RobsJester
Member
I'm also new to the Roadster family, and I too am interested in Dave's rotors and pads.
If anyone is already speaking to Dave, shoot me a PM.
Thanks,
- Rob
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I'm also new to the Roadster family, and I too am interested in Dave's rotors and pads.
If anyone is already speaking to Dave, shoot me a PM.
Thanks,
- Rob
matt_in_ca
Member
I'd be happy to serve as backup. I'm keen to pull this together sooner rather than later, if possible
Great Matt, its actually I feel to have two people organizing and keeping things going like this. HSharp and Adiggs helped me out big time with the last run. Please send me a PM of your real email address and I'll include you in with the email. I included Jason in the loop with an email to David already. Need to get a dialog going with David and those interested to keep things moving forward. Possibly a new thread with the subject of 'Taking Orders' to catch peoples attention. Also if you go back in this thread you'll see others who were interested in the rotors as well. So you should be able to get your numbers, David needs 20 sets to begin a run.
March 2016 Roadster Rotors Group Buy
Above is the link so we can start this order process. I have started to talk with the supplier and I will confirm the price shortly. We need 15 more people or sets before we can get this order started.
Above is the link so we can start this order process. I have started to talk with the supplier and I will confirm the price shortly. We need 15 more people or sets before we can get this order started.
matt_in_ca
Member
I'm running the Carbotech AX6 pads front/rear on mine. Some people are using the Carbotech Bobcat 1521 pads. If you live in an area where temps are 50F+ degrees the AX6 work great and are considered an autocross style pad and have a higher working temp than the Bobcats. The Bobcats are targeted more for the street and have a lower working temperature. I've used my AX6's when its been 30F out and they still work great. The only issue I do see which I don't know if the Bobcats would be any better is with cold rain and cold temps hitting the rotor, then you have to be aware that you're stopping distance will be significantly less and you'll have limited braking bite due to the colder conditions and cold rain. When you order the rotors David can get a discount from Carbotech, so you'll safe a few dollars there. You have the choice of the AX6 or 1521 pads.
matt_in_ca
Member
Thanks, that info is really helpful!
So we'll have the option to select either the AX6 or the Bobcat 1521, and it will be for both front and rear sets?
So we'll have the option to select either the AX6 or the Bobcat 1521, and it will be for both front and rear sets?
matt_in_ca
Member
What about brake dust? That's my biggest concern, next to stopping power. The pads I have in place now sprinkle my wheels black after even short drives. It's crazy.
I have no issues with dust with the AX6's whatsoever. I'm not the type of person who cleans and washes his car constantly either.... I can go for a month or more without washes and minimal brake dust with the AX6's. If you want even less than that, the Bobcats are to produce less. But as I mentioned there's no issue with dust and the AX6's. Yes the stocks are horrible for dust and I can't say how much I hate those crappy stock rotors.
As for the Hawks vs. Carbotechs its all what you prefer. I went with the Carbotechs since I was in contact with a forum member who autocrossed his Roadster and recommended the the AX6 for a pad that will do a very good job with a great initial bite and ability to stop the car. With that I'm very pleased with the bite the AX6 gives as well as the modulation. With the CRF rotors I didn't have any issue with heat. The Hawk HPS pads are from what I found online to be up to par or equivalent to the AX6s. Only thing about moving to the Hawks is that nobody is running these yet on the Roadsters, so there's no feedback on how well they work with the car.
Also interesting enough, it appears Hawk does not publish the operating temperature of the HPS pads. Yes I know they're for the street, but what's their working and optimal operating temps? If anyone can find this data or even call Hawk to get it, please post.
Carbotech is very open with this data.
For the AX6 the operating temperature range is 50°F to 1150°F +.
For the Bobcats the operating temperature range starts out at ambient and goes up to 900°F.
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Hawk does not publish their operating temps from what I have seen, but I personally have driven Infineon(home track) with Carbotechs "best" back to back with Hawks "best". Hawk was overall better hands down. With the weight of the roadster I would not really use anything else. Also Hawks are about 1/3 more expensive from what I remeber, but you get what you pay for. With the group discount it should soften the blow, more on pricing to come.
For dust are about on par with Carbotechs offer.
For dust are about on par with Carbotechs offer.
Hawks publish their 'track' pad temps but not street pads. Here's the PDF they supply:
http://www.hawkperformance.com/sites/default/files/downloads/Hawk_RoadRace_Bro_2013_REV (1).pdf
And with that the HP Plus which is marketed by Hawk to be a track pad you can drive to the track and home with, this pad has an advertised operating temperature of 100F to 800F. The AX6 has a lower and higher operating temperature (50°F to 1000°F +) than Hawks HP Plus. The HPS is below the HP Plus in terms of how aggressive the pad is. Looking at these numbers I'm not sold on the Hawks. Also the HP Plus is more comparable but not quite equal to the AX6. I'm guessing that higher starting temp of the HP Plus should give the pad a better initial bite, however when things start to really heat up, the CarboTech AX6s will hold up and resist fading longer (That's 200F more degrees of room you have!) Just to be complete, the Carbotech 1521 Bobcat's operating range starts out at ambient and goes up to 800°F, so same upper ceiling temp as Hawks HP Plus pads.
Kinda odd if you ask me since there are people who want to track but use the same pads driving too, without that info they're guessing on how the pads perform and where they'll fail. As for the Carbotech bests vs. the Hawk best, what models? Just saying best isn't quantitative if one pad was not compared with the appropriate pad you trying to compare to.
From what I found online, the Hawk HPS is equivalent and perform just as good as the AX6's. But without any datasheets from Hawk we don't know where the cutoff is for the HPS's.... When do they start working? And when do they start failing as the heat rises? But I'm not sold on that comparison. The AX6's are closer to the HP Plus, however, the HP Plus will exhibit brake fade much earlier on than the AX6's when you start hammering and using the brakes.
Track pads typically need to be heated up before they start to work optimally. The AX6 (autocross pad) has the working temp starting at 50F. Track pads typically start at 100F-250F. The Bobcat is a street pad, that has a working temp of ambient or whatever temp a typical street car is in. My guess is that if Hawk isn't publishing data for the street pads, its working temp I'm guessing then is ambient. With that I'd most likely, guessing since I have no data, that the Hawk HPS is mostly equivalent to the CarboTech Bobcat pad moreso than the AX6. A higher initial working temp of a pad usually translate to better overall braking bite.
Again if someone can find the data on the HPS pads and the working temps, this will allow people to actually see how well the pad will and how it is spec'd to perform. There's the HPS Verson 5.0 as well I found, its not semimetalic as the HPS but they try to say its some space-aged compound. Who knows how that one performs as well.... no data. So its impossible to gauge how well a pad will/can perform if there's no data to crunch numbers to verify how its going to perform when mounted to the car. Without that data its basically throwing it on the car and seeing how it works by feel and eye... And whenever you compare it against another pad, really a quantitative measurement should be used to get real results and data. Such as using the same car, same speed, same driver, same stopping distance and of course same weather conditions. That's a true test.
I've also found the Hawk HPS pads to be way cheaper than any CarboTech Bobcat or AX6 pads I've ever seen. You can buy both the front and back pads together for $181:
Amazon.com: 2005-2005 LOTUS ELISE Hawk HPS Front and Rear Brake Pads: Automotive
HP Plus is in the same ballpark as the HPS.
CarboTech AX6 pads typically run anywhere from $140-$160 for either the front or rear. So $300 roughly for a set:
Carbotech AX6 Brake Pads LOTUS ELISE
Also I'd consider running EBC "RedStuff" or "YellowStuff" pads over Hawks. The RedStuff have an upper working temp ceiling of 1382F and are still streetable. I run GreenStuff (next one below RedStuff) on my truck that I haul lots of heavy weight in, camper, motorcycles, etc, and love them. They have an upper working temp ceiling of 1202F. The EBCs appear to have a higher ceiling for temps than the Hawks, meaning they'll have less fade, for pads that work on the street. Also below this graph is a Car and Driver review of the Hawk HPS, Plus, and EBC brake pads. Car and Driver found that the Hawks were prone to brake fade. I knew and could interpret that from looking at the data sheet.
Car and Driver brake pad comparison:
Performance Brake Pads Compared: Hawk HPS, Hawk HP Plus, EBC Yellowstuff
HPS summary:
The Hawk HPS is a street-performance padmeant as an upgrade or replacement for stock units. These pads are very street-friendly, with minimal noise and a relatively steady pedal feel. We found a measurable improvement in stopping distance for the first few cycles. But as the test wore on, the HPS pads were prone to fade. If long days of pounding around a track are on your agenda, there are better choices.
HP Plus summary:
As the most race-oriented pad in our test, we expected the HP Plus to sacrifice usability on the street. Not so. While these Hawks are a little grabby when cold and prone to the occasional squeal, both of those characteristics are tolerable during daily driving. On the racetrack, the Hawk HP Plus pads remained solid, requiring the least force to perform the 0.5-g stop, and they provided consistent braking distances even when hot.
EBC YellowStuff summary:
Yellowstuff is a street/track pad that can be used for racing on lighter-weight cars. The EBCs’ performance remained steady as temperatures climbed with repeated stops. All three of the aftermarket pads imparted a more solid brake-pedal feel than the stock units on the street, but the EBCs struck the best compromise between pedal stiffness and easy modulation. We heard some squealing, but not enough to make us look around for piglets.
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matt_in_ca
Member
Right, that's precisely my concern. There's a lot of user feedback and experiences printed on the forum about the Carbotech pads, so in purchasing those I'll know what to expect and thus feel comfortable. I'm not sure I want to be among the first group to try out the Hawks, for I'm not sure whether my stopping power and brake dust issues will be solved...
Not sure where HPS pads came from, but those are oem+ pads.
DTC-30 is a much better pad for this car. A full set list price should run you about 350.
Also, I'm not sure what all this talk about track vs street pad is about. The major different between the two is temperature ranges. Considering the brakes on the Roadster are not really properly balanced to begin with it will lead to more dust and more heat in the pads.
Anyway, I'm happy to not order the hawk pads and order whatever the group decides. I have been through more sets of pads then I can remember, on and off track. I will be going with Hawk and I'm happy to let one in the bay area give them a try. The problem is this chassis was never designed for this much weight, and the breaks were carried over for the Elise. The breaks on this car are a joke, and they are not properly sized or balanced. The whole system needs an overhaul in my opinion. A larger master cylinder and a few more pistons would go a long way to really solving this. In the mean time really well-matched break pads will go a long way.
DTC-30 is a much better pad for this car. A full set list price should run you about 350.
Also, I'm not sure what all this talk about track vs street pad is about. The major different between the two is temperature ranges. Considering the brakes on the Roadster are not really properly balanced to begin with it will lead to more dust and more heat in the pads.
Anyway, I'm happy to not order the hawk pads and order whatever the group decides. I have been through more sets of pads then I can remember, on and off track. I will be going with Hawk and I'm happy to let one in the bay area give them a try. The problem is this chassis was never designed for this much weight, and the breaks were carried over for the Elise. The breaks on this car are a joke, and they are not properly sized or balanced. The whole system needs an overhaul in my opinion. A larger master cylinder and a few more pistons would go a long way to really solving this. In the mean time really well-matched break pads will go a long way.
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DTC-30 will not solve any dust problems. If you want a "dust free" break pads then you need to find a ceramic break pad. I have no good experience with them other than building up to much heat and cracking them.
The DC-30 has a starting working temp of 100F, that doesn't work too well on the street. What if you have to panic stop before the pad heats up? What if your driving conditions are in 45F to 50F and the pad can't heat up? It needs to be warmed up to function properly in order to stop optimally.
The HPS was one I looked at that works for the street which people who track and drive street said they were similar to the AX6 (which I disagree with looking at the stats and lack of data / specs). There are race CarboTech pads I'd love to throw on, why? I know they'll bite harder than the AX6. However, I want them to work and like I mentioned when its below 50F and raining the pads *DON'T* heat up properly and I *HAVE* to use caution and understand that this is a limitation of having better braking when things warm up. I can't even imagine if I had to wait for them to try and reach 100F in a raining cold condition. Also as you go up in more aggressive pads they'll squeal and start making ugly noises. Its all part of what comes with those pads due to their composition.
Working temperature for pads is a KEY factor on if and how well they're going to stop and when they'll fail.
If you're going to put them on and try them out that'll be a good data-point. But honestly I wouldn't run them unless its going to be a summertime pad only, track only, or if I live in an area where its constantly 80+ degrees ambient, then it won't take as long to heat up and work properly.
And temperature ranges are VERY important when selecting a brake pad. You can't ignore this data. I have a friend who races all around the world, people call him in to tune their cars and to get them performing handling and brake wise for their cars. I had very in-depth discussions with him about brake pads, brake compositions, brake working temps. This is a KEY entity of braking, pure track/race pads cannot be used on the street. They just don't work and are not safe. I discussed the AX6, the composition, the working temps of this and he said that this one just skates the edge and makes it in to working on the street and light racing since it begins working at 50F and past 1000F. Hence why its called an 'autocross' pad. People like true race / track pads since they have more bite and more modulation than what street pads offer and they can take the heat. However you ARE hammering your brakes constantly on the track. So it is possible and you can reach the 100F to 250F (initial) working temps very easily on these race pads on the track. I will state that you can NOT do that on the street in normal everyday driving conditions. Period. And I'm not talking about a quick sprint and having fun, I'm talking your daily commuting car, driving downtown and a kid's ball rolls in front of your car and you have to panic stop.
And personally if you run a race pad with a high initial working temp, where your pad has trouble for the majority the time reaching this temp, I really do feel you're jeopardizing others on the road since you can't properly stop your car until things do get heated.
Remember what we're trying to do here, trying to improve a poorly designed / inadequate braking aspect of the Roadster. Just putting on custom rotors won't help out if your pad doesn't work in the driving conditions you're putting it in. Unless you're going with a bigger rotor/big brake upgrade, you have to get your pads on the Roadster right or else things can get even worse than what we have with the crappy stock setup.
Before talking with a member about the Carbotech's back when.... I was looking to upgrade the stock brakes with the EBC's. I knew that they have a low and high working temp that work for the street, also I've ran them before. I'm not going to sway people from trying things out, but looking at the Hawk specs I don't see a brake pad they make that works optimally on the street but has a track/race pad characteristic without having a significant trade off in one or more important safety areas.
Lastly, think of working temps of brakes this way... like a set of tires or racing tires. Tires 'stick' best when heated up to an optimal temperature. Too cold and the rubber compound is to rigid so you'll just skate and slide off the road. Too hot and the tires starts to feather and shread prematurely. However, when your tire is working in an optimal range it's able to stick pretty much like glue.
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