Brake Kit Options R33 Brembo Ap R35

[V28VX37]

^^^ What he said.

In fact, if you still have the stock fronts, might be an idea to chuck them on for a bit to confirm that it's definitely a brake bias issue and not something else?

[sixmassive]

Roy, Great points. V28; No i dont have the stocks but if i really needed to, i can borrow a set.

I have JRZ RS Coilovers, and set to 4, lowered, but not slammed, with the "pineapple" as well refer to them over here. I'm running RE11 265s on all 4 corners. I street drive that same setup. Camber is not set aggressive. I leave my Attessa to stock setting.

I suppose i could add some negative camber, but i dont know how that would help with my braking.

[gtr jet]

I never had the same issue with the standard brakes as I couldn't brake as hard from the same speeds as I can now. Suspension wouldn't help my cause as it's farked.

[Komdotkom]

Why don't you data log your brake line pressures then work out the brake torque? Given that you are talking about dropping cubic dollars on a fix, I'd be making an informed decision rather than what the guy at AP said, remember he's selling the product.

+1 to everything that Roy said.

[sixmassive]

Data log my brake line pressures? What type of equipment can monitor that?

[billywhiz]

Also concur with Roy, so many things can result in a loose rear, v hot curry etc but as the OP mentioned running K-sport front brakes, std rears I'll ask a couple of questions.

Did you experience a loose rear prior to k-sports going on?

Has anything else changed since K-sports went on?

Changing Fronts and not rears can definitely mess balance up.

- if you increase front braking power only you increase weight transfer lightening the rear

- the ratio of total piston volumes can change

some specs of BMCs http://www.nissansilvia.com/forums/index.php?showtopic=2445116

I know from personal experience, I upgraded my fronts rotors only(piston volume was same), suspension setup remained the same, I noticed a looser rear end.

For now I firmed up my suspension, still playing around with how much front and rear but it's helped for now. Had a shock blow a seal so concentrating on other things at the moment.

[Roy]

Do you know what pads you have in the front vs rear ?

Personally i would get someone to record with a camera the car under a full noise stop from 120km/h and see the pitch you have in the car.

Then set all shocks to full hard and repeat.

Then leave front shocks on full hard and rear suspension on full soft...

After each try to understand if there are any dufferences in the feel of how the car is stopping

[sixmassive]

Hey guys,

So the Pads are the stock K-sport pads that came with the kit.

Rear pads are nissan pads.

Did not have the problem before the K-sports, but i couldn't brake nearly as had with the stocks vs k-sport. Nothing has changed since then.

I like the idea of logging braking distances while changing the shock rebound/compression, and will try that.

I really think its just that i am unloading the rear with such large brakes on the front. Feels like when i raced bikes; between using the back brake, and not touching it at all.

[R31Nismoid]

Dont forget caliper piston surface areas and master sizes all play a part in how it works......its not a simple task getting it right.

Yep, this is what most over look.

Surface area and the master, biggest factors to shit performing brakes.

First things first. What shocks and spring rates are you running? What tyres brand and sizes are you running? What wheel alignment are you bashing around the track on? What ride heights front and rear are you running Lastly what pads are you running front and rear?

If you are trying to get a brake setup that ensure the car is settled under big stops then its best to make sure you are looking at the right thing. 7 times out of 10 if you want to shorten braking distances or improve braking stability it will be tyres and suspension.

Yep, this is where I am heading as well after reading the posts thus far.

I wouldn't be blaming the brakes initially.

Why? Because soooo many people run upgrade kits on the front with stock rears in full weight cars. None of them have issues... Yet the OP is... Something else sounds like it is amiss here.

Hey guys,

So the Pads are the stock K-sport pads that came with the kit.

Rear pads are nissan pads.

Did not have the problem before the K-sports, but i couldn't brake nearly as had with the stocks vs k-sport. Nothing has changed since then.

I like the idea of logging braking distances while changing the shock rebound/compression, and will try that.

I really think its just that i am unloading the rear with such large brakes on the front. Feels like when i raced bikes; between using the back brake, and not touching it at all.

After reading stock pads, I think you are barking up a totally wrong tree now trying to upgrade the rears to fix this issue, I don't think it'll fix it at all.

Are we talking GTS-t or GT-R rear here?

IMO a decent set of pads and rotors in the rear is the first starting point. Also upgrade the pads in the front too. KSport stock pads aren't too bad (I used them myself) but there is a plethora of better options so change front and rear at the same time. That way you have the same compound front/rear and that'll make a difference just to start.

Then hit the stuff Roy said. I've seen a 10mm drop in the rear of a GT-R turn it from a unsettled/unpredictable rear to the total flip around of perfect grip/well seated in a corner. Something small like that can make huge differences.

I don't believe you need to upgrade rear brakes at all.There are plenty of Vic GTR guys running 350rwkw and Sub 1:20 @ Sandown and similarly blistering times at Philip Island which is all high speed stuff. Some are on semis. some extreme road tyres but they are all (monstly) running with upgraded fronts/stock rear brakes. None of them have ever had any issues you speak of.

[sixmassive]

car is all GTR

I'll price out some rotors and pads. and see where i end up.

Wont be able to run the car for a bit, at work on the rigs for another 2 weeks, then have a shoulder surgery that will slow me down for a few weeks.

[sixmassive]

here are my options for stock replacement

Front Pads;

Ebc DP4006 Yellow

Pads for rear

Project Mu B-type

EBC Red stuff

or endless pads

Project Mu Slotted rotors

[Roy]

DO NOT RUN ANY EBC PADS!!!!! if you like i can cut some planks of wood you could run that would work a tad better. Jus get some DS2500 work horse pads for the rear

[sixmassive]

EBC no bueno?

what about front

Edited November 28, 2015 by sixmassive

[R31Nismoid]

Just put a set of DS2500 front/rear. Make sure the rear rotor is good thickness and slotted.

The 2500s are a well tried and proven combo and reasonably economical on rotors as well. I ran it myself for years as have many others. Even run them in my 2 tonne HSV

Roy doesn't like the pedal feel with them though so he'll suggest anything else lol

[Roy]

Nothing wrong with DS2500 feel. They are a good work horse pad at a reasonable price. I think there are better pads out there but until you suss what you are doing long term they are a good fill gap measure.

I do loathe EBS green, red and yellow pads. Some like them but i think for track they are actually a rather rubbish performing pad, with poor feel to boot. But they are cheap and perfectly fine i guess for a spirited street car

[sixmassive]

Thanks for all the info guys

I sourced some DS2500s front and back, but they are about 20% more than others. But i didn't get into cars because it was cheap

Rear rotors? Project mu are so far the only ones, other than EBCs

[R31Nismoid]

Yeah just get Project MU.

DBA make them as well in a 4000 series, and will be cheaper. IMO that it what I would do. The rear rotor really doesn't get a heavy work out so no need to pay for top shelf. It's the front you need to worry about.

[sixmassive]

Got some Stoptech rotors on the way, and Hawk HP Plus Pads. Ferodos are hard to come by here.

Any options other than EBC for the KSport 8pot fronts?

[R31Nismoid]

1000 options.

It's a direct AP caliper size. I think CP5555 - you'll have to research. Basically gives you more options than you can think of

[gtr jet]

Yeah, they're a CP5555 copy. I run A1RM's in mine and they work a treat.