humming

iTrader: (2)

The amount of pressure we are talking about here(while bleeding brakes) isn't going to be enough to really change "bubble size"

NiklasFalk

iTrader: (1)

The suction will not reduce the pressure a lot, I agree, but it will not reduce the bubble size as the two person tango method does (unless the pedal pressure used is absurdly low).

OGRacing

iTrader: (1)

i thought it blew, but if it sucks that's ok. still finish the system off with the traditional way of bleeding brakes.

btw you guys are going threw a lot of effort to avoid having friends.

ofspunk7

Yes. This is how the system works.


So the concern using this system is that it will not do as good of a job getting all the air out of the system?

ofspunk7

(Posted at the same time)

Ok cool. I feel better using this system then. I will try to convince some friends we need to bleed brakes soon, so I can go old school too.

acedeuce802

iTrader: (1)

I have a '99 with factory brakes (other than SS lines), and I have new stock rotors, and Carbotech XP10/8's waiting to go on. I'm considering bumping up to the new TSE 11.75" front kit, and 949's rear kit that places the factory caliper over an 11" sport rotor. This seems to be a great bang-for-the-buck setup. My question is about pad selection. I'm waiting to hear back which pads are included in the TSE kit. If I were to stick with the XP8's in the rear, is the XP10 compound still a good front pad choice with this setup? Without consistent data for off-the-shelf pads, it's hard to combine pads from different manufactures front and rear, unless it's a proven setup. Does anyone have any experience with this combination or know of any proven pad combos?

For reference, it's 2450 lb (with driver), 50.2% front heavy, 235 whp, lowered about 1.5", 15x9's with 225/45/15 Gen 2 RS3's. This will be a summer daily driven car with track days and autocrosses mixed in.

OGRacing

iTrader: (1)

Your cross weight is really good!! the 11.57 kits are a perfect match for our cars, i'm currently experimenting with afco calipers on a 11.75" kit. the rear sport rotor kit is a must to balance the system if you want to keep the parking brake. if the parking brake is no biggie running a 11.75" rotor in the rear is a nice way to avoid needing to bring extra spares to the track.

Out of the available 11/75" kits on the market i would chose the V8 roadsters kit. and here is why. their caliper use the PFC 7754 pad. it's 4mm thicker pad vs the daynalight 7752 pad. that extra material will give you longer life for the same price. in the end it will cost less.
Front Big Brake Kit - V8 Roadsters

the rears iv'e always loves Good wins Customer service. a lot of people make the sport rotor->1.8l caliper kit. and they are all basically the same, when a product isn't elite i really lean towards good customer service. makes you feel taken care of if there is a problem.

Goodwin Racing Miata Big Brake Kit, REAR ONLY Version 4. for Miata 90-93


Both Kits come with Street pads. KEEP THEM FOR THE STREET!!! don't take them to a track day and expect the street compounds to work like magic. For race pads go with the PFC compound square on these systems. square= same compound front to rear. the balance with the upgraded rotor size is excellent.

For your car running the Hankook rs-3 I would recommend the PFC 11/01 compounds.
It has a smooth bight that helps the tires keep cohesion. and excellent pairing to the 225 ultra high performance street tire.
Performance Friction 7754.01.16.44 Racing Pad - 01 Compound
Performance Friction 0636.11.13.44 Racing Pad - 11 Compound

Savington

iTrader: (31)

You are mistaken, sir. 4mm is ~0.160". Dynalite pads are 0.480-0.490, which means that you think that the V8R caliper runs a 0.620-0.630" pad. This is not a pad that exists. Wilwood does make a 0.600" Dynapro pad, but it's the radial caliper pad, not the lug-mount Dynapro as V8R uses.

NiklasFalk

iTrader: (1)

That's why I bought a 7/16" Reamer for later use, sometime...

OGRacing

iTrader: (1)

Dynalight pad runs a 7112 pad shape(PFC 7752) they are 12mm thick
Dynapro radial mount runs a 7816 (PFC 7754)they are 16mm thick

ThePass

iTrader: (3)

I have a set of radial mount brackets on the way from V8R for the radial dynapro - it's a project they've been working on recently.

However, their current kits are the lug mount version AFAIK.

-Ryan

OGRacing

iTrader: (1)

i was under the impression they where using the radial. that's what i saw at the mitty.

Eipgam

OG Racing thanks for the info in this thread.

Interested to read your feedback on what you think of the following issue.

A recent issue with overheating rear rotors lead to some interesting findings. The car is a 1992 MX5 NA6 with a modified (naturally aspirated BP engine). The brake set up is the NB8B calipers with DBA rotors and Winmax W5's in the front and W3's in the rear.

From previous datalogging I know that front lock up happens at about 770 PSI, at this point there is 370 kg over the rear wheels and 710 kg over the front wheels, the car is balanced 50/50.

At recent track day I decided to do some brake temp monitoring because of an issue with the rear caliper (which has now been rebuilt). I used Paint and Temp strips.

Green to white at 430c
Orange to Yellow at 560c
Red to white at 630c

The temp stickers are single use and will show a max temp above 204c

DSCN2631 by Eipeip, on Flickr

After the first session, the decision was made to sit out the next so that rear calipers off be backed off a bit a bit...

Front Right. Winmax W5's, Trackspeed 1.5" ducts and temp was just getting to 430c.
DSCN2636 by Eipeip, on Flickr

Front left. Similar to Front right
DSCN2637 by Eipeip, on Flickr

Rear Left - In excess of 630c. This is outside the recommended temperature for Winmax W3's. The disc is also polished an no real pad material deposited onto the disc.
DSCN2638 by Eipeip, on Flickr

Right Rear - In excess of 560c with the red starting to lighten in colour.
DSCN2639 by Eipeip, on Flickr

The temp stickers did not show a temp above 204.

Jason from Automotive Plus (at the track) who also built the engine and services my car suggested that since the calipers had just been rebuilt the issue could be in the master. Jason was at the track looking after Danny Irvine's 20B PP MX5 NC (naturally aspirated).

So went looking in the datalogging. At the moment I only log front brake pressures, but...

This was on the way to the track (the car is road registered). Brake pressure is normally 209 (green), however it went up to 223 for no reason.
Brakes by Eipeip, on Flickr

This is from QR, again the brakes did not fully release. Down main straight, release, after turn 1 not fully, just before turn 2 released, after not, dipper hard brake, even more pressure left in the system, small touch for 4, but still pressure left, down the small straight into 6 hard brake and heaps left in the system.
Brakes QR by Eipeip, on Flickr

Data from Eastern Creek (a month before). Rear pads and calipers have been replaced/refurbished since Eastern Creek, but the issue is still the same, a retaining of pressure in the brake system.

Interestingly at Eastern Creek there was some brake fade, but this seems to be from pad knockback and not overheating as they came back almost instantly with a pump.

Brakes EC by Eipeip, on Flickr

The master is being rebuilt now as well as making sure the pedal is adjusted correctley (Thanks Keith from Flyin Miata) and instaling a pressure sensor on the rear brakes. Once it is all done back to some testing to see if the issue has gone.

However I have had no real issues with the OEM calipers yet, they are regularly serviced (sliders greased) and rebuilt every 12 months. The Rotors are being replaced with DBR 4000 T3 S as the front rotors are now stuffed.

Sorry for the long post, the use of metric and being naturally aspirated

This is the car going through Turn 1 at Eastern Creek at approx 170 kmh. The car makes about 182 RWHP (on a hub dyno).

IMG_1400 by Eipeip, on Flickr

OGRacing

iTrader: (1)

All that data i love you.

looking over everything your giving me an i can come up with a solution of it's the pad choice. this is how i got there.



#1 the Fronts are locking up at a relativity low pressure. that's telling me that the Brake balance is heavily leaning towards the front. and the rear pads are eater overheating, or not getting enough pressure.


With your car balanced out 50\50 and a GTC 250 wing (with two wing risers). your rear braking demands are elevated. this is telling me that the rear traction is too much for the low Tq Winmax to handle. think of it like stopping a moving rope in your hands. if that rope is pulled by a toddler then you can stop the motion no problem, it wont burn your hands. if that rope is being pulled by a Mack truck that rope is going to burn the snot out of your hands. that is exactly what your rear tires are doing to your pads. with all the added traction the winmax is failing, the rotor is blowing threw and overheating the system. that elevated head could cook the rear calipers and i think that is why you needed to rebuild the seals.

This is the compounds i would recommend. the PFC 11 compound on all axles. If you have any more issues call me and i can walk you threw fixing it. cell: 770-880-7579
Search results for: 'miata'

Eipgam

Appreciate the detailed reply.

I have lots more data by the way

Once I get home and get my car back I will check to see if the master rebuild has fixed the brake system holding pressure and causing the pads to drag. If not booster rebuild will be next and more testing. Only once this is fixed will I look at pads.

I'm looking at the Winmax 6.5's on the front and 4's on the rear as a possible combination. Once the rear brake pressure sensor is installed the decision will be made on pads and if a manual bias adjuster is needed to balance the brakes.

Had a quick look but freight and the AUD exchange rate makes it a bit on the expensive side.

OGRacing

iTrader: (1)

why do you think there is drag in the system? Floating calipers do a good job at reducing drag.

Eipgam

In the data I posted the brake system is retaining pressure. Normally the brake system runs at 200 PSI stored, however this has been increasing for no apparent reason. The increase has been upto 35 PSI. This is causing drag and can be felt when driving normally, feels like the handbrake is on.

Additional information. The car is running Jenvey ITB's and stock booster. There is adequate vacumn from the the ITB's to run the booster as the vacumn is logged. I will get into the data tonight and post if you think it will help.

This was on a normal road, normal constant speed, flat road. I wish I was showing the TPS, but you can see that in the middle to AFR is getting richer hence more load but no change in the speed. Brake pressure is green, however for some reason it went up to 223.
Brakes by Eipeip, on Flickr

The dragging can explain why there was such a big temp difference between the front and the rears.

Happy to hear other explanations, I'm trying to understand the why so that in future the data can be used to identify issues early before they develop. It is unfortunate but the way I learn is to understand the why first.

OGRacing

iTrader: (1)

a strange spike in pressure is very odd. this happens when your just driving down the road? i'm having a hard time seeing it in the graph. the green line just moves a little bit.

Eipgam

OG Racing, that is the spike that is causing the drag. In the past I was looking at peak braking presures and not looking at the 'normal' pressure. Suggestions are the master is not fully opening to allow pressure equalisation and as the fluid heats it expands and causes the drag on the brakes. I guess a bump will allow the master to move everynow and then.

If you look in the previous graphs the brake pressure increases whilst accelerating.

The marker lines on the graph show the brake pressure (green). Pink = RPM, Purple = AFR, Dark Blue = Speed, the 4 colours close together are EGT's.

Leafy

iTrader: (1)

Pad selection for mu around .35 and temp range higher than parts store pads.