Matt O.

We constantly see on here "if you upgrade the engine, you need to upgrade the brakes" and how if you want to turbocharge a 944 you have to get this and that and all that other stuff in the picture, including bigger brakes...etc., etc...

Now, this may be a dumb question, maybe I'm in a dumb mood (fall break started today) or something, but do you really need bigger brakes?

Isn't going from 100-0 or 30-0 or 60-0 the same for any amount of HP? Does this make sense...?

If I have a 165 HP 944 NA, and I'm cruising around hitting turns and what not, and I see a dear and I slam on my brakes at 65 MPH, is that not the same as if I had supercharged my 944 NA so it's now at 220 HP and hit the brakes at 65 when that deer came out?

I do understand that bigger brakes are better in general, better stopping power, safer, etc. But I just am struggling to believe that they are as important as many make them out to be. I think that when Porsche designs a car, especially one so tuneable as the 944 Turbo, they KNOW that folks are going to take these cars and mod them for the track. My feeling is that they develop everything to work in a much larger range then we give them credit for.

Ok, long post - forgive me. I've just been pondering this for the past couple days and finall decided to post here.

Please feel free tell me I'm wrong.

Thanks,
Matt

ian

Well actually if you did put a turbo / supercharger to get your power to elevated levels the distances required to stop would actually be slightly longer than before the addition (you have added more wieght therefor longer distances).

But that is not why you want to add bigger brakes. The reason they are so important is because the car is capable of so much more speed. Using a race track, in the NA you might be coming into a corner on the back strait of VIR at 115 maybe 120, a tuned turbo will be entering the same breaking zone at 150 or around there. And the distance difference between those two with stock brakes would be very large.But with the larger turbo brakes you will be able to scrub off the speed and not have to worry about the fade that the stock brakes would show.

I agree that you can lock up the stock 944 brakes, the limiting factor there is tires. So better tires normaly offer the most improvements in braking distances. Well short distances anyway. Over longer distances and repeated stops you start to see fade. My Yukon's brakes fade after one quick stop from 60. You 944 brakes are much better than that, and odds are you can cure some of the fade issues with better pads and getting air to the brakes to aid in cooling. But there will be limits to what you can do with the stock system. The 944 Turbo brakes have a much bigger swept area and also a bigger rotor to disapate the heat.

One last point, for me it is easier to modulate the 951 brakes, I'm not sure why but they offer very good feel, and although I do lock them up from time to time they are very easy to get a feel for.

Ken

I agree with you Matt. My brakes seem extrememly competent for the car. I can lock them up very easily, so they've obviously got enough power. I don't believe larger diamter brakes will increase the amount of braking force before locking. But somebody could definately step in and prove me wrong here.

I think where they're coming from is that if i say, supercharge my 944, I can reach higher speed much faster than before. So 120-130 is easier to hit on shorter sections of highway that i couldn't have gone that fast on before. Or perhaps a back windy road which i can now take the straights much faster. In either case, i will now have to brake much harder to not run off the road or rearend someone, thus the need for bigger brakes. (so they say) But in the end, if i just keep speeds reasonable, there's no need to upgrade brakes.

I could definately understand it on the track where you would want to upgrade the car as a whole to increase lap times.

SidViscous

Okay. How about this.

If you have a considerable more power under the hood, isn't it likely that your going to be going faster when you need the brakes.

AS far as stopping from a certain speed the only thing adding a turbo or supercharger is going to effect is the extra weight you have to bring to a stop. In other words negligible.

Ken

[quote]I don't believe larger diamter brakes will increase the amount of braking force before locking. But somebody could definately step in and prove me wrong here. <hr></blockquote>

Ok, so i'm probably really wrong here. Someone wanna explain why, because I'm not entirely clear on it. Thanks.

Matt O.

Thanks guys.

Completely understandable on the track. I do agree, and understand why bigger brakes help you stop faster, reducing fade, etc. I probably didn't state it well enough, but my question was mainly related to public road use. Just don't see what all the fuss is about, say, when someone says something about enhancing their engine's performance and someone always makes a comment (or two, or three, sometimes derrogatory) about getting bigger brakes.

Also, I do understand that F=MA and the heavier the car the longer it will take to stop (brakes being equal).

Personally, I feel by experience and by looking that my brakes are as good or better then my brother's former 290 HP Firebird Formula. That's mainly my point.

Thanks again for your kind replies and for not flaming!

Geo

Bigger brakes can do any combination of a number of things for you.

Greater braking power
Better modulation
Better heat dissipation

Larger diameter rotors will give the brakes more leverage on the axle/wheel, all other things being equal. This will indeed give greater braking power.

Do not under estimate the value of better modulation. You could probably install steel block and jam the brake pedal hard enough to lock up the brakes. Stopping would suck because they would be a bitch to modulate. The better you can modulate the brakes, the closer to the ragged edge you can get. If you could drive around a corner and not spin, would you think you have all the suspension you need? I can assure you that if cornering power is ultimately the same, the car that is easier to keep it on the edge will be faster in the long term.

Heat dissipation varies with diameter, pads, fluid, and thickness.

Matt, you are correct that speed is speed and the simple matter of adding hp doesn't require the addition of better brakes and suspension. However, while I would add hp without upgrading the brakes and suspension initially, I'd certainly have it in my plans. Let's face it, few of us mod all systems at once.

BTW, with the cost of the Big Reds, I'm surprised that folks are installing Wilwood, AP, or Brembo brakes with 2-piece rotors. Sure the racing calipers don't have anti-rattle clips and dust shields, but they are not that big a deal.

'88-924S

came back from lunch after 'almost' rearending someone without brake lights. Close call but the stock brakes saved my ***(for 2nd time in last two weeks!) I can't believe how well the car stops, but you know what, regardless of power, on my way back to the office I was thinking about getting bigger brakes anyway, why? control. with 2.5l four stock it's not about speed(yet) but handling for me, and integral part of handling is slowing down quickly and controllably and also yes, stopping.
my .02

Geo

[quote]Originally posted by Matt Olde:
<strong>I probably didn't state it well enough, but my question was mainly related to public road use. Just don't see what all the fuss is about, say, when someone says something about enhancing their engine's performance and someone always makes a comment (or two, or three, sometimes derrogatory) about getting bigger brakes.</strong><hr></blockquote>

Matt, while the idea is a good one (upgrading the brakes) you are 100% correct. The case gets over sold here.

Armon

all I have to say has pretty much been covered here already, so I'll just give a quickie here. If you want to decrease your overall stopping distances, you'll need more traction. If you want to get better pedal feel and less fade, then get better pads & rotors & braided lines. For daily driving, the stock setup should be fine, unless you are particularly hard on your brakes, then you might want to change pads or something. Those are the basics. I plan on keeping my brakes stock except for the pads, which will be a bit more aggressive. Eventually I am going to be road racing a bit, so I might put slotted rotors on in the interest of keeping heat away.

Geo

[quote]Originally posted by Armon:
<strong>all I have to say has pretty much been covered here already, so I'll just give a quickie here. If you want to decrease your overall stopping distances, you'll need more traction.</strong><hr></blockquote>

Or much better modulation.

BartW

A different train of thought would be that by increasing the car's horsepower you are taking the car to its next performance level and to keep that well balanced you should upgrade the brakes and suspension. Although neither of the upgrades is necessary for more power you enter a higher class of cars to compete against and want to have a car that can outstop and outhandle that class as well as outaccelarate it.

AlexE

Although I have upgraded my 86NA to 86 Turbo brakes, it really is overkill. I do get great feel around corners but I am not sure if they are a necessity if you are going to add force induction to your car.

If you are going to track the car, it is a minimun requirement to upgrade to turbo brakes, but for street use its not necessary.

On the other hand, the turbo brakes look great behind 17inch wheels!

I think if you feel the need to add turbo brakes for improved safety in a forced induced NA, then you may as well go all the way and swap the dash and add the airbags as well.

ninefiveone

I don't really think that for public road use the issue is over-emphasized or oversold.

The more HP you have, the sooner you can get yourself into bigger trouble. Brakes are what get you out of trouble. Have enough brakes for the kind of trouble you can get youself into.

Saying that one has enough brakes to stop from 65mph is the same logic that says one only needs enough HP to get to 65mph.

Bob S. 1984 Silver

Larger brakes = good news and bad news. Bad news: More unsprung weight. Good news: More mass and area for heat dissiapation, which is great for times when the veicle is being violently accelerated and decelerated (track) but kinda pointless for the street. The stock NA brakes far exceed the standard vehicle. As such, for "daily driving", massive increases in size are like pouring honey on a steak...two good things, but not necessarily together. BTW...although the added mass will permit longer use before overheating, the added mass also will take longer to cool down. The moon is a dead rock, cold all the way through; the earth still has a molten core...Started out with the same basic temperature...

And, if with the "added horsepower", you are, as one writer said, more likely to get yourself in trouble on the road, then you should rethink your driving habits on the road. The added speed, acceleration and braking have a place, and it ain't on the highway...

Cheers!!

Bob S.