Q45 Caliper/13'' Cobra Rotor BBK Upgrade Write Up
BTW, is it possible to manufacture brackets for the 13" rotors that would not require 10mm more clearance? The way I envision this being possible would be to have a two layer bracket using welding to make a "Z" joint in the bracket, bringing it back to stock distance from the hub where the caliper bolts up. That way some of us with tighter spoke clearances could install the complete BBK. Otherwise, I think I may have to stick with stock size rotors due to not having enough spoke clearance. (I'm not changing my rims, at least not for a while)
they are not for maximas but the same concept. here are the links and I found some for $100 instead
http://cgi.ebay.com/ebaymotors/ws/eB...m=190250607915
*Test Fit the Rotor and Torque Member & Rotor*
Mounting the rotor onto the hub and securing the torque member onto the bracket.
1) Place the new centering ring onto the hub for the new rotor to sit on. Make certain its flush w/ the hub.
2) After the ring is in place, put the 13'' rotor on. It should sit on the hub w/o trouble. Make sure the dust shield isn't touching the rear of the rotor.
3) Place the caliper bracket in front of the remaining two holes of the bracket and secure w/ either the stock Maxima hardware or new hardware.(17mm bolts)
4) Load the new pads into the torque member.
*Mounting the Caliper*
Rotor, caliper successfully mounted.
5) Place the new calipers onto the torque member and secure it w/ the caliper pins. (14mm bolts)
6) Re-attach the brake lines.
7) Check that all bolts are properly torqued and re-mount tire.
8) Check to see if the rotor spins freely. If not, check your wheel spokes for contact w/ the caliper. Grinding of the caliper might be necessary.
If everything is successful, dont forget to bed in those new brakes. Instructions to do so are found here: http://www.zeckhausen.com/bedding_in_brakes.htm
Enjoy!
Mounting the rotor onto the hub and securing the torque member onto the bracket.
1) Place the new centering ring onto the hub for the new rotor to sit on. Make certain its flush w/ the hub.
2) After the ring is in place, put the 13'' rotor on. It should sit on the hub w/o trouble. Make sure the dust shield isn't touching the rear of the rotor.
3) Place the caliper bracket in front of the remaining two holes of the bracket and secure w/ either the stock Maxima hardware or new hardware.(17mm bolts)
4) Load the new pads into the torque member.
*Mounting the Caliper*
Rotor, caliper successfully mounted.
5) Place the new calipers onto the torque member and secure it w/ the caliper pins. (14mm bolts)
6) Re-attach the brake lines.
7) Check that all bolts are properly torqued and re-mount tire.
8) Check to see if the rotor spins freely. If not, check your wheel spokes for contact w/ the caliper. Grinding of the caliper might be necessary.
If everything is successful, dont forget to bed in those new brakes. Instructions to do so are found here: http://www.zeckhausen.com/bedding_in_brakes.htm
Enjoy!
thanks
Oliver
BTW, is it possible to manufacture brackets for the 13" rotors that would not require 10mm more clearance? The way I envision this being possible would be to have a two layer bracket using welding to make a "Z" joint in the bracket, bringing it back to stock distance from the hub where the caliper bolts up. That way some of us with tighter spoke clearances could install the complete BBK. Otherwise, I think I may have to stick with stock size rotors due to not having enough spoke clearance. (I'm not changing my rims, at least not for a while)
I'm the one to get these brackets from. I no longer require the rings. But I do require that the rotors be redrilled to a maxima lug size so it fits properly. Automax in the group deal section sells them. I'm currently out of brackets at the moment. If one is seriously about getting more, PM me your desire.
Bringin' this thread back 
So, FMI, what is the measurement from the rotor face to the inside of the spokes that is needed to clear this Q/J BBK? Also (related), what would be the same measurement needed for clearing the Z32 calipers?
Right now, measuring from my stock rotors ('89 GXE) I have 2 1/8" clearance to inside of spokes (=65mm). So, with these same wheels (I35 sport 6-spoke) I wonder if I can fit a BBK or if I will need spacers/ other wheels.
Sorry for the "grave-digging". Still planning this out
Also, are the Q45 calipers that much bigger or better than the J30 calipers?
And, it would be nice to see a break down of the cost of the whole BBK (calipers, pads, brackets, hardware, rotors, SS lines, fluid).
So, FMI, what is the measurement from the rotor face to the inside of the spokes that is needed to clear this Q/J BBK? Also (related), what would be the same measurement needed for clearing the Z32 calipers?
Right now, measuring from my stock rotors ('89 GXE) I have 2 1/8" clearance to inside of spokes (=65mm). So, with these same wheels (I35 sport 6-spoke) I wonder if I can fit a BBK or if I will need spacers/ other wheels.
Sorry for the "grave-digging". Still planning this out
Also, are the Q45 calipers that much bigger or better than the J30 calipers?
And, it would be nice to see a break down of the cost of the whole BBK (calipers, pads, brackets, hardware, rotors, SS lines, fluid).
Q45s and J30s are essentially the same. My brackets will move the caliper out an additional 10 mm. As for clearance, I always used G/Z oem wheels that had massive clearance anyway. No spacers needed even for my 4 piston 300z units. 10mm is aobut 0.4". So I'll GUESS that your wheels would clear if I'm understanding your clearance measurement correctly
OK. Thanks Jeff. Let us know when you have more brackets available, please.
I assume you were saying that the Q/J Calipers would probably fit behind my wheels. Of course, the 300zx calipers probably wouldn't, right?
It would be nice if someone who has already done the swap on both the Q45 and 300zx BBKs to measure the distance from the face of the rotors (either Cobra 13" or other) to inside of the spokes and then subtract the difference of space between the caliper and inner spoke to come up with the exact measurement (in mm preferably) needed for spoke clearance. Has anyone done this already?
I know your brackets, Jeff, add 10mm of clearance needed. I don't know how much thicker than stock the Cobra (or other) rotors are that would also increase the necessary clearance. But, if someone who already has the different BBKs could make the measurements I described above, it seems to me that that would make it a lot easier for people wanting to know if they can clear a BBK to decide what they can do.
Thanks,
Mark
I assume you were saying that the Q/J Calipers would probably fit behind my wheels. Of course, the 300zx calipers probably wouldn't, right?
It would be nice if someone who has already done the swap on both the Q45 and 300zx BBKs to measure the distance from the face of the rotors (either Cobra 13" or other) to inside of the spokes and then subtract the difference of space between the caliper and inner spoke to come up with the exact measurement (in mm preferably) needed for spoke clearance. Has anyone done this already?
I know your brackets, Jeff, add 10mm of clearance needed. I don't know how much thicker than stock the Cobra (or other) rotors are that would also increase the necessary clearance. But, if someone who already has the different BBKs could make the measurements I described above, it seems to me that that would make it a lot easier for people wanting to know if they can clear a BBK to decide what they can do.
Thanks,
Mark
I misunderstood. You took the measurement from the rotor face to the inner spoke? You need to make a measurement from the outside of the caliper to the inner spoke. And then see if you have more than 10 mm clearance. That will roughly tell you if you have a chance. You also remember the caliper will be outward to accomodate the 13" rotor too. So if the spokes curve in, you will have less clearance there.
You could also consult the bbk wheel thread to get reference ideas
You could also consult the bbk wheel thread to get reference ideas
The distance to the inside of the spokes from my stock caliper brackets is 15-20mm depending on how far out along the spoke it is measured. I assume that means it will probably fit the Q/J calipers.
I thought that if measurements were made from the rotor face to the inside of the spokes it would be easier to measure the exact distance that the calipers stick out from the rotor thus making it simpler to gauge whether any wheel might be able to fit over a particular caliper/BBK.
Given the example of my stock setup:
Distance from stock rotor face to inner spoke = 65mm
Minus distance from stock caliper to inner spoke (close to hub) = 15mm (~20mm farther out)
Equals distance that stock caliper sticks out from rotor face ~ 50mm
Therefore, if the stock rotors are about 20mm thick (measuring my worn stock rotors, I don't know what the new stock rotor thickness is), and the Cobra rotors are 28mm thick, then that is an additional 8mm plus the 10mm from the relocation bracket for the 13" Cobra rotors. So, if I have 18mm additional clearance needed then that means the wheels I use have to have spoke clearance of at least 68mm from the stock rotor face to clear the Q45/J30-13" Cobra Rotor BBK.
It would also be good to know how far out along the radius of the spokes I would need to measure for spoke clearance given where the Q/J caliper sits on the 13" rotors.
So, given my example, my wheels might clear with very tight tolerances. I might need to shave off a bit from the Q/J calipers or fit small spacers (3-5mm).
I thought that if measurements were made from the rotor face to the inside of the spokes it would be easier to measure the exact distance that the calipers stick out from the rotor thus making it simpler to gauge whether any wheel might be able to fit over a particular caliper/BBK.
Given the example of my stock setup:
Distance from stock rotor face to inner spoke = 65mm
Minus distance from stock caliper to inner spoke (close to hub) = 15mm (~20mm farther out)
Equals distance that stock caliper sticks out from rotor face ~ 50mm
Therefore, if the stock rotors are about 20mm thick (measuring my worn stock rotors, I don't know what the new stock rotor thickness is), and the Cobra rotors are 28mm thick, then that is an additional 8mm plus the 10mm from the relocation bracket for the 13" Cobra rotors. So, if I have 18mm additional clearance needed then that means the wheels I use have to have spoke clearance of at least 68mm from the stock rotor face to clear the Q45/J30-13" Cobra Rotor BBK.
It would also be good to know how far out along the radius of the spokes I would need to measure for spoke clearance given where the Q/J caliper sits on the 13" rotors.
So, given my example, my wheels might clear with very tight tolerances. I might need to shave off a bit from the Q/J calipers or fit small spacers (3-5mm).
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