ABS and aftermarket brakes
10-07-2004, 11:34 PM
#32
Originally Posted by RACER,Oct 8 2004, 12:32 AM
Less volume=more pressure, more volume=less pressure. If you took a hose 1/2" in diameter and connected a 1 1/2" hose to it, you would have more volume, but less pressure. If you did the opposite, reduced a hose 1 1/2 " in diameter and reduced it to 1/2", you would have less flow but more pressure. It is a quite simple concept that I learned on a Toyota Atlantic Race team. I also have had the privilege of talking with the legendary Carol Smith on two occasions and I have also spoken with Derrick Dong (Technical director of Performance Friction) Performance Friction supplys pads for many teams in NASCAR as well as numerous CART teams. The drivers that like more feel in the brake pedal go with smaller caliper pistons and or smaller brake lines. The drivers that like a little bit less feel in the brake pedal go with a larger caliper piston and or larger diameter brake lines.
I don't know where the hell your coming from, but CART racing is serious shit. Carol smith has been an engineer for over forty years and was involved in Fords domination of the 24 hours of Le Mans in the late 60's. Derrick Dong is a well known, respected individual in motorsports when it comes to brakes.
The garden hose theory was just an example that Derrick spoke of. I suppose that Derrick is wrong and you are right Einstein.
These forums are open for discussion. They can be educational, entertaining and fun. If somebody writes something that you do not understand, thats quite alright. Just don't go shooting off your mouth and belittling people.
I don't know where the hell your coming from, but CART racing is serious shit. Carol smith has been an engineer for over forty years and was involved in Fords domination of the 24 hours of Le Mans in the late 60's. Derrick Dong is a well known, respected individual in motorsports when it comes to brakes.
The garden hose theory was just an example that Derrick spoke of. I suppose that Derrick is wrong and you are right Einstein.
These forums are open for discussion. They can be educational, entertaining and fun. If somebody writes something that you do not understand, thats quite alright. Just don't go shooting off your mouth and belittling people.
10-08-2004, 12:26 AM
#33
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The piston on the right is nine times larger than the piston on the left. This means that any force applied to the left-hand piston will come out nine times greater on the right-hand piston. So, if you apply a 100-pound downward force to the left piston, a 900-pound upward force will appear on the right. The only catch is that you will have to depress the left piston 9 inches (22.86 cm) to raise the right piston 1 inch (2.54 cm).
This proves my point. The piston on the right has 9 times the force as the piston on the left. As the article states "The only catch is that you will have to depress the left piston 9 inches (22.86 cm) to raise the right piston 1 inch (2.54 cm). " More volume as well as more force, but the piston on the left has to be depressed 9 inches. If you only depressed the left piston 4-5 inches, you may still have more volume, but you would have less pressure.
If the piston on the right was, lets say 4.5 inches, you wouldn't have to depress the left piston 9 inches to make the right piston travel one inch. You may have less volume, but you will have more pressure, hence more feel in the brake pedal.
So this is bullshit???
When did I drop a name on you? I was just trying to have an intellectual conversation and you start going all ballistic on me. You need to calm the F down dude.
This proves my point. The piston on the right has 9 times the force as the piston on the left. As the article states "The only catch is that you will have to depress the left piston 9 inches (22.86 cm) to raise the right piston 1 inch (2.54 cm). " More volume as well as more force, but the piston on the left has to be depressed 9 inches. If you only depressed the left piston 4-5 inches, you may still have more volume, but you would have less pressure.
If the piston on the right was, lets say 4.5 inches, you wouldn't have to depress the left piston 9 inches to make the right piston travel one inch. You may have less volume, but you will have more pressure, hence more feel in the brake pedal.
Originally Posted by Racer
The drivers that like more feel in the brake pedal go with smaller caliper pistons and or smaller brake lines. The drivers that like a little bit less feel in the brake pedal go with a larger caliper piston and or larger diameter brake lines.
When did I drop a name on you? I was just trying to have an intellectual conversation and you start going all ballistic on me. You need to calm the F down dude.
10-08-2004, 03:37 AM
#34
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>>>Data - my speedo for velocity, roller tape measure for distances, cones and chalk line for markers, $1.99 calculator for the simple math. What more do you need to measure braking distances?<<<
This is not an accurate method. It's easy to tell where the car actually stopped, but the time/place it started is much more difficult a problem. Since you are goind at least 88 feet per second. It's much more accurate to use an accelerometer device. With one of mine I just get above the target start-braking speed and then stop. Very accurate under a foot of error.
This is not an accurate method. It's easy to tell where the car actually stopped, but the time/place it started is much more difficult a problem. Since you are goind at least 88 feet per second. It's much more accurate to use an accelerometer device. With one of mine I just get above the target start-braking speed and then stop. Very accurate under a foot of error.
10-08-2004, 03:41 AM
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>>>If you read my posts completely, the 35% decrease was a comparison for the near 120MPH runs I did. I even admitted the tests could not be completely validated (120MPH tests) because I could only run the stock brakes once due to the poor results and excessive heat produced. Therefore it's hard to record an actual scientific baseline based on one run. But the reduction in distance was substantial.<<<
So at 120 MPH you are moving at 176 feet every second and you are hand measuring stops from this speed to the foot? Wow! No one else can do it.
Stan
So at 120 MPH you are moving at 176 feet every second and you are hand measuring stops from this speed to the foot? Wow! No one else can do it.
Stan
10-08-2004, 05:33 AM
#36
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Wow, I've never started a thread that got to two pages! Anyways, the original question I posted here is, Is it stupid for me to take out my ABS fuse?? Is it possible for me to stop better than the cars computer?? Thanks for everyones help so far, but I think this mught redirect y'all to my original inquiry. Although, the arguing and stuff is quite entertaining.
Jonathan
Jonathan
10-08-2004, 12:47 PM
#37
Originally Posted by E30M3,Oct 8 2004, 05:37 AM
This is not an accurate method. It's easy to tell where the car actually stopped, but the time/place it started is much more difficult a problem. Since you are goind at least 88 feet per second. It's much more accurate to use an accelerometer device. With one of mine I just get above the target start-braking speed and then stop. Very accurate under a foot of error.
On both the 120-0 (116&118 actual) and the 60-0 tests, the initial brake application left small skid marks from the delay of ABS cycling. The ABS cycled for a second and then brake modulation (much more precise with the Pinnacle calipers) kept the car nibbling in and out of ABS. I used the initial skid mark to adjust the distance relative to the stop line. The marks on the 60-0 tests ranged from 9 inches for the closest set and no more than 16 inches between the furthest. The variation was greater for the two runs previously mentioned on the high speed tests, but the baseline was adjusted and the Pinnacle brakes were very consistent.
While there's no way to determine the exact error in the test (as in +- a certain % or feet), the skidmarks and brake reaction was consistent and those numbers are pretty close to the mark.
The message still seems to get lost here ... The Pinnacle brake system is much better than stock, and the Willwood system for that matter. Sure it cost more, but that's the price you pay for true racing calipers and rotors.
The near 120 mph stop tests were not scientific due to the fact the stock brakes could not give me a good baseline (I get tired of repeating that - read before you post folks)... they barely tolerated one max effort stop from that speed. The Pinnacle system not only tolerated the stops (2 minutes between runs) they were very consistent ... and the rotors cooled very quickly. Was it 35% shorter than stock from ~120mph? You're damn right it was, and if I did a second run from ~120mph with the stock brakes ... it would have been much more than that - because the stock brakes would have failed due to energy saturation. What does that tell you - well if folks stop trying to spin the results I think it's obvious - the Pinnacle brakes are several levels above the stock brakes.
It's hard to really compare the Pinnacle to many of the other brakes out there on anything but the merrit of their performance. I would be happy to repeat the tests and feel free to line up any S2000 with stock brakes and the tire setup of their choice to compare. For that matter, bring out a Willwood clad S2000 and compare. There are a few folks that'll be at Fall Colors that have the Pinnacle system and ask them what they think of their brakes - ask to go for a ride and see for yourself. I'd be there, but work has me for the next three months. If you just don't want to believe, that's fine too - I really don't care.
10-08-2004, 01:08 PM
#39
Originally Posted by RACER,Oct 8 2004, 02:26 AM
Originally Posted by Racer
The drivers that like more feel in the brake pedal go with smaller caliper pistons and or smaller brake lines. The drivers that like a little bit less feel in the brake pedal go with a larger caliper piston and or larger diameter brake lines.
When did I drop a name on you? I was just trying to have an intellectual conversation and you start going all ballistic on me. You need to calm the F down dude.
My original argument came from the point that the Willwoods (4 puck) have less piston area than stock and therefore have less CLAMPING force - this is a fact. Whether or not they give you better feel is debatable - it depends on who you ask because how it feels to one person may not be how it feels to another.
On the Willwood debate, you argued that smaller pistons do not mean less clamping force (WRONG) and just gave better feel. Then you went on babbling about a garden hose or something.
FACT: You will have LESS clamping force with smaller pistons. If you didn't get that when it was spelled out on the "how things work" website link I gave you ... then you're an idiot.
Considering all other factors being held constant - i.e. your master cylinder and the total number of brakes in the system (duh) - a larger piston will create greater clamping force - period. You'll have to move your foot farther, but the end result is greater force.
Some people argue that having greater pedal travel gives you more control, and I can tell you my brakes with significantly larger piston area give a sense of control you can't get with stock or with Willwoods. The forged calipers in the Pinnacle system also are several times more rigid than stock or the Willwoods and this allows for a precision in feel and control you can't substitute. I can sense the onset of ABS and modulate the brakes so precisely that I can keep the brakes at the threshold of ABS, without ABS cycling - and this makes for much shorter stopping distances. You talk about feel when you have no idea what you're talking about until you drive a car with these brakes.
Stop trying to justify your position - the science is in my corner.