Folks it's done.

Porsche BIG RED brakes designs are finished for 93-02 f-body cars.

Mike's first kits will be $1595, he only
has 25 at this price so you have to reserve quickly.

The price jumps to $1995 after...

These are huge 4-piston porsche (brembo made) calipers with 13"x1.3" rotors with advanced cooling.

There is no match for the kit at this price. Forget the C5 caliper kits and 13" rotor adapter kits, and the wilwood stuff you'll never get the stopping power that matches this kit.

Remember equivalent 4-piston kits cost $2700-$3000.

You're getting alot of brakes for minimal price.

Check out the pics here:

http://prospeedmotorsport.com/f-body_brakes.htm

Remember only 25 kits at $1595!

Steve

 

After talking with Mike at Prospeed (who is a very nice guy BTW), I decided to edit all my posts out of respect to him and his product. There is certainly room for both kits to be succesful in their own niche w/o us bashing each other's products.

Chris Renner
615-944-2975


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Owner, Nashville Speed & Performance

1996 Trans Am WS6

[This message has been edited by Chris 96 WS6 (edited August 14, 2002).]

[This message has been edited by Chris 96 WS6 (edited August 14, 2002).]

[This message has been edited by Chris 96 WS6 (edited August 15, 2002).]

 

Fight! Fight!

No, but seriously, from a non-involved POV...both kits are great values for the money I'd go with Chris's C5 upgrade if I hadn't done the LS1 upgrade already, and I'd do the Big Reds if I had any money

Dan

 

I put my (deposit)order in on July 25th, one day before the deadline which said they could be had for $1500.00. Hopefully they will honor this price as I am anxiously waiting for these bad boys...

Kenny

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Chris,

Again there is no way the C5 kit is 90% as good as the Porsche kit.

Is the C5 corvette 90% as good as the 911 Porsche Turbo?

For the average street driver, yes the C5 kit can do a good job. But in that case why spend $825 when you can just use a good set of pads for $100.

When you're out on the track it's another story. You have factors such as brake fade, stopping power and high speed maneuvers.

The porsche brakes has been tested in high performance events around the world, in endurance and cup races. It is proven and world recognized.

The C5 cars, the C5R I guess or transam cars don't even use stock brakes, they upgrade to ALcon or AP or Brembo...

You have to use a similar performance baseline when comparing these systems.

Steve

 

For people who road race, C5 owners are all too happy with improvements in braking.

For a street car, things are different.

 

[This message has been edited by Chris 96 WS6 (edited August 15, 2002).]

 

The basic rigid caliper design is significantly superior to the floating caliper. Better rigidity, braking force application, and heat transfer are some of the benefits (I'm not an expert so I'm sure there's more).

Both kits are good values, $1595 for 4-piston brakes is a great deal.

Brembo wants $3,000 for their "Gran Turismo" kit, which is a 4 piston setup. The only advantage that kit has is a floating disk (which is preferable to a rigidly mounted disk, but also a lot more expensive).

 

Dave, I must disagree with your saying that the Porsche caliper is stronger because it is fixed rather than floating. That makes no sense at all. You could mount the Porsche caliper in a floating arrangement. The mounting of the caliper is very important, but has nothing to do with the innate rigidity of the caliper itself. The caliper would spread the same amount under the same applied brake pressure if it were hanging in place by a piece of string. In the mid 90’s, when AMG was still a separate company from Mercedes, they prepared all of Mercedes racecars because they had tremendous success. When Mercedes contracted with them to prepare the “E” class for the revived DTM (German Touring Car race series), the build budget was @ $800,000 per car. AMG surprised a lot of people when they chose to use 2 piston floating front calipers. They won the championship with those simple brakes on those very heavy cars. They were extremely rigid calipers, but the basic design was like the C5 front calipers.

Please explain how there is better heat transfer from a fixed caliper. The engineer wants to dissapate as much of the heat as possible in the rotor and its cooling provisions. You want to shield the caliper from heat as much as possible to keep the brake fluid from boiling.

(All other things, like rigidity, being equal) If anything, the floating caliper would have more even application of force to the rotor because it can adjust slightly to keep the pads parallel with the rotor as the rotor deflects withe the hub under trail braking.

Bob Bishop


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lateapex@worldnet.att.net
'94 Z28 with C5 front brakes and other road racing stuff

[This message has been edited by lateapex (edited August 17, 2002).]

 

Well you may be right, here's my thought process on the subject...

Ideally you put all your heat into the rotor, and then dissipate it using venting and air flow. But in the real world a fair amount of heat flows into the caliper also, and with a rigidly mounted design that heat can easily transfer into the hub, providing a larger sink capacity. In a floating design heat flowing into the hub is constricted at the (usually two) sliders, and additionaly is insulated by a lubricant.

Thermodynamics is a tricky discipline (and I'm admittedly a EE not an ME) but I do recall that the smaller the cross section the slower the transfer (at the same temperature delta).

Regarding rigidity I wasn't referring to rigidity in the caliper itself, but rather in the mounting. Same rule applies here as above, you've got two metal sliders holding all your braking force, there will be some compliance in those essentially cantilevered beams (and the cantilevering means you'll get a rotatational moment off-axis). Now this isn't as critical as flex in the caliper (compliance there directly affects braking force) it is strictly speaking a more rigid design to have your caliper directly mounted to a bracket. While it may be possible to have a floating caliper that performs great in this respect, the designer will have more variables to contend with.

It's very possible that this effect is so minimal as to not play a role in the design... but it does exist at the least.

And as far as flex keeping rotor and caliper aligned, typically a rigidly mounted caliper is coupled with a floating rotor, which gives you the double benefit of a bit of compliance (which as you said is a good thing) and a reduction in heat transfer from the hot rotor to the hub. I guess then you get the rotational compliance in the floating rotor instead of the caliper, bit this compliance can be controlled with more mounting points (than the 2 you get with a caliper) and additionaly those float points are inline (no off-axis rotational moment to be dealt with).

I'm kindof thinking outloud here... hopefully it's not too convoluted.

[This message has been edited by Dave K (edited August 19, 2002).]

 

Dave,
The 2 guide pins (sliders) don’t actually “hold all your braking force”. The guide pins allow the caliper to center itself over the pad abutment bracket and rotor, but after a certain threshold of braking force is applied, no further centering can occur. At this point, the 2 guide pins could actually be removed and would not affect the braking function. The brake pads are located in the cast iron pad abutment bracket, which is rigidly attached to the steering knuckle (or adapter) by two 14mm bolts. Those 2 non-sliding bolts resist all of the rotational braking force. When you release brake pressure, then the 2 guide pins resume their job of keeping the caliper in the vicinity of the pad abutment bracket and rotor. The only rotational force ever resisted by the guide pins would be the miniscule movement of the pad within the pad abutment bracket at the very onset of brake application. Hence the small guide pin bolts are torqued to 23 lbs/ft but the 14mm pad abutment bracket bolts are torqued to 125 lbs/ft. So a portion of the heat you were concerned with would have a path from the brake pad backing plate edges to the pad abutment bracket, which is hard bolted to a 3.5 lb. (in my case) adapter bracket that provides additional heat sinking before going to the steering knuckle and ultimately the wheel bearings. I would guess that well over 95% of braking heat that gets to the wheel bearings would do so through the rotor. I agree whole-heartedly that a floating rotor system is the best solution for both the reasons we mentioned: a significant break in the heat conduction path to the wheel bearings and the ability of the rotor to remain parallel to the caliper under suspension side load deflection.

I must say that your response is the most thought out, cogent, grounded-in-physics response that I have received in the 1.5 years I have been on this board. It is encouraging to find real adults who can discuss a subject without getting emotionally involved or taking things personally.

Thanks,
Bob Bishop


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lateapex@charter.net
'94 Z28 with C5 front brakes and other road racing stuff

 

this is interesting, I've yet to upgrade from the rather sad stock calipers, so of course I was using those as my basis for measurement. Come to think of it my old LeBarron Turbo had a similar setup as you're describing.

In the stock setup the caliper mounting bolt goes THROUGH the center of the slider. remove the bolt and the caliper pulls off the rotor and the slider can be removed for inspect/clean/regrease/pads/etc. There are two ears that stick out that the Pads contact on either edge... but the contact area is tiny. You're right that it would provide a point for resisting rotation exclusive of the sliders... but you won't get much heat through em. Sounds like the C5 setup has better contact for heat dissipation, though there has to be a limit on the contact area in order to provide a relatively low friction slide. I would have doubts on the ability of a designer to match the contact area of a metal-metal bolted assembly with one that needs to be able to move, but without seeing the specific design who can tell... and there are some very clever mech-e's out there.

I've always enjoyed solving engineering problems... such as figureing out design trade-offs in a braking system. A while back I spent a LOT of time on the rear suspension (pretty darn nice design, about as good as you can get in a live axle car) and came to the conclusion that the guys selling boxed LCA's and poly-poly LCA bushing kits don't really understand how our suspension works. Then of course there's the "cross-drilled rotor" fad, I'm amazed at how many companies claim it will improve braking distance and reduce fade when it reality it's a cosmetic upgrade with no or even negative impact on performance (unless you're running 20 year old brake pads).

Owning a car like this is a LOT more fun than the old grocery getter

 

Just incase you're referring to me, I thought I'd remind you how much you've learned about brakes from my "Big Meanie-Head" posts:

It's obvious here you don't know what swept area is or how to calculate it. Now you do.

http://web.camaross.com/bb/Forum25/HTML/001973.html

In the thread below you make the case that a floating caliper will "center itself" making up for hub flex.

http://www.LS1.com/forums/showthread...hreadid=144625

You seem to have learned from my comments that only a floating rotor can do that by your comments in this thread.

Call me a Big Meanie-Head. Call me even worse. I don't care.

But don't deny you have learned quite a bit about how brakes work from me.

------------------
96 Z28 M6
13.59 @ 102.96
MODS

 

Jon,
No, I wasn’t referring to you, directly or indirectly. It was meant to be a compliment to Dave, not a jab at anyone else. Please forgive my lapse in correct use of techno-jargon. I believe that I learned what brake swept area is from an article in Road and Track in the late 70’s; my mistake for forgetting. But, thank you for reminding me (and correcting me).

You apparently misunderstand my comments above concerning caliper centering and parallelism. The pad abutment bracket allows the pads to cant sideways as needed. This can be seen when inserting the pads; the pad doesn’t fit tightly in the bracket. That is why there are pad abutment shims at the ends of the pads, and an anti-rattle spring pressing down. When the rotor is not in its normal perpendicular position, the pads can tilt, *AND* the caliper itself can tilt slightly at the onset of brake pressure because of the clearance (slop) in the guide pin set-up. The advantage to the caliper angular adjustment is that the pistons, and backing plate on the outside, can push flatly against the back of the pads. The floating system not only allows the necessary side to side centering, *BUT* angular centering to compensate for suspension deflection while cornering and braking simultaneously.

I am sure that I have learned from you through the course of our posts. I don’t think I’ll go back and re-read them all, but let me extend a general thank you for all that you have added to these brake discussions. I imagine I’m not the only one who has benefited from your input.

Bob Bishop




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lateapex@charter.net
'94 Z28 with C5 front brakes and other road racing stuff

 

Hey Bob, sorry for ***uming that was meant as a jab at me. My bad.

I've enjoyed these brake discussions as well. I also learn from technical debates like this. Even if, for no other reason, they make me think. Sometimes when you think you know it all, it becomes apparent that you don't when you try to explain it to someone else. So, you find yourself re-investigating the subject matter you thought you already knew.... That's a good thing.

So the C5 Pad is allowed to cant on the outside bracket? I hadn't even thought of that. Interesting. I can see the inside pads doing something similar with the caliper due to slop in the guide pins, but from the initial sound of it, it sounds more like a "consequence" of the slop in the design than a "feature." But I guess it is possible that the end result is more even contact with the rotor than if they couldn't move. Hmmm.... I'll have to sleep on that one.