Printable View
The CRB have recommended a rule change to allow aluminum calipers in FC from next year. Discuss and vote here, but most importantly...write the CRB!
PS - This poll records and displays who you are and how you vote, so please only vote if you are an actual or seriously prospective FC competitor.
No. They are going to be a performance advantage and cost a lot of money to maintain the status quo and open up a bigger gap between the big spenders and the guys on budgets.
I don't think they should have been allowed in FB either, especially with the initial focus on converted cars.
To giv an example of just how bad the supply problem is, someone recently needed to send Brandon a LD20 for a fit check on an upright. They had to go to the extreme of calling Pegasus and having a caliper shipped to brandon. It was on the shelf there and the whole thing took several days start to finish. Why do we need $3000 aluminum calipers with outrageously expensive pads?
It'd be really nice to standardize allowance of all the components like this across FF, FC, and FB.
Who sells $3000 aluminum calipers for FC? Ours are $360 each and use the same pads as the LD20. How much does a new LD20 caliper cost?Quote:
Originally Posted by Wren
Nathan
New LD20 from pegasus is 389.Quote:
Originally Posted by nulrich
The PFC's are just under that with pads and I think the AP's are slightly more.Quote:
Originally Posted by nulrich
I understand that your calipers may not be terribly expensive, but when the real brake companies develop calipers from a clean sheet and don't tie themselves to 40+ year old pad shapes, the end results are expensive. The results are also very nice.
What is (are) the reason(s) why the current calipers are not sufficient?
Was this instigated by the CRB? Or by a competitor?
Before I'd vote, I'd want to hear the case for the rule change proposal.
My gut feeling is it will raise costs. Therefore, there would need to be a strong reason for changing the rule.
umm, I might make an observation: in the F2KCS paddock where aluminum calipers have been allowed all year there are, to my knowledge, zero conversions. Why? I can only surmise because no one thinks there is any performance advantage. The new Radon and RFR cars will come standard with them, but no one is rushing out to change anything that I know of.
I'm sure one can spend a fortune on Brembo F3 brake systems, but where will it get you on these cars? Better feel, maybe, but the tire dictates the ultimate stopping ability of the car.
(full disclosure: this is my request for the rule change)
Russ- my main reason is new car manufacturers want to use aluminum calipers because of cost (less) and availability. In this modern world of CNC mamufacturing, its much easier and cheaper to make an aluminun caliper.
[quote=Bob Wright;259583]I'm sure one can spend a fortune on Brembo F3 brake systems, but where will it get you on these cars? Better feel, maybe, but the tire dictates the ultimate stopping ability of the car.
quote]
I would imagine most of the F3 cailpers are differential bore. The rule states the pistons must be the same? I think there will be less to choose from with the bore requirement. True?
I don't think any quality four-piston brake caliper (including ours) has pistons all of the same size, and I think they should remove that limitation. Our steel caliper, which is currently legal in club racing, has four pistons and two different piston sizes. This rule would make those calipers illegal, which would probably upset those SCCA members that have spent a lot of money to purchase them.
Pistons with different sizes don't cost more to make in any reasonable quantity, especially with modern machine tools.
In fact, differential piston sizes will reduce cost for the competitor, since they all but eliminate pad taper wear.
It does mean you need to make a left and a right hand caliper, but, again, with modern CNC machining equipment the cost difference is insignificant.
Nathan
Nathan, you should make these very points in your input to the CRB. StanQuote:
Originally Posted by nulrich
Our F1000 rules committee did not come up with the differential bore issue in our aluminum calipers. That rule got in there by Dave G. If we eventually allow alum calipers in FC and FF, recommend we remove the differential bore verbiage from FB as well as allow them in FC and FF (as Nathan says...).
I agree. I would have sold several sets of calipers to FB competitors already, but I haven't had time to make a version with same size pistons...it would be nice not to have to!
Nathan
really dumb question here.
Why would one make 4 piston calipers with all 4 pistons not the same size?
Seems that one would want all 4 the same to have even pressure across the pad.
The reason is that pad drag during braking creates a torque which causes taper wear from in to out (leading to trailing edge) relative to rotor rotation direction. Unequal piston sizes are an easy way to counteract that effect.Quote:
Originally Posted by Steve Demeter
Wouldn't you need to carry 4 spares though, instead of 2, if the pistons were not similarly sized? I suspect that was the intent of that language to not increase that cost. Or just carry 2 cast iron calipers as spares if you damage one caliper and change the whole axle to be symmetrical caliper wise when one corner is replaced.Quote:
Originally Posted by nulrich
It depends on the chassis. If I recall correctly, later Van Diemens have the calipers behind the axle in the front and ahead of the axle in the rear, so there are four unique configurations. Not sure about other manufacturers. The simple solution is to carry a left and a right caliper as spares and be prepared to swap the crossover tube and bleed if necessary.
The same issue happens with the LD20 if you want the bleed at the top, of course ;).
Not sure I've ever seen a caliper replaced at the race track, especially the LD20s, which tend to survive even really bad crashes, but I'm sure it happens!
Nathan
I bought my Ralt in 1997 without a spare caliper, and have never needed one through numerous crashes. I put a rebuild kit in them every other year in the off-season, and have replaced one cross-over tube. That's it.Quote:
Originally Posted by nulrich
Spare uprights and a-arms? Absolutely. Spare calipers? Nope.
Afaik the only quality caliper with equal bores out there are the AP calipers. Wilwood makes some cheesy dyna lites with equal bore, but they are not worth having. We tried to make them work but eventually remade a lot of stuff to fit the PFC's. Thy were the best we could find that met the rules.
no, just because the fb rules allowed in calipers that automatically disadvantage all of the conversions does not mean that the other classes should.Quote:
Originally Posted by RobLav
We also have to stop moving the goal posts on people. We just finished a lot of work and a big expense and bow you want to allow in $10,000 f3 brake systems? Other manufacturers are in the same situation. How does this help any of the classes? They are already braking so hard in fb that it is physically impossible to work the gear shift lever fast enough by hand.
yes, but even the pfc's require 4 unique calipers and they are a 2 piston design. They are an excellent example if what the knowledgable brake designers can do with a clean slate for caliper and pad design.Quote:
Originally Posted by TimW
If anyone wants to see them we are paddocked in space 78, just up from the bathrooms.
Alternately, feel free to go down to 5 and watch where Niki, Brandon, and Schweitz get on the brakes. Then try to convince yourself that it won't be an advantage. Niki is on the ap calipers and Brandon and Tom are on the PFC calipers.
If you want to keep out the most expensive systems - generally monoblocks - just take a page from the S2 rule and state that all calipers have to manufactured at a minimum from 2 body halves (their rule states split at the centerline, if I remember correctly), with an allowance for spacers to widen the caliper if necessary. Their rule of "grandfathering" specific CI calipers is to me a mistake, since it automatically outlaws any new CI designs.
Or just state that "monoblock" designs are not allowed and then define monoblock as being the main body being manufactured primarily from a single block of material.( Stating "primarily" allows things like small bolt-on bridge pieces that can be removed to facilitate pad removal).
Both AP and Brembo offer their 4-pot calipers with equal bores, though I doubt that either sells very many that way - all other things being equal, differential bore calipers will always be superior in race-long performance.
My suggestion is to change the wording from:
toQuote:
Brake rotors and calipers must be ferrous.
If someone wants to spend a whole lot of money on an F3 brake system, let them. They'll just go slower.Quote:
Brake rotors must be ferrous.
If someone wants to waste money on MMC calipers, more power to them. It's not going to make any difference in lap time, and the stewards have no means to test alloys in any case.
If someone wants to buy monobloc calipers, fine. The dirty little secret is that they are actually cheaper to manufacture than two-piece calipers if you are running thick pads and vented rotors (which gives space to cut the bore from inside the pad/disk window). For our pad and disk sizes, it would be very difficult to make a one-piece caliper without using plugs, and the caliper is likely to end up much bigger and heavier than a two-piece design.
It would be nice if the rules for FB, FC and FF were the same.
Nathan
ReadersQuote:
Originally Posted by Stan Clayton
As a manufacture of racing calipers, I know my advocacy maybe viewed as "self promoting" so I will try to discuss this subject using what in my opinion "new rules" are for; INTENT
INTENT
- Update a 40 year old cast iron caliper design who's tooling and demand has exceeded it's time.
- Since there are now multiple touring FC/FB/F1000 type series which allow Alloy calipers, it makes since to allow these updates into the FC car population.
- It is not true that a monobloc caliper has to be more expensive than a 2-piece type.
- It is not true that differential bore calipers are more expensive than equal or same piston bore calipers.
- There's nothing cheap about racing vintage components and its not always the safest.
- As part of the caliper debate, PFC suggests this would be great time to implement wheel corner tethers.
- There has been no shortage of friction material progress. With higher .Mu values comes the by-product of added heat energy. Modern caliper designs tend to address this. Certainly the cast iron calipers featured today has not addressed the updates in friction materials.
- There is no shortage of tire development in FC. Certainly as the tires improve, the demand of the brakes increases. DO YOU THINK 40 year old designed brakes is the best choice for modern race tires?
- What keeps costs down is competition. Instead of "open" competition with caliper makes or designs, I would propose the manufactures submit a homologation white paper of what PN's are appropriate. It simplifies choices and have the homologation last say 5 years. This gives time to amortize design and tooling costs which keeps costs in check
- There is around a 6-10 lbs (depending on who you believe) weight advantage with Aluminum calipers. Simply adjust the static weight rules accordingly if there's a perceived advantage. It's what the USF2000 did.
Darrick Dong
Performance Friction Brakes
Hi Darrick:
I agree with pretty much everything you say (that must be a first ;) ).
I'm not sure homologation is practical for SCCA club racing, nor is there a need, at least in my opinion. The market just isn't big enough for competition to get out of hand, nor is the potential benefit large enough to justify expensive development. Lots of other places to spend funds for much bigger gains. Plus a little healthy competition benefits the racer.
A clarification on caliper weights. I just put an LD20 cast iron caliper on the scale and it weighs 5.2 lbs. This example has aluminum pistons (which I'm told are legal) so there may be versions that are heavier with different pistons.
Our production four-piston caliper with differential pistons weighs 2.3 lbs on the same scale. So the benefit is 3 lbs per corner in unsprung weight, which is substantial. I would consider that an issue EXCEPT that the ICP cast iron calipers weigh about the same (published weight is 2.4 lbs if I recall correctly).
Our steel caliper is heavier at 3.1 lbs, but is very stiff. I hope we don't have to make any more of those, though!
I don't see a published weight on the PFC calipers and don't know what the AP and Wilwood options weigh, but given the prevalence of ICP calipers that meet the current rules, I don't see caliper weight as an issue in a rules change.
Nathan
Rich Kirchner suggests that wheel tethers will be a great idea when PFC supplies them to all competitors for free......
And I'm also for aluminum calipers (but after fitting ICPs I'm not sure the juice is worth the squeeze for me).
aluminum caliper replacements for the van diemen conversion, and one I was considering was the willwood GP320 four piston caliper. Lug mount,and it appears to bolt right up to the VD upright. Very compact, and weighs 1.75 lbs. Anybody know about these calipers? Wren is the second person who knows what they are talking about are saying to avoid willwood calipers for this application.
I put in a call to Darrick, but both of us are pretty busy. I need to talk to him before I make a decision as well.
The LD20´s work good, I´m just looking to shave unsprung weight.
And a huge congratulations to every one who made it to the June Sprints! Maybe next year.
Brett
I am fully in favor of AL calipers in FC.
I can't for the life of me figure out from where the proposed limitation on unequal piston sizes came.
What is the motivation for that rule limitation in the proposed rule??
Is it to save money on caliper manufacture?
With modern CNC machining, the cost difference is next to zero.
Is it to somehow save money for the competitors in some other way?
I can't think of how - if there is some way, then I'd like to know. I'm willing to bet that over the life of a typical brake caliper, you run a bare minimum of 30 sets of brake pads. If the calipers cost $400 each, (so $800 for a pair), and you run $3,000 worth of brake pads in them over their lifetime (and I think that 30 is underestimating by a lot), then making the pads last longer saves more money over time than anything else - and running equal bore pistons in a 4-pot caliper will unequivocally taper the brake pads.
So, will the people that are proposing this rule (and I know you're out there on this forum) PLEASE step up and tell us why you think this is a good idea (limiting the pistons to equal sizes) ??
The fundamental problem with club racing is that the pool of people, and especially the pool of people willing to get involved and stick their necks out, is very small. Everyone knows everyone else, and certain people have had an enjoyable monopoly on the manufacture of many parts, and no one wants to stir the pot to change the status quo. Whether it's intentional or not, there are plenty of existing rules that have certain suppliers in mind - and unless the people proposing this new rule will tell us something different, then it's just normal for us to assume that this new rule proposal is just more of the same. There are no "checks and balances" in this situation - and IMO, the best interests of the typical club racer are not being served.
I think that if we are going to allow aluminum calipers, an idea which I wholly support, then I think that they should be unrestricted in terms of piston size and construction.
Cheers,
Chris C.
(as an afterthough, for the record, I am more than willing to put my money where my mouth is and serve on the Formula Car advisory committee).
Let's face it, I probably won't put aluminum calipers on my Reynard, but I do love FC racing.
I'm in favor for a multitude of reasons.
#1 I want FC to remain one of the premier classes. To remain so it must compete with every new class that comes along, FB, FE, whatever. To compete for new blood requires a certain amount of sex appeal. Today's kids are accustomed to aluminum calipers. They are already on karts, they are on FSAE cars. It's hard to explain why we have to run iron chunks on a premier formula car to folks being introduced to the class.
FC over it's whole history has been a class of change and innovation. It has no history of being frozen in stone. No reason it should freeze now. Many of us fondly remember the early days of CAN-AM because of all the neat engineering innovations. FC, being a "formula" class, has encouraged innovation over the years. It is not a spec class.
To continue to move forward the class needs to encourage builders to build new cars if at all possible. Engineers are much more interested to build to a more modern formula in terms of low cost available materials. I envision the same uprights and calipers maybe being used in both FB and FC.
CNC has changed the machining world. What used to be very expensive is not now.
About equal sized pistons... I clearly do not understand the argument for that requirement. When I owned the Tatuus, she had ICP calipers. For many years, when I can, I have crewed for DaveW at the Runoffs. He has ICPs. It is a very routine drill for us to "flip pads" every session to compensate for pad taper that develops with use. If unequal piston size is a known cure for that, why would we want to outlaw that when it doesn't even effect price of manufacture.
I don't believe this rule will suddenly antiquate all the iron calipers. Case in point. The F2KCS has allowed aluminum calipers all season. In a pro series where some pretty serious money is spent, no team has yet to fit aluminum calipers.
So I'm in favor of aluminum calipers, and uneven piston sizes.
Just my opinion.
I do not normally post my opinions in open forums however, this is a topic that I feel very strongly about.
It is time we allow aluminum calipers.
As you know Road America requires maximum straight line speed from your car to be quick. Road America is also very demanding on brakes. ICP calipers are needed to lower the unsprung weight greatly from the AP version. The calipers design makes the pads taper at a crazy rate. When the pad tapers the pistons get cocked and do not return back to their home and major brake drag occurs. Brake drag is not what you want for maximum straight line speed. So how do you fix such a problem? Easy, you put a new set of pads in every session(runoffs budget with three qualys and a race $765 just in pads). Sure you can flip them around every session to get longer life from them but after three sessions the pads are worn down so far that pistons stick from being out to far. Ok, so then lets make brake pad spacers to get the pistons back in. That works for a session or two but you still have to flip the pads every session. Sounds a little unnecessary and expensive doesn't it.
I have run my RFR FB car now for (1) year. It is equipped with aluminum calipers with four equal size pistons. I have the same brake pads I originally got with the car. Estimated pad cost for a year $0.
Do I feel much safer, yes. Does the car stop better, yes. Are brakes probably one of the most important safety factors in racing, yes. It does sound pretty dumb that we want to mandate HANS devices (not to be brand specific) before allowing a proper braking system.
Brakes are the one thing on these cars we need to be perfect. It is time we get with it and update the most important safety feature we have.
I am no way an engineer and all of the things I have said are from trial and error not mathematical equations. I do concrete. This is just common sense stuff.
This is in no way to be about the ICP as a brand they have just became the standard like Kleenex is for tissues. They are the best brakes made for the out of date rules. The people at ICP are awesome and very helpful with any questions I have had for them. And they would probably make one of the best aluminum calipers if they were allowed to.
Thanks Apexspeed for the opportunity to have such great discussions.
Niki Coello
I was going to post some comments about aluminum 4-piston calipers vs ferrous calipers we have now.
However, I now don't have to: Niki, Frog and others have said it all.
I agree 100% that they (aluminum calipers) should be allowed, and I hate to spend $ I don't need to.
The biggest reason to not allow aluminium calipers is as Dave W just said: Spending $ I don't have to.
What if there was a minium weight for the aluminuim calipers, say equal to that of the best iron calipers.
That way you get the sex appeal that the Frog wants and it does not instantly make everyone go out and spend $ for new calipers if they want to stay competitive.
Besides, with aluminum being less stiff than steel, one probably would want more meat on them any way.
Just a wild thought. nobody flame me please. just trying to pick up the best of both worlds.
Steve:
The stiffness/weight ratios of alu and cast iron are pretty close to each other - though I don't recall the exact difference between the 2. Steel has a slightly better stiffness/weight ratio than alu ( not including metal matrix alloys of course, which are much better).
The result is that to maintain a decent weight in CI, you have to do a ton of sculpting to minimize the amount of material that isn't doing much if you want to get a light weight caliper, and the problem is that all of the places that you can easily remove material are places that contribute the most to the stiffness. If you want to go to using cores in the casting pattern to get rid of material in the places that can afford to be removed and not substantially affect the stiffness, the castings then get more expensive.
In alu it is relatively easy to get the stiffness without the weight just because it is easy to form a structure that is part shell and part beam without the material left in the unmachinable areas (the cores) adding much weight. It still takes a thorough understanding of structures, and a ton of experimenting to get a lightweight caliper that still performs at a top level - it's easy to make a garbage caliper, but a bit more difficult to make a good one - AND keep it at a reasonable price.
If I were to design the "ultimate" caliper, I'd try a welded steel structure - essentially a hollow shell like a fabricated upright. Hate to think what the price would be though!
As to costs - it will always cost the manufacturer more to make differential bore calipers and keep them in stock since you've automatically increased the number of items he has to stock - every option of bore sizes doubles the number of bodies that have to be made. Maybe the cost per caliper component is the same in the manufacturing end, but inventory costs skyrocket because of the extra caliper halves that have to be produced and set on the shelf (hoping that they will all sell, which they rarely do!).
This is why our new offset-piston alu calipers (assuming that the rule change passes) will be universal - the design allows what would normally be a handed caliper be universal instead.
For the 4-pot I'm trying to see if there is a way to machine a single body for both halves, yet be able to easily provide differential bores if they are allowed.
Bad new Brett, that caliper is simply not up to the task.Quote:
Originally Posted by Brett Lane
Thanks ... Jay Novak
Jay,
That´s why I held off on them until I got more input. There are plenty of other things on the list, but am still looking for a replacement.
Brett
I totally agree.Quote:
Originally Posted by R. Pare
This is not necessarily true. Calipers are sold in sets 99% (or more) of the time. To maintain 10 car sets worth of calipers in inventory, you stock either: (a) 20 lefts and 20 rights if they are different or (b) 40 of the same caliper if they are the same. Either way, you are making the same number of calipers and tying up the same amount of capital.Quote:
As to costs - it will always cost the manufacturer more to make differential bore calipers and keep them in stock since you've automatically increased the number of items he has to stock - every option of bore sizes doubles the number of bodies that have to be made. Maybe the cost per caliper component is the same in the manufacturing end, but inventory costs skyrocket because of the extra caliper halves that have to be produced and set on the shelf (hoping that they will all sell, which they rarely do!).
This is very different from having several colors, sizes or styles of a product, where you cannot always accurately predict demand for each SKU.
In fact, the worst possible situation would be to have to make (and stock) calipers with differential bores AND calipers with equal bores. That IS more expensive than stocking just one style.
I am committed to producing aluminum calipers with differential bore sizes because I have already produced a very large quantity of pistons and seals and a number of caliper bodies. Because they are legal in the F2000 series and will come standard on at least the first twenty Rn.10 chassis, I will continue to make that model for the foreseeable future.
I would prefer not to have to make another, inferior, caliper with equal-sized pistons. That would definitely increase my cost!
Nathan
Great input from every one. My simplistic ferrous vs. Alum summary;
Lightest Weight: ICP 2.6# [ferrous] no real advantage TIE
Cost: all in the +/- $350.00 range TIE
Technology: Billet Alum. w/ different piston sizing, Upgrade to current Tech and potenial cost saving on pads Better Winner
Racing Advantage: IMHO NONE !! still same left foot on the pedal , same twitch in the toush.
SAFETY: ALUM. BETTER! CNC machined and State of art technology no brainer..
If Alum. Cliphers were approved, and I had to replace my current ferrous ones, I would go in that direction, even if at a higher price, if for no other reason than Safety.
Thanks to everyone for a VERY informative thread
Regards Ernie
Richard,
Precisely why I suggested allowing aluminum with a minimum weight.
It would not be necessary to rush out and buy lighter AL units to replace your CI units to save the unsprung weight, as you alluded that it is relatively easy to make a stiff, but light AL unit by machining from billet, but expensive as all get out to do in CI.
Personally, for me, I think it owuld help because of all the people replacing their CI ICP's with aluminum units would make a number of good used CI ICP's come on the market.:)
Let's hope that no one comes up with ones out of the metal matrix composites. I have 2 friends who work in R&D of those materials and the physicals of them are unbelieveable.;)
These developed what was used in the scramjet engine that recently flew to Mach 6 or so in the very upper reaches of the atmosphere breathing what air there was.
Just FYI - there is a lot of AP ally calipers kicking around in the UK second hand - as everyone who converted from the main national FF back to kents had to replace them for steel (same routine with the dampers)... Both Duratec and Zetec were ally caliper classes - using both types of caliper/VD upright - for years. The Mygale upright is the same also (and I belive the newer Mygale cars run the same upright as FBMW - so you can use their caliper type also).
Quote:
Originally Posted by DaveW
July FasTrack:Quote:
Originally Posted by R. Pare
[FONT=Arial-BoldMT][FONT=Arial-BoldMT]FC/FF[/FONT][/FONT][FONT=ArialMT][FONT=ArialMT]1. #1121 (Robert Wright) Allow aluminum calipers in FC[/FONT]
[FONT=ArialMT][Although Mr. Wright’s request was only for FC, the CRB has chosen to extend it to FF to continue to keep the rules of the two classes the same where possible.][/FONT]
[FONT=ArialMT]Replace 9.1.1.B.6 with:[/FONT]
[/FONT][FONT=Arial-ItalicMT][FONT=Arial-ItalicMT][FONT=Arial-ItalicMT]Unrestricted, except:[/FONT][/FONT][/FONT]
[FONT=Arial-ItalicMT][FONT=Arial-ItalicMT][FONT=Arial-ItalicMT]a. Maximum of 4 pistons allowed per caliper. All pistons in a given caliper must be of the same size. Calipers must be [/FONT][FONT=Arial-ItalicMT]ferrous or aluminum alloy.[/FONT][/FONT][/FONT]
[FONT=Arial-ItalicMT][FONT=Arial-ItalicMT][FONT=Arial-ItalicMT]b. Brake rotors are restricted to ferrous material.[/FONT][/FONT][/FONT]
[FONT=ArialMT][FONT=ArialMT]Replace the first paragraph of 9.1.1.D.10 with:[/FONT][/FONT]
[FONT=Arial-ItalicMT][FONT=Arial-ItalicMT][FONT=Arial-ItalicMT]Unrestricted, except:[/FONT][/FONT][/FONT]
[FONT=Arial-ItalicMT][FONT=Arial-ItalicMT][FONT=Arial-ItalicMT]a. Maximum of 4 pistons allowed per caliper. All pistons in a given caliper must be of the same size. Calipers must be [/FONT][FONT=Arial-ItalicMT]ferrous or aluminum alloy.[/FONT][/FONT][/FONT]
[FONT=Arial-ItalicMT][FONT=Arial-ItalicMT][FONT=Arial-ItalicMT]b. Brake rotors are restricted to ferrous material.[/FONT][/FONT][/FONT]
Maybe this should be addressed with the CRB as to get it right from the git-go. Thoughts?
Iverson
Differential bore may be an easy way to avoid pad taper, but proper design will fix it also.
The PFC's are two piston calipers that we have seen zero taper in after a lot of races, which is good considering how expensive the pads are. They also weigh more than LD-20's. It does require a unique caliper for each corner as they offset the pistons to prevent taper.