Going faster with Bigger Brakes, I don't think so....and now that you are thinking I am insane, please read on.

I think all will agree, you don't go fast by braking. Every time you brake...the clock keeps ticking and you're getting slower. If the logic of the bigger the brakes, the faster the car were taken to an extreme, we would see monster brakes on the GT3 Cup Cars, and other race purpose cars, but we really don't

Has anyone read the brake article, two parts in the July and August Panorama, by Alan Caldwell and Bob Gagnon? They are saying that braking efficiency is more a function of the tire patch and the stickiness of the tires. They add that the increased brake pad size of the Big Reds will not stop the car any quicker than stock brakes designed for your 993...their article is in contrast to what I am reading in this thread.

Also, switching to Big Reds will trip the following drivers:
The cost of rotors is greater, $150 + per rotor contrasted to less than $100 for stock,
The cost of Big Reds pads goes up as well, I pay about $450 for a set,
The unsprung weight of the Big Red over the Black calipers is a slight disadvantage.

However you do get the following benefits:
Under hard running conditions, the Big Red brakes will run cooler longer, until they ultimately overheat,
The larger calipers and rotors will act as a more efficient heat sink allowing them to run cooler longer,
The Big Red calipers do look cool, very cool

I propose that I am a great control subject here...I have a Carrera NB with Big Reds (They came on the car from the PO), and my neighbor has a Carrera NB with stock 993 brakes. We both run Pagid Orange pads. In addition, we are very similar in driving ability. We both have track records at Streets of Willow..his is counter clockwise, mine clockwise. Our cars have the same aero package and suspension......at the track, we run neck and neck...my Big Reds don't seem to help one bit as far as lap times go.

I will tell you that braking from 135 down to 55, lap after lap at California Speedway, I have confidence that the Big Reds will stop me....but my neighbor is on the track too...his brakes work just fine.

When you look at the actual brake piston caliper sizes, I don't see a lot of differences:
Brake caliper piston sizes

44/36 front 30/34 rear Carrera From Porsche Technical Specifications Booklet 1st Ed. 8/1995

44/36 front 30/36 rear RS From Porsche Technical Specifications Booklet 1st Ed. 8/1995

The Brake Boost Coefficient is different going across the spectrum. I can tell you how this is derived, it is a function of what? Is it as simple as the brake booster? Do Big Red updated cars need a new brake booster?

Brake Boost Coefficient: 993 Carrera Carrera 4 (Not 4S) Carrera RS
3.15:1 4.8:1 3.6:1

Will you stop quicker on your stock tires once you have added Big Reds....you tell me. According to Caldwell and Gagnon, don't expect this to happen. So if you don't stop any quicker...why buy them other than the they look cool aspect? I think we sometimes get into performance mod hysteria here...someone adds Big Reds and swears that their car has improved dramatically...another chimes in, then another, and before you know it..Big Brakes are the ultimate answer.

 

I agree with Martin 100%. When I put big reds on my C2, my stopping distance didn't change, however, the brakes NEVER went soft, which is all I wanted.

Now, the coolness factor is very high and if I had a street car and a couple of grand to spend, sure, I'd do the brakes, right after the RS 3.8 wing....which didn't do anything to help out either

 

Martin S. & Manny Alban- Thanks for proving with on the track experience the points we were trying to make with our article .

One correction though is that I wrote the article with Bill Gregory, not Alan Caldwell. Alan did proof read the article though and his input was valuable.

Thanks, Bob Gagnon

 

I wonder how much money you guys have saved some Rennlisters (and Panorama readers) after reading (and hopefully believing) that.

 

Well now that I have read all the above I have saved $1,000 and a continued saving of about $500 a year....wait til I tell my wife ...she will be so excited she will let me spend it somewhere else on mods!!!

So I will stick with my current stock and maybe spray the calipers at some point...thanks guys

 

Good thinking. Get that suspension sorted out.

 

Martin,
While I don't disagree with anything you said, you'll note that my positive comments about Big Reds are due to fade and fluid. With the big reds, my car is often doing double-duty at the track. I can get thru a 2-day event with the car doing double duty without having brake fade or the pedal get soft due to overheating fluid. I quite sure I couldn't have done that before the mod.

Does this improve my lap times? Yes it does. On Sunday afternoons, I don't have to brake early due to soft pedal like I would be doing with stock brakes. That said, I wouldn't recommend the mod unless you're really hard on brakes, do double duty, or really hate bleeding your brakes.

 

the correction. Bill Gregory, Alan Caldwell.....when you take these two, put in a little Cup Car verbiage, you will have an article that is right on technically.

I have been reading words of wisdom from these guys for yeras...thanks for helping me keep my head on straight, well partially anyway!

Manny's point on the 3.8 wing is well taken....been down that road too. Installed a 3.8 wing with the 993RS front splitters, NOT, the correct matching 993 RS Club Sport front splitters. The wing worked so well that I induced chronic understeer at 120 mph and drove right off the track. The car simply would not turn in and I had no other choice but to drive straight off the track...Turn 8 going into Turn 9 at Willow Springs International Raceway.

The next week I sold the tail and re-installed a matching (with the front splitter) 993RS front splitter. No problems with understeer since then! And besides, wifey really hated that big wing. She thought it made the car look very tacky. This was good because I needed her blessing to go out and buy another 993RS tail from Getty Design, have it preped, painted and installed. Did I get her blessing on this purchase, probably not...I was under the beg for permission rather than seek permission mode...now I seek permission, bigger pay off and the arguments are not quite so emotional.

As to Eric's posts above...double duty is tough on a car, especially brakes. I bleed my brakes quite often...I confess I use a Power Bleeder. I too insist on a firm pedal.....and to all of you out there that to date have not tracked your car, you are really missing an incredible experience. You will not believe what a 993 can do bone stock, much less with a few mods. I campaigned mine for a year bone stock...awesome.

 

Ummm, you mean the fancy-pants RS wing I just had installed won't shave five seconds off of my lap times??

 

Even tho I have the Big Red NA set-up (TT front, RS rear), based on articles I've read elsewhere by very knowledgeable people, I'm inclined to agree with Martin re: the limited effectiveness of Big Reds.

I have a friend who runs an NA with stock brakes but race pads. He is a very, very good driver (one of the youngest PCA, if not THE youngest, PCA instructors I know) and will thoroughly spank me at the track with his "stock" set-up. If I could do it again, I would be spending the money on track time. Having said that, the extra money I spent (I had to change my front rotors anyway along with the pads) would probably just cover a weekend or two of DE.

Btw, OEM pads are not expensive IF you got in on the brake pad sale Porsche had last year. $40 per set. Needless to say, I've got two extra front sets and one rear.

 

With the complete 993RS aero package, at 170 mph, the car will have 0 lift....this is not true of the 993 in stock aero configuration. Cup Car and I were chatting...conventional wisdom has it that the standard 993 moveable wing is the equivalent of the old Duck Tail. Frere's book, the 911 Story has some comment on the effects of this tail...I believe that stock there will be about 400 Lbs. of lift, the duck tail cuts this in half....the 993RS package brings the car to 0 lift.

When you are on a high speed track sich as California Speedway, Willow Springs International Raceway, any track where you see speeds in excess of 100+ mph, you will notice the 993RS package.

Another neighbor story....my neighbor's 993 NB, at that time, had the RS front splitters, side skirts and no tail. Driving through a high speed sweeper in his car was hair raising with lots of hopping around (Turn 8 at Willow Springs, probably 120 mph+...we are on it in 5th gear). My car with the complete RS aero package was rock solid...like a Sunday afternoon drive...there was a night and day contrast. Neighbor has since gone to the RS tail, a safety issue was the story to wifey...especially after he did a 360 when the rear end came around at 100 mph or thereabouts.

If it is the 993 RS Club Sport (3.8RS wing), it provides down force, some 160 Lbs at 170 mph...with very little lift in the front. The front lift probably occurs as a result of the tail pushing the car down in back...it tends to come up a wee bit in front even with the 993RS CS front splitters.

As said earlier...only install wings with matched front splitters if you plan on doing any high speed work...I must get back to my day job! Too much time on the List!

 

Thanks, Martin. I was being tongue-in-cheek with the comment and neglected to put in my winky smiley. I definitely have the front end winglet/spoiler issue covered and then some. We'll see how will it all works in terms of balance.

Also, aren't the 993 RS Club Sport wings and 3.8 RS wings two different styles? I think Greg Fishman has the CS wing while Manny (and I ) have the 3.8 RS wing (avatar not updated).

 

I agree with Martin (and Bob G) as well. I have been running the regular brakes since new. I have also modified my car quite significantly from the persepctive of the suspension, pads, and tires. The only thing I can say is with the regular brakes, under my set up and driving, I get cracking on the front rotors sooner than other folks. Not an issue of braking performance, just an issue of heat. I have just finished installing a brake duct hose to the rotors which should help greatly, but again, I run against many other big red folks and I never have any issue braking with them and sometimes out braking them from high speeds. If you guys are not tracking yoru cars and have big reds, then you are clearly looking for the coolness factor, no problem, I think that is great if that is what you want, but better braking performance is not going to happen.

They are cool looking though, but if you want cool and lighter unsprung weight I would go with the new Brembo sets. Better bite and lighter, then again, same argument for those, your contact patch on your tire dictates how fast you can really stop, not the size of the brakes as these Porsche brakes have plenty of stopping power.

I read somewhere that our 993's have arond 300 HP but our brakes have about 1200 brake howrsepower. If that is the case, we have plenty of braking capability. We just need to use the brakes less, whicih is what i am working on at my next track event in a weel and half.


Nice article Bob!

 

I guess I expected disagreement on this, as I have read the articles, and all of the previous posts. Perhaps my old brakes were faulty, although I only had about 28k on them. I recommend that people do what they want with brakes. I have a pretty good direct comparison...not similar cars, not similar drivers...THE SAME CAR AND DRIVER. I was fully expecting to experience no change, and would not have been surprised or disappointed to have only better longevity. I am very happy with the change, and wanted people to hear it. I am not prone to hyperbole. Knowing what I now know, and experiencing what I did this weekend...well, I've already said it. Most of the posters have them on their cars from previous owners and compare with other drivers. Has anyone made the change and found no difference? If that is true with most people, then I can only conclude that my old brakes were indeed faulty, and I'm glad I have standard stopping power now. They are great.

 

I think the thing to keep in mind is that the brakes have to be sized to their duty cycle and the correct pads chosen for the temperatures achieved.

Essentially any Porsche will do one stop from 100 MPH, the key for track use is what happens when multiple stops from high speed are made. Each track is different and it depends on the speeds and the cool off times between applications. Some tracks can be hard on brakes even with relatively slow average speeds if the corners come up before the brakes can cool.

Ideally the brakes come up to a temperature that puts the coefficient of friction of the pads in their sweet spot front and rear and they stay there for the rest of the time you are on the track without boiling fluid and/or suffering mechanical failure such as cracking or warping discs.

In F1 racing the brakes are custom sized for longevity and custom ventilated for temperature levels for each track in order to achieve this such that the minimum mass is dedicated to the job.

Another issue that makes a sensitive driver faster is the feel of the brakes, particularly if the driver is good at trail braking-something difficult to do if the brakes don't have good feel. If the calipers are flexible and/or the brakes are fading during use then the driver will not be as fast because consistency is lost- not to mention confidence if you start wondering if the brakes will be there next time.

The goal is devoting as little mass as possible to a braking system that achieves the above conditions.

Thanks again Kary