davek9

I'm not advocating or saying Non-ABS are better, really, is that how you read that?

In a panic stop they do what they do best, keep the wheels from locking and improving the panic and wet/slippery stopping distance.

However most of the time under normal driving condition and braking the non-ABS brakes that Porsche installed are more than adequate to stop the earlier lighter cars.
Heck today most motorcycles come w/ ABS, although sometimes I want to lockup that rear wheel.

I'm only trying to state they are one of the reasons the non-ABS cars are lighter and should not be a reason to rule out buying a non-ABS car. I'll add non-ABS are less complex, have you tried to buy an early wheel sensor lately

Dave

bureau13

And how much difference do you think shaving those few pounds will make? Honestly, they're both pretty small differences, I'm sure, but until I see people swapping in the old brakes, I'm going to remain skeptical of the claims that they're "just as good." I am curious about claimed or tested stopping distances, however.

bureau13

I thought the bulk of the brake-related weight increase was due to the larger calipers and rotors? I guess I've never weighed the two but I was assuming it was that, and not the ABS-specific hardware.

hwyengr

But it's not just the brakes, the S4 suspension is heavier too. An '85 5-spd weighs 3350 and an '87 weighs 3500. 86.5 is somewhere in between, but I'm guessing closer to the S4.

And nobody says "they're just as good." I'm saying "they're good enough". Don't forget that the S brakes were an upgrade from std. equipment back when you could get a non-S 928. And the standard brakes on the '78 were good enough to win Euro Car of the Year.

davek9

You are correct for the bulk of the weight, consider the wiring and all that goes w/ it adds up too.
I could not believe how heavy the Front main (internal) wiring harness is, the rears not light either

Now I know why the Track cars rip all that out and run only what's needed.

GlenL

It could be to maintain a design margin as the cars got heavier. With the stickiest street tires and the crappiest street pads, are the bigger brakes needed? I don't know but maybe so.

I'm more inclined to think it was driven by marketing and that multi-piston calipers "are better" and that they look cooler. Were they being sold on competitors cars? The "S" brakes were used on Ferrari's, at the time. Maybe they needed Brembos to sell cars.

hacker-pschorr

Items are upgraded for many reasons, in most cases you'll never know the full story from the manufacturer. Read some books by Bob Lutz and you'll discover stories on supply and parts changes for entire model lines based on who was better friends with who at different companies.
Maybe Porsche got a great deal on the Brembo's and decided to put them on everything. Maybe marketing told them the 928 needed the bigger brakes for showroom appearances and ads so they can say: "Same brakes as used on XYZ race car" or something...... The auto industry is fun that way.

In the 80's Brembo was trying to make a name for itself in the street car market. Who knows what deals were made behind closed doors to get those calipers on every Porsche leaving Stuttghart.

Bottom line is the S brakes are very capable for street and even track use.
As for "claims"..... years ago Jean-Louis posted slightly better lap times than Kibort at Road America. JL was driving his EuroS with S brakes. Kibort with S4 or greater. Road America is brutal on brakes too.

Bottom line, it's my humble opinion that you will never reach the full capabilities of the S brakes on the street in a stock 85. Especially with the stock 225's up front.


The pre-S brakes? Yes, they suck and it's amazing a company like Porsche released a 3,000lb car with such horrible brakes.

Wisconsin Joe

One thing to remember is that the "bigger brakes and bigger rotors" only really show their superiority when the brakes are applied a lot, like on a track.

If you are driving on the street, normally (or even "spiritedly"), you aren't going to get them hot enough to matter.

Cold stopping distance is going to be more about the tires than brakes.

Jadz928

I'm trust the OP has received an adequate response?
This brake discussion is interesting, but how does one suggest to make another thread?
I'm finding it increasingly difficult to follow threads around here.

linderpat

This +928

bureau13

Oops. My bad.

I'll just add that it they can't have added them for appearance purposes, because they hid them behind those damned manhole cover wheels that show nothing. But I suppose it could have been market-driven....in any case, now that I have Cup IIs, they do look mighty cool

OK shutting up now...

GregBBRD

Older cars need to be judged by the other cars that were made in the same time period. In 1978, a 928 probably stopped better than 99% of the other cars on the road. There was little chance that the Chevy Caprice in front of you was going to stop faster and have you end up in the trunk....

By today's standards, they suck.

A modern one ton Chevy truck can probably out brake a 1978 928.....making driving one of these cars an "adventure" in stop and go freeway traffic, today.

Also try to remember that it's pretty easy to increase the power output of 928s, these days. When increasing performance, always consider your brakes and upgrade as needed. When I'm stuffing 500hp stroker engines into these cars, with gobs of torque to accelerate these cars in mere seconds to triple digit speeds (without "beating" on them), I'm very concerned about making sure these cars stop.

I've never weighed all the different pieces when changing from early brakes to S4 brakes and I'm not sure I really care, as the difference in braking ability is worth every ounce, to me. I'd rather leave the 35 pound spare tire (that probably won't hold air) at home, (along with the 20 pounds of air pump, jack, and tools that I never have used) and have the better brakes and suspension.

Imo000

On a street driven car the brakes only need to be capable to bring the car to a stop from highway speed in an emergency stopping situation. If they can do that, the brakes are adequate. It is extremely unlikely that you will need back to back emergency stopping scenarios so if you can stop the car without brake fade and hold the tire friction right at the endge of locking up then, the brakes your car has a perfectly fine.

James Bailey

I think it is safe to say that tire technology and sizes have improved greatly over the last 35 YEARS which can put much greater demands on the braking system. Makes old published stopping distances suspect. The weight argument while technically accurate in reality has little real impact. While instructing on track I often would have a student ride with me in the old very brown 1980 with S brakes. We timed every lap with in car transponders so easy to see the difference on the same day, same tires just adding a 180lb-230lb passenger....the change, less than a second a lap !!

Rammer356

Funny, I was only concerned about going fast and never once thought about the brakes...... Rennlisters are all about balance!