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I am , at this time somewhat biased against Wilwood, as it seems that so many of the systems that are sold to people with street cars are worse than the stock setups they took off.
This is not an uncommon complaint, as I have heard it from several others who bought Wilwood kits for their cars, installed them and had less than satisfactory results. From when you first get the box, you are presented with disclaimers printed on the box itself, the packaging, the invoice, the bag the part come in and then you have to remove a tag that all say that "these parts are for racing only" Those 4 piston dynalite calipers with the little baby pads are inadequate for any car heavier than 2500#, especially when used with stock drums on the back. Every Wilwood product that I have installed on a customers car has produced unsatisfactory results, and I have returned several cars to stock setups in order for them to perform safely on the street. I have only had the opportunity to experience the smaller , less expensive Wilwood stuff, and have yet to use any of Wilwoods higher end calipers. I have the complete collection of Wilwoods paper catalogs and technical guides, and I will say there are some nice looking forged calipers in there, with larger pads and a little more piston area. The rotors are totally acceptable as well. I would really like to get my hands on some of those to try out. All of that said, I have yet to mess around with the small bore master cylinders and balance bar setups that Wilwood sells. Most of the cars I work on are set up to use regular dual master cylinders., and you don't usually find those in sizes smaller than 15/16". I don't know what kind of system pressures are required to get the smaller 4 piston calipers to do some work, but on 2 different cars, I have been able to generate better than 1300 psi at the MC outlet,(measured with a gauge plumbed into the system), and not been able to make a 3200# car even squeek the 70 series tires on a panic stop. ALL of that said, I know that several members here , 427v8 for one, likes wilwood products and had good luck with them, and I have talked to a few techs that say the higher end stuff works. Maybe if Wilwood would spec the systems that they sell, like Baer, SSBC, BTS, Stoptech, and give you the specs for a complete system I'd look a bit more favorably at their stuff for street use. Not everyone is an engineer, I certainly am not, but Wilwood claims to have many engineers working for them...why can't they spec a system for a car that they list a kit for.... I have a book with all of the calculations required to engineer a brake system. It was published by Ferodo in the early eighties and is a handbook specifically for automotive designers. I will gladly show it to anyone who can make heads or tails out of it. .If anyone here is truly a mechanical engineer, maybe it can be put to some good use for the site. I'd love to see a "desk top dyno" style calculator for brakes. I don't see why a billet pedal couldn't work, do the mechanical engineering and size the pedal accordingly. For materials design, I'd use 500# as your foot pressure at the pedal (that's about a 3x safety factor, as 140 #seems to be a good number for a panic stop.) and then determine that you need to generate about 1200-1500 psi in your master cylinder bore, which will be a larger lineal force at the pushrod.(you really should not need any more than that , other wise you need bigger calipers or better pads or a bigger disc. )Hope all of the above makes sense, there are several points that I could expand on, but this one finger typing stuff is a killer. In the end, all I can say is YMMV Later, mikey
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my signature lines...not really directed at anyone in particular.. BE different....ACT normal. No one is completely useless..They can always be used as a bad example |
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Ok , what brought all of that on?
You did say.... Quote:
Mikey
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my signature lines...not really directed at anyone in particular.. BE different....ACT normal. No one is completely useless..They can always be used as a bad example |
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Mikey,
I think it was coincidental that I was looking through my new Speedway catalog and that I've been thinking about the Wilwood pedals for my project and that 427V8 made a comment about Wilwood in the thread announcing your new position. I think I'll be making my own billet pedals, MC supports and linkage. I suspect the Wilwoods are castings which work well in a racing application as race drivers don't jump on the brakes like I might have to on the street. I do need to address the issue of selection of master cylinders. I'm not sure what bore MC's I need as I still haven't decided on drums or discs on the rear. You're right Paris, if there is a difference. I have the drums and the thought of not having to invest in discs makes them attractive. Thanks for you input on Wilwood. I'd rather see comments from the voice of experience than someone saying my dad used'em and them thar things worked reel goooood. Yes Paris, I know that's not spelled correctly. |
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Hmmm Wilwood... It's a big topic.
I have not used any Wilwood kit other than one I designed and now sell for 1968 - 1982 Corvettes. I use a caliper with the same piston area as stock so the braking performance is the same, which is excellent. No one else makes a cheaper better caliper. They are stiffer, lighter and leak less than the stock calipers. So they can work in the right application. That application is high performance street or track. Would I run them on a street rod? Well I'm building a '29 Dodge and I'm running GM metric calipers. It's not going to be a race car, just a cruizer so I don't need high performance brakes. One problem people have is it's very hard to design a working brake system. I had it easy I just had to duplicate what was already existing. It still took 3 tries and LOTS or research. Piston area, Master clyinder area, pedal ratio. EVERYTHING is interrelated and there is a very narrow window of acceptable values. It's a lot more complicated than you expect. If you want to run the dual MC go for it, but expect it to be an engineering exersize, not a bolt on solution. Mike I use 100 lbs pedal pressure and epect 1000 psi at that. I have an excell spreadsheet setup for Corvettes. It considers weight distribution and brake coefficient of friction. I have looked at the systems Wilwood sells and they all look undersized to me. I like big brakes. Keith |
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Quote:
Yes sir. (I never liked dissagreeing with you...you are too smart.) See some of the chinese algebra that goes into designing a brake system. This is from the engineering book I was talking about. That's one of the easy pages. See my photo gallery for a couple more pages of that...there are about 50 more like that in that little book I have, full of tables and appendixes more fuzzy math just like that.. Stoptech has some stuff like that too on their website... I would love to give this book to anyone who can make use of it for our collective knowledge... I have actually started compiling a systems spreadsheet, with as many variables as I can measure, and giving an evaluation of the system, before and after, on every car that I have to fix the brake system on, ..not very scientific, and not as precise as I can't really measure everything properly, I know. But it's the only way I know of to work these problems out.. I have actually thought about putting a blank spreadsheet up here on the forum for folks to add their own systems in. Keith..which calipers are you putting on the 'Vettes? Later, mikey
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my signature lines...not really directed at anyone in particular.. BE different....ACT normal. No one is completely useless..They can always be used as a bad example |
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Thanks Mike!
I looked through your scans and thats basically whay I have execpt I didn't see anything to handle weight distribution changes under braking. I'd post mine but it's proprietary and Vette specific so it would take a bunch of work to be generic . I use the Dynalite, the Forged and Billet Superlite 4. Their piston sizes can be had extremely close to the Stock Vette specs, a few% smaller, but the pads have a higher coeficient of friction so it works out pretty good. Pad size is smaller than stock but that doesn't matter. It saves weight and makes the caliper more rigid. |
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In that little book I have, there are about 50 more pages of brake bias calculations, friction coefficient tables....
Ya'll want some more? Check out the StopTech white papers.. http://www.stoptech.com/tech_info/te...e_papers.shtml I haven't seen Wilwood have anything like that available for viewing by it's customers. But even if they did, It would do me no good. I wished I had paid some attention in math class. Later, mikey
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my signature lines...not really directed at anyone in particular.. BE different....ACT normal. No one is completely useless..They can always be used as a bad example |
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What about the Brembo calipers that are used on the Mitsubisi Evos? Would these be adiquate for hotrod applications?
Shane |
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Asking fer more, eh Shane?
Brembo sells about 3 or 4 different calipers for street use, but , the only way to buy them is in a kit form for a specific car. They are top of the line, but with them , there is no support for building a custom kit. You have to try and find a kit that is close to what you need, then modify it to work..I spoke with the guy at Brembo America for several hours one day, he clued me in on how to navigate their site for sizes and such. ![]() Here is a nice technical drawing of that caliper, click for a pdf.. http://www.brembo.com/CatalogoHPGT/D...i/family_M.pdf There is a way to find out some dimensions, but others are unavailable...Like hat thickness...it is nowhere on the website and brembo won't give out the dimensions... You can see a rotor, but no hat. http://www.brembo.com/CatalogoHPGT/D...0957591323.pdf Now the funny thing about that brembo rotor, is that no other manufacturer makes a hat for it...Wilwood has a bunch of rotors and hats, but they won't work with the Brembo stuff. Baer , is the same, so is StopTech. No one is giving up doodly squat. Although Baer WILL sell you JUST a caliper, and you can buy some Wilwood rotors to fit your spindles, the 6 piston Baer calipers are 1200.00 EACH.....The 4 piston PBR calipers from Baer are a bit better, at about 550.00 each bought seperately from a kit. Those work well on a 3500# car with 13" rotors, I've installed a few. I will say that the Wilwood catalog and product line is by far the most accesssable, and you can truly build a custom system out of their selection. For a decent price... Someday I'll get up enough nerve to buy a set of their forged calipers and mess around with it on a car. Coleman racing is another good source for racing brakes, pedals rotors and all kinds of other stuff..They will even make custom hats for those brembo or baer or stoptech brake rotors..at 250.00 each... http://www.colemanracing.com/catalog...47607eb4705d74 I had so much trouble with trying to get a set of something other than Wilwoods for the Imperial project, that we bought a set of zo6 'vette calipers for it off of Ebay, and will get some 14" Wilwood rotors to fit the spindles. Then all I need to do is get a MC that is the same as the vette, duplicate the booster and pedal ratio, and we should have a good stopping 4500# Dodge. That will be a cool car..68 Imperial with a 440 dodge, 700r4 trans, 9"rear end with Corvette brakes.. Johnny Cash car. I think it's miller time. Later, mikey
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my signature lines...not really directed at anyone in particular.. BE different....ACT normal. No one is completely useless..They can always be used as a bad example |
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I think that some came stock with the brembos.
Shane |
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I am a mechanical engineer and have spec'd out a few brake systems. I haven't yet written a program or made my own spreadsheet to do all the calculations. There are a few however and one of them is in here.
http://www.pirate4x4.com/tech/billavista/Brakes/ |
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Thanks Triaged, that is one of the most informative articles I think I've ever read regarding brake systems.
It explains the laws of physics as they apply to braking in terms that even I can understand...and that calculator will be looked at with great interest ..(once I get it on the shop 'puter, home has no excel.) later, mikey
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my signature lines...not really directed at anyone in particular.. BE different....ACT normal. No one is completely useless..They can always be used as a bad example |
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Let me recommend two great books.
Aircraft Spruce and Specialty Company's catalog. It's free at 1-877-477-8723. It's were I buy lots of nifty stuff like composite materials, 4130 sheet and tube, hardware and some aluminum. Take a look at their website at aircraftspruce.com. And; Automotive Handbook by Bosch. It's about $45.00 at Amazon.com. Yes Paris, it's a little spendy and you're right, my nephew gave me mine. The Bosch book is an excellent resource for design considerations and engineering references with pros and cons on different designs. It has about 800 pages with about 50 pages on braking systems. See Paris, I did get something in here about brakes. |
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