Turbo 3.6 Owners: Are Your Front Rotors Cracking?
03-09-2009, 07:46 PM
#1
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Turbo 3.6 Owners: Are Your Front Rotors Cracking?
I'll be upgrading my car to the "Big Red" calipers this week. For now I'll still be using my 322mm 4/3 hole cross drilled rotors, which were standard on the Turbo 3.3.
I was wondering about the durability of the 5/4 hole rotors that came with the "Big Red" calipers on Turbo 3.6's. These rotors are badly cracked on a friend's 3.6.
So, 3.6 owners, tell me, how are your rotors holding up?
I was wondering about the durability of the 5/4 hole rotors that came with the "Big Red" calipers on Turbo 3.6's. These rotors are badly cracked on a friend's 3.6.
So, 3.6 owners, tell me, how are your rotors holding up?
03-10-2009, 08:13 AM
#2
Burning Brakes
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I have a 3.3 but have been running with 3.6 rotors for many years (since they are cheaper and can be used with 3.3 calipers) and the last couple of years in combination with big read calipers.
I track my car haven't found any big difference in durability between the two.
Driving style makes the biggest difference but break pad compound is also very important. Many compounds generate to much heat for our heavy and powerful cars when driven hard.
I use my rotors until a crack goes all the way to the top, that's what I mean with cracking, perhaps what you mean is smaller cracks around the ventialtion holes?
To my understanding the problem is the long hub, the rotor tend to bend outwards when heated hard, thus making more cracks on the outside, floating rotors are supposed to be the solution, but that's to expensive in my taste.
Again, it depends on what you mean by cracks, I get small cracks after 20 minutes of driving on the track with a set of brand new rotors.
I track my car haven't found any big difference in durability between the two.
Driving style makes the biggest difference but break pad compound is also very important. Many compounds generate to much heat for our heavy and powerful cars when driven hard.
I use my rotors until a crack goes all the way to the top, that's what I mean with cracking, perhaps what you mean is smaller cracks around the ventialtion holes?
To my understanding the problem is the long hub, the rotor tend to bend outwards when heated hard, thus making more cracks on the outside, floating rotors are supposed to be the solution, but that's to expensive in my taste.
Again, it depends on what you mean by cracks, I get small cracks after 20 minutes of driving on the track with a set of brand new rotors.
03-10-2009, 11:42 AM
#3
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I have no cracks on my turbo or GTS standard street driving. I use the same rotors and brakes on all three cars. The C2 is tracked with a dual driver and I use Pagid yellows. I have small cracks forming on most holes with roughly 7K+ hard track miles and have gone through 3 sets of pads on this set of rotors. I figure I am good for this season and then time to change.
Rule of thumb is no 2 holes should connect and no cracks to the outside edge otherwise this can result in a locked wheel. Also using the 58mm wide big red pad on the rotors designed to run the 48mm wide pad will result in a pad that is not usable on the 3.6T rotors. I find the pads cost me more than the rotors so I would consider changing the rotors with the calipers.
BTW I have purchased most of my rotors new on Ebay. Factory units come up for sale on occasion and have purchased them for between $50 and $100 as single units. I keep them in inventory since I have need for them on more than one car.
Rule of thumb is no 2 holes should connect and no cracks to the outside edge otherwise this can result in a locked wheel. Also using the 58mm wide big red pad on the rotors designed to run the 48mm wide pad will result in a pad that is not usable on the 3.6T rotors. I find the pads cost me more than the rotors so I would consider changing the rotors with the calipers.
BTW I have purchased most of my rotors new on Ebay. Factory units come up for sale on occasion and have purchased them for between $50 and $100 as single units. I keep them in inventory since I have need for them on more than one car.
03-10-2009, 11:45 AM
#5
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03-10-2009, 04:29 PM
#6
I would think cracked rotors at 195 would be a major concern! Just going 195 would be more than I would care to experience... You are a much better man than I. Do you change them after every run?
03-10-2009, 05:09 PM
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03-10-2009, 05:24 PM
#8
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The 3.3 used the medium S4 caliper with the 48mm pad. The overall diameter of the rotor is the same but the surface area for the pad does not extend as far down to the center of the hub as the 3.6 big red rotor does. It is roughly (although I never measured it) .400 less surface area from the OD to ID this is the reason why they have different cast hole pattern because the 3.3's have less surface and less holes. So you can use a 3.6 for the 3.3 but not the other way around. If you do you will find that you will have a section of pad at the bottom that has never touched the rotor and will eventually grind into the dust groove along the bottom.
Although you can probably get away with it for a while eventually it will screw up the pads and possibly the rotor. My recommendation would be to measure the distance from OD to ID and see how many mm it is exactly and see if you feel comfortable with it although once you use and cut into the pad you will be stuck with replacing them when you change rotors.
03-14-2009, 11:24 PM
#10
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You have to keep a watch out for them. I just picked up a new right hand rotor for $99 delivered about 2 weeks ago.
The 3.3 used the medium S4 caliper with the 48mm pad. The overall diameter of the rotor is the same but the surface area for the pad does not extend as far down to the center of the hub as the 3.6 big red rotor does. It is roughly (although I never measured it) .400 less surface area from the OD to ID this is the reason why they have different cast hole pattern because the 3.3's have less surface and less holes. So you can use a 3.6 for the 3.3 but not the other way around. If you do you will find that you will have a section of pad at the bottom that has never touched the rotor and will eventually grind into the dust groove along the bottom.
Although you can probably get away with it for a while eventually it will screw up the pads and possibly the rotor. My recommendation would be to measure the distance from OD to ID and see how many mm it is exactly and see if you feel comfortable with it although once you use and cut into the pad you will be stuck with replacing them when you change rotors.
The 3.3 used the medium S4 caliper with the 48mm pad. The overall diameter of the rotor is the same but the surface area for the pad does not extend as far down to the center of the hub as the 3.6 big red rotor does. It is roughly (although I never measured it) .400 less surface area from the OD to ID this is the reason why they have different cast hole pattern because the 3.3's have less surface and less holes. So you can use a 3.6 for the 3.3 but not the other way around. If you do you will find that you will have a section of pad at the bottom that has never touched the rotor and will eventually grind into the dust groove along the bottom.
Although you can probably get away with it for a while eventually it will screw up the pads and possibly the rotor. My recommendation would be to measure the distance from OD to ID and see how many mm it is exactly and see if you feel comfortable with it although once you use and cut into the pad you will be stuck with replacing them when you change rotors.
I thought I saw a post from Bill Velburg saying that the those Rotor are the same but diif part numbers. I was going to use a set of 3.3s on my 3.6T big reds ..are you sure that you are correct?
Elliot
03-15-2009, 02:26 AM
#11
Three Wheelin'
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I have had both and will second what Cobalt said. 3.6 rotors will work on 3.3 but not the other way around.
03-15-2009, 11:37 AM
#12
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