q45 brakes: locking up

[madd ocx]

hey i did a search and saw that with the q45 front brake upgrade your brakes can lock up cause of the with the 240 master cylinder with the bigger calipers. i read its more apparent with non abs vehicles. i want to get the q45 upgrade but was a little worried about this. so if anyone has any feedback using this upgrade please share, if you have or have not experienced this lock up.

[luftrofl]

Locking up as in... while braking the tire loses traction and the wheel locks?

[joshchewuhh]

i am also curious if people use the z32 MC with q45 brakes i never heard of people changing the MC with Q45 brakes

[LB.Motoring]

most shouldnt need to change the MC.

[bbejj123]

you can also do the j30 front caliper upgrade... i think its a little cheaper but im not sure the price...im using j30 front calipers and have had no problem with them locking up. Also when upgrading brakes its ideal to get a better master cylinder but u can do without it . .. just giving you an alternative =) hope that helps

[madd ocx]

Locking up as in... while braking the tire loses traction and the wheel locks?well what i mean is from what i've read is that the front tires lock up to soon and yeah the tires would skid. the back end could swerve out possibly. but as i've been searching more most people said its okay. i heard the problem mainly comes from changing the rear brakes as well and trying to keep the stock 240 master cylinder. good tires are a good plus as well.

[luftrofl]

well what i mean is from what i've read is that the front tires lock up to soon and yeah the tires would skid. the back end could swerve out possibly. but as i've been searching more most people said its okay. i heard the problem mainly comes from changing the rear brakes as well and trying to keep the stock 240 master cylinder. good tires are a good plus as well.

That's called having strong brakes. :w00t: But seriously, what do you mean by "soon?" Keep in mind that the stock brakes were designed for the stock weight and tire size of our car.

[Zhanshi]

I think what youre reading is that people are able to lock their front Q45 brakes with less effort on the pedal than with stock 240 brakes. With that being said, you will be able to stop faster with the Q45 than with stock brakes. You just need to learn/feel where the brakes start locking when you step on the pedal.

[xkamikazestormx]

almost the type of tires you are using can affect locking up the fronts too.

btw the j30 and the q45 brakes are exactly the same.

i use q45s with the stock mc and have no problem what so ever

[w0nderbr3ad]

i love my q45 brakes. still need new pads and rebleed but they lock up better than my stock ones. i don't experience any more soft squishy pedal feel.

[hijack3d]

Been using Q45 brakes w/ stock mc, stock rear calipers w/ Hawk pads... AutoX and drift last year... no problems.

[madd ocx]

http://www.ka24development.com/brake_upgrades.html this is where i saw the issue of brakes locking.

[noname7198]

I had q45 front brakes on my last s13 with the stock MC. I didn't have any problems with them locking up, I honestly didn't notice much of a difference with them over stock. I would just get better pads for the stock brakes.

[gunluvS14]

Use better tires, having proper front wheel/tires alignment and pressure can help tremendously.

With stock MC and Q45 front calipers, you might have a little trouble to modulate the brake; with a bigger MC, you can input higher pedal effort with more room for pedal modulation. But if you have crapping tires, they will still lock up regardless you have stock brake or not

[idahotuner]

i am planning on getting the q45 brakes for the front. from JGYcustoms.com

[98s14inaz]

most shouldnt need to change the MC.

You don't need to change it. Nissan Motorsports sells the q45 front brakes as a 240sx upgrade. Get better wider tires, problem solved.

i am planning on getting the q45 brakes for the front. from JGYcustoms.com

Junkyards are your friends. I hit up a junkyard that had a complete q45 and pulled calipers, hardware, shims, pads, rotors, etc all off of the same car. I ordered a rebuild kit from autozone and rebuilt the calipers myself. I think total I was out $75 each side.

[silnismo]

i don't think you have much to worry about, i have Z brakes GOOD tires and they practically never lock up, let alone q45 brakes which have 1/2 less pistons then the Z. the people that said they locked up all the time probably didnt have good tires.

my .02$

[UNISA JECS]

i don't think you have much to worry about, i have Z brakes GOOD tires and they practically never lock up, let alone q45 brakes which have 1/2 less pistons then the Z. the people that said they locked up all the time probably didnt have good tires.

my .02$

I've had Q45 and Z32 brakes all around with the same suspension and tire setup, Q45 brake are more likely to lock up over Z32 brake, stock for stock they produce more brake torque over Z32 brake and the reason they do is becasue Q45 brake calipers have more piston area than the Z32 do. I know some people that read this are gonna say how is that becasue Z32 have 4 pistons per caliper (front) and Q45 have 2 piston per caliper (front) WRONG sliding calipers effectively have twice the amount of pistion shown so they effectively have 4 pistons and not 2 pistons, the slider bracket is basically a mirror of the two physical pistons on the Q45 calipers.

(FRONT)
Q45 has a total of 9.4mm of piston area over the Z32 in the front.

(REAR)
Q45 has a total of 0.4mm of piston area over the Z32 in the rear but the Z32 has 5mm more in rotor diameter making it beat the Q45 in rear brake torque.

[silnismo]

+1 for proving me wrong!

learn somthing new everyday.

[ziptiedae86]

I also installed the Q45s in my S14 non abs. The Q45s do lock up but will stop a lot faster than stock brakes. I've learned to control it and to prevent losing control during "panic stops" by attending a novice driving school and participating in monthly autocross sessions. I have much more confidence in the Q45s + new tires than my old brake setup.

[The Chad]

Locking brakes I usually put on the driver not the brake set-up.
--A more functional brake bias via the master cyl. will only be sending more fluid functionally/quickly to the pistons.
--As far as the Q45 to Z32 debate....well i say it comes to aesthetics and long term reliability. I've allways been a fan of stationary calipers due to their infrequency of brake down due to less moving partsand of course easy pab replacement :) . Even my 1991 Volvo 240 has front 4 piston and rear 2 piston all stationary.
--Q45's and J30's are a great upgrade for the money though, and you can use the stock lines and YES THE STOCK MASTER CYL!!! I even used the stock master cyl on my Z32 set-up for a month before i swapped it out for a Z32 unit, made a big difference in pedal feel, but not in locking up vs. not locking.

[madd ocx]

thanks for the good responses! well from what i see the q45's are a good buy, just gotta use a bit more control. for the people that have them how do they stop for daily driving.. i think some of the responses are more track oriented.

[180sx_Drifter]

you shouldnt have to worry how hard they stop. just be glad that they are working. you just have to learn how to use them. i daily my car and i love em.

[The Chad]

^^ yeah man, there are similar/lighter weighted cars out there with much larger brakes, not locking up all day. I doubt you hear of people with Enzo's complaining of how their Ferrari keeps locking up...haha :)

[smelly240]

get better tires...

[madd ocx]

ok well i got good responses so now its time to go shopping around.

[D.Bo]

q45 brakes plus hawk pads = awesomeness

[NemeGuero]

I use Q45s on all 4 corners with porterfields thanks to John the man at RPsport.

My shit RAWKS. and I have stock BMC.