Experiment - GT4 Track Setup Wiki:
#121
Drifting
I just finished installing Ferodo DS1.11 pads and tried to do some bedding on my local roads. Yes, Very loud, make PFC 08 sound quiet. I'm sure I'm not completely bedded. For those installing your own brake bracket and caliper studs I have a little info. Screw in the bracket studs until about 10 mm of threaded stud remains. The 62 mm caliper stud is for the front, the 85 mm stud is for the rear. I figured big caliper, long stud. Wrong, and fortunately I checked before the Loc-Tite set. Regarding Loc-Tite, Tarett doesn't send enough with the kit. Buy a tube of Blue before you start install.
For Loctite, I thought you only needed 1-2 drops per stud for it to be effective? I've already got another bottle of blue (and the PMNA studs have red pre-applied anyway), but I'm surprised that what Tarett includes isn't enough for 4 caliper studs. Or were you trying to use it for the bracket studs as well?
#122
Rennlist Member
Another data point on the DS1.11s.. I have them paired with AP rotors and they are loud as hell on the street. Even after bedding and two days at COTA they are very loud. Great on track, and bite cold on the street, but screechy.
#123
#124
Rennlist Member
I guess I'm just unlucky. I have grinding, screeching, and squeeling. I'm trying to drown out the brakes with the exhaust, but it's going to take more than just headers.
#125
Drifting
#126
AP Rotor Awareness Issue.
I wanted to just make folks aware of a potential item when mounting the AP Rotors and re-using the oem set screws.
I ran into a problem as I mounted a new set of Forgeline GA1R Track Wheels. The new wheels immediately started having horrible vibrations. I took them off and remounted a few times only to have the issue continue.
Here is what I found and what I did to remediate:
The AP rotors I received did not come with new set screws for the rotors. These are the two screws that go in the front of the rotor. My shop just re-used the oem screws. I was also told that folks are being told to just re-use the oem screws.
Here’s a pic of the rotor mounted with the oem screws re-used.
The problem is that the hole in the rotor is v-shaped, while the oem set screw has a flat top. As a result it does not fit properly into the hole on the rotor, it will barely grab the thread, work itself loose, and most importantly, they protrude and do not sit flush. On the oem rotors it is not a problem as the hole is recessed in a way that matches the oem screws.
You do not notice this protrusion on the oem wheels as they have material removed on the back of the wheel that will fit over the protruding screws. Some aftermarket wheels, like the forgelines I got, have a completely flat mounting surface . As a result, these wheels will not be able to mount completely flush and flat against the rotor, causing them to vibrate and/or wobble. It is not visually obvious, unless you look closely. But a wheel not mounted flush can be a a safety hazard, especially on track at a high speed/forces.
I simply replaced the oem set screws with a different screw that is v-shaped and fits into the hole properly. I used M6-1.0X14mm.
Here you can see the oem screws (Flat) vs. the replacement screw (V-shaped).
On the next pic you can see the new screws installed. They grab the thread properly and no longer protrude, allowing the wheel to be mounted flush and torqued properly. This caused the wheel vibrations to go away. On this picture you can also see that the holes are v-shaped and if you look closely you can see that the flat oem set screws barelt touched the outside rim of the hole with very little surface touching.
Anyway, this has been communicated to the vendor where I got the rotors from and they were very helpful. We also communicated to Essex to either supply different set screws or change the recess hole on their rotors.
Either way, probably not a good idea to re-use the oem ones.
Later.
Happy hunting.
I wanted to just make folks aware of a potential item when mounting the AP Rotors and re-using the oem set screws.
I ran into a problem as I mounted a new set of Forgeline GA1R Track Wheels. The new wheels immediately started having horrible vibrations. I took them off and remounted a few times only to have the issue continue.
Here is what I found and what I did to remediate:
The AP rotors I received did not come with new set screws for the rotors. These are the two screws that go in the front of the rotor. My shop just re-used the oem screws. I was also told that folks are being told to just re-use the oem screws.
Here’s a pic of the rotor mounted with the oem screws re-used.
The problem is that the hole in the rotor is v-shaped, while the oem set screw has a flat top. As a result it does not fit properly into the hole on the rotor, it will barely grab the thread, work itself loose, and most importantly, they protrude and do not sit flush. On the oem rotors it is not a problem as the hole is recessed in a way that matches the oem screws.
You do not notice this protrusion on the oem wheels as they have material removed on the back of the wheel that will fit over the protruding screws. Some aftermarket wheels, like the forgelines I got, have a completely flat mounting surface . As a result, these wheels will not be able to mount completely flush and flat against the rotor, causing them to vibrate and/or wobble. It is not visually obvious, unless you look closely. But a wheel not mounted flush can be a a safety hazard, especially on track at a high speed/forces.
I simply replaced the oem set screws with a different screw that is v-shaped and fits into the hole properly. I used M6-1.0X14mm.
Here you can see the oem screws (Flat) vs. the replacement screw (V-shaped).
On the next pic you can see the new screws installed. They grab the thread properly and no longer protrude, allowing the wheel to be mounted flush and torqued properly. This caused the wheel vibrations to go away. On this picture you can also see that the holes are v-shaped and if you look closely you can see that the flat oem set screws barelt touched the outside rim of the hole with very little surface touching.
Anyway, this has been communicated to the vendor where I got the rotors from and they were very helpful. We also communicated to Essex to either supply different set screws or change the recess hole on their rotors.
Either way, probably not a good idea to re-use the oem ones.
Later.
Happy hunting.
#127
Drifting
^ Interesting! The rotors I ordered from Clark at Apex recently came with replacement screws. I was wondering why they were necessary, but now I know and will make sure that the shop that will be doing this swap along with some other stuff is well aware.
#128
Can you check what type of screws they sent you? Clark and I talked a bit and we suspect it might be just a set of replacement oem screws, in which case, the problem will persist. If they sent different screws it will be good. I just received a set of rears and they did not come with any screws.
#129
Rennlist Member
Interesting to see such different impressions. Mech33, are you on AP rotors as well? I'm planning to install those whenever I next swap pads. Did one of you maybe install brand new rotors at the same time as the DS1.11 and another didn't? Did either of you add any sort of anti-squeal plates/grease? Just trying to figure out what might account for such a significant difference here.
Can you check what type of screws they sent you? Clark and I talked a bit and we suspect it might be just a set of replacement oem screws, in which case, the problem will persist. If they sent different screws it will be good. I just received a set of rears and they did not come with any screws.
#130
Drifting
Can you check what type of screws they sent you? Clark and I talked a bit and we suspect it might be just a set of replacement oem screws, in which case, the problem will persist. If they sent different screws it will be good. I just received a set of rears and they did not come with any screws.
#131
They're black but shaped like the top screw in your earlier post. I ordered a pair of front rotors on 4/19/16 and in ONE of the rotor boxes was a bag with all 4 screws and a note saying, "These two screws are for use with the Porsche GT4. Use these to fasten the disc assembly to the hub in place of the original screws." I have since gotten a second bag to have two screws with each rotor to minimize the chances of this being done incorrectly.
#132
Drifting
Nice! Doesn't explain why the rear rotors that it sounds like you just ordered didn't come with them though, unless maybe the rear doesn't require the different screws? Maybe the OE setup is different or maybe AP uses a different hat design back there, or maybe they've since switched ALL of their hats to a new design?
#133
Not trying to be an asshat here but I addressed this issue with Jeff at Essex (AP) as well as Clark at Apex after fitting the original set as a test case. Originally I was told to reuse the Lenshead screws that came with the OEM steel rotors (999-015-025-09) only to find out that the correct ones were the ones for a 987.2 steel rotor (900-269-047-01) or the GT4 OEM PCCBs chamfered ones (900-269-047-03)
I was reassured and sent 1 screw per rotor by AP and after talking to Clark I was assured that he would cover the issue and supply 2 screws per rotor. The screws sent to me by AP were a bit longer than necessary. I bought the correct length screws through my dealer. The OEM screws had blue loctite applied whereas the AP supplied ones were bare.
I was reassured and sent 1 screw per rotor by AP and after talking to Clark I was assured that he would cover the issue and supply 2 screws per rotor. The screws sent to me by AP were a bit longer than necessary. I bought the correct length screws through my dealer. The OEM screws had blue loctite applied whereas the AP supplied ones were bare.
#134
Drifting
Not trying to be an asshat here but I addressed this issue with Jeff at Essex (AP) as well as Clark at Apex after fitting the original set as a test case. Originally I was told to reuse the Lenshead screws that came with the OEM steel rotors (999-015-025-09) only to find out that the correct ones were the ones for a 987.2 steel rotor (900-269-047-01) or the GT4 OEM PCCBs chamfered ones (900-269-047-03)
I was reassured and sent 1 screw per rotor by AP and after talking to Clark I was assured that he would cover the issue and supply 2 screws per rotor. The screws sent to me by AP were a bit longer than necessary. I bought the correct length screws through my dealer. The OEM screws had blue loctite applied whereas the AP supplied ones were bare.
I was reassured and sent 1 screw per rotor by AP and after talking to Clark I was assured that he would cover the issue and supply 2 screws per rotor. The screws sent to me by AP were a bit longer than necessary. I bought the correct length screws through my dealer. The OEM screws had blue loctite applied whereas the AP supplied ones were bare.
#135
Ok, in that case I'm wondering (hoping) that maybe this will go away as the rotors get some use on them. The PFC 08s had the worst squeal toward the end of a stop too, but it was bad when it happened. I felt bad for any pedestrians waiting at the intersection.
Nice! Doesn't explain why the rear rotors that it sounds like you just ordered didn't come with them though, unless maybe the rear doesn't require the different screws? Maybe the OE setup is different or maybe AP uses a different hat design back there, or maybe they've since switched ALL of their hats to a new design?
Nice! Doesn't explain why the rear rotors that it sounds like you just ordered didn't come with them though, unless maybe the rear doesn't require the different screws? Maybe the OE setup is different or maybe AP uses a different hat design back there, or maybe they've since switched ALL of their hats to a new design?
Edit: I checked and yes, they were all four in the second box. I only opened the first box, expecting two screws to come with every rotor. So, my rears are all good.