well aftere some custom fab work i got my new calipers on and working. They are a twin piston caliper off of a J30. Has anyone tried this before? They work awesome and still clear stock wheels

 

I wonder if these would work for the 5.5g with 6g rotors ... hmm 2 piston

 

j 30 were 2 pistons huh..... cool, that could be an option..

 

is the j30 dual piston a direct bolt on to the 4th gen maxima?

 

Need too have a few mm shaved off diameter. Other then that its a direct bolt up.

 

a few mm shaved off what?

 

I have thought about it but never tried. how is the aftermarket pad selection for these calipers? stock brake lines or?

 

Very interesting.....they fit right over the stock size 4th gen rotor ??
I may need to look into this
How do they feel ??

-matt

 

In order for them too fit you need too shave of 2-3mm off the diameter of the rotor. I am impressed with this setup, i have the 300zx calipers on my 99 and these on the 97 and honestly these feel better ( i believe its due too the master cylinder not being up too par for 4pistons) It takes alot less pedal too stop and they dont fade when you do alot of high speed stop and go.

 

I think the J30 calipers and the Q45 calipers are the same according to what i read in my 240SX days.
Nice find tilley
so you say 2-3 mm from the diameter? Is the thickness of the rotor the same? what about he mounting to the spindle anyt other work needed?

 

brakeline fits perfect and so does caliper too spindle. The maxima rotor is about 1/8" thinnner then the J30 rotor.

 

Is it also safe to assume that all J30 calipers are the same? What year did you calipers come from?

 

what has to get milled down the surface of the rotot or the circumference?

 

think about it 2-3 mm off the diameter......

 

does a j30 rotor have the same spacing? if it does wouldn't it be less work to use j30 rotors?

 

after some quick research, I think the pad selection for the J30 is worse than the max which is already pretty slim. And I found the basic rotor dimensions for both from brembo. J30: dia. = 279.5mm, thickness = 25.9mm, overall height 53.6mm. Maxima: dia. = 280mm, thickness = 20mm, overall height = 49.3mm. So I guess that answers my question about interchanging the two.

 

Tilley, Would you us the J30 rotors? I don't like the idea of the stock maxima rotors being 6mm thinner. It's just that much farther for the piston to travel before engaging.

 

Skinny,

does this mean the J30 rotors would bolt up to the max? Which year J30 rotors? I would be willing to do this on my car.

I HATE the stock maxima brakes.

 

Tilley, I guess I was asking if you had to shave 1-2mm off the stock maxima rotors or the J30.

 

I believe he was using the stock maxima rotors. The bolt pattern would probably be the same but the back spacing might not be correct when using the stock maxima caliper bracket. Switching to a 2 piston caliper is not going to reduce brake fade though, the pads and rotor have to work just as hard to stop the car being the same diameter than stock.

 

Skinny, so the advantage of this mod is what? Also, would you be concerned about the differences in widths compared to the J30 rotors? it seems as the pad wears, you would actually lose force. The pistons can only travel so far.

 

just use the j30 calipers and rotors wouldnt that be the best?

 

Just as a reminder I am not the one that did this mod. But to answer your questions, the advantage of multiple pistons is more efficient use of the braking material you already have, you get increased clamping force more evenly applied to the pads. But on a track the biggest problem with our brakes that I have found is that they fade, larger rotors stay cooler and aluminum calipers disappate heat better, but this setup doesn't involve either of these factors. You would not lose force on the pad as it wears, but I would want to make sure that the piston has enough travel to accomodate the reduced rotor thickness.

 

If anyone wants too buy a set of the J30 calipers with used pads (alot of life left) PM me. I have 2 sets

 

Tilley, you never said what year J30.

 

Im not sure i think around 95

 

So all I need to do is buy 2 calipers and pads. Turn the rotors 1-2 times to make htem skinnier and I am set to go? Do I need special brackets or anything?

 

Not skinnier 2-3 mm off DIAMETER.

 

I do have a question. Do you think a J30 rotor would bolt up correctly if I milled it? I would feel more comfortable with the right thickness rotor.

 

Nice find!

 

thinner rotors wont matter ur calipers autopmatically adjust to rotor/pad thickness.....when ur pads wear down they dont become farther apart from the rotor....same prinicple applies to rotor thickness

 

Who would I take the rotors to get the diamiter milled/smaller?

 

thicker rotors means less tendancy to warp and getting rid of heat?

 

Sorry this might be a dumb question but wouldn't the smaller rotor diameter negate the gains from having the 2 piston calipers? 2-3mm it's not something to sneeze at IMHO

 

wow these are very nice, do they clear 16 inch SE rims?

 

yes they do

 

Can you test them on the sawblades please

 

Ooooh, Tilley is such a pioneer! This is such an awesome upgrade, we should all run to the junkyards and get a set.

 

I would if i had a set.