OGRacing

iTrader: (1)

The problem is your having this pressure bump under normal driving conditions. a short but sustained +20 psi is not a characteristic i would associate with heating fluid. in fact it's very odd to see. i would double check your sensors.

Eipgam

Again thanks for the advice. Master and proportioning valve serviced, however the car only got a chance to do about 150kmh as I had to fly out for work.

Agree on checking the sensor. Whilst the wrong voltage/pressure was being used 0-2000psi at 0-5 volt instead of 0.5 - 4.5 volt the overall shape of the graph does not change much. Actually the peak brake pressure drops.

When I'm home next the plan is to redo all the sensors and ensure they all have the same ground as the voltage supply. Next track session is mid July.

OGRacing

iTrader: (1)

any updates? i would like to see why your gaining a mistrey 20psi

Eipgam

Appologies for lack of update on the issue. During this time home I only got to drive about 200km (normal road speeds) and that included bedding in new discs. Did not get around to redoing sensors either, made by the end of July...

I forgot to pull the data before I flew out, but seat of the pants tells me that there is no more brake drag. I still have to do some coast down tests to confirm, but it would appear that either the rebuilding of the master or the proportioning valve that 'fixed' the issue.

I'll be home in 10 days so will update with data etc, bonus is the car will be tested on the track whilst I'm home so can check temps as well.

PaCHeKo!

Hi Johnny,

Once again, thanks for making this thread.. I keep refering people to this thread when it comes to proper brake setup.

I decided to go with DBA rotor and HP+ to use with my Sports Brakes (See first page!)

After a couple of track session my front rotors has some marks on it.



As for performance, I don't see/feel any problem. Rear brakes looks a bit better.

Am I missing somehting?

OGRacing

iTrader: (1)

That's Rotor deformation. A few posts back i mentioned that rotors will deform. first form of deformation Is coning. That’s when the rotor will simply bend to the hottest side. 2nd form of deformation will start to look like a Pringle’s chip or a cowboy hat. (Image below). Your into the 4-5th part of deformation when it’s starting to look like a wave. It’s not the end of the world. It will cause drag. Things that will help reduce rotor drag are a full floating rotor, cooling ducts, and in this case I would recommend increasing the Tq levels in the pad. Lower TQ pads have a tendency to heat up braking components to a higher temperature over the course of a stint (session, race)

If any upcoming events are at a track that requires more from a braking system, i would upgrade the pad Mu before then.

OGRacing

iTrader: (1)

Let’s talk Rotors.

There are allot of different aspects when it comes to a rotor.
What is it made from (Iron, Steel, Aluminum, Carbon ceramic, Carbon Carbon)
Where is it made
Is it 2 piece (hat made from aluminum, Rotor ring made from iron)
if it is 2 piece does it float?

Not wanting to spend all day I’ll try to keep the answer short, and focus on the standard parts store rotor.
Standard rotors that you find on Rockauto, Autozone, and so on come mostly from the peoples republic of China. They are covered and machined with oil, the material to make them is not as pure as it should be, and are never made engineered for racing. allow me to explain.

The machining process for Chinese rotors involves blasting the machining surface and tools with a cooling oil. This it to kelp keep the tooling parts cool, this lowers maintenance costs on machines. Then factory workers will wrap the rotors with an oil impregnated paper. This oil paper is in an attempt to prevent rust during shipping, the paper does its job well. The problem with using so much oil is that, it will impregnate itself into the iron, the oil will come out under braking. Most of the time when you see issues creating and keeping a transfer layer, the oil inside the iron is causing that issue. The impurities in the rotor are kicking the transfer layer off. Racing companies like PFC, Brembo, AP, will cut the rotors "dry". Dry means to machine the parts without any oil. It is more expensive to do this but will increase the rotors ability to obtain and keep a transfer layer. It will also increase performance. Anyone that has experienced a rotor get better, is from the oil is fully cooked out. The problem with that is a rotor should be good when it come out of the box till the last day it’s used.

- this photo is from WP a big brake kit manufacture. They have no idea what they are doing.

Next is what a rotor is made from. Iron is easily one of the best materials used for rotors. Size for size an iron rotor will outperform a carbon ceramic rotor. if you have two 14" rotors one in carbon ceramic and one in iron, the iron one will generate a more consistent and higher TQ output. Not to go too far off track… but that is why you see 15-16" carbon ceramic rotors on oem vehicles. The oem manufacturers need the increased a carbon ceramic rotor’s size to get the increased performance. Carbon ceramics will outlast an iron rotor. ...sorry back on topic, right iron.. Iron is one of the most dense materials in the universe. also how pure the rotor casting is makes a considerable difference in braking performance. rotors that are casted in china are known to have excessive impurities, and are often labeled incorrectly. anyone that has dealt with 304 *Chinese* stainless will know what I’m talking about. these impurities will have a decreased effect on braking performance. I like to find Rotors manufactured and casted in the USA or Canada. the US has a higher standard of casting. again PFC, AP, and brembo all are manufactured in the USA, GB, or Italy.

finally the engineering in the rotors could take year to explain, so I’ll focus on balancing only. When a rotor gets hot it cones, it beds, and it looks like a wave. it's never still. The material is constantly flexing. think about a top fuel dragster tire in slow motion.. it's not 100% the same but it is close. that rotor is constantly trying to keep itself together and not explode. in order to stop a rotor from shaking the wheel all manufacturers will balance them. Top Motorsports brake manufacturers will balance the rotor by cutting the entire outer perimeter of the rotor on a lathe. this ensures that when a rotor is at thermal capacity, there will be no places of excess or minimal material. it makes the rotor stronger, and more resistant to cracking. Part store rotors balance the rotors by finding the heavy spot on the rotor and cutting that off.

what not to do.


In motorsports this is a huge no-no. the hard edges give a place for cracks to start, the material has a thin spot on the rotor, and it means that the material that is spinning is not balanced through the assembly. This thin material can lead to more coning (drag) and it can lead to a cracked rotor.

In conclusion, :P. is high quality rotors a waist? Like tools good quality parts are never a waste. On average a motorsports rotor will outlast a parts store rotor long enough to justify the price. Parts store rotors can work, they also let allot of people down. If it was my money, paying for my track day, I’m putting the parts on my car that will insure that I have a fun weekend. I’m not looking not fight the $30 rotor that costed me $800 of track time. Allot of people might say "they worked fine for me". Truth of the matter is 80% of the motorsports population knows how to build a motor, 10% know how to build a braking system. Remember that when you’re in the pits taking advice from other amateurs.

When looking for Rotors, Find something with a curved vein, manufactured in the USA,GB,Italy or australia... if you can.

jko

Just to follow up, I went with ATE fluid since I had some extra laying around and the pedal feels a bit better. It no longer sags as far after the first session but the travel does still increase a bit after a few sessions (same pedal pressure, more travel). I will go for the Motul600 after I run out of ATE. I'm also experiencing the same post-track day issues where the pedal travel seems to return to normal after a few days of street driving, and after bleeding I see very little/no air bubbles. Is it possible for the fluid to be 'boiled'/ruined but not see any bubbles while bleeding?

In addition, I'm having weird transfer layer issues with the prebed XP10's I bought. I have attached 2 pictures. The first picture (good transfer layer) is actually before the track day and was originally bed on XP8's about a year ago. The second picture is after the track day (bad transfer layer). After a few days of street driving, the rotor returns to the 'good' transfer layer. Any idea what is happening there? The XP8's I used never really had this issue.

Thanks.

OGRacing

iTrader: (1)

When fluid vaporizes you’ll see one of two things come out of the caliper. 1 it will just be very dark, and It will look old. No bubbles will be visible. 2 it will look like milk. You’ll get the milk look when the fluid has absorbed a large amount of water. I find it very odd that the pedal retunes after a few days. I would start looking around your master cylinder for leaks. It sounds like you might have an issue with it. If you do find the MC that has been leaking into the booster, you will need to replace the booster too. Brake fluid will eat the brake booster seals.

Carbotechs major downfall is keeping the transfer layer. They have a tendency to lose it, sometimes during an event. If you do lose it you will need to re-do the bead in procedure to get it back. The Top level pads like Padgid and PFC don’t have this problem. Top level pads don’t even have a bead in procedure. Generally if your losing transfer layer if your overheating the pads. Being that your upgraded to a higher heat pad and then had the problem is very strange. FYI I lost my transfer layer during an autocross (PFC 01 compound). Before my run I went over to a adjoining parking lot dragged the brakes, did one good stop and it was back.

I would recommend checking the MC, if that checks out I would ditch the carbos they seem to be a real PITA. You’re not the first person in this thread that has this same issue.

thumpetto007

iTrader: (15)

What pad and rotor combination would you recommend for a fast street, light track car. 2001 LS with the sports brakes. I love to brake hard. Dust is not an issue, noise would be.

No ducting, amsoil dot3 500 series brake fluid.

Side question, with stock aero, how effective are brake ducts, and where is the best location to put the "inlet" of the ducts?

jko

Thanks for the feedback. I have seen my brake fluid look 'cloudy' (darkish yellow) before but wasn't sure if I was just imagining things. I do have a spare MC on hand so I'll investigate around that area. I'm going to give Motul600 a try first and see what happens after the next event.

To be fair to the Carbotechs, they were bed in with XP8's on 185/60/14 Dunlop Z2's while the XP10's are on 205/50/15 NT01's, so there is definitely more heat now. I have seen a few other stories of people having no issues with the XP8 transfer layer but having trouble with XP10 transfer layer so I'm not sure what is going on. I still have plenty of life on the XP10's so I'm going to hold out before I consider trying a different pad. The thing I like about these Carbotechs is that they make very minimal noise on the street and are very daily drivable.

sixshooter

iTrader: (12)

My PFC 01's don't make any noise and don't have a bedding procedure. Cobalt XR2 was quiet and good also but cost about twice as much and are hard to find.

Eipgam

OGRacing another small update.

Rear brakes now locking up well before the fronts on very hard braking. Looks like a manual proportioning valve or a change in front compound or suspension changes (to slow weight transfer to the front wheels) or a combination of changes.

Notwithstanding happy now that there is no drag issues with the rears.

tazswing

Question: for brake duct hose used with Singular cooling adapters, does this need to be the 500+ degree hose? Have people melted out the lower temp hose? Obviously the high heat tolerance is less worry but is it overkill?

For HPDE, so ~25min sessions.

ThePass

iTrader: (3)

We haven't seen any failures of the lower temp (yet still high quality) black neoprene brake ducting hoses. Look for 2-ply with internal wire lining. I can't speak for the cheaper stuff that lacks those features.

-Ryan

OGRacing

iTrader: (1)

I have the low temp 3" air ducts. so far they have survived road Atlanta.

i used a quantity of 35 and it does the job for both sides.
http://www.ogracing.com/cool-brake-hose-3-diameter

DeerHunter

I use the low-temp black 3" hose and so far, so good.

tazswing

Thanks, y'all. Now down the dark path of choosing an engine oil...

Schuyler

iTrader: (1)

<p></p><p>&nbsp;</p><p>T6. Congratulations, you've found the light at the end of your path.</p>

Leafy

iTrader: (1)

The end of the path with pathetic film strength.