Wilwood Dynalite Brake Upgrade

For road racing, autocrossing, or just taking that curve in style. Oh yea, and stopping!
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Wilwood Dynalite Brake Upgrade

Post by FJCamper » Fri Oct 02, 2015 4:16 pm

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Wilwood Dynalite (about $125 ea) caliper being fitted to our LeMons SuperBug. That's silver anti-seize on the rotors and studs. We plumbed a brake bias valve into the front circuit to adjust for modulation, and were very happy with the result.

Porsche was last to the street sports car disk brake crowd, only installing disks to the 356C in 1964. Triumph, for instance, had front disks for the TR3 in 1956. Jaguar first raced on disks in 1951, winning LeMons with an XK120C roadster, and changed to four wheel disk in 1956-57 for the XK140 series.

Porsche believed its drum brakes were just fine for street and light track use (read club racing), but began experimenting in racing with disks in 1959 on a 356A in the Nürburgring, and took a class win. Disk brakes became the norm for most Porsche racers, but the street 356 had a problem. Designing a disk brake system for what the VW people today call "wide five" wheels was problematic.

The factory did design its own wide-five system but it was too heavy and bulky -- similar to but worse than the wide-five disk brake kits today. So, Porsche adopted the ATE (Alfred Teves GmbH) caliper with solid rotors to all four wheels on the 356C, which required a new bolt pattern, new wheels, and hubcaps. The one-year issue 356C then became the brake system test mule for the upcoming 1964-65 911.

The ATE caliper as first used by Porsche for the 356C, the 912, and the early 911's had dual 48mm front pistons and 35mm rear pistons.

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Finally, in 1967, VW decided to upgrade the Karmann Ghia to front wheel disks, the original single-pin ATE caliper design being updated to a larger two-pin ATE caliper and slightly larger pad in late 1971, officially for the 1972 model year.

The U-pin Girling that replaced the twin-pin ATE soon disappeared into obscurity, and the twin-pin ATE caliper became the standard in VW disk brake kits. The Girling caliper had to be removed from the car to change pads, so good riddance

The business arrangements are complex, but TRW and VARGA (of Brazil) copied the ATE design, and today, it appears the VARGA copy is being eclipsed by a generic Chinese copy.

There are small physical differences between the ATE-VARGA-Chinese versions. For instance, the VARGA rebuild kit is not guaranteed to be the same as the ATE kit. I have personally compared the more recent VARGA kits to original ATE, and seen differences, and talked to others who saw none for the first VARGA kits made years ago.

And the bleeders can be different between all of them. The Chinese bleeders are the largest of all.

When fitted with high-performance pads, the ATE design caliper is very effective, so much that on stock pads and bias-ply tires, back in 1972, a 70-0 panic brake test in Road & Track a disk/drum Ghia stopped quicker than a 911.

That implies that the Ghia had better brakes, right? No. just better at 70 and under because the Ghia was lighter.

The 911's brakes were better over 70mph. Specifically, the 911 could slow from 100 to 70 with force and control. Or from 130 mph to 100.

To get brakes equal to that for your VW takes two things. The first is the power to get to 100 mph and exceed it. The second is brakes big enough, with sensitive modulation, to stop in a straight line, lap after lap.

Brakes that are too big, with poor modulation, in any street car only cause lockups at low speeds. Common street driving speeds. That means bigger brakes don't fix sliding, they can cause sliding.

The Wilwood Dynalite caliper, made of forged aluminum and packing four 37mm pistons, was actually designed for average weight (2500 to 3500 lbs) street sedans with 300 HP. Lots of short round track V8's use them.

We VW people are lucky the Wilwood Dynalite caliper, working with a 19mm to 20.6mm VW master cylinder and the stock VW brake pedal leverage ratio, can be modulated well enough to be raced and even driven on the street.

At one time, 924 or 944 brake upgrades for the VW sedan or Ghia were the thing to do. Now, the Wilwood upgrade is easier and the payoff as satisfying.

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The Wilwood pad has about twice the surface area as the ATE. This is better for pad life, cooling, and stopping friction.

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Our custom-made 5.25-inch space caliper brackets come from http://www.vdubengineering.com They produce quality hardware.

Vital tech note for those who are planning to use one of the black-billet EMPI brake bias valves. On ours, the IN and OUT ports on the body were reversed. And they are engraved, not just marked with paper stickers. When we installed the lines off the master cylinder the marked way, the IN coming from the master cylinder and the OUT going to the brakes, the brakes would drag and lock. We actually found this same warning on the Internet from an EMPI bias-valve user. Hooking the lines up "backwards" fixed it.

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FJC

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Re: Wilwood Dynalite Brake Upgrade

Post by doc » Sat Oct 03, 2015 9:51 am

Great write up and pics! Thanks.

doc

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Re: Wilwood Dynalite Brake Upgrade

Post by Steve Arndt » Sat Oct 03, 2015 11:07 am

I have a link pin CB drop spindle brake kit with ghia type calipers. Their standard kit. I notice vdubengineering and many other places with adapters don't offer anything for the dropped disc spindle. They support the dropped drum spindle where the adapter bolts in place of the backing plate as shown above. I want to make a basic bracket that bolts to the disc caliper area on the cb dropped spindle to go from the standard small ATE ghia caliper bolt pattern and adapt to the Wilwood spacing. Nobody offers this adapter so I assume there is a technical reason. I haven't measured it to see what the hold ups would be. Any ideas, has anybody done this?

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Re: Wilwood Dynalite Brake Upgrade

Post by Piledriver » Sat Oct 03, 2015 3:35 pm

You can get generic weld or bolt on prefab caliper mounts for the Wilwood calipers.
Should be relatively straightforward to grind a little off the outer edges of of the factory spindles for clearance and add a crossbar, or fab something similar to the mounts shown above.

The (lower two) pictured calipers are actually the old style forged billet dynalites.

I scored a set of the newer style forged dynalites, attracted by price and very light weight, but Superlights are far better calipers, much stiffer, esp if you install the optional bridge bolt, and cost little more.
(harder to find killer deals on though, I picked up a pair of used dynalites for $90, internally indistinguishable from new, off a race car, they probably swapped to superlights)

Forged dynalite:
http://www.wilwood.com/Images/Caliper/C ... ite-lg.jpg

Forged superlight ("internal" crossover plumbing, recent units)
http://www.wilwood.com/Images/Caliper/C ... nal-lg.jpg

The superlights use far more common 3.5" caliper bolt spacing...

I need to find a set of shorter bolts as I really don't need 1.25" rotors, removing the spacers they become .81"s.
There are different models for various widths, most just use different cross bolts/spacers.

Another method I intend on attempting this fall is using the Wilwood/coleman steel hats over cut down stock drums/discs as hubs. This is intended to adapt for the light+inexpensive+excellent Coleman rotors.
(surprisingly couldn't find any reasonably priced aluminum hubs for VW)
This will probably be the setup on the 914, perhaps the T3.

The end result should still be at least 3-5 pounds/corner lighter than stock (unsprung weight), even with much larger ventilated brakes.

Performance Friction sells pads for all of these in a huge array of compounds, including a "street" compound (20)

Oddly, you can order them at O'Reillys Auto Parts, but you can easily beat their price online.
(they may price match)
Last edited by Piledriver on Mon Oct 05, 2015 1:25 am, edited 1 time in total.
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Re: Wilwood Dynalite Brake Upgrade

Post by andy198712 » Sat Oct 03, 2015 4:18 pm

How much of an issue is no dust seal on a daily though?

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Re: Wilwood Dynalite Brake Upgrade

Post by PhillipM » Sat Oct 03, 2015 4:58 pm

Wasn't a big issue on ours, just clean the pistons before you push them in to fit new pads, they didn't like being stood for long periods in damp conditions though - dragged a little until they'd been warmed up. Saying that, I've just switched to the midilites with the dust seals anyway:

Image

Same pad, not much more money, nice thick beam for stiffness.

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Re: Wilwood Dynalite Brake Upgrade

Post by Piledriver » Mon Oct 05, 2015 1:26 am

That EMPI brake bias valve is the usual pressure limiter style?
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Re: Wilwood Dynalite Brake Upgrade

Post by FJCamper » Mon Oct 05, 2015 3:24 pm

Hi Piledriver,

Yes, the EMPI bias valve appears to be conventional in every way with the exception of the markings being reversed.

We were just plain puzzled by our brakes dragging and locking after we installed this valve, and on Googling up info (we were desperate) saw a product review from a customer who had bought one and he said his was backwards. So we reversed our lines so that the line from the master cylinder front circuit went to the OUT, and that fixed it.

At the track, we began with the valve full open, and on our Friday practice day before the SAT-SUN race, while bedding in our brake pads, tightened up two and one half turns until pedal modulation felt good at 100mph to 75mph panic application and there was no low speed lockup.

We did get enough racing laps in to get the brakes and fluid operationally hot, get the oil temp up to 220 F.and there were no surprises. The race morning temp was dry and cool, middle 60's I'd say, so we had weather on our side.

We were on the same 60-series Accellera 205 front and 225 rear tires that boiled our fluid in similar weather, same track, back in May. A change down to 50-series tires fixed the fluid boiling. The Wilwoods are letting us use the 60-series tires now.

FJC

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Re: Wilwood Dynalite Brake Upgrade

Post by Piledriver » Fri Jan 01, 2016 11:44 pm

PhillipM--- what rotors are those?
Ceramic coated aluminum?

I was... bad today...

Finally got some Speedway steel hats, it all looks like it dimensionally works out almost too well.

Have all the bits in hand or coming to redo the squarebacks brakes, Forged Dynalites up front, very slightly modded Speedway 8x7", 3" offset steel hats (opened .002" to be 78mm hubcentric and modded all 4 hubs to suit, centering the hats as well, even my rears have been hubcentric for a few years now)

This is probably a qualifying round for the 914 brakes this spring, may still go with wide5s on that just to try it. (not VW, Wilwood, have most of the junk to do it, the fronts almost trivial, rears may need the "big bearing" setup)

This is bizarrely going to save me money (or cost very little extra) vs buying new stock front rotors and 914 rears.
I couldn't find new T3 late front rotors that were actually hubcentric anyway, so I'm punting.
I have already spent stupid $$$ on shipping trying.

The delta in rotor costs alone make this almost sane, esp as I have a full set of Wilwood 11.75" rotors in hand.
Speedway sells decent rotors for 8x7" for $25, Wilwood gets $35...

Scored a staggered set of nice & cheap 16x6-16x8 928 slots ET50ish. Too bad they'll hide the new brakes.
Needed new tires anyway.

2015 Mustang GT rear calipers ($99 for the pair new pulls allegedly) should be workable with the 11.75x.810 rears and the forged dynalites/hats/vented discs etc up front. Bit bigger than the passat calipers on there, but should match the new fronts well.

Cut down some old 914 front discs as they were handy, free and hubcentric.
Bearings same/offsets close enough with the new hats/discs.
The hub offset is so close to stock its hard to believe.

May be able to move the rear hubs in ~1/2" and shorten the stub/nut to clear the porsche wheel caps
Won't do the former unless needed for wheel clearance.
I even have a full set of new studs and Porsche wheel nuts/locks on the shelf, and all the rotor hardware.

Will post pics when done.
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Re: Wilwood Dynalite Brake Upgrade

Post by Piledriver » Sun Jan 03, 2016 2:04 am

Gotcha of the day:
(aircooled) VW hubcentric vs. Porsche hubcentric

Went to pop the 7slots on the back of the square to see what spacers I'd need to clear the spring plate (1" looks plenty with the 245s) and had a #$%*^%$! moment.

VWs hubcentric size on the front of late 914s, t3, most factory steel wheel=78mm
Porsche hubcentric size is 71.3 (hub) or ~71.6mm (wheels) usually a tiny bit bigger to allow for corrosion/dirt.

I had previously only fitted Porsche rims to the 914, the rear of which is not normally hubcentric, so i didn't run into anything.

My rear T3 hubcentric modified hubs are of course for the 914 Mahles I'm running, so 78mm.
Will have to fix that after work Monday, along with cutting out the centering step for the hats, currently 914 rotor ID (via some silicon bronze TIG work, T3 rear hubs appear to be steel, but just in case)

Given time they'll become 5x130 and get studs as well...
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Re: Wilwood Dynalite Brake Upgrade

Post by Steve Arndt » Sun Jan 03, 2016 12:17 pm

Frank, how long until you get some racing in with the new brakes?

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Re: Wilwood Dynalite Brake Upgrade

Post by FJCamper » Sun Jan 03, 2016 10:19 pm

Hi Steve,

We run Feb 6th and 7th at Barber Motorsports Park near Birmingham, seven hours each day.

We're getting ready right now. Our enduro engine is a 2.2 litre 9:1 compression, dual Kads with 44mm throttle bodies and 34mm venturis. Barber is a uphill, downhill track with lots of curves. We tune for torque there to get out of the corners fast.

We're looking forward to it. I'm expecting good things from the Wilwoods, even though our intentions for them was slowing from way above 100 to 75. More Daytona or Sebring brakes.

FJC

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Re: Wilwood Dynalite Brake Upgrade

Post by PhillipM » Mon Jan 04, 2016 9:36 am

The discs are coated steel, I don't think ceramic coated aluminium would cope with the heat in that diameter - or the shock when they go through a stream whilst red hot.

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Re: Wilwood Dynalite Brake Upgrade

Post by VW&MGman » Wed Jan 06, 2016 8:21 pm

Hi FJ,

Would you know what the Wilwood part number is for those calipers?


Thanks,

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Re: Wilwood Dynalite Brake Upgrade

Post by FJCamper » Thu Jan 07, 2016 12:19 am

Wilwood Dynalite 120-6808 on Porterfield R4 pads.

We're aboot to really put these brakes to the test at Barber.

Flat towing the Bug the other day, the pickup truck driver felt a significant drag, enough so that in a few minutes he had to park and check out the problem.

Some parts and equipment tossed onto the floorboard, driver's side, and partially depressed the brake pedal, just partially, and he burned hell out of his fingertip touching the brake rotor to see if it was hot.

If we didn't fully bed the pads at CMP, they are bedded now.

FJC

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