011 370ztt Rep Power: 29539	They are much more prone to cracking than blank or slotted, especially with track use. edconline likes this. __________________ 2011 MB Touring-Sport-6sp-Nav/GTM TT/FI TT TDX/JTran/Kosmic/Eibach/Hotchkis/SPC/CSF/RPS/SoThatsWhereAllMyMoneyWent

04-23-2014, 07:36 AM	#9 (permalink)
edconline Track Member Join Date: Mar 2010 Location: Edmonton Posts: 855 Drives: 10' MB Z34 6MT T/S/N Rep Power: 23	They may have said that however unless their rotor design defies conventional wisdom/practices re: curved vane rotors, I think it was bad information. Installation: MOTOR Magazine Article \| MOTOR Information Systems https://www.drt-sport.com/faq How to properly install plain, slotted, or drilled brake rotors Good discussion on it here: Direction of rotation - RacingBrake Forums __________________ View Journal Audio Build

04-23-2014, 07:41 AM	#10 (permalink)
Sh0velMan A True Z Fanatic Join Date: Jan 2012 Location: Dallas/Ft.Worth Posts: 3,349 Drives: Noisily. Rep Power: 21	A key point that may be being missed in those articles vs this discussion: It's internal vane orientation that matters, not the slots on the outside. So you gotta be sure the internal vanes are pointed the right direction. DEpointfive0, slam1918 and Hotrodz like this. __________________ Buy My Car! \| Build Thread

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04-23-2014, 05:07 AM	#7 (permalink)
slam1918 Base Member Join Date: Feb 2012 Location: Tequesta, Fl Posts: 60 Drives: 10 370Z White A/T Rep Power: 14	Funny Z1 tech told me on the phone cooling vanes in between the rotor surfaces go toward the front to scoop air and assist in cooling but I will triple check with them. Maybe if Z1 is peeking in on this site they can chime in. The pic is front & rear but thanks for pointing that out. I'll confirm today.