Q45 Brakes - Stopping Distance?

[Memme]

I think my calipers were off a 94...

So I'm trying to do some rough calculations on braking distance, Feet:Weight (per 100lb)... or something like that... I don't know that it will have any accuracy at all, so it's just for my own amusement...

Basically I found that the Q45t has a stopping distance of 146' from 60-0. Not sure that's accurate, but it was all I could find.

Not sure on the 94's or other specs... but that would make the ratio something like this:

146:42

So what I'm thinking is... let's see... how would this translate to the change in weight on the 240SX.

I think something like this... for every 100# it takes 3.47 feet for those brakes to stop the Q45.

So... 3.47 x 28(s14) should equal some very vague, and very basic calculation for a potential decrease in stopping distance for an S14 with Q brakes...

Based on that: 60-0 = ~97'

The best information I could find on 60-0 for an S14 was ~125'

http://www.edmunds.com/used/1998/nissan/240sx/13277/specs.html

So that's a decrease of approximately 28'... which is quite a difference, and having these brakes, I do not find it to be an unreasonable result.

But if anyone has done some real world testing, or has some comments on the method I used, or other variables that I should consider... understanding that we're basing this on stock, not including upgraded pads/tires/et cetera... Any alterations to the formula that might make it more accurate, let me know!

I know there's very little point... and I should just test it myself... but it's fun and I wanted to play with the numbers, so I did.

:wave:

---------- Post added at 12:22 PM ---------- Previous post was at 10:54 AM ----------

No thoughts on this at all?

Lol... anyone have the numbers for the Z brakes?

I'm wondering how they compare.

[Spyder]

The problem quickly becomes not the brakes but the tires, especially on one stop. Most people are able to lock their stock brakes (non abs car). What you will find is that over 10 stops the larger rotors and calipers help a lot more because they are able to dissipate the heat and allow for more braking less fading. It is a common misconception that Z or Q brakes stop better because they don't. a stock brake system with better pads will stop a car just as well as with of them or the most expensive carbon brake setup, at least once.

[Memme]

But doesn't greater clamping force = greater stopping power?

Umm... yes it does.

And I can tell you with certainty that I could not lock up my stock brakes... I never literally stood on them... but under very heavy pressure, they did not lock. And I was actually trying to lock them... So to even get the same level of clamping force from my stockers would've required far more from my foot on the pedal, and even then I can not agree that the clamping force/stopping distance would be equal.

I can also tell you that most definitely, the Q brakes have greater stopping power. So I have no misconceptions about that. That is a fact that I have confirmed with real world testing myself.

Those shits will stop my car much faster than the stockers did, and they are quite capable of locking the tires... so I can see what you're saying in certain specific situations with certain criteria for certain applications in a theorhetical sense...

But when it comes to me going out there with my Q brakes, or my stockers, and seeing which ones keep me from going off a cliff... I'm putting my trust in the Q brakes. Because they will absolutely stop my car in a shorter distance, and that is not a misconception... that's the absolute truth.


That's why I said this part:


... understanding that we're basing this on stock, not including upgraded pads/tires/et cetera...

Because I know tires/pad combos come into play... they're clearly variables... but that's not what I'm talking about because I can't get any reliable numbers or data on that... we're basically talking about increased clamping force, increased diameter, more pistons, and greater pad surface area... which all adds up to, in my experience, stopping the shit out of my car a lot faster than the stockers could.

[super240sx71]

Ive locked stock brakes a couple of times messing around lol. But z and q45 stop a helluva lot faster as long as you can keep them from locking with sucky tires.

[Memme]

Yeah, well also considering that I probably would've locked up with my 195's on the front a lot easier with the Q brakes, but now I have 235's... which is a good bit more rubber... so surfing the edge of lock is at a higher level than it would've been...

But there's definitely a stopping distance benefit between a smaller single piston setup, and dual piston setup with a greater clamping force... even without the increased traction up front.

Both of those factors are working to my advantage.

[super240sx71]

I flat spotted my 235s because my damn caliper pins froze on one side it also broke my rotor in two pieces lol. Pretty intense ride for a few minutes.

[Memme]

Holy crap...

[Grimace]

I went from stock to Q45 brakes on my old car, I hated them with the shitty tires. I then ran 205/55/16 Dunlop Z1 star specs and loved them. I them moved to 275/40/17 Nitto NT-05's and faded the shit out of them. I moved to 300zx brakes and never looked back.

[Memme]

Are you talking about running 275's up front?

[Spyder]

But doesn't greater clamping force = greater stopping power?

Umm... yes it does.

And I can tell you with certainty that I could not lock up my stock brakes... I never literally stood on them... but under very heavy pressure, they did not lock. And I was actually trying to lock them... So to even get the same level of clamping force from my stockers would've required far more from my foot on the pedal, and even then I can not agree that the clamping force/stopping distance would be equal.

I can also tell you that most definitely, the Q brakes have greater stopping power. So I have no misconceptions about that. That is a fact that I have confirmed with real world testing myself.

Those shits will stop my car much faster than the stockers did, and they are quite capable of locking the tires... so I can see what you're saying in certain specific situations with certain criteria for certain applications in a theorhetical sense...

But when it comes to me going out there with my Q brakes, or my stockers, and seeing which ones keep me from going off a cliff... I'm putting my trust in the Q brakes. Because they will absolutely stop my car in a shorter distance, and that is not a misconception... that's the absolute truth.


That's why I said this part:



Because I know tires/pad combos come into play... they're clearly variables... but that's not what I'm talking about because I can't get any reliable numbers or data on that... we're basically talking about increased clamping force, increased diameter, more pistons, and greater pad surface area... which all adds up to, in my experience, stopping the shit out of my car a lot faster than the stockers could.

Better clamping force DOES equal better stopping power, until you over come the friction the tires can provide. Ironically everyone thinks that 300z brakes are superior to Q's truth of it is that they provide less clamping force because of 2 things. 1)They have smaller piston area and 2) they are a fixed position where as the Q's are sliding. Based on how hydraulics work sliding creates 2x the force.

Q's absolutely have better stopping force, and heat dissipation, No doubt. They have a larger piston area, larger pads and the torque angle is farther out from the center of the rotor.

I KNOW the q's stop the car faster but the same car with 195's it wouldnt stop faster it would stop the same or worse because it would be hard to modulate aka omfglockthefuckupgooffacliffanddie..

I also know you aren't trying to bring other wheel and tire combinations into this equation but reality is they are as important if not more so then actual brakes from a single stop point of view. Once you can lock your tires up that means you have as much stopping power as you can ever use, to make it stop better you need better tires or different weight distribution... or different brake bias.

If you are really interested in the way brakes work, specifically on S chassis I will find a link to a real discussion on the topic not just some random heresy.

I may be the new guy around here but I know my shit and I won't lead you in the wrong direction I will instead tell you what I know, provide links,facts and figures to back it up and let YOU make the decision to do as you wish with it from there.

[Grimace]

Are you talking about running 275's up front?

Yes, I ran them on my daily for a couple of months before it got totaled. I'm running the same setup on my new Silvia.

http://i631.photobucket.com/albums/uu34/Grimace_240/Kouki/12-27-2009014.jpg

[Memme]

Well yeah, lock is a factor... and based on the things I heard a million times I felt liike Q brakes were going to just lock the fuck up like crazy, and blah blah blah... but that's not what happened at all... not with the Michelin Pilot 235's up front... which might also be a factor in what I've experienced... probably is, no doubt I'm going to have better friction than some shitty 195's... I'm sure that's true.

And I think the reason everyone likes Z brakes is aesthetic... I never have believed they were superior brakes to the Q... but "they say Nissan on them"... Yeah, and they also have freaking clearance issues and that's a major pain in the ass... plus they're more than 5 times the price of Q brakes... which you can get for less than $50 per side...

But yeah, if you've got relevant data on the Q brake swap, and what it can do, hook it up.

---------- Post added at 09:37 PM ---------- Previous post was at 09:36 PM ----------


Yes, I ran them on my daily for a couple of months before it got totaled. I'm running the same setup on my new Silvia.

http://i631.photobucket.com/albums/uu34/Grimace_240/Kouki/12-27-2009014.jpg

OMFG?!

And those steer okay?

[Grimace]

Well yeah, lock is a factor... and based on the things I heard a million times I felt liike Q brakes were going to just lock the fuck up like crazy, and blah blah blah... but that's not what happened at all... not with the Michelin Pilot 235's up front... which might also be a factor in what I've experienced... probably is, no doubt I'm going to have better friction than some shitty 195's... I'm sure that's true.

And I think the reason everyone likes Z brakes is aesthetic... I never have believed they were superior brakes to the Q... but "they say Nissan on them"... Yeah, and they also have freaking clearance issues and that's a major pain in the ass... plus they're more than 5 times the price of Q brakes... which you can get for less than $50 per side...

But yeah, if you've got relevant data on the Q brake swap, and what it can do, hook it up.

---------- Post added at 09:37 PM ---------- Previous post was at 09:36 PM ----------



OMFG?!

And those steer okay?



For a car with stock tire size, and under 300whp, The Q45 brakes are a better choice over the 300zx's. However, If you have 300whp+ and meaty tire's you NEED 300zx's at least.

Q45's can be very good brakes provided you take care of them, and use GOOD parts. I ran them with power slot rotors and Hawlk HPS pads. If you run durlast rotors and weaver pads...... Guess what, They are going to suck dick.

As for actual numbers, I can't help you there. I never timed my 60 to 0 stops.


And yes, My 275's can steer fine. I can go lock to lock with zero problems. Well at least with the Kouki front I could. Now that my Silvia has a Zenki front im not so sure.

[Spyder]

Well yeah, lock is a factor... and based on the things I heard a million times I felt liike Q brakes were going to just lock the fuck up like crazy, and blah blah blah... but that's not what happened at all... not with the Michelin Pilot 235's up front... which might also be a factor in what I've experienced... probably is, no doubt I'm going to have better friction than some shitty 195's... I'm sure that's true.

And I think the reason everyone likes Z brakes is aesthetic... I never have believed they were superior brakes to the Q... but "they say Nissan on them"... Yeah, and they also have freaking clearance issues and that's a major pain in the ass... plus they're more than 5 times the price of Q brakes... which you can get for less than $50 per side...

But yeah, if you've got relevant data on the Q brake swap, and what it can do, hook it up.

---------- Post added at 09:37 PM ---------- Previous post was at 09:36 PM ----------



OMFG?!

And those steer okay?

Read this:
http://www.240sxforums.com/forums/nissan-s13-240sx-89-94/125569-everything-know-about-s13-brake-system.html

there is also this,similar to the first link:
http://en.wikibooks.org/wiki/Nissan_240SX_Performance_Modification/Brakes#Pads

Math and stuff..:
http://forums2.freshalloy.com/showthread.php?t=94734

If I were to only read one, I would read the last one although the most complex it explains it the best. Good reading!

---------- Post added at 11:46 PM ---------- Previous post was at 11:44 PM ----------


Yes, I ran them on my daily for a couple of months before it got totaled. I'm running the same setup on my new Silvia.

http://i631.photobucket.com/albums/uu34/Grimace_240/Kouki/12-27-2009014.jpg

Not to thread jack but holy shit, got a side shot? I want to see how low it is with monster tires like that :D

[Memme]

I'm curious what the overall diameter of those wheels are... because with 235/45/17's I have a little rub when backing out of a parking space.

But that's with 17x8's with a ET42... and 8MM spacers.

So either you've got lower overall diameter, or something with the rims offset or something... I would not have thought it possible to run 275's up front.

---------- Post added at 01:22 PM ---------- Previous post was at 01:10 PM ----------

That write-up by Asad is great. I haven't been on FA in a while...

I wish he had calculated the FBT for Q fronts... because based on your information, and the information in that thread, you're definitely right about the Q's being superior in clamping force to the Z brakes.

[Tank]

Good thread and good info. I got my Q45 calipers from Pull-a-Part both sides $27.

[Memme]

Me too...

And for anyone who wants Q brakes, I'll do it for $220 installed!

Or $100 if you provide the parts. :)

Only 5 lugs need apply... unless you want to pay the extra cost for a 4 lug rotor conversion... which can be had.

[Grimace]

For those who wondering, My specs are 17x9 +25. I had to cut and weld up parts of the inner fender, Notch and weld the lower spring perch, and preform a 40mm pull on the fenders to tuck 275's.

The car isn't super low because it was setup for grip racing. You DO NOT want a slammed suspension for that.
http://i631.photobucket.com/albums/uu34/Grimace_240/Kouki/12-27-2009008.jpg

Then the fender of slight roll vs pulled.


slight roll
http://img.photobucket.com/albums/v223/teckademics7420/Kouki/IMG_5971.jpg

Pulled
http://i631.photobucket.com/albums/uu34/Grimace_240/70bbf11d6507.jpg


This setup its pretty much a no go on S13's. I'm pretty sure I can get it to fit up front with a Zenki front end, but not 100% yet.

[Spyder]

I'm curious what the overall diameter of those wheels are... because with 235/45/17's I have a little rub when backing out of a parking space.

But that's with 17x8's with a ET42... and 8MM spacers.

So either you've got lower overall diameter, or something with the rims offset or something... I would not have thought it possible to run 275's up front.

That rub can be fixed, I am running 18x7.5 ET 42's with 235/45 I do have 15mm spacers as well, Also sitting pretty low... A little more hammer work and a few pieces of metal removed should fix that. I can go lock to lock with no scrubbing.. That was my inital goal and it took me a while to get there, several times on and off with the front wheels. The best way in my opinion to see where stuff is scrubbing is to flat black the wheel wells then go for a spin, then see where you are are and anything that is shiny hit with a sledge lol.



That write-up by Asad is great. I haven't been on FA in a while...

I wish he had calculated the FBT for Q fronts... because based on your information, and the information in that thread, you're definitely right about the Q's being superior in clamping force to the Z brakes.

Indeed Asad's thread is great, there is a lot to be learned there.

I also wish that there was a comparision but if you look at the date there is a reason there wasn't... no one knew it could be done at that time. However even with a 15/16 MBC (best bias for what we are talking about) they tend to be a little front biased so I have the altima/z31/stock concoction on my rear to help balance the bias even more, plus the larger rotors have better heat dissipation, and retain a stock ebrake as I know you know.

The Q's are superior in terms of clamping and with a 28MM rotor they also dissipate heat nearly as well as a Z32 30mm and better then a Z32 26MM. They also clear wheels much easier then Z brakes. The only place they lack is in the brake pad department, there just aren't as many options as there are for the Z's which is unfortunate or I would have personally gone that route.

---------- Post added at 07:30 PM ---------- Previous post was at 07:27 PM ----------


Me too...

And for anyone who wants Q brakes, I'll do it for $220 installed!

Or $100 if you provide the parts. :)

Only 5 lugs need apply... unless you want to pay the extra cost for a 4 lug rotor conversion... which can be had.

This is a good price, if by "conversion" you mean drilling new holes its not all to difficult ;)

---------- Post added at 07:31 PM ---------- Previous post was at 07:30 PM ----------


For those who wondering, My specs are 17x9 +25. I had to cut and weld up parts of the inner fender, Notch and weld the lower spring perch, and preform a 40mm pull on the fenders to tuck 275's.

The car isn't super low because it was setup for grip racing. You DO NOT want a slammed suspension for that.
http://i631.photobucket.com/albums/uu34/Grimace_240/Kouki/12-27-2009008.jpg

Then the fender of slight roll vs pulled.


slight roll
http://img.photobucket.com/albums/v223/teckademics7420/Kouki/IMG_5971.jpg

Pulled
http://i631.photobucket.com/albums/uu34/Grimace_240/70bbf11d6507.jpg


This setup its pretty much a no go on S13's. I'm pretty sure I can get it to fit up front with a Zenki front end, but not 100% yet.

Fantastic, and i'm sure well worth the effort!

[Memme]

That rub can be fixed, I am running 18x7.5 ET 42's with 235/45 I do have 15mm spacers as well, Also sitting pretty low... A little more hammer work and a few pieces of metal removed should fix that. I can go lock to lock with no scrubbing.. That was my inital goal and it took me a while to get there, several times on and off with the front wheels. The best way in my opinion to see where stuff is scrubbing is to flat black the wheel wells then go for a spin, then see where you are are and anything that is shiny hit with a sledge lol.



Indeed Asad's thread is great, there is a lot to be learned there.

I also wish that there was a comparision but if you look at the date there is a reason there wasn't... no one knew it could be done at that time. However even with a 15/16 MBC (best bias for what we are talking about) they tend to be a little front biased so I have the altima/z31/stock concoction on my rear to help balance the bias even more, plus the larger rotors have better heat dissipation, and retain a stock ebrake as I know you know.

The Q's are superior in terms of clamping and with a 28MM rotor they also dissipate heat nearly as well as a Z32 30mm and better then a Z32 26MM. They also clear wheels much easier then Z brakes. The only place they lack is in the brake pad department, there just aren't as many options as there are for the Z's which is unfortunate or I would have personally gone that route.

---------- Post added at 07:30 PM ---------- Previous post was at 07:27 PM ----------



This is a good price, if by "conversion" you mean drilling new holes its not all to difficult ;)





How are you liking those Altima/Z?

I'm looking to do that as the very next mod I do... that's why I'm looking for an S14 rear knuckle... because I cannot remove my stock Caliper bracket due to a 17mm bolt with a busted head... swapping out the spindle seems like it will be easier than removing the bolt.

But yeah, for having Q brakes installed I'd say that's a good price... if I make $100 doing it... then I'm happy to do it!

I'm not looking to do much work for people in the summer though... but in the fall, I'd be going at it... if people want it, I'll do it... I'm going to start stocking up on calipers/brakets and rotors to either sell or sell/install.

I used all PAP parts except for the pads, and I'm quite happy with the deal.

I probably shouldn't do it for that cheap though, because not only is it the time to remove from the donor car, but it's the install too... so... yeah that's cheap. But I think I'd do it for $100+parts.

[Spyder]

How are you liking those Altima/Z?

Ehh, you don't want me to base my opinion on what I have right this second lol... Ihave 2 different sets of pads on the rear because I had to change one of the calipers as it was absolutely soaking the rear pads. I have old nasty fluid and stock brake in the front with who the hell knows pads, lmao.

My SS lines and pads will be here shortly and once they are I will install the 300z fronts,SS Lines,new pads,15/16 and entirely flush the system with blue... I'm expecting a difference :twisted:



I'm looking to do that as the very next mod I do... that's why I'm looking for an S14 rear knuckle... because I cannot remove my stock Caliper bracket due to a 17mm bolt with a busted head... swapping out the spindle seems like it will be easier than removing the bolt.

But yeah, for having Q brakes installed I'd say that's a good price... if I make $100 doing it... then I'm happy to do it!

I'm not looking to do much work for people in the summer though... but in the fall, I'd be going at it... if people want it, I'll do it... I'm going to start stocking up on calipers/brakets and rotors to either sell or sell/install.

I used all PAP parts except for the pads, and I'm quite happy with the deal.

I probably shouldn't do it for that cheap though, because not only is it the time to remove from the donor car, but it's the install too... so... yeah that's cheap. But I think I'd do it for $100+parts.
I think your pricing may be a bit low, but that will sell to people on here ;) I'm assuming you have tryed an easy out and some heat to get that bolt out?

[Memme]

Ehh, you don't want me to base my opinion on what I have right this second lol... Ihave 2 different sets of pads on the rear because I had to change one of the calipers as it was absolutely soaking the rear pads. I have old nasty fluid and stock brake in the front with who the hell knows pads, lmao.

My SS lines and pads will be here shortly and once they are I will install the 300z fronts,SS Lines,new pads,15/16 and entirely flush the system with blue... I'm expecting a difference :twisted:


I think your pricing may be a bit low, but that will sell to people on here ;) I'm assuming you have tryed an easy out and some heat to get that bolt out?

Nope... I've tried nothing... being that it's a pretty damn solid bolt, grade 8, and pretty damn seized... I figured it would be an effort in futility. Probably manage to break some bits, and work myself into a really pissed off frenzy... so... yeah...

This issue was supposed to be resolved by Balanced Performance in Sugar Hill back when I first moved here so I could swap out my rotors and shit... but I found out that what they charged me $186 for was to basically "pivot" the caliper bracket on the broken bolt so that the rotor could be taken off... then they resurfaced the rotor, which was a damn waste since they're cheap as hell...

Since then I have done that same job myself more than twice... The first time I came back around to needing that done is when I found out that's what they did...

Because the busted bolt was still there, and I pivoted the damn thing myself too... which kind of pissed me off. Because I paid $186 for them to work around, rather than solve a problem. Creating a future problem for me, since now I can't swap out the goddamned bracket to upgrade or replace it since the busted bolt is still in it...

Thanks guys... I could have done that myself! :goodjob:

[Spyder]

Nope... I've tried nothing... being that it's a pretty damn solid bolt, grade 8, and pretty damn seized... I figured it would be an effort in futility. Probably manage to break some bits, and work myself into a really pissed off frenzy... so... yeah...

This issue was supposed to be resolved by Balanced Performance in Sugar Hill back when I first moved here so I could swap out my rotors and shit... but I found out that what they charged me $186 for was to basically "pivot" the caliper bracket on the broken bolt so that the rotor could be taken off... then they resurfaced the rotor, which was a damn waste since they're cheap as hell...

Since then I have done that same job myself more than twice... The first time I came back around to needing that done is when I found out that's what they did...

Because the busted bolt was still there, and I pivoted the damn thing myself too... which kind of pissed me off. Because I paid $186 for them to work around, rather than solve a problem. Creating a future problem for me, since now I can't swap out the goddamned bracket to upgrade or replace it since the busted bolt is still in it...

Thanks guys... I could have done that myself! :goodjob:

WOW, I would be PISSED. There are tools for removing that bolt... I could very possibly help you with that if you are interested. All we need is a lot of heat and the proper tools.

[Memme]

WOW, I would be PISSED. There are tools for removing that bolt... I could very possibly help you with that if you are interested. All we need is a lot of heat and the proper tools.

Oh... I was pissed for sure. It had been months though... so I didn't say anything to them about it.

Yeah, I do need to get this done for sure, but first I need to find the Z31 brackets and get some Altima Rotors... then I can do it all.

Of course if I just get the bolt out, and put another 17mm back in there, I guess that would be good.

I talked to Terrence at America's Best in Alpharetta and asked him what he thought about it, going for removal or swapping out the spindle... he said swap the spindle... which for my skills/tools would technically be easier, but if you think you'd have a good shot at it... doesn't hurt!

I'm pissed that I got worked over like that by BP though... It's like... "Gee thanks for that... I wasn't nearly as concerned about the damn rotor as I was the freaking BROKEN BOLT!" Dammit... that's what I get for assuming they removed it and replaced it properly.

But you're in Buford, and I'm there all the time... In-laws live off Clack Road/Mt. Moriah... so if you want to check it out I'm sure I'll be over there soon.

[garagelu]

Q45 brake setup is pretty incredible IMO. When I had them, I loved them. After the Q45 setup, I went to the r33 GTS brake setup which is a 4 piston floating caliper and I couldn't tell a huge difference in braking power.

But now I got sti brembo calipers all around and nothing beats them.

[Turboboxer]

Q45's can be very good brakes provided you take care of them, and use GOOD parts. I ran them with power slot rotors and Hawlk HPS pads. If you run durlast rotors and weaver pads...... Guess what, They are going to suck dick.



Told.

[Memme]

Q45 brake setup is pretty incredible IMO. When I had them, I loved them. After the Q45 setup, I went to the r33 GTS brake setup which is a 4 piston floating caliper and I couldn't tell a huge difference in braking power.

But now I got sti brembo calipers all around and nothing beats them.


I bet... got any pics of the car?

---------- Post added at 09:30 AM ---------- Previous post was at 09:23 AM ----------


Told.

Whatever, you got told by Bourbon.

[garagelu]

I bet... got any pics of the car?





Here's a side view of my pictures so you can see the brembos.

http://farm3.static.flickr.com/2528/4145399102_b169faeb71_b.jpg

[Memme]

Nice!