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Big Brake Upgrade

15K views 43 replies 11 participants last post by  RAH 
#1 ·
Would like to have some advice on big brake upgrade.
I have now sourced all the parts I need to do a complete brake overhaul and upgrade on my Passat, with multiple options for rotor sizes front and back.
I've heard that up to a 330mm(13.00) dia. rotor will be fine and I don't to worry about biasing. I'm really wanting to go with 355mm(14.00) dia. rotors. So with that option per what I've heard, I might have an issue with biasing.

Couple of questions, at what point do I have to really start worrying about brake biasing? If I put larger rotors on the back will that offset the difference of putting the 355mm rotors up front?


When I finally get to fitting this upgrade to my car I will supply pictures and all the info I've obtained to get to this point.
BTW, this is way beyond the W8 option I originally opted for.
 
#2 ·
Which Passat? Not many options on a FWD for rear brake upgrades. Rotor size is not the main influence on brake bias, pads make a larger difference and calipers can have a reverse effect depending on piston displacement and master cylinder size.
 
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#3 ·
Which Passat? My 98 GLX FWD.
I've found a kit from Stop-Tech that has 355mm front rotors and keeps the stock rear rotor dia for the W8. I know the regular Passat GLS does not have rear rotors as big as the W8 from stock.
So with some knowns between the W8 and regular Passat I can come up with some rough calculations and keep things proportionate. I've found a few brake bias calculators on-line that take into account many, many options.

I think with that I can come up with some comparisons between what I have and what I'm trying to achieve.
 
#5 ·
I did an upgrade on mine a long time ago (2004) with the Audi TT 225 set up, 312mm front. All that need to be changed was the rotors and the carriers and it worked out very well! i did EBC rotors, slotted and dimpled and EBC red stuff and blue racing brake fluid. To this day, that set up works very well! I have been thinking of upgrading once again to the 355mm upfront and place the 312 in the back, but more work is required for that to happen and we will be working on the power upgrade for her as well.
 
#7 ·
the 355mm upfront and place the 312 in the back, but more work is required for that to happen.
That's close to what I'm wanting to do.
Here's what I have:
Picked up a set of aluminum steering knuckles, wheel hubs, and 2 piston Lucas calipers from member vwb5t.
I also have a second set W8 aluminum steering knuckles, purchased a while back from eBay.
I just purchased a set of front 6 piston and rear 4 piston calipers from a 2004 VW Touareg. Those will be here next week.
I have the 355mm and 330mm front rotors but haven't gotten the rears yet. Still haven't decided what size. Will probably end up putting the regular W8 front rotor on the back.
With the Touareg calipers, I'll need to do some custom fab work to get those to bolt up to the A8 steering knuckles. Different size bolts. If my memory is correct, the Touareg uses 16mm and the Passat/Audi uses 14mm caliper mounting bolts.

I have enough parts here to do two front upgrades. I'm actually thinking of taking the second set and upgrading my wife's 2003 GLX front brakes to the standard W8 set-up.
 
#8 ·
The reason for this upgrade on my car is simple, I live and drive in Phoenix. There are an alarming number of complete idiotic ass-clowns down here that don't have any clue on how to drive, and do 100 mph whenever they see a few hundred feet of open space on the road. A few months back I had a harrowing experience because of one these douche-bag ass-hats. I vowed to myself I would never let that happen to my wife and I again. Yeah I know I can't control other people, but being able to stop my car in a much quicker and shorter distance than factory is goal number 1!

This is a daily driver that sees rain maybe 6 times a year, a lot of highway driving. I have a set of 19" staggered wheels that I will probably put back on my car. I'd rather have 18" wheels but will see how much of an outlay I'm going to be up against first.
All this purchasing of parts for the brake upgrade (very cheap compared to a new kit like say Brembo) and all the other stuff I'm going to do to the car is ramping up quick. I'll need a new set of shoes for the 19" wheels. New rubber for the 19 inchers is cheaper than new 18" wheels and new rubber for them.
If I stick with the 19" wheels the size will be P235 in front and P265 in back. At the same time I will be swapping out the factory suspension and putting my PSS9 coil-overs in.

The reason for the (2) different front rotor sizes, if the 355mm front rotors create a squirrely braking condition I'll downsize the fronts to the 330mm. This isn't just about straight line braking. I need this car to be able to brake in any scenario. Which will be tested before I just go pound down the road.
 
#9 ·
I installed a set of 13.1" rotors with stock calipers on a Supercharged B5.5 V6 4Mo sedan (it was ECS Stage2 or Stage3 many years ago). The owner used PBR Ultimate pads up front and PBR Metal Masters on the stock rear brakes. That car could stop like it ran into a brick wall, even with OEM brake lines. The 330mm will be plenty with decent pads.
 
#10 ·
Hello Andreas,
"I need this car to be able to brake in any scenario." I don't know what this means, but it sounds scary. I don't know what driving in Phoenix is like, but reckless drivers are everywhere. Being able to stop on a dime "in any scenario" does not sound like an enhancement of your defensive driving skills. Yesterday, here in North Jersey, a driver of some kind of Ford SUV, decided an 18 wheeler was driving too aggressively in the left hand lane. The Ford got in front of the truck and hit the brakes (just ordinary Ford brakes, I imagine). The truck (air brakes) panicked and flipped onto the median divider and slid on the divider for half a football field. Fortunately, no one was killed. In the interest of fair play, both drivers were charged. There were no winners.
 
#11 ·
I completely understand where your coming from, and you're right. It is not an improvement of my defensive driving skills. But I want my car to respond the way I want it to without losing control. Better tires, bigger brakes and a suspension that is second to none will fit that bill nicely.
Phoenix is not the worst for epically bad drivers, LA, Atlanta and Houston have their fair share too. I've driven in the 3 previous areas mentioned, but it just seems as though Phoenix drivers drive much faster most people anywhere else.
I've been to Houston a number of times and they drive fast there, but even faster in Phoenix.

I know in reality my car won't stop for every type scenario or situation I get into, but I'm looking for a MAJOR upgrade from factory so I can stop with much shorter distances when all hell happens in front me. The two biggest things I see down here are people driving in the carpool lane and suddenly realize they need to be getting off on the next exit that's less than a football fields length. Those people suddenly slam on the brakes and cut across 6 lanes of traffic like they're making a right hand turn.
The other major offense I see is people wanting to get into the next lane or the lane your in and they just move over, like now! Traffic regularly moves between 70 and 95mph on average, bumper to bumper, when it's moving. When somebody just decides to move over, more times than not I don't have any place to go except slow down to avoid getting my front corner clipped off. I need to have my car slow down in an instant to avoid getting wrapped up with the asshat who just decided to get in front of me because the rear of his car hasn't cleared the front mine yet. That miniscule moment of time that I need to slow down to avoid being hit is to short of a time for the factory supplied brakes to perform what I need them to do. but then just as fast, I need to be off the brakes so the guy behind me doesn't end up in my trunk. I haven't even been here a year yet and I have seen more epic accidents than all my years living in WI combined.

Side note.
I don't really condone such high rates of speed in such congested areas, but when everyone on the road is doing 85mph in a 55 or 60mph zone, being the keeper of speed is not very safe either. That just causes everybody to run right up on the tail of the person who is driving by the legal limit, and then at the very last moment decide change lanes. You then end up with a continuous chain of people swerving left and right to avoid the 'slow person'.
 
#12 ·
GrandpaBill

I was trying to think of an analogy in my previous post. It's like comparing a 1972 Ford Pinto to a current Porsche 911 Carrera. While the Pinto has the all necessities to go down the road, the Porsche is far superior in everyway. That's a comparison to what I'm trying to achieve. The Passat is a fairly capable car right of the box, but I'm looking for something much more refined.
 
#15 ·
Can't wait to see.

On a side note. I got cut off yesterday afternoon on a busy road with no warning (sometimes they put the turn signal on to let you know they are coming over whether you like it or not). The guy got a blast from my horn as a sign of disapproval. At about 50mph, the jackhole brake checked me to an almost dead stop. The TT/A8 caliper/rotor combo made it feel like I hit something, it stopped me so hard. Tires were scrambling for traction to keep the ABS from coming on. Anything that was laying on the seats was now on the floor. That's in a B5.5 wagon. Can't imagine what your new setup would feel like.


That was my first thought. You can brake hard enough, but the guy behind you most likely cannot.
 
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#14 ·
The Touareg calipers came yesterday. Holy crap those things are HUGE! The 17Z brake pad is as big as the factory Passat caliper.
Will post pictures soon.
 
#16 ·
I just got back from a trip to Sweden in a Volvo V90 with all the assist features and heads up display (great for keeping you close to the ever changing speed limits there). Outside of Amal, (famous for this film that had to be renamed in English: https://en.m.wikipedia.org/wiki/Show_Me_Love_(film) ) a student driver had whacked a Bambi and stopped completely in the middle of the road right past a hill. All the alarms and brake assist turned this into a drop-the-anchor perfect stop non-event.
Only tangentially relevant but wanted to share. Something tells me I’ll be driving a gizmo-machine in the next few years.
 
#20 ·
In the end I'm wanting to go with 18inch wheels, But I'm not 100% sure those are going to clear the caliper.
I do have a set 19inch wheels that I can use if need be. My only reasoning for NOT using the 19inch wheels is the distance between the road and the lip on the rim. While most of the roads here in AZ are decent, compared to WI they are stellar, I'd like to have just a smidge more room. But then again, I ran the 19inch wheels in WI for almost 2 years without bending the rims. That's saying something. Might as well just use them and be done with it.
 
#21 ·
Was perusing around the internet last night and found an older Big Brake Upgrade post from 2009 from some member back then, be darned if I can find that post now.
But anyways, The OP of that post did basically the same thing I'm wanting to do, and claims the Touareg calipers fit inside a stock 17" wheel. I think a 5mm spacer was used to clear the spokes of the wheel and caliper.
When I find that post again I'll put a link to it here.
 
#22 ·
Took some time tonight to get most of the parts out of the boxes they came in and roughly lined up the caliper to the W8/A8 steering knuckles (uprights). The mounting pattern (distance from both mounting holes) on the caliper is exactly the same as the steering knuckle. Might have to ream out a mm or two in the upright and viola, the caliper will be mounted to the upright. At this point in time I'm trying to find the part number for the Mercedes Benz 330mm x 32mm rotor. Whatever year/model rotor it is, it's a direct fit for the specific upgrade I'm doing.
 
#23 ·
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#24 ·
#25 ·
Otra Vez!
It happened again today! 60mph power slide because some douche bag ALMOST ran me off the road. Thank goodness my ABS module is out for repair otherwise I seriously doubt I'd be writing this now.
Dead even with some person (them in the #2 lane I'm in #3 lane ) she just starts moving into my lane like I didn't exist. I had stand on the brakes because I literally ran out of road on my right side. Car went into a slide at about a 30 degree angle in my lane with the front pointing towards the #2 lane. I seriously don't know how I got out of that without trading paint colors.
 
#27 ·
The second time I had to stand on the brakes the car slowed down considerably but my car pulls very hard to the right during heavy braking, so in between sliding and not sliding, if ABS would have been hooked up I would have for sure been sandwiched between this person and the concrete wall on my right.
There is something definitely wrong with the left front caliper that keeps it from applying the same amount of braking force as the right side.
I've had that problem before. The caliper is binding somehow. When I finally get to repairing all the stuff on the list this will be included. A complete overhaul of the whole braking system. New master cylinder, complete system flush with alcohol and whatever else it may need.
 
#28 ·
Wanted to do a rear brake upgrade for the looks after I installed the A6 321mm rotors and calipers. I often heard that Passats chew up rear rotors and pads. I assumed that my rear pads and rotors were worn out so I bought a set. To my surprise they were actually in pretty good shape. I guess since my front brakes as so much more efficient my rear brakes don't have to work as hard.
 
#30 ·
Actually, quite the opposite on the B5/5.5. I replace fronts 2x on average to every rear brake replacement. My first set of rear pads made it to 70k. Same thing when my wife had her B6 A4.
 
#31 ·
It varies depending on the model. My rear pads have over 100K and are still in great shape, well over 50% remaining; PBR deluxe and no visible wear on the rotor. I would have to check the mileage on the fronts, but they are also holding up well, but the rotors do have some lip. I tend to coast and downshift to slow rather than use the brakes, so that helps. I also tend to take corners a bit faster than average, saves the brakes, eats the tires.
 
#32 ·
I regret I don’t have much to offer in terms of brake upgrade topic but I may contribute to the topic of idiot drivers. I think the dumbest drivers are across the south east, particularly in Atlanta area, where I am now.
I have seen people coming to a complete stop at the merge ramp onto I-75 with the terrified and panicked facial expression, people smash their brakes on a mild curve or slope, which I believe they are concerned that their 2018 mustang may roll over. The most annoying drivers are those who are on the phone doing 55-60 mph in the 70mph highway passing lane. (Although it’s illegal to hold the phone driving)
I figured it out tho. I realized that every damn soul has to drive in the United States in order to survive ; the too young, the too old, those inept dumbasses who are not supposed to sit at the wheels etc. there is no advanced public transportation. Plus everyone gets drivers license in 15 min. In Europe, the left lane occupiers are rare occurrence and if it happens, they are collectively punished by other drivers. I love watching on YouTube the 250-300 kmph pulls on the German autobahns, (where there is no speed limit) and the passing lane is always empty. There is no way you can do a 70-75 mph constant driving here. Even on a 6 lane highway. Everyone picks a lane and adopts it, driving however they want until their exit.
Is there a state in America where the drivers are relatively better? I swear sometimes I feel I could move there if such place existed.
 
#33 ·
Germany is no car paradise either, but the big difference is that driving school is actually thorough and challenging. You will probably fail the first time, because it’s not about your experience, it’s about knowing rules and rights of way, and you get observed in a 45 min drive through various scenarios.

My son in the US has his learners, and he wasn’t clear about flashing stop lights and the full meaning of “right on red after stop”. The basic of the basics in my book, but hey this is ‘Murka.
 
#34 ·
Hey Andreas-

The other day I was searching for some unrelated stuff when I stumbled across this thread....it was the first time I had heard about the T-reg/Cayenne 17z/18z mod....and even though I have more than enough projects to address on the Unicorn I can’t seem to stop thinking about this damn brake upgrade! I just wanted to get an update on your impression of the “new” BBK since you’ve had it installed for a while now. Any issues that stick out in your mind? Advice or suggestions are welcomed!

Thanks man!
 
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