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BeastMode13's Dual Purpose P3D Build Journey
- Thread starter beastmode13
- Start date
I have to share couple shots of a part. The attention to detail is amazing, especially on a none visible part. Colin Chapman would approve of with this part.
MarcG
Active Member
That guy was a genius! So many inventions that radically changed race cars into what they basically are today.
Do you remember approximately, what was your required working range?
I don't want to buy a full-size standing 12T press - 6T should be enough, I suppose...
I want benchtop to save some space and found one that has 0 - 9.5 inch working range.
https://www.amazon.de/dp/B074N1Q2V6/ref=sr_1_17_sspa
What do you think?
Thanks
@Mash
Check the pressing video I posted to get a sense of the range. Range will not be a problem, but pressure will. Before I made the purchase of the 12T press, I consulted with MPP about an A frame 6T bench top version just like the one you highlighted. You need the extra pressing pressure of the 12T to get the stock bushing out.
Check the pressing video I posted to get a sense of the range. Range will not be a problem, but pressure will. Before I made the purchase of the 12T press, I consulted with MPP about an A frame 6T bench top version just like the one you highlighted. You need the extra pressing pressure of the 12T to get the stock bushing out.
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Thanks a lot, they cost the same, but I hate wasting space on something I will most probably use only once. Going to consider 12T, since I ain't gonna find out workshop during lockdown for a long time now.
The engineer in me appreciates all the attention to detail with these parts. Stainless steel piston with anti-knockback springs. The slight dome on the backside of the piston to add stiffness. Vented edges to improve cooling.
If you have 50yrs of winning professional racing experience at every level. Then let us know. Otherwise , I prefer my info from AP.
Ventilated, Domed Back, Stainless Steel Pistons
There are people who will tell you that aluminum pistons are great for track calipers. They will tell you that the expansion rates of the pistons and caliper body need to be the same when heated. This argument is completely invalid and unproven. Those same people tend to get upset when you point out the fact that every serious race caliper, from every serious race caliper manufacturer on the planet uses either stainless steel or titanium pistons, period. There is a reason for this: they're better!
Stainless steel pistons are far superior to aluminum pistons in creating a thermal barrier. They are much better at keeping heat out of your brake fluid and preventing a soft pedal from fluid fade on the track. This has been proven over and over again at all levels of motorsport. While most aftermarket calipers use a pressed aluminum piston, the Pro5000R's use an expensive machined stainless steel piston.
To add stiffness to the pistons, AP designed the back of the piston with a domed back. At first glance this seems like a trivial design element. It is not. When domed back pistons were introduced in professional racing, driver feedback was immediate and resoundingly positive. The domed back adds considerable stiffness that can be felt through the pedal, and they have now become the standard vs. which all designs are judged.
For even greater heat resistance, there is ventilation on each piston. The air gaps around the piston edge allow for even more cooling air circulation around the pistons. All of these features slow and repel the influx of heat into the brake fluid, preventing brake fluid boiling and fade.
Anti-knockback Springs
Not only are the pistons stainless steel, they are also fitted with anti-knockback springs. Springs in pistons you ask? Yes, springs. If you’ve ever gone through a series of S turns and then had your pedal drop when going into the following brake zone, you have experienced knockback. To say it is disconcerting is an understatement. You’ll often see pro drivers ‘pre-tap’ their brakes lightly when approaching a brake zone. They are fighting knockback.
Knockback is a phenomenon that is common with fixed calipers. Knockback occurs when your car’s wheel, hub, and bearings deflect during cornering, allowing your brake disc to move out of sync with your caliper and brake pads. The amount of knockback varies by vehicle, and depends on the amount of deflection seen in the parts listed above. As the brake disc deflects, it actually pushes the pads away from each other, forcing the caliper pistons back into their bores. The piston seals don’t have enough tension in them to completely return the pistons to their original location. That means there is slack in the system that needs to be taken up. When you press the brake pedal, it will continue to drop until that slack is taken up.
Anti-knockback springs help alleviate this situation by putting some tension on the back side of the pistons. When the disc deflects and makes contact with the pistons, the springs push the pistons back into their proper location, reducing slack in the system. That means less pedal drop and far fewer pucker-factor moments when going into heavy brake zones.
There are no major downsides to lightweight AKB spring as long as the caliper is designed to accommodate them. More specifically, AKB springs do not create any increased drag or wear on the pads and discs as long as the shape and material of the piston seals takes them into account.
As you're driving the suspension is constantly compressing, the disc is moving around laterally, and the pads are being pushed slightly away from the disc. Think of the seals in the caliper as a spring or hinge attached to the side of the piston, rather than just a ring through which the piston slides. In an AP Racing competition caliper, the groove in which the seal resides isn't a square cut groove.It has angles. When the pistons slide in or out there is friction between the outer piston wall and the seal, and the seal distorts a bit as shown in the illustration below.
A caliper piston sliding out to the left would distort the seal in this manner (the slashes are the seals on either side of the piston):
/
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\
As the piston slides back in to the right, the seal does this:
\
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/
There is a certain amount of tension or friction that needs to be overcome before the piston actually starts moving through the seal ring. That tension/friction keeps the piston from dragging on the disc once the pistons are pushed back into the bores by the disc/suspension movement.
When AKB springs are added, a little more force is required to push the pistons back into their bores than would be required without them. After the spring is compressed, it unloads and pushes the piston back to 'neutral.'
With the proper seal and spring the goal is to keep the piston in the 'neutral' position, not pressed against the disc. The piston is still able to slide freely in either direction, but a bit of friction or tension needs to be overcome initially to get it moving in either direction. The seal offers that first bit of friction to limit movement, and then the spring provides additional resistance. The end result is that the properly designed AP Racing calipers won't drag or create additional or unnecessary wear.
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I was driving a car with such springs on AP calipers. It was possible to hear that brakes always pressed a bit. I don't know what was range loss or spring rating.
About free flow - you re cooling brakes when you release them - plenty of airflow there.
Lucky13
Member
Lucky13
Member
MasterC17
Active Member
You were joking but you were right. RB is really a street oriented setup, AP is a track oriented setup. Everything in the AP kit will last longer and perform better on-track by a notable margin. It's the same reason I went with the AP kit.
lol - yes those are most certainly smiley faces!
Good eyes on catching the Smiley Faces.
I drew them to test if the anti-knockback springs are pushing the pad against the rotor.Just as @MasterC17 wrote. RB is a great street setup, good for occasional track days. I plan to do more track days than just occasional.
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