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03-12-2019, 12:36 PM | #751 | |
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Quote:
In fact, this is precisely the logic behind today's "brake assist" nannies - the system applies the brakes more rapidly than an unsure driver will ever do, shortening the stopping distance by getting you up to max deceleration sooner. But aside from brake assist not being under the driver's control, it really isn't any different from installing pads with stronger 'bite', that develop a similarly high amount of braking from less pedal pressure and generally less pedal stroke. Whether it's artificially increasing the rate of hydraulic system pressurization or increasing the 'mu' of the pads/rotors, they're just different ways of getting brake torque up to where you need it sooner than with standard mu pads and average-driver rates of pedal application. There is one caution . . . once you've driven a car equipped with pads that have noticeably stronger bite than OE or mass-market OE replacement (especially mass-market bargain ceramics), you may never want to go back. The necessary pedal modulation is something that most people should be capable of learning. Norm
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Last edited by Norm Peterson; 03-12-2019 at 12:44 PM. |
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04-15-2019, 01:51 PM | #752 |
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This is a very helpful post and I can see your point. I ended up upgrading my stock cast iron brakes to a Wilwood kit mainly because I was having a terrible time with my OEM brakes leaking, uneven wear, and eventually both rear calipers seized up. I had bought the car used with only a few thousand miles on it, but you could tell the car sat idle a lot. I made the upgrade because the timing was right and I got a great deal. I did noticed a huge difference and I'm glad I upgraded, but you make a good point.
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04-28-2019, 10:01 PM | #753 |
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Davenow,
Great thread. Thanks. Tried to explain all this to my 16 yo son a while back, but it seemed to really sink in after he read your post and some of the replies! He just saved himself (and me) a bunch of cash. I did let him paint his calipers and get a set of shiny cross drilled rotors though Now everybodys happy Peace. |
04-29-2019, 08:16 AM | #754 | |
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Quote:
Pads with stronger initial bite will get you stopped a tiny bit shorter because the amount of braking force at the contact patches ramps up faster. It may only be a small thing, but it's there. Norm |
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05-18-2019, 07:57 PM | #755 |
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Just swapped a 255 into an 02 RS. Would my stock brakes be enough to stop with this extra power I'm getting?
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05-20-2019, 08:38 AM | #756 |
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05-20-2019, 09:15 AM | #757 | |
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Quote:
The question isn't the extra power.....it's how fast are you going where you have to slow down. A 165 hp car going 120 mph needs the same braking power as a 5000 hp car going 120 mph. |
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04-22-2020, 02:07 PM | #758 |
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I have been saying this for YEARS!! It's basic physics....yet I always hear "oh dude, you're running XXX hp and stock brakes. that's dumb"
after a while you get tired of explaining it to people. HOWEVER, I will say, in my own personal testing, as far as pedal feel and reducing stopping distance, some upgrades do make sense, but not for the reasons people think they should for...i.e. more HP. I drive a an Audi A3 Quattro. That is a HEAVY car. It's been a few years so I can't actually remember the numbers, but we did real-world testing of stopping distance. By simply swapping out pads to a better compound over stock, and going to slotted rotors....we were able to actually measure a noticeable difference in stopping distance. This is of course, taking into consideration tire friction coefficients, road temp, ambient temp, etc. In summary, with the stock brakes, in a 60-0 stop, I was just barely able to break traction and have the ABS kick in. With upgraded pads and rotors, and all other variables being as equal as possible, I was able to get the tires to break traction sooner, and allow the ABS to do its job sooner, effectively shortening the stopping distance. GRANTED, I recall it was only a few feet, nothing to write home about, but still, a difference. And another benefit, was overall less heat saturation at the rotors after a panic stop, which plays a role in stop and go spirited driving . after a few red-light launches and grabs, you would notice a difference as a side note....people also need to "stop" calling them "breaks". It's BRAKES...although the argument can be made that you are taking a break from travelling hahaha |
04-22-2020, 06:11 PM | #759 |
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At least theoretically, and most likely for practical purposes with a skilled driver, you want to stay just below where the ABS gets involved. A released brake does reduce total stopping power and will result in longer stopping distances.
The advantages of ABS are not what most people think they are. I hear you on "breaks". Like "thread depth" for tires. Norm |
05-23-2020, 01:22 PM | #760 |
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Useful info
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05-23-2020, 02:18 PM | #761 |
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I believe the basic premise of this thread is, can you currently lock the brakes/invoke the ABS?
If yes, better brakes gain little until you increase tire grip. This is the part that is not correct and why I have hated this thread for the last 15 years. When the tire is locked it is sliding - i.e. very little traction - and the brakes are not moving - so they are not doing anywork. The power drain is the LOWEST When the tire is rolling at it's max grip/slip angle it has much more traction - so the power requirement to do this is HIGHEST. And the brake's are moving and creating heat rapidly Yes the tire controls the absolute limit - until the brake cannot hold the tire at it's limit with any precision. ABS is not it either - you are still sliding the tire - just less. This is static versus dynamic friction - that is all This will be my yearly NASIOC post |
08-04-2020, 11:03 AM | #762 |
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well said
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08-17-2020, 10:04 AM | #763 |
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awesome
Thanks!
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08-17-2020, 11:13 AM | #764 |
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Actual threshold braking involves a small amount of slip. I think this is somewhere in the 5% - 10% range. Basically it's a lot like slip angles when cornering; tire distortion and a certain amount of sliding between some or all of each tire contact patch is involved. Your tire is neither fully rolling nor is it fully sliding, what it's doing is somewhere in between (but closer to rolling).
Norm |
05-25-2021, 06:35 PM | #765 |
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Non Brembo OK
Unless you track your car, no need for upgrades. I've never ran out of braking pwr with stock, then again, don't drive like I stole it.
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05-25-2021, 07:39 PM | #766 |
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You and KNS are both right, just different applications. Even a stock GC8 2.5RS has marginal brakes for the track. Upgrading to the 4 pot fronts and H6 rear caliper bracket are enough to make it work well ON THE TRACK. For the street, stock is fine.
2.0L early WRXs are underbraked for the track stock. The 06/07 4/2 pots are better, but still not quite enough ON THE TRACK. For the street, stock is fine. When you're on the track, you're threshold braking a lot. This creates a lot of heat and with too much heat either the pads fade or the fluid boils (or both). There's lots of solutions, but when you're out there and fade comes, you need to address it with different techniques. I've done "NASCAR" braking with my cars when in showroom stock class (no caliper or rotor size changes allowed). This is braking earlier and lighter than full bore "going for lap time" late, hard braking. The added time allows the heat to be dissipated over a longer period and the lighter braking creates less heat. Over the entire corner, you're really creating the same amount of heat, but here, the temperature of the brakes is cooler when you let off them. Would bigger brakes help that situation? Well, sure. But if you buy new cars with a rulebook under your arm, that may not be acceptable. I know it wasn't for me. |
07-19-2021, 07:45 AM | #767 |
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Bravo thanks for info
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07-22-2021, 03:12 PM | #768 |
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Would you say that upgrading brakes is completely pointless, or is it more of a time and place kind of thing? You listed all the reasons that you shouldn't upgrade your brakes, but what about the benefits? Sure, if you're just daily driving, stock brakes are fine, but if stock brakes work "just as good" as 8 pot Brembos, why is Brembo still around?
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07-22-2021, 03:22 PM | #769 | |
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Quote:
Norm |
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08-06-2021, 09:30 PM | #770 |
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Great reading through this post lol
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02-14-2022, 01:54 PM | #771 |
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Oh wow, too many variables to make statements in OP and throughout the responses. Making a blanket statement like OP does, makes me shiver to start, then some of the responses... eeek.
Any spirited driving up in mountains, or on back roads will add heat to the entire system. I've personally experienced better braking (less fade) with just a quick swap of rims; air/ventilation allowing brakes to breath; same tires etc. Point being... every little bit helps. For those that Auto-X, which I would imagine would be a greater portion of "enthusiasts" brakes are genuinely an issue. I think OP... posted in the wrong forum, post that on a general automotive forum and yes I'd agree. But I believe most people on here are enthusiasts with more discerning tastes. Ya missed the mark my man... |
04-29-2023, 06:06 PM | #772 |
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Was considering upgrading my brakes... thanks!
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