Big Brakes
04-29-14, 09:28 AM
#1
Big Brakes
While at DGRR beating the crap out of my car (someones gotta show those FC's and RX8's up!) I've found that my brakes completely suck. Brand new Master Cyl, Brand new Calipers, Brand new decent pads, and all 5 SS brake lines. Brake fade out the wazzu! I know respeed used to sell the T2 brake upgrade kit, but it seems respeed is no more. So, rotor people, what can I do?
04-29-14, 10:02 AM
#2
LOL, I had the same experience at DGRR two years ago, so I feel your pain.
Here is what I did:
https://www.rx7club.com/1st-generati...twist-1029145/
That solution is a bit pricey and fabing the caliper bracket took some engineering.
There are alternatives, others who have done dyi turbo II upgrades will chime in, I've seen it dealt with several ways.
While I was dealing with this I spoke with Charles at KC Raceware, (Thats who made my hubs) He says that the biggest problem is getting the heat out of the caliper and advises the first change should be a air duct directing air to the caliper, so you may want to try that before you make major changes, it may make the difference, and could save some $$.
Here is what I did:
https://www.rx7club.com/1st-generati...twist-1029145/
That solution is a bit pricey and fabing the caliper bracket took some engineering.
There are alternatives, others who have done dyi turbo II upgrades will chime in, I've seen it dealt with several ways.
While I was dealing with this I spoke with Charles at KC Raceware, (Thats who made my hubs) He says that the biggest problem is getting the heat out of the caliper and advises the first change should be a air duct directing air to the caliper, so you may want to try that before you make major changes, it may make the difference, and could save some $$.
04-29-14, 10:08 AM
#3
I planned to have brake ducting before DGRR but that didn't end up happening. I have an airdam I was going to use to funnel air from where the fog lamps would go and duct them right into the calipers. Maybe I'll try that first and then if I'm still having issues go from there.
04-29-14, 10:18 AM
#5
Yea, I think that airdams can actually hurt brake cooling cause they keep air from getting to the brakes. I have one also I am try to figure out how to incorporate ducts. I am unlucky in that mine has no fog light or brake duct built into it, so I am pondering how to get some in there.
04-29-14, 10:23 AM
#6
my fluid was all new too, flushed clutch and brake fluid really well before I left. I don't remember brake fade as bad two years ago but then again my car handled better this year and I'm sure I was probably harder on the brakes. I have the under tray for the rad but the beauty panel looked like it would hinder brake cooling so I took it off, it was so bad I thought my master cyl went bad, then I grabbed a metal brake line and it was pretty hot.
Trending Topics
04-29-14, 11:57 AM
#8
You didn't specify the kind of pads you have or the fluid you are using. All of these are suspect if they are not up to the task. Also do you have air ducted to the front brakes?
I am not familar with where you are driving but I have raced successfully with stock GSL brakes for many years. I never had a fade issue and my car hit over 100 every time I drove it.
The following suggestions will work and are allot cheaper than putting on bigger brakes.
For pads, nothing works better than real racing brake pads. Not high performance street pads - racing pads. I used Hawk Blues on my race car. They are expensive, eat rotors dust like crazy but they never fade. They also heat up fast and are good for autox and street driving. Not a super high torque pad so brake lock up is not a big problem. There are other brands out there - look for a pad that can live at 700-1000F.
For fluid I recommend Motul 600 because it has a high boiling point. In a budget pinch you can use Ford Heavy Duty DOT3 or Willwood 600. The Ford fluid has a 500F dry boiling point and it a bargain from you local Ford dealer. The difference between using Motul (or similar) and a lesser quality fluid is that you will need to bleed your brakes less with Motul.
Brake ducts make it all work. You need a 2.5-3" hose pointed to the back of the hub center. This will cause the air to pump through the rotor vents and also cool the wheel bearings. Draw in air from the front of the car.
I am not familar with where you are driving but I have raced successfully with stock GSL brakes for many years. I never had a fade issue and my car hit over 100 every time I drove it.
The following suggestions will work and are allot cheaper than putting on bigger brakes.
For pads, nothing works better than real racing brake pads. Not high performance street pads - racing pads. I used Hawk Blues on my race car. They are expensive, eat rotors dust like crazy but they never fade. They also heat up fast and are good for autox and street driving. Not a super high torque pad so brake lock up is not a big problem. There are other brands out there - look for a pad that can live at 700-1000F.
For fluid I recommend Motul 600 because it has a high boiling point. In a budget pinch you can use Ford Heavy Duty DOT3 or Willwood 600. The Ford fluid has a 500F dry boiling point and it a bargain from you local Ford dealer. The difference between using Motul (or similar) and a lesser quality fluid is that you will need to bleed your brakes less with Motul.
Brake ducts make it all work. You need a 2.5-3" hose pointed to the back of the hub center. This will cause the air to pump through the rotor vents and also cool the wheel bearings. Draw in air from the front of the car.
04-29-14, 12:34 PM
#10
I'm also interested in a picture (pictures) of your brake ducts. I didn't have them ducted, I ran out of time and spent my last night before DGRR setting up a diff at 4:30am on the kitchen table next to a pot of coffee. I was using valvoline synthetic dot 4 fluid, which I just looked up and it looks like it's dry boiling point is 446*. Pads were street pads, and that could be my biggest problem right there. I didn't expect them to be as good as race pads but I did think they'd be a lot better then what they were. My speedometer is off by 20mph now but I was no where near 100mph, the road just doesn't allow it.
04-29-14, 12:57 PM
#11
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,844
Received 2,605 Likes
on
1,848 Posts
my fluid was all new too, flushed clutch and brake fluid really well before I left. I don't remember brake fade as bad two years ago but then again my car handled better this year and I'm sure I was probably harder on the brakes. I have the under tray for the rad but the beauty panel looked like it would hinder brake cooling so I took it off, it was so bad I thought my master cyl went bad, then I grabbed a metal brake line and it was pretty hot.
granted on the street this is maybe impractical, but isn't the dragon a 35mph speed limit anyways? i've seen bicycles go faster
04-29-14, 01:40 PM
#12
You didn't specify the kind of pads you have or the fluid you are using. All of these are suspect if they are not up to the task. Also do you have air ducted to the front brakes?
I am not familar with where you are driving but I have raced successfully with stock GSL brakes for many years. I never had a fade issue and my car hit over 100 every time I drove it.
The following suggestions will work and are allot cheaper than putting on bigger brakes.
For pads, nothing works better than real racing brake pads. Not high performance street pads - racing pads. I used Hawk Blues on my race car. They are expensive, eat rotors dust like crazy but they never fade. They also heat up fast and are good for autox and street driving. Not a super high torque pad so brake lock up is not a big problem. There are other brands out there - look for a pad that can live at 700-1000F.
For fluid I recommend Motul 600 because it has a high boiling point. In a budget pinch you can use Ford Heavy Duty DOT3 or Willwood 600. The Ford fluid has a 500F dry boiling point and it a bargain from you local Ford dealer. The difference between using Motul (or similar) and a lesser quality fluid is that you will need to bleed your brakes less with Motul.
Brake ducts make it all work. You need a 2.5-3" hose pointed to the back of the hub center. This will cause the air to pump through the rotor vents and also cool the wheel bearings. Draw in air from the front of the car.
I am not familar with where you are driving but I have raced successfully with stock GSL brakes for many years. I never had a fade issue and my car hit over 100 every time I drove it.
The following suggestions will work and are allot cheaper than putting on bigger brakes.
For pads, nothing works better than real racing brake pads. Not high performance street pads - racing pads. I used Hawk Blues on my race car. They are expensive, eat rotors dust like crazy but they never fade. They also heat up fast and are good for autox and street driving. Not a super high torque pad so brake lock up is not a big problem. There are other brands out there - look for a pad that can live at 700-1000F.
For fluid I recommend Motul 600 because it has a high boiling point. In a budget pinch you can use Ford Heavy Duty DOT3 or Willwood 600. The Ford fluid has a 500F dry boiling point and it a bargain from you local Ford dealer. The difference between using Motul (or similar) and a lesser quality fluid is that you will need to bleed your brakes less with Motul.
Brake ducts make it all work. You need a 2.5-3" hose pointed to the back of the hub center. This will cause the air to pump through the rotor vents and also cool the wheel bearings. Draw in air from the front of the car.
I have been racing my GSL-SE in lemons/chump for three years now. so 12 hour + races and the ONLY think I can't complain about on the car is the brakes.
Pads are key. I use hawks blues as mustanghammer mentioned and they are just as he describes.
When my rx7 was a street/autocross car I used hawk HP plus'. These are billed as the street/track pad from hawk. They worked great but they did squeel when cold and just puttering around town.
04-29-14, 01:41 PM
#13
35r 13b first gen
iTrader: (3)
Join Date: Apr 2002
Location: Richland Center WI
Posts: 1,290
Likes: 0
Received 0 Likes
on
0 Posts
I'm running the dot 5 synthetic It's boiling point is 550 degrees F. If u go this route make sure u flush your system because it is not compatible with DOT 3/4. Brake fluid is hygroscopic. It's the only automotive fluid that absorbs water. It actually pulls moisture out of the air if say your master cyl cap is off/ loose. Thus most manufacturers recommend flushing your brake fluid every so many miles and or when you do a brake job. DOT 5 is not hygroscopic.. However if moisture does get into the system somehow, the moisture will essentially remain in one spot (rust out). Regular dot 3/4 will absorb and spread the moisture throughout the fluid lowering it's boiling pt.
I do have a TII brake swap but braking is phenomenal so far..
I do have a TII brake swap but braking is phenomenal so far..
04-29-14, 02:27 PM
#15
My brakes worked perfectly on the dragon this year but I have the TII swap on mine and I run it pretty hard. Which FB was yours? I ran up on a pair of off white one on one run and 2/3 way through they ran slower than when I caught them (didn't think about brakes getting toasted)
I have the silver FB with the single turbo 13BRE swap
I have the silver FB with the single turbo 13BRE swap
04-29-14, 02:53 PM
#16
Cshaw, exactly what 'decent pads' were you using? 20 years ago I did track days at Summit Point on Mazda factory pads which lasted exactly 8 30 minute sessions with fade coming 20 minutes in. So a few pumps brought them around. I switched to ferodo ds11 and never had another issue. They're no longer available, but I suspect the Hawks are just as good. I've been away from the scene for a few years. I just put on some FF rated Beck Arnley pads, bedded them properly, and my brakes are significantly better than last year at Deals Gap, though I may not be pushing as hard as you. I think that brake size is not necessarily your problem, though bigger would certainly be better.
Edit:
Try driving when the pavement's wet. It's much easier on all equipment. 'Cept maybe wipers.
Edit:
Try driving when the pavement's wet. It's much easier on all equipment. 'Cept maybe wipers.
04-29-14, 02:59 PM
#17
Sorry don't have any images for brake duct routing.
What we did was run them along the frame rail in the wheel well. I did flatten the hose little to keep the tires off of them. I held them in place using a piece of aluminum that I riveted over the hose. I have seen guys use short pieces of oval exhast tubing in this area to protect the hoses.
+1 on better tires. In my experience, if you had brake fade on an RX7 race car you are 1. using the brakes too much, 2. have crappy tires or 3. all of the above.
What we did was run them along the frame rail in the wheel well. I did flatten the hose little to keep the tires off of them. I held them in place using a piece of aluminum that I riveted over the hose. I have seen guys use short pieces of oval exhast tubing in this area to protect the hoses.
+1 on better tires. In my experience, if you had brake fade on an RX7 race car you are 1. using the brakes too much, 2. have crappy tires or 3. all of the above.
04-29-14, 06:20 PM
#18
Sorry don't have any images for brake duct routing.
What we did was run them along the frame rail in the wheel well. I did flatten the hose little to keep the tires off of them. I held them in place using a piece of aluminum that I riveted over the hose. I have seen guys use short pieces of oval exhast tubing in this area to protect the hoses.
+1 on better tires. In my experience, if you had brake fade on an RX7 race car you are 1. using the brakes too much, 2. have crappy tires or 3. all of the above.
What we did was run them along the frame rail in the wheel well. I did flatten the hose little to keep the tires off of them. I held them in place using a piece of aluminum that I riveted over the hose. I have seen guys use short pieces of oval exhast tubing in this area to protect the hoses.
+1 on better tires. In my experience, if you had brake fade on an RX7 race car you are 1. using the brakes too much, 2. have crappy tires or 3. all of the above.
Most people dont realize how much speed they can carry through a corner, as long as the line is right and steering input smooth.
2 cents
04-29-14, 09:44 PM
#19
If you're looking to add ducts, my experience may be useful. This is a post from back in '07 --> https://www.rx7club.com/1st-generati...talled-617284/
04-30-14, 07:07 AM
#21
I use the tires they use on the legends race cars, though not true race rubber, i can grab the tread and squeeze them together cold, they're very soft. The speed limit at the dragon is basically ignored by everyone other than trucks and people who I think accidentally end up there lol (yes there are police, drive at own risk, everyone is "speeding") I don't claim to be a race car driver, but I feel like I was pushing my car as hard as I possibly could have for what it is (stock springs/shocks/ride height). Tires wanting to howl through turns, *** end to breaking point. I'm going to upgrade pads, I guess I didn't realize how much of a difference they actually made when it came to brake fade. I wasn't there last year, but two years ago I was on an single turbo FD's *** (had coilovers too) so hard he asked if I was mad he didn't pull over. I thought it was awesome my little 1st gen with stock port 12a and stock suspension could keep up with a single turbo FD on coils. My car was the custom silver metallic 85 gsl with blue front bumper and darker grey pass front fender, car was wrecked when I got it.
04-30-14, 10:11 AM
#22
Moderator
iTrader: (3)
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,844
Received 2,605 Likes
on
1,848 Posts
oh you need tires, those ledgends are so squirrley that THEY don't know where they are going to go when they turn the wheel either. i believe those tires last a season or two
04-30-14, 10:41 AM
#23
i got about 18k miles on a set of them. I'm moving up to 15's as soon as the wallet allows. I'll have a lot wider wheel, better fitment, better tire selection, etc etc. I am pretty impressed with the legends tires for the price though. It seems with 13's you either buy all seasons or track tires, there isn't much if any in between. I think a 15x8" wheel +0 offset should fit with a set of flares, but again I've not yet looked into it. I'm going to have a shop drill my axles to 4x114 and i'll use press in studs (hate lug bolts).
04-30-14, 10:42 AM
#24
35mph...ha. locals in their "regular" car are fast cause they are so used to the roads. this was my first time at DGRR and in my group, i was the slowest one by far! i did not have an issue with braking as i was not comfortable finding out the limits of the car up there but i did use a lot of engine braking to slow me down though. i'd also like to find out more about making brake ducts...