Quote:
Originally Posted by M3SQRD
1. All based on feel and extensive experience with the 1521 pad on many different cars with different power/torque and different weight + actual comparisons between different performance street pads and race pads on different cars + over 30 years of track experience. I’ve had quite a few professional race car drivers, including James Clay, in the passenger’s seat commenting on how good my braking abilities are. You don’t need to see a pad’s friction curve to understand how it performs with temperature. It’s something you actually perceive while actually braking. I’ve never seen a friction curve for a single stock pad from any manufacturer ever yet we’ve all identified their limitations and characteristics both good and bad. Linear vs. progressive vs. digressive braking/torque are things you discern while decelerating with brakes applied. Pad release and modulation are additional characteristics you can feel when applying the brakes. Max operating temperature is another one that you can identify qualitatively without having seen a friction curve in advance. To quantify things, there’s a road I use to test/compare brake pad parameters. It has a 1,900 ft drop in elevation over a 2/3 mile distance with several fast and slow corners. I’ve faded every stock pad on every different car on this section of road. I haven’t come close to fading the 1521 pad used on the same eight cars. In addition, the DS2500 did not fade but both Hawk pads did fade. Finally, the R4-S did not fade. 1521 pedal characteristics were constant from the first corner at the top to the last corner at the bottom as well as all corners in between. Always had a high level of confidence based on pedal consistency. DS2500 performed similarly but had a nonlinear feel, strangely it had both progressive and digressive torque/bite. R4-S felt linear, consistent and confidence inspiring. 1521 performance wasn’t affected by weight. Forgot to mention the PFC z-rated pad earlier. It’s very similar to the DS2500 except it had a linear feel/torque.
2. A COF of 0.45 at 75 C to a COF of 0.2 at 750 C has a % diff of (0.20-0.45)/0.45*100 = -55.6%. I used 0.25 as the reference in my original calculation which is incorrect. So the % change of P2’s mu from max to min COFs is -55.6%
3. How do you know the class the 1521 is in if you have absolutely no actual experience with the pad? I would never use the DS2500, or the 1521, on the track. You think the P3 will perform similarly to the DS2500 even though the DS2500 min COF is 0.35 vs. 0.25 for the P3. The P3, just like the P3, starts to lose friction with temperature at 75 C - both have very digressive pad performance with increasing temperature. What exactly does “light track capable pad” even mean? The elusive dual-use pad doesn’t exist. I have used the same DS2500 pad shape in two AP Racing brake kits and I would not use this compound on a track.
Race pads from most manufacturers do not come with friction curves yet somehow people make it work. Yes, people may like specific things from a pad and if they are able to identify what they like then they can qualitatively and quantitatively compare pads from different manufacturers and/or different compounds. Friction curves for stock pads don’t exist so, based on your data approach, how is it possible to identify a pad that is better or worse than the stock pad? How do you even define the performance of the stock pad?
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Obviously a dual duty pad doesn't exist, but a dual duty pad for the street and auto x does. Jeff ritter was the one that described the ds2500's as an almost unfadeable pad capable of light track duty. He talks about it here:
https://www.essexparts.com/news-blog...te-grand-sport
We're able to identify the stock pads have a high temperature poor performance because the delta between it and an aftermarket pad is so much greater that it becomes noticeable. But when comparing between two aftermarket pads designed for higher performance the delta is more often than not smaller - especially pads competing in the same segment. So to avoid confounding variables like different weather conditions, different tires, different cars and obviously the driver (bias, braking style, etc) having data helps firmly quantify the results. I'm not saying it's impossible to do it just on feeling alone, but you need alot of feedback to ensure the replicate count is high enough to negate any confounding variables, and I don't necessarily know if anyone has tried as many pads as you have on this platform.
I've seen people say they faded the ds2500's on the street and others say they're unflatable on the streets. So does the guy saying the ds2500's fade also say these pads suck because they can't handle his useage on the street? Or is it his driving style? That's an example of the driver making the difference, and where data could help shed the light on the true capabilities of the pad.
Obviously if you're as accredited on the track as you say you are your opinions matter - but when talking about something as subjective as how things feel without a high replicate count to back it up, then we will need data. But at the end of the day the p2's are here to be a better option than the akebonos and be capable of hard spirited driving all for an affordable price. Most people on the street don't even fade the stock pads and only just start to have issues with the akebonos when pushed hard. So it's unlikely many people will want or need to spend the extra $200 on the 1521's for the added performance that they will never use. Remember the goal here is low brake dust and a tad bit more capability on the temp range, we're not talking about trying to get the street greatest pad ever here.
And also at the end of the day it's going to be up to the buyer whether they feel that extra $200 is worth it or not. My only goal here is to try and make more choices available which is always a good thing.
Edit- Btw I just realized this but you guys in the states are really lucky. Paragon offers free USA shipping on orders over $100. So that's going to be really nice for you guys vs. paying that nutty shipping from Europe.