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View Full Version : N14 Rear Brake Upgrade/Info



Ruddigger
27-10-2015, 06:58 PM
So ive been playing with the rears on bot N14's and years ago there was a large amount of info on here. So i would like to try and build up a bit of thread

Now few questions

1 - Are my N14 brakes radioactive

https://fbcdn-photos-e-a.akamaihd.net/hphotos-ak-xaf1/v/t1.0-0/p370x247/11163775_10153838675011019_944198171156006562_n.jp g?oh=8ad1abcce5ae3643c0a86b081ae8236b&oe=56C5495C&__gda__=1454945360_3f63ac96df9e2e2475adbdd8d831e6e 0

2 - Are GTiR rears the same as N15's

3 - I know the N15's bolt up to the rear of an N14 but i must of been missing something the other day as i could get the handbrake cable angle working

https://fbcdn-sphotos-f-a.akamaihd.net/hphotos-ak-xpl1/v/t1.0-9/10460263_10153838675016019_782713727799926295_n.jp g?oh=e1caf2c50c46bdececac3cf6d52da615&oe=56C4CE62&__gda__=1451602374_a0c32e49b1ca97db20d80cf5fd7c201 d

Im also looking at fitting up a set of maxima to JAPSSS in the near future

https://scontent-lax3-1.xx.fbcdn.net/hphotos-xta1/v/t1.0-9/12109241_10153838682011019_8277519161598784766_n.j pg?oh=8fdcbdf61420a8ac959c68f003d935a9&oe=56B9CE9E

Feel free to add any information that could be relevant to the thread.

Leesss
27-10-2015, 06:59 PM
I run gtir rears on sssmk.2

SSS_Hoon
27-10-2015, 10:10 PM
Fairly sure the ir rears on n14 u need to swap the left n right.

As in left caliper goes on the right side for the handbrake cable to line up.

Martin
28-10-2015, 07:04 AM
I wouldn't upgrade N14 rear brakes at all - they don't do that much work and the regulator/spliter significantly limits hydraulic pressure to the rear
Worst case scenario - in an emergency you could lock them up and get a nasty swing from the rear

Ruddigger
28-10-2015, 04:13 PM
Fairly sure the ir rears on n14 u need to swap the left n right.

As in left caliper goes on the right side for the handbrake cable to line up.




Nope , Ive tired both on the one side and no luck ,

That's why i must be missing something , Lee any ideas?

Leesss
28-10-2015, 04:54 PM
I swapped left to right for the gtir, hooked the handbrake up before I bolted the caliper on. had to use gtir rotors too not n15

Ruddigger
28-10-2015, 05:08 PM
I swapped left to right for the gtir, hooked the handbrake up before I bolted the caliper on. had to use gtir rotors too not n15

WTF im doing something wrong then... ill take photos and do a right up

Spectrix
28-10-2015, 10:49 PM
Ruddigger; you're attempting to fit N15 SSS rear calipers? They won't fit onto the N14.

AFAIK GTiR calipers / discs are the only bolt on option you'll find as they have the correct hat height and handbrake setup.

Boosted VLAD
29-10-2015, 05:21 PM
Okay here it goes,
This is all REAR Brake info,

Gti-r brakes mount onto an N14 with a left to right swap, handbrake hooks straight up, done it numerous times



Gti-r and N15 SSS discs have a 12mm depth difference, N15 SSS (45mm) Gti-r (33mm) and the handbrake cable doesn't hook up, if you try to fit N15 SSS callipers to an N14, IT DOESNT WORK



You can bolt 278mm A32 maxima A32 rear brakes onto an N15 SSS, you just have to re drill the rotors to 4x100, handbrake cable hooks straight on, happy days



On an N14, you can re drill 278mm maxima rotors to 4x100, space the hubs out 12mm each, and use Gti-r callipers with A32 calliper carrier bracket,

Boosted VLAD
29-10-2015, 05:25 PM
And just a bit of extra REAR brake info

Gti-r, N15 SSS and A32 maxima are all the same piston size and take the same brake pads

Ruddigger
29-10-2015, 06:56 PM
Ruddigger; you're attempting to fit N15 SSS rear calipers? They won't fit onto the N14.

AFAIK GTiR calipers / discs are the only bolt on option you'll find as they have the correct hat height and handbrake setup.

So i somehow must have a set of N15 rear calipers then... How did i get them...?

Cool thanks for clearing all that up .

Why did i think the GTiR and the N15 were the same ? i know the pads are the same correct?





Okay here it goes,
This is all REAR Brake info,

Gti-r brakes mount onto an N14 with a left to right swap, handbrake hooks straight up, done it numerous times



Gti-r and N15 SSS discs have a 12mm depth difference, N15 SSS (45mm) Gti-r (33mm) and the handbrake cable doesn't hook up if you try to fit N15 SSS callipers to an N14, IT DOESNT WORK



You can bolt 278mm A32 maxima A32 rear brakes onto an N15 SSS, you just have to re drill the rotors to 4x100, handbrake cable hooks straight on, happy days



On an N14, you can re drill 278mm maxima rotors to 4x100, space the hubs out 12mm each, and use Gti-r callipers with A32 calliper carrier bracket,

Thanks Boosted VLAD You have dropped a good amount of info in here, Yer i knew all about the dics sizes and depth and what not just could get my head around the calipers. Simple anwser is i have N15's lol

Yer ive got the maximas sitting at home for JAPSSS will play with them one day , but from what your saying you dont think ill be able to bolt them up to an N14????

EDIT!! Just re read what you wrote , i get it now cheers

Radar
29-10-2015, 07:54 PM
I wouldn't upgrade N14 rear brakes at all - they don't do that much work and the regulator/spliter significantly limits hydraulic pressure to the rear
Worst case scenario - in an emergency you could lock them up and get a nasty swing from the rear

I'd suggest that if on an n14 you have n15 sss/gtir front brakes, then upgrading the rears to gtir units is maintaining the brake bias. Ive never known rnn14s or n15s for having a tendency to swap ends. ;)

I have both on my n14. It causes no issues and i have found that on the track makes for a more balanced vehicle under brakes. I much prefer it to when i only had upgraded the front end.

Martin
29-10-2015, 09:59 PM
All the Pulsar Challenge cars are running stock rear brakes - you wanna see how often people lock up the rears, every lap!
More rear braking capability is not going to help (imo)

Spectrix
30-10-2015, 02:03 AM
Changing to larger rear discs doesn't necessary increase the likelihood of lockups.
I'm running the A32 278mm rear disc / A32 rear caliper combination and I find it less prone to tripping the ABS system braking hard into corners.

It may be that it's not as on/off as the standard setup is.

Martin
30-10-2015, 08:49 AM
The standard setup is not on/off - it's due to sudden weight transfer to the front leaving the rear high and light - only encountered during extreme braking

Leesss
30-10-2015, 04:42 PM
All the Pulsar Challenge cars are running stock rear brakes - you wanna see how often people lock up the rears, every lap!
More rear braking capability is not going to help (imo)

didn't know you knew what brake set up I bolted to my car when I changed the rear brakes, thanks for clearing that up for me......

Ruddigger
30-10-2015, 05:09 PM
Changing to larger rear discs doesn't necessary increase the likelihood of lockups.
I'm running the A32 278mm rear disc / A32 caliper bracket combination and I find it less prone to tripping the ABS system. It may be that it's not as on/off as the standard setup is.

Surely having a bit more diameter on the disc could also heap with heat distributions/dispersion even if it doesn't truly increase brake performance


The standard setup is not on/off - it's due to sudden weight transfer to the front leaving the rear high and light - only encountered during extreme braking
LOL dude if you dont want people to put them on there car you can just say so , we wont be offended :P

I just want to fill the back wheels up abit the N14 look so small


didn't know you knew what brake set up I bolted to my car when I changed the rear brakes, thanks for clearing that up for me......

Yer lee didnt you change your rears for the challenge car :)

Spectrix
30-10-2015, 09:08 PM
Surely having a bit more diameter on the disc could also heap with heat distributions/dispersion even if it doesn't truly increase brake performance

Yeah, I changed my rear brakes for balance since fitting such large calipers & discs on the front.
I doubt the rears are at risk of boiling fluid on track days like the fronts, more just the diameter increase so as not to upset bias.

Martin
30-10-2015, 10:29 PM
LOL dude if you dont want people to put them on there car you can just say so , we wont be offended :P

Does not worry me mate - but I hate seeing people spending $$$ for the wrong reason/expectation


I just want to fill the back wheels up abit the N14 look so small

Now that I can relate to!

My daily (not a Pulsar) has 357mm floating rotors with 6 pot calipers (same brake pad as a Corvette C5)

https://dl.dropboxusercontent.com/u/98085974/SkodaOctavia/HPABBK2.jpg

(Also have a similar setup for my 350Z)

Martin
30-10-2015, 10:31 PM
didn't know you knew what brake set up I bolted to my car when I changed the rear brakes, thanks for clearing that up for me......

I meant calipers (and rotor diameter) - we're not allow to change them in the Pulsar Challenge

Martin
31-10-2015, 01:44 PM
LOL dude if you dont want people to put them on there car you can just say so , we wont be offended :P

I love upgrading cars and especially innovative options like using brakes from other models and even brands to obtain improvements

The thing I'm not buying into is this brake bias/balance issue

My Pulsar has been corner weighted, 64% weight at the front - that's before you get load transfer during hard braking
Some of the improved production racers joke that the rear wheels on FWD are only there to keep the bum off the ground
Clearly an exaggeration of the simple fact the FWD are front biased

At my first Pulsar Challenge race day I had plastic hub centric rings
The fronts melted but the rear ones were fine
If the rears are not making much heat (and not much weight down the back), no need for more rear braking power

Remember the GTIR version will have more rearward weight due to the rear diff etc
So it will be able to do more braking at the rear

My VW turbo wagon has 200kw at the flywheel
Upgraded the front rotors by 50mm and used huge 6 pot calipers
I have so much front braking I can stab the brake pedal at 110kmph and get the front tyres to chirp before the ABS kicks in
I have had it around Wakefield - drives great, no brake bias problems

My wife's car is a Mazda3 SP23 - I've always been disappointed with it's outright braking ability
At 120k she's finally worn out the front rotors which presented me with the perfect opportunity to upgrade
I've obtained the front brake calipers from the Mazda3 MPS turbo (cheap too) - they are really huge - although the front rotors are only 20mm larger
To my surprise the SP23 (115kw) and the MPS (190kw) both use the same rear brake calipers and rotors
Using DBA T2 sloted rotors, ProjectMu pads and braided lines
Can't wait to finish this job (next weekend) and bed the pads in

This photo shows the stock and turbo calipers - huge difference in size
https://dl.dropboxusercontent.com/u/98085974/Mazda3/IMAG1341.jpg

Ruddigger
31-10-2015, 02:57 PM
Ok your the boss i wont do it :)

Martin
31-10-2015, 03:55 PM
Don't be like that mate, we all do things do our cars just because we can and want to
I just don't want everybody thinking larger front brakes mean you need larger rear brakes (on a FWD)

Firko
03-11-2015, 08:45 PM
i can vouch for this set up off the dial

however i too have upgraded my challeng cars brake i have n15 sss on the rear only difference I noticed was the pads cost more
Does not worry me mate - but I hate seeing people spending $$$ for the wrong reason/expectation



Now that I can relate to!

My daily (not a Pulsar) has 357mm floating rotors with 6 pot calipers (same brake pad as a Corvette C5)

https://dl.dropboxusercontent.com/u/98085974/SkodaOctavia/HPABBK2.jpg

(Also have a similar setup for my 350Z)

gtir_woody
07-11-2015, 03:44 PM
As above, with the 278mm maxima rear rotors you can re drill them and use GTIR calipers with maxima calipers brackets. The part numbers for the brackets are 619-503 or 14-1506. Im going to be using them on my GTIR.

http://s14.postimg.org/dz1c258ep/image.jpg (http://postimage.org/)

cav21
08-11-2015, 12:28 PM
With using the gtir caliper and maxmia caliper mount will you still have to space out the rear hub, but im doing a five stud cnversion usinf the maxmia rear hubs

gtir_woody
10-11-2015, 11:39 AM
I'm not sure if the maxima hubs change the offset but using the maxima caliper bracket with gtir caliper changes the position of the caliper to suit the maxima rotor correctly.

Ethanolaholic
16-11-2015, 02:52 PM
Just to update this in terms of the hand brake cable brackets themselves you need the GTiR brackets to make the GTiR calipers fit with the handbrake, I found this out the hard way and just to show the differences below is a pic showing a gtir, n15 and n14 handbrake brackets :)

(In order from left to right, Gtir, N15, N14)

http://images.tapatalk-cdn.com/15/11/15/bc3a39faf55eda75501cdf8ac2c71dfe.jpg

Sent from my iPhone using Tapatalk

Martin
23-11-2015, 07:29 AM
So in the weekend (at Wakefield Park) a new entrant in the Pulsar Challenge had ProjectMu Race pads front and rear
(This is N15 front calipers and stock N14 rear calipers)
Both rears were locking badly at the big brake points making turn in very risky
Normally only the inside rear locks up
Doing less/earlier braking resulted in slower lap times
The braking areas are the main overtaking opportunity so not being able to go deep really hurt
They went into the city and got some stock Bendix CT rear pads - this solved the problem and these pads handled the 1 hour enduro just fine

Boosted VLAD
23-11-2015, 02:09 PM
There's something I want to explain to you all as there seems to be a lot of debate about upgrading rear brakes

What I want to make very clear to you all is that there's more to braking than just installing big front brakes, doing a brake test and locking up the rear brakes and thinking: "well, if I can lock the rears up, they must be good enough"

No, No and just No, Listen.... Please....
Let's look at the science behind it

When you brake, you create weight transfer, it's just simple physics,

Our cars come with a near 60/40 brake distribution, that's a fact

If you swap your front brakes to 310mm 4 posts and leave the rears stock, you now have yourself a 80/20 brake distribution you will create MORE weight transfer to the front and MORE DOWNWARD force over the front tyres, PROVIDED that the front tyres are ABLE to provide ENOUGH GRIP, this is Physics and fact

If you create MORE front weight transfer and DOWNWARD FORCE over the front, you will have LESS WEIGHT on the back wheels

This Physics and Fact and it is absolutely INARGUABLE

So what happens here is that it takes LESS effort from the rears brakes to lock up the rear wheels because there is LESS WEIGHT on the rear tyres

You have now completely thrown off the bias and REDUCED BRAKING EFFICIENCY DRASTICALLY and therefore INCREASED STOPPING DISTANCES

(Note, from inside the car it may feel like your braking harder because it feels like you've dug an anchor into the ground In front of you, you feel the rears lock, and you come to the conclusion that the rears are well and truly good enough because you can still lock them up)
This couldn't be further from the truth and stopping distances WILL tell you a different story

Now can people see the bigger picture? :)

Ethanolaholic
23-11-2015, 02:18 PM
Well said @BoostedVlad


Sent from my iPhone using Tapatalk

Boosted VLAD
23-11-2015, 03:11 PM
As you can see, WEIGHT TRANSFER and AVAILABLE TRACTION are the 2 things that are responsible for all this happening,

Just so people can understand this completely,
I want to give another example:

If you were driving on a road covered in ice and you have the same 80/20 brake distribution,
And you hit the brakes the scenario would be very different,
Because your front tyres WOULDN'T have the traction to stop the wheels from locking up, you would most likely LOCK THE FRONT BRAKES FIRST and then probably all 4 brakes (as long as you don't have ABS),

This is because there is not enough FRONT END GRIP and FORWARD WEIGHT TRANSFER to create REAR END LIFT

So this also concludes that even something like putting better tyres on your car on all 4 corners of your car can make it MORE LIKELY for the rears to lock up because you have MORE FRONT END TRACTION and can create MORE FORWARD WEIGHT TRANSFER which results in MORE REAR END LIFT and LESS REAR END GRIP

I hope all this makes sense, as i am terrible at putting my thoughts into words

SSS_Hoon
23-11-2015, 05:30 PM
Would adjusting the fluid flow change the bias? As in put a restrictor in the line for the fronts?

Or a brake bias controller? Would that be a viable option for those running stock rear n 4pots up front?

BaronVonKebabalot
23-11-2015, 05:49 PM
Here, here, well said NA Vlad

gtir_woody
23-11-2015, 05:58 PM
I don't think adjustable brake bias is legal? If you care about that.

Martin
23-11-2015, 07:35 PM
Would adjusting the fluid flow change the bias? As in put a restrictor in the line for the fronts?

Has the same effect as not upgrading the front brakes - makes the work and cost pointless


Or a brake bias controller? Would that be a viable option for those running stock rear n 4pots up front?

That will stop the rears locking which is helpful


A number of Pulsar Challenge cars have removed the brake booster and changed the brake pedal ratio
This is to give more feel and control (modulation) over the brakes

Dareya
23-11-2015, 09:03 PM
I guess in my n15 race car I never had anything but standard brakes on the rear with cheap pad,because on the track the rear doesn't do much at all.The front does all the work oh and I did use the handbrake for the starts :)

Bengineering
03-12-2015, 04:32 PM
The thing I'm not buying into is this brake bias/balance issue

My Pulsar has been corner weighted, 64% weight at the front - that's before you get load transfer during hard braking
Some of the improved production racers joke that the rear wheels on FWD are only there to keep the bum off the ground
Clearly an exaggeration of the simple fact the FWD are front biased

Brake bias definitely matters.

Stock N15 brake bias is roughly 61/39. Brake bias is important because it relates directly to weight transfer and traction under braking.

As your brakes work, they convert kinetic energy into heat. As your chassis is slowed down by the brakes, the weight is transferred across the center of gravity in the direction the car is moving, much the same way weight transfers across the center of gravity under cornering. However, weight transfer occurs at the point where the force is applied.

E.g: fuel tankers. If you were able to look inside a fuel tanker you would not see a single large tube but a series of segmented compartments. This is because when the vehicle brakes, if it were a single compartment, all the inertia in the fluid would rush forward as one enormous wave. Having the fuel separated into compartments means that under braking the inertia is distributed evenly between each compartment, so multiple smaller waves are generated. The same weight is being transferred, the transfer is just spread over multiple center lines so the net effect on the vehicle is significantly less.

Imagine your car is broken into two compartments, split down the middle, and your brakes are responsible for their own compartment. Brake bias is generally setup to somewhat mirror weight bias; I'm guessing a stock Pulsar has a weight distribution of somewhere around 60/40, hence the brake bias of 61/39.

Now, if you shift your brake bias to 80/20 but your weight bias remains the same, the amount of energy being absorbed by the front end is increased by almost 20%, increasing weight transfer to the front end under braking by roughly the same.

Now, as I said above, weight transfer occurs at the point where the force is applied, which in this instance is the wheels. So when you brake, weight moves along the center of gravity, with the wheels as its centerline.

We all know that less compressive force in the rear suspension under braking (caused by the increased weight transfer to the front suspension) reduces the coefficient of friction the tires can generate on the road surface, aka, grip. Less grip means less ability to keep the wheels spinning under braking as the energy generated by the caliper more rapidly exceeds the friction coefficient of the tires, so the wheels stop spinning and the brakes lock. They lock much earlier than they would if the rear had adequate weight transfer under braking. The lack of traction under braking in the rear also causes the car to become unstable, and it can move sideways much more easily.

So, hopefully I've explained this well and thoroughly enough to alleviate the misunderstanding regarding the importance of brake bias.

I would also like to point out that I understand many of you have real world experience at the track, but that often there is more to a situation than a first glance will tell you, and without considering ALL the forces and physics involved, no adequate conclusion can be reached. So when you see a guy changing to ****ter bendix rear pads and his locking up stops, you could take that as a sign that the rear brakes are too strong, but only if you don't consider the other forces involved in the equation.

Timmy
16-05-2017, 07:33 AM
Hey guys,

Whilst doing some research on my rear brake upgrade on my N14 SSS. I am running A32 front calipers and rotors, N15 SSS master cylinder and wanted to keep the brake bias the same.
I really wanted to run the 278mm A32 rear rotors, GTIR calipers on the A32 caliper brackets.
The down side is, I hate wheel spacers.

Anyway I have made a discovery that there is a 280mm rotor, 33mm hat height, 63.6mm bore, 10.2mm thick. They are also 4x108

So you would need to:

*Machine the rotor down to 278mm (2mm off OD, although not confirmed if you need to)
*Machine the bore out to 68mm (4.4mm)
*Skim the rotor down 0.6mm each side to give you a 9mm thick solid rotor.
*Redrill to 4x100

I like this option much more than the 12mm wheel spacer option...

These rotors are standard fitment on the 2002 to 2005 ST170 Ford Focus

Let me know what you think.