Better brakes that break-even - OR - Brakes that break the bank?

[bxd]

I have started several threads over the past few months attempting to get input or advice on the things I feel should be upgraded or replaced in my car. These things are generally functional improvements, not visual, with the caveat that some things are, well, both. Tires, for example, are one of those things that exist in both camps; most of us prefer high-performance tires, but we also want them to look era-correct, AND be easy on the wallet. We've spent a lot of time discussing the merits of different tire manufacturers, models, sizes, brands, compounds, applications, etc., and everyone seems to have their own opinion on where that "sweet-spot" is. Some of you have no problem spending $2,000 on a set of tires that last 5k miles, others want the least expensive tires they can find, and most of us are probably somewhere in the middle... I guess most things we do or don’t do to our cars could be debated in the same way. Brakes are another one of these topics…



My reasons for upgrading some of the functional elements on my car stem primarily from my experiences driving at speed; on the track, doing vintage rallies, or participating in other events where the car is being asked to perform at a relatively high level. I found that my car is wonderful to drive in anger, fantastic in fact… it handles like a housefly, is totally stable at high speed and inspires loads of confidence. This wonderful-ness is not without a few exceptions however, brakes being one of the top, if not THE top concern. My brakes overheat and totally fade after 4-5 hard laps and take a while to come back down in temp. I think I understand why, and what to do to fix the problem, but I’d like to hear what some of you guys have done to address this issue. But before you chime-in, let me expound a bit.

Under normal driving conditions, my car stops very well… it’s got SC front calipers, and vented rotors all around, and they do the job nicely… so I don’t think I need larger calipers – I just need to keep what I have cooler. I understand most of why they overheat, but I want to work through each part of the system to thoughtfully upgrade where needed. To that end, I just got a cooling duct kit for the fronts (thanks, Marco) and that should help a lot. I am also replacing the stock rubber lines with stainless lines and will be doing a full system flush with high-temp fluid. That will also help, but I know there’s more to it than that. I’m not in a position to replace the calipers, and don’t want to run giant 930 brakes, so I’m looking to upgrade or replace the next most important items; rotors, pads and brake fluid.



Yes, I’m wrestling with what to do with rotors and pads… and like the tire thing, this a worthy area for stupid questions to be hucked over the fence, and expert opinions to be howitzered back. I’ve read a ton about cryogenic crystal alignment, slots vs. no slots, aluminum carriers for lower unsprung weight, rotor mass for heat dissipation, this pad compound vs. that compound, but a lot of what is said varies wildly. Some say cryo-treated rotors are the best, others say they don’t have any noticeable benefit over non-cryo rotors. Low unsprung weight is a key element for quick rotational direction change, but having rotors with more mass helps them dissipate heat better, like a great big heat-sink… Tons of directions to go on this one, but I’m seeking that sweet-spot where I stick with solutions that look mostly correct, and offer noticeable improvement over what I have now, but that aren’t overly high in price.

I’d like to hear from you guys about what rotors, pads and fluid you use, and why. Your opinions on what the factory used, and why, are also something I’d love to hear more about. Functionality, price, looks, availability, authenticity; these are all factors I’m interested in.

[merbesfield]

I'm interested as well.

[Paragon]

Are you getting pad fade (firm pedal but the car doesn't want to stop) or fluid fade (soft pedal)? What pads and fluid were you using when this happened?

[bxd]

Hi Jason,

A bit of both... but if I had to say one was more obvious than the other I'd say pad fade more than fluid overheating. The pads are stock OEM SC and the fluid is whatever my shop put in there last year... probably Dot4.

[91133]

My observation is that you want the best from your braking system 'as is' rather than upgrading it per se. Everything (pads, fluid and rotors) you mention is a consumable element of the braking package.

My recommendations and YMMV etc, is to go for high dry boiling point fluids like Castrol SRF or Brembo LCF600. Elf HTX115 is also good value for money in this area. The first 2 are around 312 degrees C I believe. This is well above Dot5.1 standard...goodbye fluid fade.

As far as pads are concerned, the latest tech is for a very high co-efficient of friction at all temp ranges (This is why DS11's were no good on the street as they only worked over 500 degrees C). For pads in the 0.6 to 0.7 mu range, look at Ferodo DS3000 and Mintex M1177 - they work well on the street as well. Needless to say, rotor wear goes up.

As far as rotors go, you could gas slot your rotors but there's a swept area price with that and if you have not been experiencing glazing, it's probably not worth it. Stock OEM rotors should be fine within your parameters but do make sure they have plenty of meat as the thinner the rotor gets, the less ability it has to dissipate heat.

My .02 and very much a thumbnail. Other swill have varying views I am sure.

Cheers,
Mark

[Paragon]

A couple things here. As you mentioned, the brake cooling will help quite a bit...even with what you have now. 911 rotors are relatively cheap with Zimmerman, Sebro and even very inexpensive Chinese units being available. Some competition pads like a slotted or drilled rotors...we sell Pagid and that's what they recommend. Drilled rotors will crack, it's not if, it's when. Slotted rotors do much of the same thing as drilled without the cracking issue. High temp fluid like ATE TYP200 works great and it's very affordable. Most of the race pads will be on the high end $ wise. We often joke that we need a pad that will stop like crazy, be rotor friendly, make no noise or dust and cost very little. That's tough to find. We sell a decent amount of the Pagid RS44, RS14 and RS29 for the 911 application. There are some very affordable ceramic based pads in the marketplace now, that while not a race pad, they will handle higher heat situations like you're encountering.

I think that if you're rotors are in decent shape, I'd just get a better pad to go along with the high temp fluid and brake cooling you're installing.

[bxd]

This is all excellent input!

If I were to replace the rotors, is there one or two that stand above the rest in performance vs. cost? I mean, as with all things, I could just go buy the most expensive rotors I could find, but that isn't in keeping with the sweet-spot concept.

[91133]

This is all excellent input!

If I were to replace the rotors, is there one or two that stand above the rest in performance vs. cost? I mean, as with all things, I could just go buy the most expensive rotors I could find, but that isn't in keeping with the sweet-spot concept.

Not to my knowledge. '69 was the first year of the vented rotor I think so you've pretty much already got the only 'tech' improvement your current system can make the most of. On reflections, my comment regarding the M1177 compound may be off in that they might be a bit hardcore if you are getting groceries and the M1166 compound might be better for you.

I also assume from Jason's comments that the Pagid's are more competitively priced in the US - they are a LOT more expensive here.

Mark

[CamBiscuit]

Hi Jordan

In my old 2.3 ST replica I did a bit of tarmac rally and historic racing as well as general street and fun stuff. You don't need to go crazy! I had very good success with Hawk Blue pads, racing brake fluid and I had the non 'S' front bumper with the spot light holes open and no other ducting. Stock cast Iron M callipers on rear and alloy S callipers up front with stock ventilated rotors due to our historic racing regs.

No overheating issues ever, even on tracks that were known to be hard on brakes. Car weighed about 960kgs / 2110 pounds.

Good luck

[bxd]

Thanks, Mark. I do appreciate your clarification, and yes the car has to be drivable on the street too.

My hope for this thread wasn't to specifically speak about my needs, but rather to hear about what others have done to their own cars to fix this same type of issue... I can't be the only one fighting this problem.

I'm not wholly against upgrading my calipers, if that's what should be done to get the most out of the car... my point was that I prefer not to jam a big brake kit onto a setup that wasn't designed to handle it. I'm all for using modern fluids and pads, but I would like to solve the problem in a way that may have been done by privateer racers back in the day, prior to things like 930 brake kits being mass produced. For example, would S calipers work far better than my SC units? Is there an alloy version of the SC that might work better? Are the OEM rotors better than Zimmerman? Is there a recommended rotor that looks stock but has an aluminum carrier? That type of thing.

I warned you there might be some silly questions being chucked around