Wilwood G Body brake kit - any good?
 

Looking for real world feedback on the Wilwood brake kit now offered for the 911.

https://www.wilwood.com/BrakeKits/Br...axle=Front+Kit

How does it all work on the track? Bias OK with stock brake master cylinder? Did everything bolt up nicely?

I am thinking of installing this kit and running some track days. I have a Garmin Catalyst so could do some before and after comparisons on braking points and Gs pulled etc... Would be interesting, right?

Thanks

Overkill , unless you have doubled your horsepower magically these components won’t come into play , if you were to go ahead and bite the bullet your stock M/C would need upgrading at least to turbo 23 MM …Bert

what front struts do you have / what year car?

I guess print advertsing still works- that add in Panorama was great.

I spoke with a long time engineer and sales rep from Wilwood about this at VIR a few years ago. At the time they are working on edging into the European market. Apparently they chose to start on the G body cars- we're all for it and excited to see what they come up with for the late model stuff.

We sell Wilwood, give us a call and let's get some real world feedback.

--Aaron

I looked into them in depth and called the company a few times. My primary concern was unsprung weight reduction. Their calipers weigh about half the weight of the Carrera calipers and there are few options out there for these cars. If you buy the four corners, it doesn't come with rear rotors so you have to use Zimmerman or OEM in the rear. I asked about bias and they said they come set up with OEM bias and that you can change it. The price is right and they have a good reputation on the track as "off-brand Brembos". I'm building my car in Germany and brake upgrades have to be TUV approved so went with Cargraphics instead but would've otherwise gone with the cheaper Willwoods. Not the answer you were looking for but hope it helps.

They really don't publish enough technical specs to have an opinion one way or the other, Their attitude seems to be trust me it's ok

I refuse to deal w/ people like that.

If you are only running a few track days then most brake upgrades aren't going to be worth the cost of entry

What you should do id learn to use the existing brakes more sparingly

use fresh Castrol SRF brake fluid, the best there is for stressed brakes

use high temp track oriented pads which will usually have a thermal brake built in.

add 964/99 style scoops to direct cooling air to the rotors

I'm sure it bolts up nicely. Wilwood makes kits that fit.

As far as bias - those calculations vs. stock are pretty easy - have you run them? I'm sure WW did - the ****ty WW kits are where idiots used WW parts and 'designed' there own kits.

I'm less happy with the 32 vane solid mount non GT37 rotor. It's already a smallish 300x28mm disc with a Superlite 16mm pad, that's 200 WHP/sub 3000 lb car range or so.

That was my point, yes i's easy enough to 'run the numbers' but the numbers need to be provided by the supplier. w/o complete valid specs you get to trust them, I wouldn't as I've seen too many poorly speced 'kits'

The point of a BBK is t enlarge the thermal envelope of the brake system, you don't need a huge increase in brake torque as the limiting factor there is the tires' ability to grip.

while increasing the thermal envelope it's important to keep bias and pedal feel as optimized as possible.

the easiest way to increase the thermal envelope is to increase cooling air flow, rotor size, rotor air flow characteristics and of course lighten the load through weight reduction w/ better technique.

stock 911 from '69 thru '83 use 284x20 and 290 x20mm rotors, in heavy use the fronts will tend to overheat much more than the rears, this can be moderated w/ good fresh fluid, track oriented pads and cooling air flow improvements and/or increasing front rotor size.
first step up in front rotor size is to use the '84-89 911 fronts 284 x24mm, the usual max is the 930 304x32 though bigger can be fitted, the nice thing about the '84-89 fronts is that bias and pedal are unaffected. For rotors thicker than 24mm a bigger caliper is required. Besides being larger the 930 rotors feature improved internal architecture that greatly improves cooling.

another strategy to alleviate front overheating is to move bias back, but there is a limit as to how far back bias can safely be moved, stock brake torque bias used through '83 is very close to the max useable. The only penalty for too much front is wasted resources.

usually but not always a bigger front rotor is accompanied by a bigger rear rotor. heat is much less of an issue in back, so bigger rotor is more of a tool to help keep bias where you want it though it does help keep the thermal balance optimized as well.

Thanks for the comments.

The car is an 85 911. I have owned the car over 30 years and done a a number of track days in those that time. It has cooling ducts leading to backing plates, stainless lines, and has used various track pads and ATE blue / gold fluid. I've pretty well maxed out the things you can do with stock pieces.
My front calipers need to be rebuilt (again) as the boots a crispy, and my front rotors are warped. So time for some maintenance. Bolting up new parts for $1500 that are lighter, and increase the diameter and width is pretty appealing.

Was also curious about these compared to those 930 ERX kits.

A friend just bought a willwood kit for his Miata and was very impressed with the quality and how light they are.

The cooling ducts/backing plates are useless way too small to move any meaningful amount of air, use 964/993 type A-arm scoops
https://cimg6.ibsrv.net/gimg/rennlis...fc3c2d7b20.jpg

Ate is a fine street fluid but it's boiling points are 388/536 wet/dry

Castrol SRF is 518/608 this is the one to use for thermally stressed brakes

warping rotors is a myth, most likely the pads have left uneven deposition this is normal and can be cleaned of w/ emory cloth

there are several different types of common rotor issues

holey rotors will crack most easily
https://cimg2.ibsrv.net/gimg/rennlis...c4e27603cb.jpg

It's also natural to develop hotspots
https://cimg2.ibsrv.net/gimg/rennlis...339734181a.jpg
If these hotspots a re blued when they cool the rotor is toast

Lighter means little in this context

if you want better brakes that work and bolt up out of the box and have great parts/pad availability but a set of Elephant Racing 930s and a 23.8mm m/c to run them.

You should try to find a OEM 930 setup, my friend who's a PCA instructor installed that in his 88 Coupe and he loves them.He bought the whole kit from Steve Weiner many years ago when they were still
somewhat affordable at the time.Nothing wrong with Wilwood, but if you can get a set of 930 brakes it would be perfect.Bill is the brake guru, good advice ...
As for my car,an 89 Coupe i got a smoking deal on a near new set of 996TT complete all around brake kit.The bias was completely front minded and it was dangerous when the road or track were wet.I ended up setting up
my brakes with a Fabcar dual master and Tilton bias valve setup and it was a bunch of fun outbraking GT3's in the black run group when i was doing PCA DE's !
It's gone back to street duty only now and i'm going to tone down the brakes a little and make them more user friendly.

Cheers
Phil

Wilwood has 14 "variations" of the kits.

Just select the year/model of whatever hubs you're running.

Basically there are "M" and "S" hub front kits- options are calipers only, 11.1" one piece rotors, and 12.9" 2 piece ultralight HPS 32 vane rotors.

The rear is pretty easy, 20 or 24mm thick factory rear rotors- calipers only or choose your 1 piece rotor (blank or slotted)

Not sure what size wheels most of you run- but this must be taken into consideration.

rennpartbrakes.com until this becomes rennpart.com

--Aaron

https://cimg2.ibsrv.net/gimg/rennlis...1a27193685.png

For fun I looked at the cost of 4 options:

https://cimg4.ibsrv.net/gimg/rennlis...0ab2c73afa.png

The OEM package is ATE, Zimmerman, Textar from a well known Porsche online site.
The Porsche kit is the same site, but using all Porsche parts and an stainless brake line kit
The Elephant racing kit is the street kit.
The Wilwood kit is the higher cost 12" front rotor kit and the complete rear kit with rotors.

So if you are doing a mild restoration and want to refresh your brakes what to do.... what to do. If originality is not a consideration the Wilwood kit is awful compelling. It has to be a step up for the original set-up.

The last thing to consider is cost
the first is what do you need

here's a survey of the brake stress index for a most stock 911 variants
https://cimg8.ibsrv.net/gimg/rennlis...4922b34db2.gif
For track you you really want to be under 325

If just modifying bakes the rotor sizes and cooling ae the main considerations

here are the thermal indexes for most stock rotors
https://cimg7.ibsrv.net/gimg/rennlis...8ee73e5f6f.jpg

here a survey of bias, torque and thermal performance
https://cimg2.ibsrv.net/gimg/rennlis...2c94b9e5ca.gif

a historical perspective of brake stress
https://cimg3.ibsrv.net/gimg/rennlis...5683f9b613.jpg

again Wilwood isn't included because they don't provide enough information

like piston sizes and do they have outer seals like stock, effective rotor diameter vs actual etc.

Thanks for your comments and information Bill. Much appreciated.

A barrage of information as always. Appreciate the level of detail you provide. What I'm fuzzy on is how do the various kits impact that brake stress index number? Would you just assume the 86 930 number carries over to the US Carreras if outfitted with the 930 brakes? I'd imagine the vehicle's weight plays a considerable factor.

Based on what you've said re: BSI number a stock US 3.2 Carrera wouldn't have adequate brakes for track use in stock form.

I think what I like many are looking for is "for application X you should select Y"

Good info. the 930 was always the factory hot setup, but ratty sets are what, 10k now?
The elephant kit is nice.
Master/rotors/calipers, fit under 15" fuchs, work with factory mounting

BSI melds, brake thermal capacity which is a function of rotor size, chassis mass and speed potential.

the bigger the rotors the lower BSI, the more chassis mass the higher the BSI, the more speed potential the higher the BSI

For a BBK to be worthwhile you want bigger rotors better bias and a better pedal feel, but the rotors can't be too big or they won't fit in the wheel space and there is a cost in unsprung rotating mass

for a 3.2 Carrera 930 brakes are about all you need, 304x32 front and 309x28 rear, these fit in 15" wheels 8 or 9, and w/ a bit of extra bother 7s

Finding rotors that fit can be challenging

911 rotors fit and 930 rotors fit but no other Porsche 1 piece rotor fits.,
in increasing order of thermal capacity
911 fronts are 282x20 or wider 292x24 or 930 304x32
911 rear are 290x20 or wider 290x24 or 930 309x28

front 2 piece can be found, you just need an easy to make flat hat so you could get various sized rotors to fit, apparently that's what Willwood offers

rear is another kettle of fish as you need ~330mm for a 2 piece that retains the parking brake, these won't fit 16'

so in back you use stock 911, or wide 911 or 930
and of course you need calipers that fit the rotors stock 911A fit 282x20, wide 911 A fit 282x24 930 or 964 or 993 fit 930 304x32

similarly in back

next you want bias optimized the old 911 1.491 is pretty close to ideal more front wastes brake resources more rear can get dangerous I use 1.426 in both of mine but the cars are specially setup for it, for fixed bias i wouldn't go any lower

930s are 1.579

You don't really need more brake torque unless you go to stickier tires, as the weakest link for brake torque is almost always the tires
and lastly pedal feel
you want a pedal ratio ratio( composed of hydraulic and mechanical specs) that gives a nice high hard pedal feel. the hydraulic ratio needs to be in the range 38 to 25 the lower the better to a point, the lower # gives a better feel at the cost of more leg effort, 32 is the low end that Porsche uses for street cars.

I have owned a specialty vehicle shop for the last 22 years, we focus primarily on domestic cars but have done our share of imports including early and late 911's. We install about 40 Wilwood kits a year, again mostly domestic. I've never had a comeback, ever. Not once. Their kits are well engineered and transform the braking performance of the vehicle. Of course, pedal ratio and master cylinder bore must also be correct, and the rest of the steering and suspension must also be up to the task. There's a ton of specs on the site, and virtually anything else you need to know is only a phone call away. They will actually pick up the phone and answer all your questions, I can't say the same about Brembo, AP or Baer. I've never installed the 911 kit, nut I have no reason to believe it won't work very well.