J30 Brake conversion
12-04-2005, 12:57 AM
#1
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J30 Brake conversion
Well, i did this brake swap about 2 months ago and now that ive proven it to myself i thought it would be a good thing to share it with everyone else. It uses the J30 calipers which is an upgrade because it is two piston and has more mass to suck up heat. It also uses the J30 Rotor, which is the same diameter, but is MUCH thicker. Stock rotor is about 3/4 of an ich where as the J30 rotor is 1-1/8 of an inch think. That means that there is alot more mass there to absorb heat also. The swap was pretty strait forward requireing very little fabrication, and all bolt on factory parts. It is a fairly easy swap to do.
Picture of the Two rotors next to each other
As you can see, theres alot more meat on the J30 rotor. In my eyes thats the most atracting part about this swap.
Pic of the assembled setup.
The only thing i had to fabricated is the 1/16 inch spacer that had to be made, or bought to space the Rotor out from the hub just enough to make it clear the caliper mount. Since i had to use the Maxima caliper mount, which is made for only a maxima rotor (3/4 inch), i had to make sure that the rotor was directly in the center. therefore the spacer was made. On a side note, if any of you are wondering, I had to use the maxima caliper mount becuase the j30 one spaced it about a 1/4 inch into to far towards the center of the hub. once i had the rotor spaced out i had to file a little on the caliper mount just to give it a little extra clearence so wheh your taking a turn the warping of the hub doesnt start makeing the rotor rub the caliper mount. This only took a matter of minutes on each side. the last thing i had to do was modify the maxima pads to fit into the space between the caliper pistons and the rotor. I found the the J30 must have thiner pads that maximas becuase when i put new maxima pads on it (maxima caliper mount) i found that the pad where always rubbing just a tad. it still drove fine but it made me nervouse haveing my brakes always rubing a little, so what i did to solve that poblem, I took them to a sander. It worked great, i took just enough off to make it not rub and not make any unwanted heat.
so hears a few pictures..
Edit: Added this photo because is shows the clearance between the rotor and the mount
I also added this because it shows one of the spots where you must file a little to get the caliper to clear the caliper mount freely, I clears without fileing but not loosly enough for my liking.
This entire brake upgrade at the time of installation cost me less than $100 I had just bougt new pads previous to install so im not counting that.
Calipers i got for a deal, $10 a piece,
Rotors where form slauterzone, Lifetime warrenty, but still crap. but hey... they where cheap. $35 a piece.
Feel free to ask any questions.
IM bad a typing what im thinking so im very sorry if this post is vague in places or just hard to understand. I will try and fix that if there are any problems.
Jeremy.
Picture of the Two rotors next to each other
As you can see, theres alot more meat on the J30 rotor. In my eyes thats the most atracting part about this swap.
Pic of the assembled setup.
The only thing i had to fabricated is the 1/16 inch spacer that had to be made, or bought to space the Rotor out from the hub just enough to make it clear the caliper mount. Since i had to use the Maxima caliper mount, which is made for only a maxima rotor (3/4 inch), i had to make sure that the rotor was directly in the center. therefore the spacer was made. On a side note, if any of you are wondering, I had to use the maxima caliper mount becuase the j30 one spaced it about a 1/4 inch into to far towards the center of the hub. once i had the rotor spaced out i had to file a little on the caliper mount just to give it a little extra clearence so wheh your taking a turn the warping of the hub doesnt start makeing the rotor rub the caliper mount. This only took a matter of minutes on each side. the last thing i had to do was modify the maxima pads to fit into the space between the caliper pistons and the rotor. I found the the J30 must have thiner pads that maximas becuase when i put new maxima pads on it (maxima caliper mount) i found that the pad where always rubbing just a tad. it still drove fine but it made me nervouse haveing my brakes always rubing a little, so what i did to solve that poblem, I took them to a sander. It worked great, i took just enough off to make it not rub and not make any unwanted heat.
so hears a few pictures..
Edit: Added this photo because is shows the clearance between the rotor and the mount
I also added this because it shows one of the spots where you must file a little to get the caliper to clear the caliper mount freely, I clears without fileing but not loosly enough for my liking.
This entire brake upgrade at the time of installation cost me less than $100 I had just bougt new pads previous to install so im not counting that.
Calipers i got for a deal, $10 a piece,
Rotors where form slauterzone, Lifetime warrenty, but still crap. but hey... they where cheap. $35 a piece.
Feel free to ask any questions.
IM bad a typing what im thinking so im very sorry if this post is vague in places or just hard to understand. I will try and fix that if there are any problems.
Jeremy.
12-04-2005, 07:29 AM
#2
sweet, any chance of a more detailed write up later down the road? Not to doubt your work in anyway, since this is a pretty sweet looking job, but my main concern is that since the braking system on the maxima were designed around a flimsy looking rotor and caliper compared to that of the j30, the parts might be a bit weaker (thinner caliper mount, or a cheaper type of metalurg.) When doing the swap, the new system will no doubt have more clamping power, which in turns creates more stress on the caliper mount, so will it stand up to the new stress introduced? Sorry that I had to pose that question, but brakes are vital to your safety and mine (if I were to do the swap.) Thank you for your contribution though.
12-04-2005, 09:31 AM
#4
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Originally Posted by disgruntled
sweet, any chance of a more detailed write up later down the road? Not to doubt your work in anyway, since this is a pretty sweet looking job, but my main concern is that since the braking system on the maxima were designed around a flimsy looking rotor and caliper compared to that of the j30, the parts might be a bit weaker (thinner caliper mount, or a cheaper type of metalurg.) When doing the swap, the new system will no doubt have more clamping power, which in turns creates more stress on the caliper mount, so will it stand up to the new stress introduced? Sorry that I had to pose that question, but brakes are vital to your safety and mine (if I were to do the swap.) Thank you for your contribution though.
I understand your concern.. but this is how i see it. The most stress your caliper mount will ever see is that of brakeing just before you lock up your tires, or sometime around there. The factory brakes have plenty of power to do that so that means that the caliper mount is plenty strong for even the upgrade. Anyhow, the main reason for dong this upgrade isnt really for the extra brakeing power (in my eyes the factory brakes are plenty powerful) it is to have more mass to suck up more heat meaning.... your going to have that same braking power even after mashing the brakes 15 times in a row while going around a road course. Also, when comparing the J30 caliper mount with the maximas, they really look the same. There was no noticably larger or more reinforced areas. Again, this is just how i see it, and thankyou for your concern.
Jeremy
12-04-2005, 02:27 PM
#8
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Originally Posted by vansskaterfreek
well the way i look at it... when your brakes lock up... you are putting the same amount of stress on them no matter how hard you press on them
12-04-2005, 07:35 PM
#17
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Originally Posted by andy044
how does the increas in rotateing mass play in?
Jeremy
12-04-2005, 09:49 PM
#21
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stop faster...maybe a little, thats all up to how much traction you have and youf ABS. if you have it. The whole goal of a brake upgrade is to be able to stop fast over and over again and not overheat your brake and get massive fade... Mainly on a road course. cause you dont want your brakes dieing as your going into a turn out of a straitaway at 100 mph. I never had my old brakes fade, but i was a little nervous.
Jeremy
Jeremy
12-05-2005, 09:13 AM
#26
Originally Posted by Mizeree_X
Looking good! Are the J30 calipers the same as the 2-piston Q45 calipers?
So i assume if they thing the brake is go enough for HEAVY Q45, and they work great on a heavy J30, they must be a good upgrade for a Maxima. Good find.
12-05-2005, 09:40 AM
#27
Normally, you do just that. And just have a machine shop shave 3 mm off the radius of the rotor. Seems like alot less trouble than what he did.
Mix/Matching the mounts and calipers also explains why he had to do odd things to the pads and why he had to use a spacer. Never understood that until he posted what he did
Mix/Matching the mounts and calipers also explains why he had to do odd things to the pads and why he had to use a spacer. Never understood that until he posted what he did
Originally Posted by internetautomar
why didn't you use the bracket off the j30 along with the caliper?
12-05-2005, 10:46 AM
#28
Originally Posted by twinkle
are you not reading the whole post again brian, cause I'm pretty sure that he said it put the caliper 1/4" too close to the center of the rotor, ie it DIDNT fit 
12-05-2005, 11:03 AM
#30
Use J30 entire assembly + Shave 3mm from J30 rotor radius ( I think ), bolt on the assembly.
Doesn't anyone read the 300z coversion? It's the same procedure. The J30 and 300z mouting dimensions are the same (I believe). The 300z instructions have been around for years.
Personally I'd rather have the torque arm advantage of the 13" cobra rotor. But the good thing is my brackets might work for this conversion also. If someone is looking for a 13" rotor bbk w/ only a 2 piston caliper. Should allow more options for wheels. ie.. less spoke clearance is needed. Exactly WHICH wheels is a subject researched not by me. As I've not done this swap. You would need about 10mm more than normal I believe as my brackets space the caliper OUT a bit more.
Doesn't anyone read the 300z coversion? It's the same procedure. The J30 and 300z mouting dimensions are the same (I believe). The 300z instructions have been around for years.
Personally I'd rather have the torque arm advantage of the 13" cobra rotor. But the good thing is my brackets might work for this conversion also. If someone is looking for a 13" rotor bbk w/ only a 2 piston caliper. Should allow more options for wheels. ie.. less spoke clearance is needed. Exactly WHICH wheels is a subject researched not by me. As I've not done this swap. You would need about 10mm more than normal I believe as my brackets space the caliper OUT a bit more.
Originally Posted by internetautomar
that was b4 the spacer, I think he was using bare calipers (bracket not included) so he reused his factory brackets instead of the j30 brackets which jeff sez need to have the rotor shaved to use the j30 rotor if I understood him correctly
12-05-2005, 10:10 PM
#34
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Originally Posted by Jeff92se
Normally, you do just that. And just have a machine shop shave 3 mm off the radius of the rotor. Seems like alot less trouble than what he did.
Mix/Matching the mounts and calipers also explains why he had to do odd things to the pads and why he had to use a spacer. Never understood that until he posted what he did
Mix/Matching the mounts and calipers also explains why he had to do odd things to the pads and why he had to use a spacer. Never understood that until he posted what he did
Jeremy
12-06-2005, 12:04 AM
#35
Originally Posted by Jeff92se
In fact, I'd be willing to sell a set of bbk brackets and rings for a significant discount to someone willing to try this.
AND a J30?
Oh wait, that would be me. Can someone tell me exactly what do i have to do to help. Buuuuut give me some time, casue i have been really busy right now and really can't spare any time till may be Christmas.
04-22-2007, 08:33 PM
#36
Old thread, I know, but this is where my conversion began...I am here to tell you that the way Maxmaxima91 did it did not work for me, although I was using Q45 calipers instead of the ones from the J30. There are way too many clearance issues and after two afternoons carefully grinding and dremeling everything to fit together, I decided to scrap the idea. 
So tomorrow I am going go the other route. I will have a machine shop grind 3mm off the rotor radius, and the same must be ground off the inner radius where the rotor contact surface becomes the art that mates to the hub. I will be using Q45 brackets and brake pads to complete the setup.
I also need a couple of those rubber boots for the brake pins...Hopefully one of the local parts stores can order them 'cause it will be a PITA to have to order them from Nissan...
So tomorrow I am going go the other route. I will have a machine shop grind 3mm off the rotor radius, and the same must be ground off the inner radius where the rotor contact surface becomes the art that mates to the hub. I will be using Q45 brackets and brake pads to complete the setup.
I also need a couple of those rubber boots for the brake pins...Hopefully one of the local parts stores can order them 'cause it will be a PITA to have to order them from Nissan...
04-22-2007, 09:24 PM
#37
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Join Date: May 2004
Posts: 181
Originally Posted by maxitech
Old thread, I know, but this is where my conversion began...I am here to tell you that the way Maxmaxima91 did it did not work for me, although I was using Q45 calipers instead of the ones from the J30. There are way too many clearance issues and after two afternoons carefully grinding and dremeling everything to fit together, I decided to scrap the idea.
So tomorrow I am going go the other route. I will have a machine shop grind 3mm off the rotor radius, and the same must be ground off the inner radius where the rotor contact surface becomes the art that mates to the hub. I will be using Q45 brackets and brake pads to complete the setup.
I also need a couple of those rubber boots for the brake pins...Hopefully one of the local parts stores can order them 'cause it will be a PITA to have to order them from Nissan...
So tomorrow I am going go the other route. I will have a machine shop grind 3mm off the rotor radius, and the same must be ground off the inner radius where the rotor contact surface becomes the art that mates to the hub. I will be using Q45 brackets and brake pads to complete the setup.
I also need a couple of those rubber boots for the brake pins...Hopefully one of the local parts stores can order them 'cause it will be a PITA to have to order them from Nissan...
Just buy a caliper rebuild kit at the autoparts store and it should come with that, its only like 5 bucks
04-23-2007, 01:53 AM
#39
Hmm. I've been here since Sept 2005, WhyTF did I not see this thread back then? Anyway I got access to all these parts incredibly cheap and think I might give it a shot just for the hell of it. The most expensive part is getting the 1/16 inch spacers but I guess I'll get cut something out of a freezer pizza cardboad 
