Brake Thoughts for 1989 G50 911

[JonasJMac]

Just finished the second consecutive track weekend where I cooked my brand new brakes and rotors on 1989 911. What I mean by cooked is glazed them up and grooved the rotors. I've been told to keep and eye out for 930 brakes. Any one else have any suggestions for brake options for these cars. I'm looking to see what exactly I have on now and before.
Thanks!

[campbellcj]

Hmm. Carrera brakes are already pretty stout. What pads and fluid? Is it a heavily brake-intensive track? Do you have any cooling installed or is that potentially an option for you?

[JonasJMac]

Rotors/brakes #1 were OEM. Rotors #2 were either Brembo/Zimmerman but don't know other details about pads right now. All tracking has been done at VIR on the full course. The brake fluid was the blue racing fluid. Was flushed the week prior to each event. Not sure if cooling is option. I suppose I may just need to take it easy on the brakes at track and work on lines until I can afford a newer track car.

[juanbenae]

im with chris, start with a more track dedicated brake pad that will aid reducing the heat transfer into the caliper. a cooling project can get pretty involved, however the 993 brake scoops can be adapted to the a-arms of our era cars pretty easily. some go as far as welding mounting tabs to the a-arm, others such as myself have used a quality zip-tie to affix them. somebody else may recall a DIY thread for these scoops that they could link you to. they do provide improved cooling, especially if the stone guards backing plates are removed from behind the rotors.

[juanbenae]

http://forums.pelicanparts.com/porsche-911-technical-forum/623752-brake-upgrade-early-cars-steel-trailing-arms.html

here is a thread on the topic. I searched "993 brake scoops"

[michael lang]

JonasJMac, please understand no disrespect intended in any way, shape or form, you shouldn't be having this problem with your car's braking especially on a track like VIR. There are so many places where your car's brakes have long periods of cooling. Carrera brakes are simply just that good on their own. I have thought in the past of doing an upgrade to something like Boxster brakes to get a larger contact patch of pad material on the rotor surface but after really thinking about it decided that my reward to effort wasn't justifying the expense and 930 brakes are really just ridiculously expensive when you break it all down.
I would start by looking in the mirror, you have to ask yourself why is this happening? Evaluate the way you apply the brakes, the way they are released. Look at your braking markers at the track, do they need to be adjusted farther out or closer in? Think about possibly adjusting your braking marker out a little more before turn in to give your car more time to settle and get your to a speed that you're comfortable with as you go through the turn BUT using less pressure on the pedal so you don't scrub off all your speed. One thing that I will do from time to time is jump in an instructor's car that is similar to mine and watch him while he drives so that I can emulate what he is doing so I can develop that habit in my own car. The reason why I will only get in a Carrera like mine is that I'm trying to get to the next level and if I get in a newer much faster car is that the car will be so much faster that I will never give my eyes a chance to adjust properly to the increased speed that whatever excersize I'm learning will be useless and wasted time.
If you feel that you absolutely must spend some money and hang some parts, start with a cooling kit of some type, the 993 kit is very basic and requires minimal effort, I'm not big fan of that one. I have the duct kit installed in my car with the ducting going directly into the rotor backing plate. I have had that on my car for about six or seven years, been fine and doing its job. If that's not enough for you, then I would suggest if you haven't already done so, go with solid discs front & rear. The crossed drilled look nice but as your speed increases they just don't hold up, way too thin and crack like you wouldn't believe. I hope this helps you, best of luck this season. See you at the track.

[JonasJMac]

Mike
I wholeheartedly agree and appreciate the feedback. I felt I was not aggressive at all with the brakes however I did do some braking exercises where I felt I was reaching the threshold at turn 1 where I felt the back becoming very unsettled. also agree with the instructor comment, as the few times I have been out in an instructors 3.2 the braking was much less compressed and smoother as opposed to my most recent experience with a Corvette. Different car, differnt tactics.

[michael lang]

You're welcome, again, no disrespect intended or implied. You didn't really state your experience level or run group but the way you asked about the upgrade makes one think you may be a little new to this. I know I asked atleast one or two of those types of questions when I was brand new to this. Books and video about this sport along with ride alongs will increase your speed more than you can possibly imagine. Anyway, best of luck and have fun.

[juanbenae]

another great exercise if in fact you are learning a new car is look for some 911 youtube laps at the tracks you frequent. something like a cup car may not be relevant, but look around some. somebody here may have just the video you are looking for,,, might even PM you a link if they do not care for forum posting of their video and you ask nicely...

another note, while looking for the link above I saw a post were a guy took mud flap material mimicking the 993 diverters lessening the opportunity to tear them off during an off. I really thought that idea was the berries! sometimes the only substitute for money is a clever imagination and some time...

[wildcat077]

I used the 993 diverters at one point and after grinding down two and losing one off a speed bump i made some backing plates with 3 inch cooling duct flanges and ran 3 inch sceet hoses to the front bumper.

Brake upgrades are a good worry free track day insurance,regardless of the cost,considering one three day track event could cost anywhere between 600 to 800 dollars,if not more !

Just sayin ...

Cheers
Phil

[dhc]

Originally Posted by michael lang

JonasJMac, please understand no disrespect intended in any way, shape or form, you shouldn't be having this problem with your car's braking especially on a track like VIR. There are so many places where your car's brakes have long periods of cooling. Carrera brakes are simply just that good on their own. I have thought in the past of doing an upgrade to something like Boxster brakes to get a larger contact patch of pad material on the rotor surface but after really thinking about it decided that my reward to effort wasn't justifying the expense and 930 brakes are really just ridiculously expensive when you break it all down.
I would start by looking in the mirror, you have to ask yourself why is this happening? Evaluate the way you apply the brakes, the way they are released. Look at your braking markers at the track, do they need to be adjusted farther out or closer in? Think about possibly adjusting your braking marker out a little more before turn in to give your car more time to settle and get your to a speed that you're comfortable with as you go through the turn BUT using less pressure on the pedal so you don't scrub off all your speed. One thing that I will do from time to time is jump in an instructor's car that is similar to mine and watch him while he drives so that I can emulate what he is doing so I can develop that habit in my own car. The reason why I will only get in a Carrera like mine is that I'm trying to get to the next level and if I get in a newer much faster car is that the car will be so much faster that I will never give my eyes a chance to adjust properly to the increased speed that whatever excersize I'm learning will be useless and wasted time.
If you feel that you absolutely must spend some money and hang some parts, start with a cooling kit of some type, the 993 kit is very basic and requires minimal effort, I'm not big fan of that one. I have the duct kit installed in my car with the ducting going directly into the rotor backing plate. I have had that on my car for about six or seven years, been fine and doing its job. If that's not enough for you, then I would suggest if you haven't already done so, go with solid discs front & rear. The crossed drilled look nice but as your speed increases they just don't hold up, way too thin and crack like you wouldn't believe. I hope this helps you, best of luck this season. See you at the track.

+1 Well said. Get an instructor to ride with you and observe your braking technique. You may be using your brakes a bit too long, i.e. applying too early, as you approach turns. Stock Carrera rotors, a nice track pad, and possibly brake ducts is really all you should ever need to DE your car. I have that setup; I have run in the Instructor group for 7 years with that.

[Zack at Pelican Parts]

Jonas, if you're spending a significant amount of time on the track, a set of cooling ducts would go a long way towards preserving the health of your brakes. A little driver mod never hurts, either.

I'm not sure which wheels you might be running, but if you're also considering a brake upgrade, the Boxster calipers are always a nice OEM+ direction to go in. I've seen them mounted on many vehicles due to their popularity and durability.

Let me know if you have any questions, and of course, you can find our entire catalog of brake enhancements for your Targa right here.

[KTL]

The Carrera brakes are good but even in capable hands at a track hard on brakes they get VERY hot. The pads are small, which don't do much in terms of isolating heat from the calipers. The calipers are iron and absorb & retain the brake heat quite well. The rotors are rather thin and they are straight-vaned which is a rather basic vane structure not too good at "pumping" air thru the rotor to cool itself. The seals are not very heat tolerant. The dust seals are not a big concern but they do turn to dust (literally) which is a sign the brakes get very hot. If subjected to the intense heat long enough, the pressure seals will leak when they cool down. I've seen and heard many instances of guys who track their cars and after having done a number of track days, when they come out to the garage they find a pool of brake fluid on the floor from the front caliper(s) leaking. That's dangerous.......

So all of that points to the brakes needing to be cooler in some way. Getting cooling air to the brakes addresses the problem at the source. The 993 scoops work great and the ducts feeding air to the center of the rotors are even better.

Next in line (very close in line) is using dedicated real deal race pads. OEM pads are fantastic pads but they can't handle the abuse of track duty very long. They will indeed overheat and mess up your rotors. Using "combo" street/track pads is false economy IMO. The best way to approach it is to have inexpensive OEM pads for street use and install the pure race pads for track duty right before you go to the track. A good pad we use that replaced the dearly departed tried and true Performance Friction PF97 compound is the Raybestos ST43 endurance pad. Excellent peforming all around pad, hot or cold.

OE Zimmerman, Sebro or Ate rotors are great rotors that can withstand the incredible abuse they're subjected to. But they still need to be kept cooler to prolong their life. Fancy drilled rotors are a waste. Slotted rotors are sharp looking but unnecessary. Stick with the stock German stuff and you'll be fine.

Agreed with everyone that said driver learning is a key factor in the problem. Learning the old 911 on the track is hard enough and braking properly is a big part of getting the old 911 around the track effectively. Driving with someone that does it well is a key eye-opening experience to see how you should approach it.

General description of the approach to taking a corner in the 911 is, with the caveat that this is a general procedure and your corners and methods may vary dependent on type of corner, talent level, track conditions, blah blah blah etc. etc. legal disclaimer. Be smooth, be committed and brake in a straight line. Transition from throttle to brake quickly and smoothly, set the nose with some initial brake pressure and once vehicle weight has transferred forward to "set the nose" it's time to lay on the brakes HARD to maximize available grip & deceleration. Smoothly release brakes as you're nearing your turn-in point, get back to the gas smoothly for turn in and commit to the gas A LOT as you're turning-in to transfer weight rearward which stabilizes the rear of the car while you traverse the corner.

[cashman]

Agree with the above comments. There is something a miss if you are having brake issues at VIR. Either equipment related or driving style. Vir is rather forgiving on brakes compared to some of the other tracks in the NC area. My car is a stock 3,000 LB Cab. I run standard Carrera calipers. Standard Zimmerman Rotors. Motul 600 (ate should be fine for VIR), and track pads (PFC97, PFC08, Now PFC11) Apex performance can get you these. I will try Poterfield R4 as my next pad. I run 9.5/10ths, brake hard when required, and have no issues. I'll actually use my pads with less meat on them at VIR because I know they will last. I have removed the rotor stone protector plates, have the hub block off plates and do occasionally run with the 993 diverters but none of these should be required for VIR. My guess is you need better pads.
Good luck resolving the issue.

[moneymanager]

+1 for the Raybestos st-43's. A superb track pad. In my warm clime they even work well on the street.

[Astroman]

The PCA E class track record at VIR in an '80s 911 with completely STOCK brakes is 2:10. And those guys can run 11s and 12s all day long during a 90 minute race.

Good cooling, good pads, good fluid, and stock rotors... They work well enough to go very fast.

[OffCamber00]

Originally Posted by moneymanager

+1 for the Raybestos st-43's. A superb track pad. In my warm clime they even work well on the street.

+2 However, too noisy for street use here in CLT.

[RichardNew]

I would spend my money on a really good coach. That will do more for you than parts. I suspect you'll have the very same problems not matter what parts you install.

Patrick Long spends a lot of time with his coach. Something to think about.

Richard Newton
Car Tech Stuff

[$ Short]

I'm using 996/boxster s calipers. Adapters were from Rebel S Racing. Porterfield R4S brake pads.

[Antonov]

My new to me G50 Carrera has 951 Calipers on stock carrera rotors. At buttonwillow recently experienced some fade towards the end of the day, brakes got really hot, pedal got mushy (Ate Blue Porterfield RS4, no ducting)

I'm looking to go to a thicker (32mm) 2 piece rotor. Naturally VCI 930 kit is quite appealing, but I'm wondering if there are other caliper options that accommodate the readily available 930 2 piece 32mm rotors without the cost of 930 calipers ($4500+).

I like 930 rotors vs Big Reds because I'd like to be able to run 15's or 16's.

Thanks in advance.