I wholly agree - writing my letter as we speak. Having spoken with people that were around when the FB rule was made, which is where this idea came from, I think, they said it was added at the last minute as a money saving measure.Originally Posted by Rick Iverson
Since we all agree that it's not - I think we don't need to restrict the calipers to equal-sized pistons.
Cheers,
Chris C.
How expensive are the pads? And how about the calipers?
That's hard to believe...they weigh more than 5.2 lbs each?!? Do you have a weight on the caliper?They also weigh more than LD-20's.
Nathan
They are not heavier than the AP LD-20s, they are about a pound heavier per caliper than the ICP LD-20s.
Guys, I dont have an FC or FF, but I'm just curious to know why the Wilwoods are considered unusable in these applications? Is it inadequacy of brake torque, structural failures, or simply too heavy/overdesigned?
Alloy??
I'll apologise in advance if the thread gets highjacked as that's not my intent BUT I would rather have a sequential box for the money than alloys. Talk about modern? There you go.
JIM (2006 GLC CFC Champion)
You can't get some compound like PFC-01 or another good compound for any of their calipers that I have seen that might work on a formula car.
The calipers aren't stiff enough and they just don't build race worthy calipers.
I enjoyed Brandon trying to describe what it was like to have Wilwood's on his car. He said it was always interesting because he never knew what was going to happen when he pushed the brake pedal.
Companies like PFC, AP, or Brembo have thousands of brake systems racing on 4 or 5 continents every weekend. ICP has been building calipers for SCCA racing for a long time. That experience is everything and it shouldn't be a surprise that their products are superior. It's crazy to think that giving them free rein to put new brakes on these cars won't be an improvement.
The restriction for FB was to keep out the ultra-high dollar calipers that only come as differential bore. Since 4-pot calipers - at least from the usual suppliers - are overkill pad-size wise for FF & FC, the rule won't affect these classes much, if at all. From my supplier viewpoint, either way the rule goes is OK, since I will have both types available, and the taper problem can be addressed thru some design tricks.
Wilwood has tons of experience (they started making brake systems in 1977), and it wouldn't surprise me if they have more brake calipers racing on any given weekend than PFC, Brembo, AP and ICP combined. They do make some decent products, but the particular caliper that is the appropriate size for our FB/FF/FC application isn't designed for the kind of braking torque we develop. They are also building to a very low price point.
Radon Sport is a new company, but I designed my first brake caliper in 1996 and I've designed braking components for motorcycles, cars, and aircraft over the years, including taking brake systems through the full DOT certification process. I will put my experience up against anyone's, but that doesn't mean anything in racing.
I do believe our caliper is the best available, and it is certainly the lightest and stiffest of any I've tested. However, having a number of decent choices available has to be good for the FF/FC/FB community, and should reduce costs for everyone.
Nathan
Ok, I see now - the proper compound of pad is not available - and the calipers arent stiff enough.
If that is the case - then how is this move going to reduce costs for anyone but the manufacturers ? If the wilwoods dont work, what other low cost alternatives are available for competitors? I mean, significantly cheaper than the proven ICP cast iron ones already available?
I dont mean to throw a monkey wrench in the proceedings here - just trying to understand how this move reduces costs, thats all.
Reduce caliper costs?
It doesn't, at least not in the sense that you will suddenly have good $150 calipers to play with.
Any decent caliper made in the sort of short runs common to racing is going to cost at least $250, and generally another $100-$200 more than that. VERY good calipers will start at $500 or so and go up from there to whatever you want to spend for custom stuff.
Surprise, I'm going to have to disagree with that.
The cost of the caliper at our production quantities is a combination of material cost, manufacturing cost, and amortization of engineering, tooling, and marketing.
I buy about 40,000 lbs of aluminum a year, so my price is pretty good. I imagine anyone else making a production run of calipers will pay about the same. Ironically, the most expensive aluminum alloys are the worse choices for a caliper body. So, excluding exotic materials like MMCs, everyone's material cost is about the same.
Assuming a CNC-machined caliper body and turned pistons, manufacturing cost is closely tied to design. An inexperienced designer, or one that isn't intimately familiar with CNC machining, will often design a part that is very expensive to machine, while someone else might design one that is much less expensive to machine and performs as well (or better).
The final cost is probably the biggest variable. A large company with a huge marketing budget has a big cost adder without any benefit to performance or quality. Similarly, an established company will need to amortize the cost of their staff engineers and overhead pretty quickly. That can easily double or triple the cost of the caliper.
In contrast, a small independent company like Radon (or ICP) has much more flexibility (and no real marketing budget!).
At $360, our caliper is amongst the least expensive, but I think it's the best. It's definitely better than more primitive designs costing twice as much from big companies. Maybe I should triple the price.
You don't always get what you pay for, especially in racing. I can give you tons of examples.
Nathan
If Niki's experience (post # 29) is any indicator, the per-race PAD costs will be very much reduced, in addition to making the brake system more reliable and less of a hassle.
Dave Weitzenhof
To agree with Niki - we run the same calipers as per his FB car here in the UK - and his assumptions on pads are spot on.
Weight vs drag
Readers
PFC has for years been working on the reduction of brake drag. When people tout light weight, seldom do they discuss hot brake drag.
Everyone who has a FC or has worked on a FC or F1000 or FB car knows what it's like to push one of those cars around the paddock after a session. Especially places of high brake demand like Road America. Its amazing the brake drag for such a low brake demand type car.
When brake pads taper, there are many things that influence that taper. Poor force distribution, poor dynamic disc symmetry, poor torque take out and pad material migration at elevated temps are just a few. Each one of those influences have much to do with the overall performance of the car's grip model.
So what has more influence for reducing performance, carrying around +1.0lb of unsprung weight per corner or having 4 to 8hp of brake drag? How much does this lost HP costs?
I see the thread here has been lively and well thought out. So when modern brakes are considered, one should look at design features, stiffness vs. mass, costs vs. componet features, service vs. will that guy really understand my venue??
Darrick Dong
Performance Friction Brakes
I've pushed a number of F2000 cars around the paddock right after lots of races and other sessions, and I've never experienced any brake drag or difficulty in pushing the cars. None of the mechanics or other competitors in the F2000 series that I asked have witnessed any either. I haven't asked everyone, though, and don't often attend club races, so maybe you can tell us who and where someone witnessed this?
What does the PFC two-piston LD20 caliper replacement weigh? I asked an early purchaser to weigh one for me, but he was only able to report the weight without the adapter bracket for lug mount. Can you share the total weight including bracket? I imagine it's closer to 2 lb heavier than our caliper. Most race engineers would trade a precious body part for a 2 lb reduction in unsprung weight!So what has more influence for reducing performance, carrying around +1.0lb of unsprung weight per corner or having 4 to 8hp of brake drag? How much does this lost HP costs?
No car in the F2000 paddock is losing 4 to 8 hp from brake drag. Knowing the mass and thermal time constant of the braking system and using high school physics will tell you this is impossible without catastrophic brake failure.
There is no evidence suggesting brake drag in the data, either. Don't take my word for this, though. We had a IRL support engineer from Alcon, a Pi IRL data support engineer, as well as a former Newman Haas race engineer in our trailer this weekend looking at some of the brake data, and they will confirm this. IRL engineers care a LOT about brake drag, so I tend to trust their opinion. (I appreciate their help, by the way, staying late to help the designer of a lowly F2000 car shows the level of respect the F2000CS is getting at even the IRL level.)
If you have data showing brake drag, please share it, I think everyone would be interested.
I agree completely with you on this, Darrick (might be a first!).So when modern brakes are considered, one should look at design features, stiffness vs. mass, costs vs. componet features, service vs. will that guy really understand my venue??
We should have an exciting announcement regarding F2000 braking systems within the next two weeks. It was a very productive weekend in that respect.
Nathan
Drag vs. Weight-cont
Quote:
Originally Posted by Brakeguy1
Everyone who has a FC or has worked on a FC or F1000 or FB car knows what it's like to push one of those cars around the paddock after a session. Especially places of high brake demand like Road America. Its amazing the brake drag for such a low brake demand type car.
I've pushed a number of F2000 cars around the paddock right after lots of races and other sessions, and I've never experienced any brake drag or difficulty in pushing the cars. None of the mechanics or other competitors in the F2000 series that I asked have witnessed any either. I haven't asked everyone, though, and don't often attend club races, so maybe you can tell us who and where someone witnessed this?
Quote:
So what has more influence for reducing performance, carrying around +1.0lb of unsprung weight per corner or having 4 to 8hp of brake drag? How much does this lost HP costs?
What does the PFC two-piston LD20 caliper replacement weigh? I asked an early purchaser to weigh one for me, but he was only able to report the weight without the adapter bracket for lug mount. Can you share the total weight including bracket? I imagine it's closer to 2 lb heavier than our caliper. Most race engineers would trade a precious body part for a 2 lb reduction in unsprung weight!
No car in the F2000 paddock is losing 4 to 8 hp from brake drag. Knowing the mass and thermal time constant of the braking system and using high school physics will tell you this is impossible without catastrophic brake failure.
There is no evidence suggesting brake drag in the data, either. Don't take my word for this, though. We had a IRL support engineer from Alcon, a Pi IRL data support engineer, as well as a former Newman Haas race engineer in our trailer this weekend looking at some of the brake data, and they will confirm this. IRL engineers care a LOT about brake drag, so I tend to trust their opinion. (I appreciate their help, by the way, staying late to help the designer of a lowly F2000 car shows the level of respect the F2000CS is getting at even the IRL level.)
If you have data showing brake drag, please share it, I think everyone would be interested.
Quote:
So when modern brakes are considered, one should look at design features, stiffness vs. mass, costs vs. componet features, service vs. will that guy really understand my venue??
I agree completely with you on this, Darrick (might be a first!).
We should have an exciting announcement regarding F2000 braking systems within the next two weeks. It was a very productive weekend in that respect.
Nathan
Nathan
We do have comprehensive data as to dynamic drag for the brake systems. At this time, we don't have any data of the Radon caliper package but we do of AP, Alcon and Brembo calipers. We will be posting a new website update with these data points readily available at www.performancefriction.com;
Drag data on the dyno is measured in coast-down time. We have a procedure of 20 stops from 120mph-40mph at -1.0g to get the brake temps consistent and use the same brake pad compound with same inertia. This data is coupled with fluid displacement at elevated temps. Teams use their own chassis dyno to verify their own coast down numbers. It's never just one thing that influences the drag.
And for the record, there is no bracket needed for the PFC Zr55 caliper as we have done extensive FEA and have assembled a couple of different strategies but at this writing so as not expose too much we'll just say we have it figured out.
I won't argue about your "pushing F2000's" around the paddock. But I will say, I'd like you to post your drag simulation on a public format so all can come to their own conclusions.
Respectfully
Darrick Dong
Getting off the topic
Hi all,
Although the discussion about the merits of the various brake calipers are very interesting, I think that we are getting somewhat off the topic, which is whether or not the SCCA should change the rules to allow aluminum brake calipers in the FC class, and if so, what limitations should be on them.
I'm wondering if we could start a new topic to continue the lively discussion about the various brake calipers, while still continuing our discussion about the change to the rules.
Thanks!
Chris C.
There's your problem. Measuring brake drag on a dyno isn't useful unless you race on a billiard table. Ask any brake engineer and they'll explain why. And, you might want to look at F2000 braking data at some point, 20 stops from 120 to 40 mph doesn't happen at any track I've visited. Measuring brake temps on F2000 cars is instructive as well.
Sounds good. Requiring people to buy new uprights in order to use your brake calipers shrinks your market quite a lot, and adding a bracket dramatically reduces the stiffness while adding weight.And for the record, there is no bracket needed for the PFC Zr55 caliper as we have done extensive FEA and have assembled a couple of different strategies but at this writing so as not expose too much we'll just say we have it figured out.
I'd be glad to. We'll put something together on the web site when we can spare the time from building cars! I'm sorry I missed you at Watkins Glen, but if you attend any of the remaining F2000 pro races let's get together after a session and push some hot cars around.I won't argue about your "pushing F2000's" around the paddock. But I will say, I'd like you to post your drag simulation on a public format so all can come to their own conclusions.
Regards,
Nathan
Running Cost
So as everyone wants the alloy caliper can we all afford it? I can only comment on what I know so if this sheds some light on the alloy brake .
Radon Sport:
As Nulrich quotes if i read it correctly his caliper is $360 a straight bolt on replacement to the LD20 and it utilizes the LD20 pad, so running cost similar to what you have now.
We have never used them.
RFR:
I will be interested to see whats on Ralph's new car, if its whats on the F1000 then your brake bill will be very low like what Nikki says.
When we first ran the RFR the brakes were great and never an issue, quality stuff, should be same on f2000.
PFC:
We updated at the begining of the season to the alloy caliper with an initial investment :
Calipers $535 each
Uprights $502 plus steering blocks etc
Pads are $300 per axle from Haas, we use 1.5 sets a weekend and they come in 01 & 07's.
Quality caliper.
Hope this helps.
Last edited by LFC; 08.04.10 at 12:42 AM.
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