Upgrading Front brakes only really bad for track duty?

[skyline23]

Hi Guys,
I was hoping to hear people's experience with upgrading just the front brakes to a big brake kit, and keeping the rears OEM size with track pads and better rotors...I read some people comment on this upsetting the brake bias, but then see a bunch of people still do this..are these people who do this maybe not tracking the car then and only doing it for looks? Or is the bias not that bad where it is still manageable on the track?..Any input on this subject would be great..I tried searching but couldn't find any detailed info on this matter...

Also, for those of you who do this, would love to know how much longer are pads and rotors lasting compared to when you were tracking with the OEM stuff?

 

[docjohn]

the simple answer is yes,I have the brembo "indy" race caliper with 12.4 inch rotors and oem rears with ferrodo 2500 front pads and the xp 8 rears...very well balanced.I also have front brake ducts .Ryneen has the lotus brembo caliper and oem rear and he has good bias.Peter mills has the AP front, oem rear and has a good setup.All of these are track tested.

 

[CL65 Captain]

I'm also running Brembo GT (lotus) up front and oem rear.

 

[Hrant]

As noted above, it is an option and many have done it with no issues. The trick in such a scenario is knowing what pads to mix and match in order to keep a "relatively" more front bias (about 60+/-) for track purposes than the OEM set-up.

Only recently and the newer after market BBQ kits (except for StoptTech which did this from the beginning) have addressed the bias issue in such application as a total kit.

Now remember that for street driving, you will need to revert back to a bake balanced street pads where the front bias is closer to 55. If this is a mixed use street/track car and you want a set of mixed pads for both use, you may be able to find a compromise in pad selections that work in both scenarios (but expect more squeal and brake dust than street option - occasionally your first two stops may surprise you if the pads need some heat).

Having said this, in most track situations if you are on street tires, your limiting factor in braking is not the brakes but rather the tires - this with OEM brakes with good track pads and brake fluid. If you are running on R or slick tires, then you will definitely appreciate improvements with an upgrade even if it is only for the front; but your OEM sized rear pads will wear out faster now than before if you correct for bias (add more bias to the rears).

 

[scammy]

quick question guys are you using 91-96 size rotors and callipers or 97 onwards size rear rotors with bigger piston callipers or who is using what and which do you feel is better for brake balance

the simple answer is yes,I have the brembo "indy" race caliper with 12.4 inch rotors and oem rears with ferrodo 2500 front pads and the xp 8 rears...very well balanced.I also have front brake ducts .Ryneen has the lotus brembo caliper and oem rear and he has good bias.Peter mills has the AP front, oem rear and has a good setup.All of these are track tested.

ok should i ask it this way what years are your OEM rears

 

[ryneen]

I have the Brembo Gran Turismo BBK on the front and the stock calipers and rotors on the rear. I've run several different pads and finally settled on Performance Friction PFC01 pads for the front and Carbotech XP10 pads on the rear. I never change the pads between street driving and track driving anymore because it's just not necessary. This setup is perfect for the wife to drive around town and for me to drive it at the track at 10/10ths with the right bias and no fade. I highly recommend this setup. I do have stainless steel brake lines and run Motul 600 brake fluid for what its worth.

 

[Zsolti - Hungary]

At the moment I do run on slick tires with my OEM caliper/OEM size 2piece Stoptech aero rotirs at the front and Powerslot at the rear with Carbotech XP10 front and XP8 rear pads. I like the setup a lot, but want to improve a bit. I would prefer STOPTECH calipers and rotors for the front and OEM at the rear.

Question:
What brakepad combination should I use in order to maintain the good bias and stoping power combo as described above with the STOPTECH CALIPER/ROTOR at the front and OEM CALIPER/POWERSLOT at the rear. If it is working than I can use the money of the rear BBK setup to an OS Gikken LSD:tongue:

 

[CB72]

At the moment I do run on slick tires with my OEM caliper/OEM size 2piece Stoptech aero rotirs at the front and Powerslot at the rear with Carbotech XP10 front and XP8 rear pads. I like the setup a lot, but want to improve a bit. I would prefer STOPTECH calipers and rotors for the front and OEM at the rear.

Question:
What brakepad combination should I use in order to maintain the good bias and stoping power combo as described above with the STOPTECH CALIPER/ROTOR at the front and OEM CALIPER/POWERSLOT at the rear. If it is working than I can use the money of the rear BBK setup to an OS Gikken LSD:tongue:

I don't know if you've seen this table that contains most of the calipers you can find on the market with the corresponding F/R bias?
http://daliracing.com/v666-5/catalog/index_browse_part.cfm?focus=299

 

[docjohn]

quick question guys are you using 91-96 size rotors and callipers or 97 onwards size rear rotors with bigger piston callipers or who is using what and which do you feel is better for brake balanceok should i ask it this way what years are your OEM rears

I have a 96

 

[9doors]

I'm running Tarox up front and OEM on the rear (with an extension bracket from Tarox so I can run a larger rotor). Very happy. :biggrin:

 

[scammy]

thanks Doc, thought i might have to ask who is running NA1 or NA2 rear brakes and send everyone off on a tangent.
So if you are upgrading your fronts to a BBK would the bias be better or more OEM like if you used what you have or the larger later model rear rotors

 

[Zsolti - Hungary]

I don't know if you've seen this table that contains most of the calipers you can find on the market with the corresponding F/R bias?
http://daliracing.com/v666-5/catalog/index_browse_part.cfm?focus=299

I know this it is a good table:smile:

But from this I still do not know which brakepads to use. HEre is how I understand the situation:
I use the OEM ('92) calipers and size of rotors. With the slick tires I had to increase the brake power for which I use Carbotech pads. In order to have a bit more bias to the front I use XP10 front and XP8 rear.
If I would put Stoptech BBK to the front with the OEM at the rear the bias would be somewhere around the 75% zone. In order to get back towards the original 61% I have to use a less aggressive brakepad at the front than the rear. Theoritically I will not have an increased braking power compared to my current OEM setup with carbotech pads, but the only thing I will gain is the decresed rotor temperature at the front (due to the fact that I will have larger rotors which can "eliminate" the heat better). That is what I want because with my current setup I'm satisfied with the braking power and there is no fading, but the rotor temperature is getting too high which results craking at the rotor.

So the question is which brakepad to use in the front with Stoptech BBK in order to "decrese" the performance of it to match the OEM rear with Carbotech XP8 (or XP10?? maybe).
Am I right or do I think something wrong?

(I have used Ferodo DS2500 with OEM setup at the front and it is way worse then the carbotech setup regarding the braking power....)

 

[docjohn]

thanks Doc, thought i might have to ask who is running NA1 or NA2 rear brakes and send everyone off on a tangent.
So if you are upgrading your fronts to a BBK would the bias be better or more OEM like if you used what you have or the larger later model rear rotors

I don't know but i think the difference would be too small to notice.For the track you need a good track pad in the back which has high heat tolerence,the rear gets less cooling air than the front.So I would use a rear pad at least one level higher geared to track than the front.

 

[nsxtasy]

thanks Doc, thought i might have to ask who is running NA1 or NA2 rear brakes and send everyone off on a tangent.

LOL! Scammy is referring to the fact that there's no such thing as NA1 or NA2 brakes. There are two setups, the '91-96 setup (all '91-96 cars had the NA1 engine) and the '97-05 setup (for cars with the NA2 engine as well as the NA1 engine).

Getting back to the braking discussion, how much track experience do you have? If you're a relative novice - say, fewer than 20 track events - then upgrading your brakes really won't do anything for you. You should be working on your braking techniques. (Most novices use more braking than they need, and use less as they gain experience.)

Another recommendation I have is to take an incremental approach to upgrading your brakes. Are you actually having a problem with your brakes, and if so, what is happening? Do you not have enough braking power? (As noted above, that may be due to limits in your tires rather than your brakes - what tires are you using?) Are your brakes overheating/fading? What have you tried? You can spend a relatively small amount of money to upgrade your pads and rotors, without spending the bigger amount of money for bigger calipers. Additional venting/ducting is another inexpensive upgrade that can help. I'm not saying you shouldn't get bigger calipers, but you might not need to spend the big bucks, you may get all the braking you need without spending that much. Many of us have done a lot of track driving with the stock caliper setup and have found it to be all we need.

 

[docjohn]

So the question is which brakepad to use in the front with Stoptech BBK in order to "decrese" the performance of it to match the OEM rear with Carbotech XP8 (or XP10?? maybe).
Am I right or do I think something wrong?

(I have used Ferodo DS2500 with OEM setup at the front and it is way worse then the carbotech setup regarding the braking power....)

I like my ds2500 xp8 combo,but you might try ryneens pfc 01 xp 10 combo when you go bbk.

 

[9doors]

I like my ds2500 xp8 combo,but you might try ryneens pfc 01 xp 10 combo when you go bbk.

You can go PFC01 & XP10 right now if you want. I have a set of PFC01's for the front OEM calipers for sale (which will save you time & $) and you can easily and quickly get a set of XP10's for the rear.

 

[docjohn]

You can go PFC01 & XP10 right now if you want. I have a set of PFC01's for the front OEM calipers for sale (which will save you time & $) and you can easily and quickly get a set of XP10's for the rear.

now you know its not nice to solicit items for sale based on forum posts.....tsk tsk..........btw if you had read the whole thread you would know I have a Brembo Indy( F-40) caliper.

 

[9doors]

Just trying to help the community, not make any $$. Also my post was directed to the OP. I know you, Jim, & Ryneen all run Brembo.

PFC on an OEM caliper is a lot quicker and cheaper to test/play with starting out than a BBK.

jmho

 

[CB72]

I know this it is a good table:smile:

But from this I still do not know which brakepads to use. HEre is how I understand the situation:
I use the OEM ('92) calipers and size of rotors. With the slick tires I had to increase the brake power for which I use Carbotech pads. In order to have a bit more bias to the front I use XP10 front and XP8 rear.
If I would put Stoptech BBK to the front with the OEM at the rear the bias would be somewhere around the 75% zone. In order to get back towards the original 61% I have to use a less aggressive brakepad at the front than the rear. Theoritically I will not have an increased braking power compared to my current OEM setup with carbotech pads, but the only thing I will gain is the decresed rotor temperature at the front (due to the fact that I will have larger rotors which can "eliminate" the heat better). That is what I want because with my current setup I'm satisfied with the braking power and there is no fading, but the rotor temperature is getting too high which results craking at the rotor.

So the question is which brakepad to use in the front with Stoptech BBK in order to "decrese" the performance of it to match the OEM rear with Carbotech XP8 (or XP10?? maybe).
Am I right or do I think something wrong?

(I have used Ferodo DS2500 with OEM setup at the front and it is way worse then the carbotech setup regarding the braking power....)

I believe you will not find a very satisfactory answer to this question.
In principle you could improve the rear braking torque with higher "mu" pads versus the front.
For instance the DS 3000 has a mu of 0.62 versus 0.50 for the DS 2500.
This would improve the rear torque by .62/.50= 1.24.
The problem here is that the DS 2500 is a sport pad whereas the DS 3000 is a pure racing pad that only delivers the stopping power at high temperatures.
In your case, I would definitely not run DS 2500s up front...
I currently run with Pagid pads and I found a table that gives the mu coefficient of their pads : http://www.braketechnology.com/techinfo.html
In fact you could use RS 19's up front with RS 14's for the rear except that while I love the RS 19s I have NEVER managed to bed the RS 14s....
My advise: get a proper brake system for all four wheels because you will end up there in the end...

 

[skyline23]

Thanks for the responses so far..to answer your question, I would say I am still a novice/low intermediate then, as I have about 15 track days and a skip barber school under my belt. For more details on my car, I have removed the front splash guards, run race pads,ate type 200 fluid,and added brake deflectors, and am seeing rotor temps of about 500 degrees after my 20 minute session,which is very close t the 530 degree boiling point (i flush my brakes every event just to be extra safe). I'm sure I have a lot to learn in terms of using my brakes more efficiently, but my car also has 370+whp which probably has something to do with the brake fade I experience. To clarify, it is not lack of power that I am having problems with, as I am not on slicks, but lack of ability to run full 25 minute sessions without cooking the brakes.

LOL! Scammy is referring to the fact that there's no such thing as NA1 or NA2 brakes. There are two setups, the '91-96 setup (all '91-96 cars had the NA1 engine) and the '97-05 setup (for cars with the NA2 engine as well as the NA1 engine).

Getting back to the braking discussion, how much track experience do you have? If you're a relative novice - say, fewer than 20 track events - then upgrading your brakes really won't do anything for you. You should be working on your braking techniques. (Most novices use more braking than they need, and use less as they gain experience.)

Another recommendation I have is to take an incremental approach to upgrading your brakes. Are you actually having a problem with your brakes, and if so, what is happening? Do you not have enough braking power? (As noted above, that may be due to limits in your tires rather than your brakes - what tires are you using?) Are your brakes overheating/fading? What have you tried? You can spend a relatively small amount of money to upgrade your pads and rotors, without spending the bigger amount of money for bigger calipers. Additional venting/ducting is another inexpensive upgrade that can help. I'm not saying you shouldn't get bigger calipers, but you might not need to spend the big bucks, you may get all the braking you need without spending that much. Many of us have done a lot of track driving with the stock caliper setup and have found it to be all we need.

 

[nsxtasy]

Thanks.

You might want to consider using a higher-temperature brake fluid, such as RS683 or Motul RBF 660 or RBF 600, which will give you another 60 degrees or more of protection from boiling, compared to a fluid that only has a 530-degree boiling point. You can see a comparison of braking fluid boiling points here.

Also note that the temperature of the rotors is generally hotter than the temperature of the brake fluid, so you aren't necessarily at the threshold of boiling based on rotor temps.

You also might benefit from installing air ducts from the front air dam to the rotors.

If I were you, I would upgrade the fluid first. If you're having any problems after that, then do the air ducts. I wouldn't go to bigger calipers unless you're still having problems after switching to a higher temp fluid and air ducts.

 

[Hrant]

Thanks for the responses so far..to answer your question, I would say I am still a novice/low intermediate then, as I have about 15 track days and a skip barber school under my belt. For more details on my car, I have removed the front splash guards, run race pads,ate type 200 fluid,and added brake deflectors, and am seeing rotor temps of about 500 degrees after my 20 minute session,which is very close t the 530 degree boiling point (i flush my brakes every event just to be extra safe). I'm sure I have a lot to learn in terms of using my brakes more efficiently, but my car also has 370+whp which probably has something to do with the brake fade I experience. To clarify, it is not lack of power that I am having problems with, as I am not on slicks, but lack of ability to run full 25 minute sessions without cooking the brakes.

I am assuming you measured the rotor temps immediately after hot laps with no cool down [cool down may bring them down by about 100-150F). If so, the rotor temps you see are within normal range if you are using aggressive race pads. The rears are probably about 100F higher than the fronts. Just consider the optimal operating temp of your race pads and compare them to your rotor temp. I bet your race pads are rated something between 200-1200F. Get better brake fluid and see if it helps.

 

[Venom2049]

I recently bought a set of Stoptech Bbk ( just the front ) and I was wondering if it would be better for someone like me ( no track experience at all ) to have 2 piece rotors ( Racing Brake i.e. ) font and back plus racing pads to start instead of having just a BB on front. I know is not my thread but any suggestion would be highly appreciated.

 

[ryneen]

I recently bought a set of Stoptech Bbk ( just the front ) and I was wondering if it would be better for someone like me ( no track experience at all ) to have 2 piece rotors ( Racing Brake i.e. ) font and back plus racing pads to start instead of having just a BB on front. I know is not my thread but any suggestion would be highly appreciated.

For the first few years of tracking my car, I ran the stock size rotors front and rear along with stainless steel brake lines, Motul 600 fluid, Carbotech XP10 pads and Dali brake ducting. This setup never faded even when driving hard. I upgraded to the Brembo Gran Turismo BBK and my laptimes were not really any faster. However, my rotors would last almost an entire year as opposed to about 3-4 weekends with the stock size rotors. I hope this answers your question.

 

[Zsolti - Hungary]

For the first few years of tracking my car, I ran the stock size rotors front and rear along with stainless steel brake lines, Motul 600 fluid, Carbotech XP10 pads and Dali brake ducting. This setup never faded even when driving hard. I upgraded to the Brembo Gran Turismo BBK and my laptimes were not really any faster. However, my rotors would last almost an entire year as opposed to about 3-4 weekends with the stock size rotors. I hope this answers your question.

Thanks..this was what I thought, but it is good to hear that it is not only theoretical.