Cross Drilled Rotors - Who uses them?

2FastLX · 09-28-2001, 12:23 PM

I ordered Power Slot slotted rotors, but instead I received Power Stop's cross drilled rotors. I've heard that cross drilled rotors are prone to cracking so I'm kind of scared to put these on my car. Power Stop says these rotors are intended for street use only so they should be fine right? I really need to get my car back on the road so my only other option would be to send these back and buy some stock replacements. I don't race my car much, unless a Camaro pulls up next to me, and I rarely take it to the strip (twice in a year and a half). What do you think I should do?

After seeing these rotors they appear to be very well made and the holes in the rotors are chamfered which would help prevent them from chewing up the pads, and prevent them from cracking as well I would think.

Thanks.

------------------
Gunning for 12's!

Buy your parts here
ICQ# 42269241

89 Cobra LX · 09-28-2001, 01:13 PM

I think you may have been confused. There isn't a company named Power Slot. The company's name is Power Stop. They do carry two different kinds of rotors (slotted and cross-drilled).

I am running Power Stop cross-drilled on the front of my stang (the rear still has the drums) with high-performance pads. I don't have any complaints. They have not cracked and there was a noticable difference stopping distance. If you have wheels that show the brakes, it will look tits! I have 4-lug Cobra R wheels and with the brakes visible the front of my car looks very cool.

Hope this helps.

------------------
Eric - 89 Mustang LX coupe
302 - Cobra Intake - GT40p heads - TFS stage 1 cam - FRPP 1.6 roller rockers - Naturally Aspirated
3:73 gears - KYB shocks and struts - Eibach springs - HPM Mega-bite Jr lower control arms - HPM upper control arms

2FastLX · 09-28-2001, 01:36 PM

Ok, maybe they are made by the same people, but I did order the slotted rotors. They have different part numbers in Holcombs catalog.

I have the same setup as you with Cobra R's. I figured the cross drilled would look even better than the slotted, but I was just scared from everyone saying they crack. I'm going to paint my calipers red to match my car so it should look pretty good.

How long have you had yours? And how many miles have you put on them?
Thanks for the quick response.

89 Cobra LX · 09-28-2001, 02:35 PM

They were installed this spring, so I don't have more than a couple of thousand miles on them. I can't really say they are long-lasting... but for as popular as they are, they must be pretty good.

When I purchased the rotors I also had a hard time choosing between the two. I purchased them from HPMotorsport here in Omaha and I specifically asked about the drilled rotors cracking. They told me that they have never seen it in person, but they had heard it as well. I imagine the stock brake system doesn't provide enough force to crack the rotors. Those other high-performance brake set-ups might be able to do some damage.

On a different note, I like what you're doing by painting the calipers. I wish I would've when I had everything apart. I found some Cobra R medallions from Dugan Racing to replace the generic center caps from the fake Cobra R wheels. The center caps look just like the real Cobra R caps except for the R is in Blue and it matches my paint. Dugan also sells the medalions in yellow and red. If you have generic center caps you may want to give Dugan a ring to get everything matching in red.

Good luck with your decision, maybe someone else on the board can offer some advice on the rotors cracking.?

------------------
Eric - 89 Mustang LX coupe
302 - Cobra Intake - GT40p heads - TFS stage 1 cam - FRPP 1.6 roller rockers - Naturally Aspirated
3:73 gears - KYB shocks and struts - Eibach springs - HPM Mega-bite Jr lower control arms - HPM upper control arms

Chevyguy · 09-28-2001, 03:57 PM

I'm pretty sure you cannot turn the cross drilled rotors. No info about cracking though, that could be a problem with poor machining quality causing stress cracks in the rotors????

------------------
Frank W
90 5.0 LX coupe Daily driver. Silencer removed, K&N filter. Flexalite fan, 3 core radiator. FMS flywheel and Clutch, FMS blue wires Energy Suspension end links
88 Notch 2.3L 5 speed Parts/beater car My two Notchbacks

74 Chevy Laguna Type S-3 305 Finally fixed getting a 454 to put in garage
<A HREF="http://www.chevellepages.com/folingo" TARGET=_blank>www.chevellepages.

Unit 5302 · 09-28-2001, 07:15 PM

The potential for cracking is much higher with cross drilled rotors because of the heating and cooling cycles involved. Cross drilling stock Ford rotors (the rotors are weaker than the GM's) is a recipe for cracking.

The rotor is significantly weakend by the holes drilled through them, so when they heat up and cool down fast it makes them crack as the expand and contract.

Aftermarket cross drilled setups are much better than stock cross drilled setups. You'll have a greater chance of cracking with the cross drilled, but it's up to you.

84LX89GT · 09-29-2001, 12:05 AM

I have seen cracked cross drilled rotors, but they were on an 80's volkswagen Jetta. Just like Unit said, They crack in between the holes after they're heated up a bit. That's a pretty scary thing to see. I also know that they aren't turnable, so if they warp or cracked, you're out $90 (or however much you spend on each one).
When i do my brakes, i'm going to buy brand new regular rotors, with performance pads, steel piston calipers, steel caliper busings (from steeds), stainless steel brake lines, and use DOT 4 brake fluid. Since my GT has 4 wheel disc brakes, this should knock my wind out when i stop, but will hopefully save my @ss when i'm driving like a jack@ss or when someone else is.

------------------
Mustang Parts Specialties ripped me off, it could happen to you as well.
'84 Mustang 5.0 LX
my LX
'89 Mustang GT
my GT

09-28-2001, 12:23 PM	#1
2FastLX The Photoshop Guru Join Date: Feb 2001 Location: Mecca, Indiana Posts: 1,419	Cross Drilled Rotors - Who uses them? I ordered Power Slot slotted rotors, but instead I received Power Stop's cross drilled rotors. I've heard that cross drilled rotors are prone to cracking so I'm kind of scared to put these on my car. Power Stop says these rotors are intended for street use only so they should be fine right? I really need to get my car back on the road so my only other option would be to send these back and buy some stock replacements. I don't race my car much, unless a Camaro pulls up next to me, and I rarely take it to the strip (twice in a year and a half). What do you think I should do? After seeing these rotors they appear to be very well made and the holes in the rotors are chamfered which would help prevent them from chewing up the pads, and prevent them from cracking as well I would think. Thanks. ------------------ Gunning for 12's! Buy your parts here ICQ# 42269241

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09-28-2001, 01:13 PM	#2
89 Cobra LX Don Corlione Join Date: Jun 2001 Location: Omaha NE USA Posts: 491	I think you may have been confused. There isn't a company named Power Slot. The company's name is Power Stop. They do carry two different kinds of rotors (slotted and cross-drilled). I am running Power Stop cross-drilled on the front of my stang (the rear still has the drums) with high-performance pads. I don't have any complaints. They have not cracked and there was a noticable difference stopping distance. If you have wheels that show the brakes, it will look tits! I have 4-lug Cobra R wheels and with the brakes visible the front of my car looks very cool. Hope this helps. ------------------ Eric - 89 Mustang LX coupe 302 - Cobra Intake - GT40p heads - TFS stage 1 cam - FRPP 1.6 roller rockers - Naturally Aspirated 3:73 gears - KYB shocks and struts - Eibach springs - HPM Mega-bite Jr lower control arms - HPM upper control arms

09-28-2001, 01:36 PM	#3
2FastLX The Photoshop Guru Join Date: Feb 2001 Location: Mecca, Indiana Posts: 1,419	Ok, maybe they are made by the same people, but I did order the slotted rotors. They have different part numbers in Holcombs catalog. I have the same setup as you with Cobra R's. I figured the cross drilled would look even better than the slotted, but I was just scared from everyone saying they crack. I'm going to paint my calipers red to match my car so it should look pretty good. How long have you had yours? And how many miles have you put on them? Thanks for the quick response.

09-28-2001, 02:35 PM	#4
89 Cobra LX Don Corlione Join Date: Jun 2001 Location: Omaha NE USA Posts: 491	They were installed this spring, so I don't have more than a couple of thousand miles on them. I can't really say they are long-lasting... but for as popular as they are, they must be pretty good. When I purchased the rotors I also had a hard time choosing between the two. I purchased them from HPMotorsport here in Omaha and I specifically asked about the drilled rotors cracking. They told me that they have never seen it in person, but they had heard it as well. I imagine the stock brake system doesn't provide enough force to crack the rotors. Those other high-performance brake set-ups might be able to do some damage. On a different note, I like what you're doing by painting the calipers. I wish I would've when I had everything apart. I found some Cobra R medallions from Dugan Racing to replace the generic center caps from the fake Cobra R wheels. The center caps look just like the real Cobra R caps except for the R is in Blue and it matches my paint. Dugan also sells the medalions in yellow and red. If you have generic center caps you may want to give Dugan a ring to get everything matching in red. Good luck with your decision, maybe someone else on the board can offer some advice on the rotors cracking.? ------------------ Eric - 89 Mustang LX coupe 302 - Cobra Intake - GT40p heads - TFS stage 1 cam - FRPP 1.6 roller rockers - Naturally Aspirated 3:73 gears - KYB shocks and struts - Eibach springs - HPM Mega-bite Jr lower control arms - HPM upper control arms

09-28-2001, 03:57 PM	#5
Chevyguy Backyard Mechanic/Chemist Join Date: Feb 2001 Location: Acton MA USA Posts: 435	I'm pretty sure you cannot turn the cross drilled rotors. No info about cracking though, that could be a problem with poor machining quality causing stress cracks in the rotors???? ------------------ Frank W 90 5.0 LX coupe Daily driver. Silencer removed, K&N filter. Flexalite fan, 3 core radiator. FMS flywheel and Clutch, FMS blue wires Energy Suspension end links 88 Notch 2.3L 5 speed Parts/beater car My two Notchbacks 74 Chevy Laguna Type S-3 305 Finally fixed getting a 454 to put in garage <A HREF="http://www.chevellepages.com/folingo" TARGET=_blank>www.chevellepages.

09-28-2001, 07:15 PM	#6
Unit 5302 Registered Member Join Date: May 1999 Posts: 5,246	The potential for cracking is much higher with cross drilled rotors because of the heating and cooling cycles involved. Cross drilling stock Ford rotors (the rotors are weaker than the GM's) is a recipe for cracking. The rotor is significantly weakend by the holes drilled through them, so when they heat up and cool down fast it makes them crack as the expand and contract. Aftermarket cross drilled setups are much better than stock cross drilled setups. You'll have a greater chance of cracking with the cross drilled, but it's up to you.

09-29-2001, 12:05 AM	#7
84LX89GT Mustangs Join Date: Jul 2000 Posts: 1,938	I have seen cracked cross drilled rotors, but they were on an 80's volkswagen Jetta. Just like Unit said, They crack in between the holes after they're heated up a bit. That's a pretty scary thing to see. I also know that they aren't turnable, so if they warp or cracked, you're out $90 (or however much you spend on each one). When i do my brakes, i'm going to buy brand new regular rotors, with performance pads, steel piston calipers, steel caliper busings (from steeds), stainless steel brake lines, and use DOT 4 brake fluid. Since my GT has 4 wheel disc brakes, this should knock my wind out when i stop, but will hopefully save my @ss when i'm driving like a jack@ss or when someone else is. ------------------ Mustang Parts Specialties ripped me off, it could happen to you as well. '84 Mustang 5.0 LX my LX '89 Mustang GT my GT