Brembo 4 piston users....

[GordsFord]

One observation from the second photo is that the scallop pattern seems to approximately follow the location of each of the internal fins within the rotor. It is probably hotter there than in the metal between the fins which is directly cooled by the air flow within, and out of the rotor.

Gord

GordsFord

 

[gcassidy]

It's probably my fault, Tom. I sucked at English in school. LOL

And I agree with all that's been said. I'm not a brake expert, so I've probably been confusing you guys.
Now, while I started this post to point out what happened to the clip on my caliper so others may check theirs when the have the chance, I'll never turn down free advice about my brakes.

As said above, they are Brembo rotors that only have 900 miles on them, 800 street and 100 track (2 weekends ago). These are my 3rd set in the years I've been tracking the car, the ones just removed had reached min thickness with only the usual spider heat checking they usually get, no large cracks. When on the street, I use Hawk HPS, and the track pads I was removing were Hawk DTC70. Hawk Performance: Motorsports
The pads were at the end of their rotation, having 6 track days (about 1~2 hours a day) on them and an average of .223 pad material left. They have given their life for me and are greatly appreciated.

Now, as for the NASA HPDE a couple weekends ago, I was running my BFG R1's, and it was dry with lots of grip. I was breaking as hard as I ever have, running in the instructor and TT group, so they were probably getting the most workout they ever will. I never got into abs. And since less than .25 inch pad material is not much insulation, I'm sure the fluid was getting pretty hot. Its the Wilwood 570.

I don't know how all this plays into the smear you guys are seeing on the rotors. I have cooling ducts, and don't know if there's something other than compressing my breaking zone to cool down the brakes more. Summit Point main has 2 long breaking zones, and 3 somewhat shorter ones.

Another thing that may throw a wrinkle into reading these rotors is I drive to and from Summit Point with the DTC's on, since it's only an hour away. I don't know if that might have an influence on what the rotors look like right now.

I'm open to advice, but am unlikely to switch from Hawks right now. I'm enjoying a good relationship with Jay Andrews of Andrews Racing, and like the advice he has offered on brakes. And no, he hasn't seen this yet.

Here are the removed and retired DTC70 pads. They show no heat cracking and just a little crumbling. I used to get a bit of that sometimes with Hawk Blues, but never enough to be a problem.

Any ideas? I have the clip back in with hi-temp loc-tite, and found another screw very slightly loose when removing the others to put loc-tite on them. The street pads are back on, and this weekend I'll put some street miles on it and expect everything to be OK.

 

[Sloe Truk]

[snip]Now, as for the NASA HPDE a couple weekends ago, I was running my BFG R1's, and it was dry with lots of grip. I was breaking as hard as I ever have, running in the instructor and TT group, so they were probably getting the most workout they ever will. I never got into abs. And since less than .25 inch pad material is not much insulation, I'm sure the fluid was getting pretty hot. Its the Wilwood 570.
[/snip]

Did you bed the pads to the new rotors? Did you season the rotors when you installed them?

 

[gcassidy]

I bedded my used street pads to the new rotors. And I'll always bed new track pads. When changing back and forth from the HPS to Hawk Blues (or now the DTCs) before or after track events I've never re-bedded the pads. I know there are some who have track pads/rotors and street pads/rotors, but staying within the same manufacturer is supposed to minimize the influence of the transfer film. And for years I don't think I've had any problem following that routine.

As for seasoning the rotors, I went through the cycle process of 3 average stops , driving for 10 min, and 3 somewhat harder stops, then letting them sit overnight, then repeating.

For what its worth, the inside of the drivers rotor, that wasn't in contact with the loose clip, looked the same as the pass side rotor.

 

[gcassidy]

Something I wonder about...am I getting enough cooling air into my brake ducts?
I have these inlets from Quantum Motorsports, and figured they would be getting air rammed into them at whatever speed I was driving at. But my wife (the science teacher) wonders if there may be some turbulance at the inlet that keeps all the air from entering.

Is there any way to find out how much air you're getting through the ducts?
Ideas?

In front...

From behind...

 

[BlackBolt9]

I was just coming back to this thread to suggest that the smooth spots on the pads look to me as if they may be glazing a little bit which is typically cause by getting really hot. However you are on pretty good pads which should handle temperature pretty well, so I was going to suggest that maybe you need to work on your cooling ducts a bit.

From looking at the pictures, I would agree with your wife that you are not getting as much air as you could be. You are probably flowing close to the 3" diameter of air but you are not getting the increased airflow you would see if it was closed off to the bumper. As of right now, once the hose get backed up it cannot create pressure to force air through because it will just bleed off around the outside. If it was sealed, once the hose because backed up, there isn't a place to bleed off except in from of the bumper cover, this should cause more higher pressure air to force it's way through your brakes. Alos the design of your backing plate could make a difference in this as well.

I would see if you could improve it as I think it could help and shouldn't cost a lot of money to do.

 

[Sloe Truk]

Well to address the differences in pad bed in, I generally default to stop tech since the are succinct about the matter. I'm trying to find an article on the advatanges of seasoning new rotors, but you can google as well as I can.

As far as your air flow quandry: I think there are two viable solutions. The expensive one is to install a flow meter in line and get an actual CFM rating. The rooute I think I would go wouold be to source a MAF froma junkyard and and wire the power to it, and pull the signal wire back into the car where you could read it, then as the control for the experiment I would install in a short piece of 3" PVC tube and drive in a straight line. Use the differences in the voltage levels to determine the delta of the two flows and make your decision based upon that data. There might be some turbulence up front that would prevent airflow.

If this link works I'll show you what I did in my L, it is similar due to the fog light appatures, but basically I used several funnel fittings from home depot to get as much air in there as possible. http://www.nloc.net/photopost/showgallery.php?cat=1473

 

[BlackBolt9]

Well to address the differences in pad bed in, I generally default to stop tech since the are succinct about the matter. I'm trying to find an article on the advatanges of seasoning new rotors, but you can google as well as I can.

I will disagree with you on these things. Pad bed in is manufacturer specific and you should contact that specific manufacturer about their procedures. Just as an example, the Performance Friction pads we run in the Koni Challenge race cars don't "need" to be bedded per se. The drivers go out on brand new pads and scuff them in during the warm up and recon laps before the race start all the time. FWIW Hawk is usually pretty good about returning emails to their tech department. I had an answer within a few days when I asked about pads for the stock Lightning brakes.

As far as the rotors, I haven't heard this from a manufacturer but from experience rotor seasoning is more important with cheap rotors than expensive ones. For our endurance races as an example, we won't use anything other than Brembo or Performance Friction rotors which don't require seasoning. We don't have the time to season as we may run out of rotor life and need to change them between qualifying and the race. We don't run Stop Tech, Coleman, etc. for this reason. Are their rotors made from a cheaper material? Cast in an inferior way? I don't have the answer but I have the knowledge that they aren't as good for whatever reason.

As far as your air flow quandry: I think there are two viable solutions. The expensive one is to install a flow meter in line and get an actual CFM rating. The rooute I think I would go wouold be to source a MAF froma junkyard and and wire the power to it, and pull the signal wire back into the car where you could read it, then as the control for the experiment I would install in a short piece of 3" PVC tube and drive in a straight line. Use the differences in the voltage levels to determine the delta of the two flows and make your decision based upon that data. There might be some turbulence up front that would prevent airflow.

If this link works I'll show you what I did in my L, it is similar due to the fog light appatures, but basically I used several funnel fittings from home depot to get as much air in there as possible. Brake ducting - NLOC Gallery

I agree with you on using a MAF sensor, but the only problem is trying to calibrate the sensor. And yes it does need some calibration as if on one pass you get 3.5V out then the next pass you get 4V, what does that mean? A MAF function is not linear so you can't assume you are X amount better, it could be X^Y amount better without knowing what the sensor calibration curve is.

FWIW here is what I did with my Lightning on the front and rear. The front flows so much an instructor that was following me said it looked like an F1 car coming into the corner because of the giant black brake dust clouds coming out of the wheels. The rears made such a big difference that I went from blowing through a set of rear pads in a day or so to making several weekends, no changes other than the hoses.

http://www.svtperformance.com/forums/2nd-generation-22/506937-lightning-brake-cooling.html

 

[mu22stang]

gcassidy, is it possible to clamp a 5"-to-3" rubber reducer to seal the interface between the fog holes to the brackets? It's hard to tell if you have clearance for them as they are about 6"-8" long. Doesn't Anthony include those on his '94-'98 kits? You may have to get creative in order to continue using the mesh, or just remove it altogether and leave the ducting off until events.

Also, it looks like you have the first generation backing plates, if I'm not mistaken. I got those same backing plates from Tcoupe, and I notice a HUGE gap between the rotor surface and the plate. To remedy this, I installed new hardware with approximately 3/4" spacers (comprised of one size up nuts) in between the backing plates and the spindle. This minimized the gap to about 1/4" from almost an inch.

 

[Sloe Truk]

I will disagree with you on these things. Pad bed in is manufacturer specific and you should contact that specific manufacturer about their procedures. Just as an example, the Performance Friction pads we run in the Koni Challenge race cars don't "need" to be bedded per se. The drivers go out on brand new pads and scuff them in during the warm up and recon laps before the race start all the time. FWIW Hawk is usually pretty good about returning emails to their tech department. I had an answer within a few days when I asked about pads for the stock Lightning brakes.

As far as the rotors, I haven't heard this from a manufacturer but from experience rotor seasoning is more important with cheap rotors than expensive ones. For our endurance races as an example, we won't use anything other than Brembo or Performance Friction rotors which don't require seasoning. We don't have the time to season as we may run out of rotor life and need to change them between qualifying and the race. We don't run Stop Tech, Coleman, etc. for this reason. Are their rotors made from a cheaper material? Cast in an inferior way? I don't have the answer but I have the knowledge that they aren't as good for whatever reason.



I agree with you on using a MAF sensor, but the only problem is trying to calibrate the sensor. And yes it does need some calibration as if on one pass you get 3.5V out then the next pass you get 4V, what does that mean? A MAF function is not linear so you can't assume you are X amount better, it could be X^Y amount better without knowing what the sensor calibration curve is.

FWIW here is what I did with my Lightning on the front and rear. The front flows so much an instructor that was following me said it looked like an F1 car coming into the corner because of the giant black brake dust clouds coming out of the wheels. The rears made such a big difference that I went from blowing through a set of rear pads in a day or so to making several weekends, no changes other than the hoses.

http://www.svtperformance.com/forums/2nd-generation-22/506937-lightning-brake-cooling.html

And I agree with you on all points, conceeding the points that most people do not have access or funds to the higher end of the spectrum of parts. One should always follow the OEM instructions on friction material, pads/clutches etc... I mentioned seasoning rotors, cause it never hurts, most applications that most of us have access to, would benefit from it.

The OP and many of us out there are using off the shelf components was intended to that end. Myself I am still using the OE Brembo caliper and OE rotors on my Z. All of the others fail miserablly. I was able to source some used race brembos that will work with my fitment this past weekend and was surprised at the complete difference in apearance and weight, I can't remember which race series these came from but they are about 1/2 the weight of the same friction ring that I would normally expect. I don't even want to know what these cost new (and they only run one race on these) and they were barely scratched.

The MAF solution was very generalized, if one wanted to add a wheatstone bridge network to it for calibration and scaling it could be done and cheaply. Calibration would lend itself to sourcing a controlled flow of CFM to set and scale the range of the MAF, again though you have to keep in mind that a MAF was designed for laminar flow and I would not think that the high pressure zone of the front of a Cobra or anything really would be laminar. I think at best one could chart the readings and take an average, and compare that to a desired average. So assuming a 3" straight piece of PVC all but pegged the MAF at 4.5 V. when measuring the flow in the brake duct an average MAF voltage was derived at 3.5V and one wanted more flow, changes could be made in the ducting and retested. WASH RINSE REPEAT. F1 teams spend gobs of money with CFD and wind tunnel testing for stuff like this, I was just trying to help the OP and his wife, the science teacher, in the quandry of turbulence.

 

[brkntrxn]

LOL, I think this just turned into a Corner-Carvers thread. , just kidding, good tech, very good tech. I always appreciate reading everyone's opinions and input. And several of us rely on Bryan's experience and BS to guide us through our track escapades.

My .02? Although no one asked.... At our level, just run the damn thing. If anything, I would swap rotors to the opposite side the next time I ran at that same track to see if something was specific to that side to that track configuration.

 

[BlackBolt9]

The OP and many of us out there are using off the shelf components was intended to that end. Myself I am still using the OE Brembo caliper and OE rotors on my Z. All of the others fail miserablly. I was able to source some used race brembos that will work with my fitment this past weekend and was surprised at the complete difference in apearance and weight, I can't remember which race series these came from but they are about 1/2 the weight of the same friction ring that I would normally expect. I don't even want to know what these cost new (and they only run one race on these) and they were barely scratched.

Trust me, I can understand that. My experience comes from working with a race team not driving for one My personal experience with my Lightning has left me on stock calipers and cheap chinese rotors. So I know the pain that comes with inadequate parts as well. I was just saying to check with the specific manufacturer instead of just using Stop Techs advice because they are all just a little different. To be honest I don't even know what pads Stop Tech uses, are they their own or someone else's?

As far as rotors go, for anything under a continuous hour I've never seen a problem even with the cheaper rotors. Start getting into the 2-3 hours of race use and I would bet that you see a difference though. And I will agree that seasoning these rotors definitely improves their life. I'm guessing it has something to do with improving their grain pattern through the heat cycles.

The MAF solution was very generalized, if one wanted to add a wheatstone bridge network to it for calibration and scaling it could be done and cheaply. Calibration would lend itself to sourcing a controlled flow of CFM to set and scale the range of the MAF, again though you have to keep in mind that a MAF was designed for laminar flow and I would not think that the high pressure zone of the front of a Cobra or anything really would be laminar. I think at best one could chart the readings and take an average, and compare that to a desired average. So assuming a 3" straight piece of PVC all but pegged the MAF at 4.5 V. when measuring the flow in the brake duct an average MAF voltage was derived at 3.5V and one wanted more flow, changes could be made in the ducting and retested. WASH RINSE REPEAT. F1 teams spend gobs of money with CFD and wind tunnel testing for stuff like this, I was just trying to help the OP and his wife, the science teacher, in the quandry of turbulence.

Completely agreed, I just didn't know if they would have the means to even come close to properly calibrate the sensor and I have no idea just how much curve, a MAF curve is since I haven't really played with one much. I wasn't sure if it would be closer to a line or an exponential curve.

I guess I was just agreeing with brkntrxn and suggesting he try to tie things up a bit and see if it works better. He isn't having a major problem as it is so a huge improvement isn't really needed. Not very scientific though :-D

 

[Sloe Truk]

LOL, I think this just turned into a Corner-Carvers thread. , just kidding, good tech, very good tech. I always appreciate reading everyone's opinions and input. And several of us rely on Bryan's experience and BS to guide us through our track escapades.

My .02? Although no one asked.... At our level, just run the damn thing. If anything, I would swap rotors to the opposite side the next time I ran at that same track to see if something was specific to that side to that track configuration.

Good Idea Kev you have one occasionally oke:

See ya at VIR ina few days

 

[Sloe Truk]

Trust me, I can understand that. My experience comes from working with a race team not driving for one My personal experience with my Lightning has left me on stock calipers and cheap chinese rotors. So I know the pain that comes with inadequate parts as well. I was just saying to check with the specific manufacturer instead of just using Stop Techs advice because they are all just a little different. To be honest I don't even know what pads Stop Tech uses, are they their own or someone else's?

I think Stop tech uses porterfield and porsche, I think.

As far as rotors go, for anything under a continuous hour I've never seen a problem even with the cheaper rotors. Start getting into the 2-3 hours of race use and I would bet that you see a difference though. And I will agree that seasoning these rotors definitely improves their life. I'm guessing it has something to do with improving their grain pattern through the heat cycles.

That is the way I understood it as well, it is supposed to heat the metal so much that is changes the crystaline structure of the metal.

I guess I was just agreeing with brkntrxn and suggesting he try to tie things up a bit and see if it works better. He isn't having a major problem as it is so a huge improvement isn't really needed. Not very scientific though :-D

Oh crap you are agreeing with Kev. I agree as well.

 

[gcassidy]

Wow, thanks for the info and advice everyone. Bryan and Tom, both of your links work, and I can see different approaches to achieve the same end results. Trent, I was already thinking of contacting Anthony about some of his '94-'98 foglamp adapters (and still may), but I'm gonna go check out Home Depot first. I might be able to cobble together something to get around the "pipe in the wind" effect.

I'll probably work at getting the intake area sealed, and then not worry about what it's actually flowing. I'm not sure I could get a maf working there, and even with my wife's help, don't know if I could get accurate and informative data. And if I get the intake to successfully funnel down to the 3" pipe, I'm not sure what I'd do with the data anyway. Where would I go from there?

The backing plates I have are aluminum and from an outfit in Florida called Need For Speed (I don't know if they're still around...the web site isn't). There's an honest 1/2" between the backing plate at the duct to the rotor. I probably could shim it a bit closer, but I'm gonna work at the intake end first. Here's what they look like (sorry for the mud, that was after a really big, muddy off at VIR in the spring ).

And I always appreciate and listen to Kevin's advice. :rockon: Can't say why, though. :smmon:

Now it's on to fixing the leaking front seal in my diff before VIR in a few weeks. Always something new.:bored:

 

[Sloe Truk]

Wow, thanks for the info and advice everyone. Bryan and Tom, both of your links work, and I can see different approaches to achieve the same end results. Trent, I was already thinking of contacting Anthony about some of his '94-'98 foglamp adapters (and still may), but I'm gonna go check out Home Depot first. I might be able to cobble together something to get around the "pipe in the wind" effect.

I'll probably work at getting the intake area sealed, and then not worry about what it's actually flowing. I'm not sure I could get a maf working there, and even with my wife's help, don't know if I could get accurate and informative data. And if I get the intake to successfully funnel down to the 3" pipe, I'm not sure what I'd do with the data anyway. Where would I go from there?

The backing plates I have are aluminum and from an outfit in Florida called Need For Speed (I don't know if they're still around...the web site isn't). There's an honest 1/2" between the backing plate at the duct to the rotor. I probably could shim it a bit closer, but I'm gonna work at the intake end first. Here's what they look like (sorry for the mud, that was after a really big, muddy off at VIR in the spring ).

And I always appreciate and listen to Kevin's advice. :rockon: Can't say why, though. :smmon:

Now it's on to fixing the leaking front seal in my diff before VIR in a few weeks. Always something new.:bored:

YOu are welcome, hope it didn't turn into a "corner carver's" thread whatever that means :burnout:

I'm not online often but if you want/need to ask a ? just pull on Kevin's chain he generally has a way of getting a rise out of me.

If you want to experiment with the MAF concept I can write something up, but honestly without more feedback, i.e. rotor temps, friction material temps as a baseline and improvement or worse performance as feedback you are pretty much shooting in the dark, and we can do that for free epper:

Been a pleassure hangin out here again, far better than some of my past experiences on SVTP. I can't say that strongly enough. Kev, dammit you were right, again.

 

[gcassidy]

:lol: Always good to have another person knowledgeable in the black magic of keeping cars running on track.

What Kevin was referring to is corner-carvers.com. A great website forum of road racers and open track junkies. But they have very little tolerance if you don't "bring the tech" or use the search function and do your own research. For example, posting up "I have a Mustang, what brake pads are best for it?" would get you flamed immediately. As is to be expected, there have sometimes been some very heated debates about technical issues with various products or practices that different experts in the high performance automotive field will have. But it's a gold-mine of information.

Don't be a stranger to this forum. :beer:

 

[Sloe Truk]

:lol: Always good to have another person knowledgeable in the black magic of keeping cars running on track.

What Kevin was referring to is corner-carvers.com. A great website forum of road racers and open track junkies. But they have very little tolerance if you don't "bring the tech" or use the search function and do your own research. For example, posting up "I have a Mustang, what brake pads are best for it?" would get you flamed immediately. As is to be expected, there have sometimes been some very heated debates about technical issues with various products or practices that different experts in the high performance automotive field will have. But it's a gold-mine of information.

Don't be a stranger to this forum. :beer:

Will do! :beer:

 

[brkntrxn]

YOu are welcome, hope it didn't turn into a "corner carver's" thread whatever that means :burnout:

Get out of your 350Z world and open your eyes, man!!!! Like Greg said, Corner-Carvers.com is a great resource of info.

I'm not online often but if you want/need to ask a ? just pull on Kevin's chain he generally has a way of getting a rise out of me.

Damn, you been checking out my ass again? Good grief, want me to tell my wife? You know she will kick your ass. Guess I gotta wear a long shirt when I work grid with you at CMP and VIR in a couple of weeks. I guess all that time we spent under my car this summer fart gave you "feelings". :lol:

See you next Thursday as we terrorize a few Porsche's at VIR!!!!! :beer:

For everyone else's benefit.... every core group of track junkies has one person that has done it longer and does more track days each year, one person that has spent more fruitless hours under their vehicle brainstorming how to fix an issue, one person that has contacts with more "in the know" people in the tracking world. Bryan is that guy for us. I don't believe half the crap he says and will gladly call him out on it, LOL just playing oke:, but you get my point.



So back to the original topic. Good find on the loose clip, Greg. And good job on using all of your available braking power so that we may learn from your experiences.

My .02 and I will take change.

-Kevin

 

[Sloe Truk]

Get out of your 350Z world and open your eyes, man!!!! Like Greg said, Corner-Carvers.com is a great resource of info.

yeah, yeah, whatever. You know I am not that technical of a guy, I'm not one to sit around and beat a dead horse.

Damn, you been checking out my ass again? Good grief, want me to tell my wife? You know she will kick your ass. Guess I gotta wear a long shirt when I work grid with you at CMP and VIR in a couple of weeks. I guess all that time we spent under my car this summer fart gave you "feelings". :lol:

dewd, tell Dawn, she knows I like it rough

See you next Thursday as we terrorize a few Porsche's at VIR!!!!! :beer:

can't wait, finally got the car tuned. I had to, the new exhaust leaned me out so much I was deep into the 14s for a/f ratio.

For everyone else's benefit.... every core group of track junkies has one person that has done it longer and does more track days each year, one person that has spent more fruitless hours under their vehicle brainstorming how to fix an issue, one person that has contacts with more "in the know" people in the tracking world. Bryan is that guy for us. I don't believe half the crap he says and will gladly call him out on it, LOL just playing oke:, but you get my point.

I will say it is a ton more fun doing it in a group of like minded people. FOr years I was a group of one, which blew. We are an odd bunch, pretty diverse crowd. Two Cobras, a Vette, three 350zs, 1 G35, a couple of E30s, and the occasional Mini.

So back to the original topic. Good find on the loose clip, Greg. And good job on using all of your available braking power so that we may learn from your experiences.

My .02 and I will take change.

-Kevin

still slightly concerned about the smearing, it is a sign of over heated friction material. In my humble opinion, it is not a huge deal, but perhaps on the next set of pads, I would perhaps go up a level of aggresiveness (I know squat about Hawk pads) or improve the ducting. Mine still smear but it is track dependant and that may very well be the case ere as well.

Kev, I bet money this event at VIR is goingt o be very much like the Darkside event, where it is more of a "social" event rather than a driving event, oh wait aren't all PCA events like that :lol: