Brake Advice DE releated

pmajka · 08-26-2006, 05:38 PM

88 carrera.
Finished my first DE. My Brakes were not up to snuff. Over heated and warped rotors first day. (mind you only god knows if they are origional from 1988).

So, i need new rotors (considering slotted rotors), but am wondering if i am gonna smoke and twist them too. An instructor stated he has the Boxter Brakes on his car (umm...monoblock??) and he drives like the devil is on his tail.

any recommendations or personal experience?

gchappel · 02:39 AM

As you learn to drive, your stock brakes will be fine. They do require care- fresh fluid, thick-relatively new pads. You may have to bleed before each track day- no big deal once you get used to it. Stock rotors work fine, at least for me.
The first couple of times at the track you are probably over brakeing.
Do a search here of the boxster setup- it changes the bias between front and rear brakes- and may not be the wisest thing to do.
If your car is in good shape, and brakes are maintained- they do fine on the track. I have an 85carrera that I have wrung the ***** out of at sebring, brakes are not the problem. Need more power

Gary

Eagledriver · 08-26-2006, 06:39 PM

It is unlikely that you warped your rotors. What happens is that the pads start to melt and the material sticks to the rotor. When that happens you feel the pulsing like a warped rotor. Solution is better pads and new rotors. Many of us rece with stock Carrera brakes so they can work ok.

-Andy

widgeon13 · 08-26-2006, 07:08 PM

I would endorse everything that has been said above, get new pads that are suitable for track use but not racing pads, (they don't work well for normal street use). Bleed the system before a track day within a week or so of DE. Make sure the brakes pistons are not frozen and move freely, you can check this when you replce the pads. Put a brake duct cooling hoses on that get more cool air to the rotors. Most people who are driving stock set-ups can drive the balls off the car and never have to upgarde brakes. The other thing is that when you use your brakes, hammer them as hard as possible w/o causing lock up then get off them. Most of your braking early on will be done in a straight line.

You have plenty of braking capability on your stock set up, certainly for DE. Ride with an instructor driving your car and see what it can do before you put more money into making it go faster or stop better. You will be amazed to see that you are probably only using 65 -70% of the cars capabilities, I kid you not.

Jeff Alton · 08-26-2006, 11:30 PM

Boxster brakes are not really and upgrade. IF you actually warped your rotors, a bigger caliper (boxster) on the same rotor will make matters worse. You may just have pad material on the rotors as stated above...

However, do a search on 993 brake cooling diverteres and you will find some good info. I have installed these on 3 carreres and with good pads and good fluid (motul rbf600) these cars mods work very well. We have a tight track up here that is hard on brakes and these guys have no complaints about there braking performance now.

That said, if you have a big bank account you can upgrade to 930 brakes (still fit inside 16 inch wheels) or go to something like I have in a Brembo GTP set up. The last time I checked for a customer, big reds were NLA new. However, they may be available used for a good price.

A good pad and good fluid and some form of brake cooling should keep you okay for the time being. Try that first, it is cheap. If you have some money to spend, then maybe upgrade to a bigger rotor/caliper combo.

You can also do a search for Bill Verburg's posts on the subject. He is our resident expert. No one seems to know more than him.

Cheers

pmajka · 08-27-2006, 02:57 AM

can anyone recommend a suitable pad...this is my daily driver, but, i have 2 more DE's in next 3 months.

Jim Smolka · 08-27-2006, 03:19 AM

I like the Hawk HP plus pads, ATE blue brake fluid. Slotted rotors are good. PP has a tech article on brake ducts.

charleskieffner · 08-27-2006, 03:47 AM

zimmerman cad plated drilled rotors, ATE BLUE fluid, new caliper kits/bearings, brake ducts and PBR deluxe pads. works great! not a daily driver . while we were in there replaced e-brakes, they were junk from PO driving with e-brake still on. works great also when we go hit the twisties early in the am before it gets insane hot out during summer. cant comment on cold weather since it hasnt been cold here in 48 years!

IROC · IROC's Garage

Quote:

Originally posted by widgeon13
The other thing is that when you use your brakes, hammer them as hard as possible w/o causing lock up then get off them. Most of your braking early on will be done in a straight line.

This is really the key. As long as your brakes are in good working order, then really all you need to do is modify your braking technique. It may be counter-intuitive, but braking as hard as you can for as short a time as possible is the best way to brake (to manage the amount of heat in your braking system). This actually allows the brakes to cool more than braking easier for a longer period of time.

The reason is that even though the same amount of heat energy is being dissipated by the brakes (slowing your car from X mph to Y mph puts the same heat load into the brakes regardless of how "hard" you brake), you are braking for a shorter period of time, so they have longer to cool.

Mike

1982911sc · 08-27-2006, 06:04 AM

I just replaced all four pads, I went with the Textar fronts, Jurid backs...these are basically the OEM pad. Great for street and DE. And not too $$!

sfoster13 · 08-27-2006, 09:36 AM

Motul 600 + ajusa brake cooling kit including deflection plates (from our host) + new brake lines + PFC 97 pads + fronzen/slotted rotors + caliper rebuild = the first time i didn't boil my brake fluid at the track

JeremyD · JeremyD's Garage

For sebring - I would go with a full race pad like the porterfield r-4 or hawk blue or PF-97 - they will squeak during city driving though.

Also check out your seals - in my experience - you need a OPTIMAL brake situation for a track like sebing. That means at least Motul 600 - better yet with castrol SRF. Rotors - zimmermans.

If it;s a coupe - you have a chance - if it's a targa or worse yet a cabriolet = a brake upgrade may be in your future.

Bill Verburg · Bill Verburg's Garage

Boxster calipers are absolutly not the solution, they will make things worse as far as overheating the rotors goes.

Use stock rotors, stock calipers, fresh track appropriate pads, fresh DOT 4 fluid, ducat as much air to the front rotors as you can, lighten the car as much as you can

If that doesn't work then 930s are the next step.

Dixie · Dixie's Garage

+1 on Bill Verburg's solution.

Jim Smolka · 08-28-2006, 02:20 PM

On the 3.6 SC, a set of modified Outlaw front calipers, Carrera rotors, 930 MC, and ATE Blue break fluid. Amazing stopping power at CMP especially at turn 1 & 11. No brake fade, rock solid pedal even w/o ducts. Lots of late braking

widgeon13 · 08-28-2006, 02:30 PM

The guy just finished his first DE day and some are already advocating different brake setups on a stock car. I can assure you that if he had a ride with an instructor and in his own car, he would see that he is really not getting all that can be squeezed out of a stock 911. He needs to learn to drive the stock car before he spends money and and time modifying it.

Jim Smolka · 08-28-2006, 02:38 PM

widgeon13,

Of course the best money spent on any 911 is track time. However, having been on the track with just stock brakes and not having 100% confidence in them is troublesome. Yes, one can drive slower and work on the line, technique, smoothness, etc; however, having amazing brakes on the track takes some of the worry out of ones mind and then helps one focus on the driving. Speaking as a PCA instructor, a student's brakes are very important to me.

pmajka · 08-28-2006, 03:00 PM

I agree, wait this is about me .

Seriously, The instructor i rode with was going much faster and using brakes longer and harder than me. So from what i have read here, new pads, rotors and air channeling should help a ton.

No need to upgraded calipers yet.

Bill Verburg · Bill Verburg's Garage

Quote:

Originally posted by Jim Smolka
Carrera rotors

Carera rotors are the problem, changing calipers does not change that. Bigger calipers only raise the rate at which kinetic energy can be converted to thermal energy in the rotor i.e. faster temp rise for a given rotor mass.

The whole game is keeping rotor temps down and handling the temp increase that you have to.

you keep temps down by[list=1][*]cooling[*]increasing the rotor mass to slow the rate of temperature rise[*]decreasing the cars mass to reduce the energy of the system[/list=1]

you handle the heat w/ [list=1][*]pads[*]fluid[/list=1]

2.7RACER · 08-28-2006, 03:39 PM

Lots of great advice here.
Street pads really aren't up to the job of stopping at race track speeds.
If they were adequate, all the after market suppliers would not be in business.
For my money ATE Blue and Pagid pads work well. The Pagids are expensive, over $250 for the fronts. And they aren't the best on the street. Some of the other high performance pads work well with the same problem on the street.
My answer is to run the performance pads on the track then replace them with street pads after the weekend.
Pad replacement is quick and simple. Remove the front tires, knock out the pins, release the clip, retract the pad slightly, pull the pads.
Keep the right and left, inside and outside pad pairs together.
Insert the race pads and put things back together. Shouldn't take over 1/2 hour. Always check the brakes before moving the car.
Replace brake fluid once per year.
Use ATE Blue or Motul, no issues with these premium fluids.
The more aggressive pads will wear you rotors faster than street pads. But they will slow or stop your car and save you a trip to the body shop or worse.
Don't compromise on brakes or tires. This is high speeds we are talking about, not some video game.
Oh, by the way, in ten years at various tracks, I've never had brake trouble or had to bleed my brakes. Stock or the improved system I currently run.