Thread: Infiniti Q45 / J30 Front Brakes Swap Conversion

Started this thread cause of a bit of misinfo I've come across.
I've read posts that state Q45 front brakes are a straight swap on to our cars. SOOOooo today I was down at the junkyard, aaannnndddd I came across a pair of Q45 Torque Members (mounts between the caliper and the knuckle).... I found a 94 Max and a 98 Max... (same front brakes as B15).... Didn't fit. Why because B15 280mm rotors are just too big. Just like the 300z brake swap. So the rotor diameter should be reduced, not a direct bolt on swap. G20 guys use 273mm rotors, I just looked it up and there it was. Sorry no pics... didn't expect to find Q45 Torque Members

*1992 Q45 Torque Member

my boy actually used the q45 rotors.

Ah I didn't have any at the yard to try.

Putting the puzzle pieces together.

Still doesn't make sense. 94 Q45 FSM Shows 280mm Rotors. He must of machined the rotors or torque member.

Either that or all the coke i did (diet) is eating my brain.

nah, he just redrilled the rotors for 4x114.3, that was it...

I need PICS.
Something does not compute.

yea he's not around anymore.

No Nissan/Infinti RWD chassis front brake caliper and rotors will work on a B15 without turning down the outside diameter of the rotor period.

And I'll metion the obvious things like upgrading to 5 lug or re-drilling the 5 lug 5.x114.3 rotors to 4 lug 4x114.3 is also needed but that's duh.


See post #41
5-Lug Conversion Discussion Thread

Unisa Jecs... Love it! Hillarious! You know more about our brakes than we do right off the bat... LOL Must be your overall Nissan / Infiniti knowledge and experience. Thanks again.

I've concluded my decision process on brake upgrades. I'm not doing Q45 or 300z RWD fronts for obvious reasons.... rotor downgrade FTL!!!.

Soon I'm doing 6th Gen 04-08 Maxima front Calipers, Rotors and Pads. The only moddifing part is re-drilling (enlarging) the caliper mounting holes on the knuckle for the larger bolt size. This will be a nice upgrade IMO. Calipers and Rotors are LARGER

For the rear I've ordered 95-98 torque members and rotors. They will be like the rear brembo set-up in a factory brembo equipped car. Rock Auto has these torque members for $10 ea, no excuse noT to do it now.

Originally Posted by 5er

Unisa Jecs... Love it! Hillarious! You know more about our brakes than we do right off the bat... LOL Must be your overall Nissan / Infiniti knowledge and experience. Thanks again.

I've concluded my decision process on brake upgrades. I'm not doing Q45 or 300z RWD fronts for obvious reasons.... rotor downgrade FTL!!!.

Soon I'm doing 6th Gen 04-08 Maxima front Calipers, Rotors and Pads. The only moddifing part is re-drilling (enlarging) the caliper mounting holes on the knuckle for the larger bolt size. This will be a nice upgrade IMO. Calipers and Rotors are LARGER

For the rear I've ordered 95-98 torque members and rotors. They will be like the rear brembo set-up in a factory brembo equipped car. Rock Auto has these torque members for $10 ea, no excuse no to do it now.

Thats really the only nice big upgrade IMO that you mentioned, i'll being doing that same specific upgrade myself. Buy yourself a nice 9/16" HSS drill bit and use some lube or cutting oil and you'll be fine and go a straight as you can when enlarging the holes in the spindle.

awesome!

I was at the junkyard today and I found these for $55... Complete front calipers with pads off a 95 Infiniti J30. They were calling my name, so I bought em... I'll try and make em fit with a grinder.

I want big brakes and I started this project with a goal, not to get B15 front rotors shaved down to fit Q45 / J30 calipers and I figured it out.

First don't grind down the Q45 / J30 torque member 3 mm like I did...
Second don't shave down the Q45 / J30 caliper clips like I did...
Third don't fucking try to grind 3mm of the caliper underside like I did...
Of course this mounts up and all nice after spacing with a couple washers to get the Q45 / J30 brackets centered... but I wasted many many hours doing it... on one side !

I got to thinking once I was almost done that those Q45 / J30 pads were pretty similar to ones on the B15, about the same width, but a little taller. So I put my old B15 torque member (caliper bracket) on and bolted the fucking Q45 / J30 caliper to it like it was made to fucking fit. Just a mm shaved off the outside caliper fingers so they don't rub the B15 torque member.

So SCRAPIN and everyone you right... they just bolt on LOL

I'm reshaping the Q45 / J30 Pads so they fit our caliper brackets, but regular B15 Pads will work.

I'll post some pics when I finish in a few days so we have a definite record.

Brake Swap
1990-1996 Q45 / 1992-1997 Infiniti J30

No rotor machining required.
Re-use the B15 caliper bracket.


Spec-V B15 Caliper(Model CL25VB)
Cylinder bore diameter 57.2mm (2.252")
Pad Lining Length x Width X Thickness 125.6mm x 46mm x 11mm (4.94"x1.811"x0.433")

Vs.

J30 / Q45 Caliper ( Model CL28VF )
Cylinder bore diameter 42.8mm (1.685") x 2
Pad Lining Length x Width X Thickness 127mm x 56mm x 9.5mm (5"x2.2"x.0374")


To use the Q45 / J30 brake pads I reshaped mine with a grinder... 5 minute job. B15 pads will work but cover less surface area. No pic of the modded pad.

B15 Caliper Smalllllllll...

Q45 / J30 Caliper Bigggggg... I opted for a trim, due to the use of my stock B15 caliper bracket

Trimmed with a grinder...


Tons of room for any rim.
Done!

Any difference in brake feeling? And where exactly did you have to grind?

Originally Posted by Papisonice

Any difference in brake feeling? And where exactly did you have to grind?

Brake feeling... well I feel better that I had new ceramic pads , as for improvement in power... well they grip hard when I stand on it. I haven't had a chance to torture them up to this point but they outperform the stock setup.

I ground... more like feathered... the caliper where it might come into contact with the brake pad clips once assembled. The shiny bare metal spot in this image shows the work complete. Very little shaved off and I haven't had any issues with this at all. You may not have to grind.... I may have just been a bit paranoid.

Awesome write-up. After seeing at least two different caliper swap possibilities I almost regret waiting so long to find a spec with Brembos.....almost

ABS compatible??

dunno... if you try it, let everyone know.

So pretty much go out and buy/acquire some Q45/J30 rear calipers and they are a direct swap for our rear? Upgrading to dual piston rears soon then ...opefully I can find a junkyard out here