DE Brake question
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From: Chicago Area
IF you put new pads on, do break them in. For the track pads I have (KFP from Paragon-Products), I can find a nice lonesome road and do about 10 sequential HARD stops from about 65 mph. That will usually get smoke billowing out of the wheel wells and cook off all that gaseous stuff. I then drive on home, let them cool and all is good.
It's a drag to show up for a DE and get "green fade".
IMHO, stock pads are fine for your first few DE's. If they are relatively thick, you should be able to go home on the same pads you drove up on. Now, when you get to changing the fronts every day or two... then it is indeed time for a pad upgrade.
Never hurts to bring along a set of used pads. If you find you are really blazing through the pad material, you can always have a back-up. As noted above, inspect pads after each run session. I just takes a few minutes right after checking tire pressures.
Just my 2 cents, adjusted for the rising price of oil = well, just about zero.
It's a drag to show up for a DE and get "green fade".
IMHO, stock pads are fine for your first few DE's. If they are relatively thick, you should be able to go home on the same pads you drove up on. Now, when you get to changing the fronts every day or two... then it is indeed time for a pad upgrade.
Never hurts to bring along a set of used pads. If you find you are really blazing through the pad material, you can always have a back-up. As noted above, inspect pads after each run session. I just takes a few minutes right after checking tire pressures.
Just my 2 cents, adjusted for the rising price of oil = well, just about zero.
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From: Stanfordville NY
more brake tips
Dave makes a great point. Make sure to bed in the pads properly. Directions will come with most pads and will vary by type. When you get your brakes hot, avoid coming to a full stop with the brakes on. This will leave pad material on the roters and create all kinds of havoc. Proper bedding and cool down greatly improve performance and rotor life.
Race Car
Joined: Jan 2004
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From: Charlotte, NC
PCA CMP run format is run until checkered flag. I have never noticed a heads-up warning indicating that you have one more lap. You get the checkered flag 2/3 of the way through the last lap. This leaves ZERO time for the brakes to cool off as you don't have a cool down lap.
My car has those slotted dish wheels which do not maximize brake breathing. So frequently, I will take a nice little drive a couple miles up the road after a run to give the brakes a chance to cool.
Just a suggestion.
I will be at the CMP event - hope you get off the waiting list and get to the track!
My car has those slotted dish wheels which do not maximize brake breathing. So frequently, I will take a nice little drive a couple miles up the road after a run to give the brakes a chance to cool.
Just a suggestion.
I will be at the CMP event - hope you get off the waiting list and get to the track!
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From: Oklahoma
a debate we had on bimmerforums was about changing out rotors when you change your pads. but if you change pads frequently because of wearing them out or just because they suck, do you necessarily need to change the rotors too?
if not, then i'm assuming that's when you use the bed in procedure that dave described, right?
if not, then i'm assuming that's when you use the bed in procedure that dave described, right?
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From: Chicago Area
My front pads/rotors ratio is about 3.5/1. I run non-drilled, Porsche or Zimmerman OEM rotors and just change pads until the rotors start to look a bit small with the micrometer. Normal inspection required (measure, inspect for abnormal grooving/cracking, etc.).
The only rotors I have had to pull straight off the car and pitch into the bin were those evil aftermarket drilled rotors. The previous owner put them on and they became junk (grooving badly in line with the drilled holes).
That was one bit of bling that was simply a bad idea.
New pads = the same bed-in procedure for me. It's not uncommon for me to change to fresh pads in the paddock, bed them in, and let the car cool in the hotel parking lot overnight.
When changing pad make/material, I've seen a transition period required to get the old pad material worn off the rotors and/or new pad material deposited. This is typically when I switch back to stock pads for the winter commute mode. You can get funky braking during this period. Changing over to the same brand/compound has never presented this funky transition behaviour.
The only rotors I have had to pull straight off the car and pitch into the bin were those evil aftermarket drilled rotors. The previous owner put them on and they became junk (grooving badly in line with the drilled holes).
That was one bit of bling that was simply a bad idea.
New pads = the same bed-in procedure for me. It's not uncommon for me to change to fresh pads in the paddock, bed them in, and let the car cool in the hotel parking lot overnight.
When changing pad make/material, I've seen a transition period required to get the old pad material worn off the rotors and/or new pad material deposited. This is typically when I switch back to stock pads for the winter commute mode. You can get funky braking during this period. Changing over to the same brand/compound has never presented this funky transition behaviour.
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From: Simpsonville, SC
Hi Guys
I talked to Matt at Carbo Tech he recommended the Panther + for my first DE. I decided to take my Acura as I don't know if I will have the Porsche and running correctly by the end of the month.
I checked the DE status sheet at the PCA and I am still listed as Waiting List it hasn't been updated since 8/24 so I assume that to mean that there hasn't been a change.
We shall see how this plays out.
I talked to Matt at Carbo Tech he recommended the Panther + for my first DE. I decided to take my Acura as I don't know if I will have the Porsche and running correctly by the end of the month.
I checked the DE status sheet at the PCA and I am still listed as Waiting List it hasn't been updated since 8/24 so I assume that to mean that there hasn't been a change.
We shall see how this plays out.
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From: Charlotte, NC
Originally Posted by CurlyDE
I am going to pick up a set of HP Plus pads for this DE. Do you guys think that I should replace the rear pads also? I currently have the MetalMaster pads front and rear.
Again, I'd call either of those characters I mentioned to Kool (Matt at Carbotech or Andie and CobaltFriction) and get their pad recommendation. I'd be shocked if HP+ was in their top 3.
Race Director
Joined: Jan 2002
Posts: 10,170
Likes: 2
From: North NJ, USA
Originally Posted by Dave Swanson
IF you put new pads on, do break them in. For the track pads I have (KFP from Paragon-Products), I can find a nice lonesome road and do about 10 sequential HARD stops from about 65 mph. That will usually get smoke billowing out of the wheel wells and cook off all that gaseous stuff. I then drive on home, let them cool and all is good.
It's a drag to show up for a DE and get "green fade".
IMHO, stock pads are fine for your first few DE's. If they are relatively thick, you should be able to go home on the same pads you drove up on. Now, when you get to changing the fronts every day or two... then it is indeed time for a pad upgrade.
Never hurts to bring along a set of used pads. If you find you are really blazing through the pad material, you can always have a back-up. As noted above, inspect pads after each run session. I just takes a few minutes right after checking tire pressures.
Just my 2 cents, adjusted for the rising price of oil = well, just about zero.
It's a drag to show up for a DE and get "green fade".
IMHO, stock pads are fine for your first few DE's. If they are relatively thick, you should be able to go home on the same pads you drove up on. Now, when you get to changing the fronts every day or two... then it is indeed time for a pad upgrade.
Never hurts to bring along a set of used pads. If you find you are really blazing through the pad material, you can always have a back-up. As noted above, inspect pads after each run session. I just takes a few minutes right after checking tire pressures.
Just my 2 cents, adjusted for the rising price of oil = well, just about zero.
The proper bed-in procedure for KFP's is:
10 stops from 20mph (@ .45g's - ie: NOT up to lockup)
10 stops from 40mph
10 stops from 60mph.
I tend to be able to do the 20 and 40mph stops in the school lot next door to my house. The 60mph stops are a bit more difficult given my 'test track.' Once the KFP's start squeeling like a pig in a butcher's shop - that's when you know they've been bedded in!
Originally Posted by renvagn
...IMHO 951 brakes are one of the weak points of the car...
I use the stock Porsche rotors on my 944S2. (Porsche OEM brand - NOT the Zimmerman's). My brake setup is identical to the stock 951 brakes (Brembo 4-piston calipers, solid & vented rotors). With the KFP track pads, and regular bleeding of my brake fluids, I have no problems on the track. That said, if my pads do run a little low (less tham 1/2 the pad left), I will get a bit of brake fade - primarily due to heat transfer through the pad. But I wouldn't claim that to be a factor of poor brakes, and the stopping power is still there, the brake pedal just travels further. (Note: I don't have SS brake lines - just the stock rubber ones - not a big fan of the SS brake lines)
I am curious why you feel the 951 brake setup is a weak point of the car. (There are other things I would consider to be a weak point, such as the A-arms and the inherent power steering fluid leaks our cars exhibit).
-Zoltan.
Last edited by Z-man; Aug 30, 2005 at 04:51 PM.
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From: Simpsonville, SC
Originally Posted by Z-man
I am curious why you feel the 951 brake setup is a weak point of the car. (There are other things I would consider to be a weak point, such as the A-arms and the inherent power steering fluid leaks our cars exhibit).
Instructor
Joined: Nov 2004
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From: Statesville, NC
We've done the DE's at CMP in a street - tired, stock HP RX7. The Hawk HPS brakes would fade at the end of each session.
...and CMP is more than an auto X. Even our RX7 is over 90 MPH thru the kink.
Nice folks at the track. Have fun.
...and CMP is more than an auto X. Even our RX7 is over 90 MPH thru the kink.
Nice folks at the track. Have fun.
Addict
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Originally Posted by CurlyDE
I am going to pick up a set of HP Plus pads for this DE. Do you guys think that I should replace the rear pads also? I currently have the MetalMaster pads front and rear.
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Mark,
For a dedicated track car or one which will be lowered or see lots of track use, you'll want to upgrade the control arms.
As far as brakes, these cars are heavy compared to the older 911's which seem to scamper around and have nice tight turn in. We have to contend with inherent push and a wider cornering arc. Engine wise look to Lindsey for waste gate upgrade, 3 bar fuel regulator, either a boost enhancer or boost controller, 3" exhaust and get it dyno with the chips remaped. It will be a much better car with less lag around town and at the track. As far as the power steering resevoir and tubing parts that can be fixed. Also don't use any rotors other than stock 9sun set porsche in OR) or Brembo cross drilled ($$$$$) which you will not probably require.
Mark
For a dedicated track car or one which will be lowered or see lots of track use, you'll want to upgrade the control arms.
As far as brakes, these cars are heavy compared to the older 911's which seem to scamper around and have nice tight turn in. We have to contend with inherent push and a wider cornering arc. Engine wise look to Lindsey for waste gate upgrade, 3 bar fuel regulator, either a boost enhancer or boost controller, 3" exhaust and get it dyno with the chips remaped. It will be a much better car with less lag around town and at the track. As far as the power steering resevoir and tubing parts that can be fixed. Also don't use any rotors other than stock 9sun set porsche in OR) or Brembo cross drilled ($$$$$) which you will not probably require.
Mark
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Joined: Jan 2002
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From: North NJ, USA
Originally Posted by renvagn
Also don't use any rotors other than stock 9sun set porsche in OR) or Brembo cross drilled ($$$$$) which you will not probably require.
Mark
Mark
First you say that the brakes on a 951 aren't up to the task, and then you recommend Brembo cross-drilled rotors.
Many track folks that I've spoken to do not like the cross-drilled rotors: they tend to crack and wear quicker than solid rotors, they tend to wear brake pads quicker, and all the little holes (which are cast, not drilled, BTW), tend to fill up with brake dust material and need to be literally drilled out. I have heard these complaints from 944, 964, and even 993 owners. Many switch back to solid rotors, or possibly the slotted ones. As far as cross-drilled rotors offering better stopping power - IMHO, cross-drilled disks offer more bling power than better stopping power.
Unless your 951 is making north of 400hp, the solid stock rotors along with the stock Brembo calipers with a good set of track pads are quite suitable for track use, especially DE's. If you feel the need to upgrade, then go with the 'big blacks' The brakes from the 944 Turbo S, which, IIRC, are the same units found in the 928 GTS.
What experience do you have to support your reasoning?
-Z-man.