B7 Front Brake Upgrade simplified

[DPDISXR4Ti]

I've read bits and pieces on this topic but I just want to verify that I'm getting the right stuff before I actually go ahead and do it. All I'm looking to do is a modest upgrade to better front brakes without adding much (if any) un-sprung weight. (i.e. So don't tell me about how much better the S5 calipers are, cause I don't need that much brake, and I hate the idea of adding weight at the corners.)

I think all I need is calipers (with brackets) and rotors from a 2005 - 2008 (B7) A4, yes? The existing brake line on my car will work with the B7 calipers, yes? What about the splash shield?

My understanding is that the 2006 - 2011 A6 also uses the same caliper and rotor should I go the low-mileage wreck route and want to broaden my donor options. Correct?

[MikTip]

I have the B7 A4 brakes on all 4 corners of my B6. You are correct about the B7 A4 fronts.
IMO you really need the rear brake too! They are 43mm larger than the B6 rears and balance out the
braking considerably! No clue on the A6 brakes.

[texasboy21]

I also suggest adding some stainless steel brake lines to your upgrade. They firm up the pedal considerably and help with initial bite. Goodridge are the hotness.

[rich045]

i have the b5 s4's, the only thing that weights a bit more is the rotor, the caliper doesnt weight much more than the stock b6 stock caliper. thats my .02 cents
the only advantage i see from the b7 a4 brakes would be wheels clearance?

[DPDISXR4Ti]

i have the b5 s4's, the only thing that weights a bit more is the rotor, the caliper doesnt weight much more than the stock b6 stock caliper. thats my .02 cents
the only advantage i see from the b7 a4 brakes would be wheels clearance?

But I think the B7 caliper actually weighs less than the B6 caliper, so overall weight (caliper & rotor) might be about the same. I've read up some on the other options, and the B7 stuff seems to suit my requirements best. I'd probably eventually do the B7 rears as well, but want to just get the fronts done sooner rather than later. Keeping the project focused on just that for now will actually make it happen.

[rich045]

But I think the B7 caliper actually weighs less than the B6 caliper, so overall weight (caliper & rotor) might be about the same. I've read up some on the other options, and the B7 stuff seems to suit my requirements best. I'd probably eventually do the B7 rears as well, but want to just get the fronts done sooner rather than later. Keeping the project focused on just that for now will actually make it happen.

anything you do will definitely upgrade the brake feel. Even though my b6 came with new pads and rotors, the car felt like it could not stop on time. I am not sure how to describe it but going from a 2 pot caliper on my subaru to this, it felt iffy. After i did the b5 S4's, what a big difference it makes, the larger rotor and 2 pot caliper definitely makes me feel like i can stop on a dime.

[MikTip]

i have the b5 s4's, the only thing that weights a bit more is the rotor, the caliper doesnt weight much more than the stock b6 stock caliper. thats my .02 cents
the only advantage i see from the b7 a4 brakes would be wheels clearance?

Factory Audi went to a larger calipers and rotors for the B7...because the B6 brakes were terrible!
The advantage of the B7 brakes are much improved braking over the B6's.

[texasboy21]

But I think the B7 caliper actually weighs less than the B6 caliper, so overall weight (caliper & rotor) might be about the same.

The difference in caliper weight is moot and can be made up by dropping a couple of gallons of gas in the tank. The larger and heavier rotor (compared the the stock B6) will make your car feel slower, and the steering heavier. Its essentially the same thing as adding on massive wheels and tires.

Im not sure of the weight of the stock rotors, but my 321mm Zimmerman rotors weight 19.x lbs!

[rich045]

The difference in caliper weight is moot and can be made up by dropping a couple of gallons of gas in the tank. The larger and heavier rotor (compared the the stock B6) will make your car feel slower, and the steering heavier. Its essentially the same thing as adding on massive wheels and tires.

Im not sure of the weight of the stock rotors, but my 321mm Zimmerman rotors weight 19.x lbs!

if anyone has the b5 s4 brakes laying around or the b7 a4 brake set up, we can do something for comparison cause i have the b6 a4 calipers, rotors, pads and lines still attached, i can put it on the scale and weight it.

[rich045]

well i got bored and did this.

calipers (with pads and lines) weight 26.6 and rotors weight 32.8 so the grand total for stock brakes is 59.4 lbs.





yea, i was bored at work, lol

[DPDISXR4Ti]

The difference in caliper weight is moot and can be made up by dropping a couple of gallons of gas in the tank.

That's not true at all. There's a world of difference between un-sprung weight and sprung weight.

[Charles.waite]

weighing used rotors is somewhat pointless. Besides centric posts weights on their part finder website for rotors.

B7 calipers do indeed weigh significantly less. The reason being is that the inboard half of the caliper is aluminum rather than cast iron.

And yes sprung weight (and rotational weight even in the case of rotors) can play a huge role. I went to b6/7 S4 calipers which are the same as b7A4 calipers except the carriers are larger to clear 345mm rotors and I will say the overall weight it definitely higher due to the significantly larger rotor (remember area and therefore volume increases by the square of the radius) however the braking is MUCH MUCH improved.

You need b7A4 or B5S4 rotors (they're the exact same) for B7A4 calipers. You also need the caliper as well as the carrier. A6 calipers will work. They will list 320mm or 319mm but they are indeed the same and the radius difference is due to the difference in hubs and rotors not calipers or carriers. I can't really confirm what years came with these calipers though. if they look physically the same as the B7 A4 calipers they likely are.

B5S4 calipers are quite heavy, like the b6 calipers because they're all iron. Likewise the S5 calipers are all iron I believe.

[MikTip]

Unsprung weight on a street drive car is moot!

Dont think anyone here is that sensative to feel the weight differance between B6 & B7 brakes....while driving.

[MikTip]

If you are, swap out the rear suspension knuckle for the S4 aluminum knuckle!

Its 5 pounds lighter than steel B6 version!

[Charles.waite]

Dont think anyone here is that sensative to feel the weight differance between B6 & B7 brakes....while driving.

My car felt like it would crash a lot harder over potholes and expansion joints after my S4 fronts. Centric lists the S4 345mm Front rotors as 25.5lbs while it lists the 288mm A4 fronts as 17.5. 8 extra lbs at each front corner is somewhat significant. Having said that my suspension is quite worn and my control arms are toast so if they were refreshed I doubt I would have noticed the difference. I think the extra weight is simply putting too much stress on the already shot bushings and ball joints...

If you are, swap out the rear suspension knuckle for the S4 aluminum knuckle!

Its 5 pounds lighter than steel B6 version!

That. Plus it adds like 10hp because its an S4 part...

[DPDISXR4Ti]

Unsprung weight on a street drive car is moot!

Dont think anyone here is that sensative to feel the weight differance between B6 & B7 brakes....while driving.

My guess is that between the lighter B7 calipers and the heavier rotors, it's going to come in about the same overall. As Charles indicates, going with the B5 S4 calipers, you're going to be heavier and it IS noticeable for anyone who drives with a reasonable attention level. I know when I shaved 7 lbs off a corner by going with lighter wheels (on a different car), it absolutely was noticeable. So in short, your opinion is moot! :)

As to the AL S4 rear knuckle, while I realize your comment was somewhat in jest, the front is much more sensitive to un-sprung weight changes than the rear.

[texasboy21]

That's not true at all. There's a world of difference between un-sprung weight and sprung weight.

Thats correct, but I said calipers not rotors.

[DPDISXR4Ti]

Thats correct, but I said calipers not rotors.

I'm not sure what your point is then.

[ADCS]

well i got bored and did this.

calipers (with pads and lines) weight 26.6 and rotors weight 32.8 so the grand total for stock brakes is 59.4 lbs.

yea, i was bored at work, lol

Just to add to this....Here are weights of the B8 S5 and B6 A4

B8 S5:
Front caliper, with flex line = 9.8lb (4.445 kg)
Front caliper carrier = 5.1 lb (2.313 kg)
Front rotor = 25.6 lb (11.612 kg) [NEW Centric high carbon blanks]
Front pads, no sensors = <5lb so my scale didn't pick them up, I would guess about 3.5-4.0 lb (1.588 - 1.814 kg) [NEW StopTech street performance]
Total static weight, one corner: 44.5 lb (20.185 kg)

B6 A4, 1.8T: - Pads/Rotors have 32,612 kms on them.
Front caliper, with flex line = 7.6 lb (3.448 kg)
Front caliper carrier = <5lb so my scale didn't pick them up, I would guess about 3.0-3.5 lb (1.361 - 1.588 kg
Front rotor = 15.8 lb (7.167 kg) [USED Zimmerman blanks]
Front pads, with sensors = <5lb so my scale didn't pick them up, I would guess about 2.5-3.0 lb (1.134 - 1.361 kg) [USED Hawk HPS]
Total static weight, one corner: 29.9 lb (13.562 kg)


Delta per corner: 14.6 lb (6.622 kg)
This increase IS noticeable due to the vast increase in moment of inertia.

[MikTip]

My guess is that between the lighter B7 calipers and the heavier rotors, it's going to come in about the same overall. As Charles indicates, going with the B5 S4 calipers, you're going to be heavier and it IS noticeable for anyone who drives with a reasonable attention level. I know when I shaved 7 lbs off a corner by going with lighter wheels (on a different car), it absolutely was noticeable. So in short, your opinion is moot! :)

As to the AL S4 rear knuckle, while I realize your comment was somewhat in jest, the front is much more sensitive to un-sprung weight changes than the rear.

So you "noticed" 7 pound reduction in the weight...on a different car...but not an Audi B6 Quattro?

Not the brakes, but a reduction in the wheels?

Funny I thought were were discussing weight differance between B6 & B7 brakes...

Dont think anyone here is that sensative to feel the weight differance between B6 & B7 brakes....while driving.

Noticable for any one with a reasonable attention level....Hmmmmm...

[MikTip]

- a lighter wheel which readily moves in response to road bumps will have more grip and more constant grip when tracking over an imperfect road. For this reason, lighter wheels are sought especially for high-performance applications. In contrast, a heavier wheel which moves less will not absorb as much vibration; the irregularities of the road surface will transfer to the cabin through the geometry of the suspension and hence ride quality and road noise are deteriorated. For longer bumps that the wheels follow, greater unsprung mass causes more energy to be absorbed by the wheels and makes the ride worse.

http://en.wikipedia.org/wiki/Unsprung_mass

[DPDISXR4Ti]

I haven't installed these yet, but here's what it will cost to do my B7 front brake swap
Low-mileage used B7 calipers w/ pads $70
New black oxide coated B7 rotors $110
Total cost: $180

Anyone know for sure if the B6 caliper bolts are the same as the B7? The junkyard included 3 of the required 4 bolts with the calipers. I suspect they are the same - and obviously it will be easy enough to verify - but just figured I'd ask in case anyone can confirm without me getting dirty. :)

Note to self.... weigh B7 stuff before installing and report back to this thread.

[LordO]

I haven't installed these yet, but here's what it will cost to do my B7 front brake swap
Low-mileage used B7 calipers w/ pads $70
New black oxide coated B7 rotors $110
Total cost: $180

Anyone know for sure if the B6 caliper bolts are the same as the B7? The junkyard included 3 of the required 4 bolts with the calipers. I suspect they are the same - and obviously it will be easy enough to verify - but just figured I'd ask in case anyone can confirm without me getting dirty. :)

Note to self.... weigh B7 stuff before installing and report back to this thread.

The B6 brakes and the B7 brakes use the same bolts.

[DPDISXR4Ti]

The B6 brakes and the B7 brakes use the same bolts.

Great, thanks.

[ADCS]

You should buy new bolts to secure the caliper to the upright (21mm?). Also inspect your caliper slides/bushings and replace as needed (ideally with Tyrol solid bushings).

[SlickFix]

(i.e. So don't tell me about how much better the S5 calipers are, cause I don't need that much brake

But...but...

[Charles.waite]

You should buy new bolts to secure the caliper to the upright (21mm?). Also inspect your caliper slides/bushings and replace as needed (ideally with Tyrol solid bushings).

I second replacing the slides and bushings with OEM at least ($30 on eBay). Tyrolsport busgings are even better.


Posted from my iPhone. Any misspellings are Siri's fault.

[n7plus1]

according to those pictures, theres at least a pound of dirt on them which would be negated given you are going to finish them off nicely with paint, right?

[diagnosticator]

Factory Audi went to a larger calipers and rotors for the B7...because the B6 brakes were terrible!
The advantage of the B7 brakes are much improved braking over the B6's.

Yeah, but Audi knew from the start that the stock B6 brakes are crap. Audi cheeped out with the '03 B6 especially.

[n7plus1]

Yeah, but Audi knew from the start that the stock B6 brakes are crap. Audi cheeped out with the '03 B6 especially.

you dont have to tell me twice. got shafted with teh 245's in teh back...right?

[daverdfw]

i have an 03, and i am waiting on some 245mm rear rotors and HAWK HPS pads, doing the fronts later. Looking at getting Hawk HPS pads, centric rotors, SS lines and the Tyrolsport kit. hopefully that will make it a bit better. Whats the split on the breaking on these cars front to rear?

[Charles.waite]

you dont have to tell me twice. got shafted with teh 245's in teh back...right?

My 2004 had 245s also. 288 B7 A4 rears are much more suitable for a car this size.

[AudiTLC]

all the unsprung weight makes a difference to the suspension and feel. Not contradicting anyone here, just adding my experience.

I've run some vastly different tire/wheel combos so I know this first hand.
On my truck, i've had a 120lb tire/wheel and something closer to 65lbs- talk about huge difference!


On a lesser scale, I had lighter wheels on my B6 and B5. It is very noticeable, and feels more sporty.
OEM wheels are heavy.

Thanks for this info on B7 brakes! Certainly looks like a worthwhile upgrade

[Charles.waite]

all the unsprung weight makes a difference to the suspension and feel. Not contradicting anyone here, just adding my experience.

I've run some vastly different tire/wheel combos so I know this first hand.
On my truck, i've had a 120lb tire/wheel and something closer to 65lbs- talk about huge difference!


On a lesser scale, I had lighter wheels on my B6 and B5. It is very noticeable, and feels more sporty.
OEM wheels are heavy.

Thanks for this info on B7 brakes! Certainly looks like a worthwhile upgrade

I observed a small, but noticeable increase in "bounciness" for lack of a better term, once I installed the S4 fronts. The roads around me are terrible and I definitely feel it a bit more than I did before. However my suspension is all original OEM sport parts with 96k miles on them, and my control arms are beyond shot (getting replaced in the coming months). Between the worn CA bushings/balljoints and the worn shocks, I'm 100% positive I wouldn't have noticed any difference if those parts had been new.

[Fast4esT]

im seeing front reman calipers from TRW, WBR, A1Cardone and Centric for 50-75 each with carriers, rears are roughly the same prices, the TRW calipers are the most expensive but some of the others are pretty good, especially since they are remaufactured.

anybody tried calipers/parts from partsgeek.com? thats where i saw these, under 2005 audi s4

[daverdfw]

yeah i would be interested in the remans as well, since i am just replaced my rears with the stock size , but the fronts i wouldnt mind dropping in some reman calipers and larger rotors.

[Fast4esT]

Lot easier to paint or clear coat looks good

[Charles.waite]

What's the consensus on remained calipers? I bought used pull offs when I did mine. Had to put in some sweat equity cleaning them up, and I rebuilt the caliper myself too, it's actually really easy.

Anyway are remained calipers as good as OEM used?


Posted from my iPhone. Any misspellings are Siri's fault.

[Four-Play]

I actually have a set of both B6 S4 and B7 S4 calipers sitting in the garage. If you guys wanna see the weight difference of just the calipers I can weigh them. They are both calipers+carriers+pads, only missing the brake lines. It'd be tomorrow night before I could get the info up here to this post tho

[Charles.waite]

^those are the same calipers though...


Posted from my iPhone. Any misspellings are Siri's fault.