Revisit - Brake Cooling
05-05-2003, 10:19 AM
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Revisit - Brake Cooling
I just spent about 30 minutes reading the archives regarding brake cooling. I read where the kits designed for the 89 and prior cars won't fit will on the 964s, but I am not sure why, particularly on a C2. Is it because of the under trays?
In the recent edition of Pano, page 31, the AJUSA ad is showing a brake cooler kit for a 993 - On sale for $265 - I need to call, but does anyone have experience with this kit - is it a fog light replacement or an under-the-car scoop design?
Also read where Manny had 6 hours of labor to make an OG racing cooling kit work - was this the Pre-89 version, or the discontinued 964 model?
Thanks for any information and/or insights.
Chuck
93 C2
In the recent edition of Pano, page 31, the AJUSA ad is showing a brake cooler kit for a 993 - On sale for $265 - I need to call, but does anyone have experience with this kit - is it a fog light replacement or an under-the-car scoop design?
Also read where Manny had 6 hours of labor to make an OG racing cooling kit work - was this the Pre-89 version, or the discontinued 964 model?
Thanks for any information and/or insights.
Chuck
93 C2
05-05-2003, 10:47 AM
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Chuck,
I had the kit for the 964. I don't think they specified at the time, if it was for a C2 or C4. I do remember my mechanic saying that he thought it would be impossible to make it fit onto a C4. FWIW, I've had it in for awhile now and the only damage I've incurred is when I would autocross and go close to lock to lock on the steering. I simply moved the bottom airscoop and voila, problem solved. Interestingly, the many times I've driven four wheels off the track, I've driven damaged an airscoop.
I had the kit for the 964. I don't think they specified at the time, if it was for a C2 or C4. I do remember my mechanic saying that he thought it would be impossible to make it fit onto a C4. FWIW, I've had it in for awhile now and the only damage I've incurred is when I would autocross and go close to lock to lock on the steering. I simply moved the bottom airscoop and voila, problem solved. Interestingly, the many times I've driven four wheels off the track, I've driven damaged an airscoop.
05-05-2003, 10:52 AM
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Hate to answer your various questions with questions, but was interested in some background. Have you cooked your C2 brakes at the track? After how many sessions? Was the fluid fresh? What kind of pads?
I recall you used to have an SC, Chuck, so I know you're not some track newbie. I just thought a little more information might be useful for this discussion.
Last year was my first year of DE's and after boiling fluid using street and performance pads, I switched to Pagid Orange and Hawk Blues and eliminated any fade issues. Like Bill Gregory, I also installed a set of <a href="http://www.seinesystems.com" target="_blank">Seine Systems</a> titanium brake shields for added insurance.
I just got back last night from a two-day DE at Road America and didn't have any fade. I was doing some pretty serious braking, too, but the combination of pads, shields and cool weather allowed me to go deep and hard throughout the school. Hopefully, this level of performance will hold up as temps increase.
0.02
I recall you used to have an SC, Chuck, so I know you're not some track newbie. I just thought a little more information might be useful for this discussion.
Last year was my first year of DE's and after boiling fluid using street and performance pads, I switched to Pagid Orange and Hawk Blues and eliminated any fade issues. Like Bill Gregory, I also installed a set of <a href="http://www.seinesystems.com" target="_blank">Seine Systems</a> titanium brake shields for added insurance.
I just got back last night from a two-day DE at Road America and didn't have any fade. I was doing some pretty serious braking, too, but the combination of pads, shields and cool weather allowed me to go deep and hard throughout the school. Hopefully, this level of performance will hold up as temps increase.
0.02
05-05-2003, 11:49 AM
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Joey - well, I did in fact fry my brakes at a Drivers Ed event - I was running ATE Bleu, about for months old, and street pads. It was the first DE with the C2 and I thought I was going to take it easy. But I kept going deeper and deeper into Turn 1 at Summit, and . . . .well, there was a "funny" feeling in the brakes all of a sudden.
I am shopping for slotted rotors and new pads now, and was toying with the idea of coolers. A few years ago, I put a set of coolers on the SC after frying street pads on that car and never had a problem again. (Just DE's no racing) - Based on your experience, I probably should just go with the new rotors and pads now and see how they do without coolers. Save a few bucks.
Chuck
93 C2
I am shopping for slotted rotors and new pads now, and was toying with the idea of coolers. A few years ago, I put a set of coolers on the SC after frying street pads on that car and never had a problem again. (Just DE's no racing) - Based on your experience, I probably should just go with the new rotors and pads now and see how they do without coolers. Save a few bucks.
Chuck
93 C2
05-05-2003, 03:23 PM
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I built a braking cooling setup for my SC, with intakes through the front valance, hoses into wheel shrouds and backing plates in the hubs. It worked great and eliminated any and all problems of hot fluid or warped rotors.
Unfortunately, space in the 964 wheel well is very limited and I'm not sure if a decent size hose can be routed through there to the wheel. The car came to me with intakes in the fog light locations and small 2" hoses that dump into the wheel well, but it doesn't look like a very serious attempt to cool brakes. (The previous owner increased rotor and caliper size until he got to Big Reds and 13" Alcons and stopped having problems.)
I would be interested to hear if someone has a good approach to 964 brake cooling that does not involve putting hoses through the trunk.
Strabo
Unfortunately, space in the 964 wheel well is very limited and I'm not sure if a decent size hose can be routed through there to the wheel. The car came to me with intakes in the fog light locations and small 2" hoses that dump into the wheel well, but it doesn't look like a very serious attempt to cool brakes. (The previous owner increased rotor and caliper size until he got to Big Reds and 13" Alcons and stopped having problems.)
I would be interested to hear if someone has a good approach to 964 brake cooling that does not involve putting hoses through the trunk.
Strabo
05-05-2003, 05:09 PM
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I can shed some light on this topic, and welcome all insights..... I installed the Porsche kit (others make them too) that replaces the fog lamps with hoses that route to the wheel well and shoot air towards the hub. No comparison to the choices on the pre-89 911's, where it's easy to route air directly to the hub. With these 964 kits, you can also go with a larger hose to get more air near the hub. Of course rear backing plates are off, and always fresh ATE.
As Manny said, his are 964 variety. I just looked at a set yesterday, and they didn't convince me as a great solution. I'll look for another answer.
Someone was asking about adapting the 968 scoop to a 964, but don't believe he got an answer. Holler if it looks like the 993 kit might work.
The reason I'm very interested in this is because I just upgraded to S4's in front, which are very nice at the track, however, after 3 events, heat cracks are already developing in the rotors!
So, looks like I'll go to cast-hole rotors and have them frozen, which should run cooler and better last longer. A friend has this setup on his C2, and has quite a few days on his rotors which are still in good shape. However, I'd like to find a solution that will get air to the hub.
One thing I've eye'd, but haven't gotten underneath to scope out...I've noticed there's a fair amount of room coming over the front swaybar...Certainly enough room for a hose to lead right over the swaybar, along the a-arm to the rotor hub. You could put it under the sway, but it might get crushed. Just forward of this are the two black plastic undertrays. I wonder if there's enough room for either a scoop or naca duct. Might not be, as I said, I haven't been underneath yet.
As Manny said, his are 964 variety. I just looked at a set yesterday, and they didn't convince me as a great solution. I'll look for another answer.
Someone was asking about adapting the 968 scoop to a 964, but don't believe he got an answer. Holler if it looks like the 993 kit might work.
The reason I'm very interested in this is because I just upgraded to S4's in front, which are very nice at the track, however, after 3 events, heat cracks are already developing in the rotors!
So, looks like I'll go to cast-hole rotors and have them frozen, which should run cooler and better last longer. A friend has this setup on his C2, and has quite a few days on his rotors which are still in good shape. However, I'd like to find a solution that will get air to the hub.One thing I've eye'd, but haven't gotten underneath to scope out...I've noticed there's a fair amount of room coming over the front swaybar...Certainly enough room for a hose to lead right over the swaybar, along the a-arm to the rotor hub. You could put it under the sway, but it might get crushed. Just forward of this are the two black plastic undertrays. I wonder if there's enough room for either a scoop or naca duct. Might not be, as I said, I haven't been underneath yet.
05-05-2003, 07:16 PM
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I took a quick look and I think your idea might work. Need to remove the front pan to really scope it out, as I don't remember what it looks like in there.
And even if the hose gets a little bit crushed, that's not too bad. It was necessary to flatten the duct hose on earlier cars where it snaked through the A-arm.
Now that you have come up with an option for routing the hose, what are your thoughts on getting the air to the rotor? For my SC I fabricated a shroud to force the air into the eye of the rotor and a blocking plate to force it out through the radial vents. As I recall, there were quite a few happy hours invested in that little project, but it worked super.
Of course, the simplest way is just to attach the open end of the hose to the strut, pointing at the rotor. It can be argued that this cools just one side of the rotor, but I have seen it done without adverse effects.
Strabo
And even if the hose gets a little bit crushed, that's not too bad. It was necessary to flatten the duct hose on earlier cars where it snaked through the A-arm.
Now that you have come up with an option for routing the hose, what are your thoughts on getting the air to the rotor? For my SC I fabricated a shroud to force the air into the eye of the rotor and a blocking plate to force it out through the radial vents. As I recall, there were quite a few happy hours invested in that little project, but it worked super.
Of course, the simplest way is just to attach the open end of the hose to the strut, pointing at the rotor. It can be argued that this cools just one side of the rotor, but I have seen it done without adverse effects.
Strabo
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05-05-2003, 07:57 PM
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica"><strong>what are your thoughts on getting the air to the rotor?
Of course, the simplest way is just to attach the open end of the hose to the strut, pointing at the rotor. </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Strabo,
Like the SC air cannisters available (on my SC I had air piped from the valance to the air cannister), I was thinking of using some sheet aluminum attached to the screws that held the backing plate in place, with a hole for the piping to point through. Maybe a loop of aluminum around the hose, pop riveted to the plate to hold the end of the hose steady.
I'm not keen on pointing more air at the face of the rotor, as you're only cooling one side. When I went to the S4's, and pulled the pads after the first day, the backing plate on the side with the air hitting the rotor were still orange. On the side away from air source, the backing plates showed black coloring, which I believe is from heat. So, getting air to the center of the hub to exhaust out the vanes would be my goal.
Of course, the simplest way is just to attach the open end of the hose to the strut, pointing at the rotor. </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Strabo,
Like the SC air cannisters available (on my SC I had air piped from the valance to the air cannister), I was thinking of using some sheet aluminum attached to the screws that held the backing plate in place, with a hole for the piping to point through. Maybe a loop of aluminum around the hose, pop riveted to the plate to hold the end of the hose steady.
I'm not keen on pointing more air at the face of the rotor, as you're only cooling one side. When I went to the S4's, and pulled the pads after the first day, the backing plate on the side with the air hitting the rotor were still orange. On the side away from air source, the backing plates showed black coloring, which I believe is from heat. So, getting air to the center of the hub to exhaust out the vanes would be my goal.
05-05-2003, 08:56 PM
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">I was thinking of using some sheet aluminum attached to the screws that held the backing plate in place, with a hole for the piping to point through. Maybe a loop of aluminum around the hose, pop riveted to the plate to hold the end of the hose steady. </font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">That's exactly how I made mine. The SC rotors were not quite wide enough to take the full width of the tubing, so it was necessary to cut a funny angle to make it fit. But the larger C2 rotors would probably eliminate that problem.
The loop of aluminum (to attach the hose with a clamp) pointed slightly upward and rearward, behind the strut. I also attached the hose to the strut, with room to expand and contract as the steering turned.
How about the blocking plate inside the hub? Without it, much of the ducted air escapes without going through the rotor vents. I have never had a C2 hub apart, so I don't know where to put the blocking plate.
Strabo
The loop of aluminum (to attach the hose with a clamp) pointed slightly upward and rearward, behind the strut. I also attached the hose to the strut, with room to expand and contract as the steering turned.
How about the blocking plate inside the hub? Without it, much of the ducted air escapes without going through the rotor vents. I have never had a C2 hub apart, so I don't know where to put the blocking plate.
Strabo
05-05-2003, 10:27 PM
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica"><strong>
How about the blocking plate inside the hub? Without it, much of the ducted air escapes without going through the rotor vents. I have never had a C2 hub apart, so I don't know where to put the blocking plate.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">The SC air cannister I used had curved in edges to try to keep the air in the rotor hub (assuming you had another plate behind the hub to keep the air in). I'm drawing a blank at the moment, however, I want to say on the C2 that a separate blocking plate isn't needed in the hub.
The kit I looked at yesterday used a flat aluminum plate screwed in where the backing plate goes. I need to get back to the hub and look at how much space is there. The other thing to be careful of is the abs wiring. On the factory cup cars, they used insulation on the wiring between the abs sensor and strut. So we need to be careful not to do something that exasperates heat near the sensor wiring (unless you add some of the available insulation that places like Summit Racing carry). The Porsche insulation part is NLA.
How about the blocking plate inside the hub? Without it, much of the ducted air escapes without going through the rotor vents. I have never had a C2 hub apart, so I don't know where to put the blocking plate.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">The SC air cannister I used had curved in edges to try to keep the air in the rotor hub (assuming you had another plate behind the hub to keep the air in). I'm drawing a blank at the moment, however, I want to say on the C2 that a separate blocking plate isn't needed in the hub.
The kit I looked at yesterday used a flat aluminum plate screwed in where the backing plate goes. I need to get back to the hub and look at how much space is there. The other thing to be careful of is the abs wiring. On the factory cup cars, they used insulation on the wiring between the abs sensor and strut. So we need to be careful not to do something that exasperates heat near the sensor wiring (unless you add some of the available insulation that places like Summit Racing carry). The Porsche insulation part is NLA.
05-06-2003, 06:34 AM
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Bill, are you using 965 rotors with your S4 calipers?? If so, you're one-helluva late braker to crack those rotors up within THREE events!! <img border="0" title="" alt="[Eek!]" src="eek.gif" />
It took about 8-10 events on my 965 rotors with Big Red calipers to start seeing some good cracks. <img border="0" alt="[grrrrrrr]" title="" src="graemlins/cussing.gif" />
But at the rate I was COOKING the factory 964 rotors...I'll gladly replace these rotors once, event twice a year!
It took about 8-10 events on my 965 rotors with Big Red calipers to start seeing some good cracks. <img border="0" alt="[grrrrrrr]" title="" src="graemlins/cussing.gif" />
But at the rate I was COOKING the factory 964 rotors...I'll gladly replace these rotors once, event twice a year!
05-06-2003, 06:57 AM
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Well, you guys have lost me a bit - we'll just have to wait until you find the proper solution and let us know.
I did have one thought, however, but I don't know know if it makes sense. Would it be possible to cut two rectangular shaped holes in the under tray and fabricate from fiberglass two scoops that would hang below the tray to capture the air. The scoops would be shaped on the upper side of the tray into 3 inch circular output to which the flex hose could be attached. The bottom side would show the scoops hanging about 1 to 1.5 inches below the tray and facing forward to catch the air under the car. Or am rambling without sufficient knowledge?
Chuck
93 C2
I did have one thought, however, but I don't know know if it makes sense. Would it be possible to cut two rectangular shaped holes in the under tray and fabricate from fiberglass two scoops that would hang below the tray to capture the air. The scoops would be shaped on the upper side of the tray into 3 inch circular output to which the flex hose could be attached. The bottom side would show the scoops hanging about 1 to 1.5 inches below the tray and facing forward to catch the air under the car. Or am rambling without sufficient knowledge?
Chuck
93 C2
05-06-2003, 09:20 AM
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica"><strong>are you using 965 rotors with your S4 calipers?? </strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">They are 928 86-91 S4 rotors.
05-06-2003, 10:58 AM
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Scupper,
The problem with scoops is that they get knocked off. My first attempt at brake cooling used scoops mounted to the A-arms od an SC. I was not willing to spend hundreds of dollars for fiberglass scoops, so I fabricated some from aliminum. After I lost one in a minor off-track excursion I switched to bring air in through the valance. I ended up giving all my aluminum scoops to others who had theirs knocked off.
You can see scoops at <a href="http://www.ajusa.com/cgi-bin/inventory/view_product?prod_id=47&part_number=" target="_blank">http://www.ajusa.com/cgi-bin/inventory/view_product?prod_id=47&part_number=</a> . Note that these are for earlier cars, not 964s.
With the 964 you can replace the fog lights with ducts quite easily and not worry about scoops. Here is a link to the ducts: <a href="http://www.performanceproducts.com/ProductPage.aspx?productname=Performance+Air+Inlets&productid=104580&pro ducttype=20" target="_blank">http://www.performanceproducts.com/ProductPage.aspx?productname=Performance+Air+Inlets&productid=104580&pro ducttype=20</a>
Strabo
The problem with scoops is that they get knocked off. My first attempt at brake cooling used scoops mounted to the A-arms od an SC. I was not willing to spend hundreds of dollars for fiberglass scoops, so I fabricated some from aliminum. After I lost one in a minor off-track excursion I switched to bring air in through the valance. I ended up giving all my aluminum scoops to others who had theirs knocked off.
You can see scoops at <a href="http://www.ajusa.com/cgi-bin/inventory/view_product?prod_id=47&part_number=" target="_blank">http://www.ajusa.com/cgi-bin/inventory/view_product?prod_id=47&part_number=</a> . Note that these are for earlier cars, not 964s.
With the 964 you can replace the fog lights with ducts quite easily and not worry about scoops. Here is a link to the ducts: <a href="http://www.performanceproducts.com/ProductPage.aspx?productname=Performance+Air+Inlets&productid=104580&pro ducttype=20" target="_blank">http://www.performanceproducts.com/ProductPage.aspx?productname=Performance+Air+Inlets&productid=104580&pro ducttype=20</a>
Strabo
05-06-2003, 11:41 AM
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The 964 fog lamp replacement cooling solutions are also available from Porsche Tequipment, FVD, and Mike Shaw, amongst others. These run a hose to the wheel well to get more air moving towards the rotors.