The Truth About BBK's
#32
01-27-2010, 12:49 AM
Relying on the ABS to "correct" a bias problem is NOT a proper way to design a brake system. Again, read the links provided.
Just because it's "worked w/o a problem" is one poor arsed way to evaluate a brake system. I'm sure I could run 4 lugs vs 5 and have it "work w/o a problem" also. Still ill advised.
Are there front only bbks that are okay to use? Yes. Are all of them designed this way? No. Do people know which ones are and which ones are not? Probably not. Read the links.
Just because it's "worked w/o a problem" is one poor arsed way to evaluate a brake system. I'm sure I could run 4 lugs vs 5 and have it "work w/o a problem" also. Still ill advised.
Are there front only bbks that are okay to use? Yes. Are all of them designed this way? No. Do people know which ones are and which ones are not? Probably not. Read the links.
#33
01-27-2010, 01:22 AM
#34
01-27-2010, 01:26 AM
#35
01-27-2010, 01:33 AM
all I know is I dont remember seeing anyone say anything about correcting bias with ABS (other than you of course)...
and I dont need to read links about using front BBK with OEM rear - because I know several people personally that have done it and many, many people on the forums that have done it. What more would I need to know?
Its weird that you wold tell someone to read something that they aren't even interested in...
and I dont need to read links about using front BBK with OEM rear - because I know several people personally that have done it and many, many people on the forums that have done it. What more would I need to know?
Its weird that you wold tell someone to read something that they aren't even interested in...
#36
01-27-2010, 01:47 AM
Since a lesson is in order here:
This thread is in response to all the “if it’s not Stop-Tech, then it’s crap” posts. It seems the only requirements to be a brake expert are reading the Stop-Tech White Papers, browsing the Zeckhausen Racing website, and hating any non-Stop-Tech BBK.
Stop-Tech’s front BBK reduces stopping distance by utilizing a smaller piston area than stock. Yes, the Stop-Tech front caliper has less stopping torque than the stock caliper. Stop-Tech BBK's are the best available. But "brake balance" can be achieved by lessor brake companies.
The proper question to ask is the size of the pistons and the rotor. I’ll explain.
First, all brake kits operate on the same principals. Hydraulic fluid is pushed through a line that compresses a piston which pushes the pads on the rotor.
Second, total piston area determines the torque of any given caliper. For example, the stock caliper on a 2005 6MT has two 1.75 inch pistons. Do some math and the total area is 4.8 inches. This calculation uses the pistons on only one side of the caliper. So, a six piston caliper’s piston area would be based on 3 pistons. Strangely, the stock sliding calipers brake as if they had identical opposed pistons (why? Ask a physicist).
Third, the number of pistons does not affect torque. I doesn’t matter if you get 4 inches of piston area with one big piston or 9 tiny pistons.
Fourth, rotor diameter effects brake torque. For example, if the only modification you did to your stock brakes was increase the front rotors to 14 inches then front brake bias would increase 2%. A 13 inch rear rotor would reduce front bias 2%. That rear rotor upgrade is starting to look pretty good now...
Fifth, our cars come from the factory overly front brake biased (74% front/26% rear). Although this increases stopping distance, a front biased vehicle is easier to control.
Therefore, reducing front brake bias will balance the car and decrease stopping times. However, shift the bias too far and the rears may lock up before the front. VERY DANGEROUS!
Stop-Tech has determined that magic amount of brake bias to magically balance a 350z/G35. I would love to know the piston area of the Stop-Tech front BBK.
So you want to know the effectiveness of your specific BBK. Get a ruler and measure the piston areas and rotor diameter.
Then use a brake bias calculator like the one at http://dsr.racer.net/brake_bias.htm. If the ratio is the same as stock, then your brake distance will be unchanged. If the ratio is more front biased you will take longer to stop and unnecessarily burden your front brakes.
If you are going front only, make sure the total piston area (and front brake bias) is slightly less than stock. A general rule of thumb is no more than 5%. Also, search the forums and call the distributor to determine if there are any problems with that specific BBK locking the rears.
For example, I have Wilwood 6 piston calipers on 13 inch rotors. The total piston area is 4.06 or .74 inches less than stock resulting in 72%/28% bias or 2% more rear bias.
A Wilwood 6 piston superlight BBK with a 13 inch rotor will stop in a shorter distance than stock.DOMO
Of course different BBK's will have better heat dissipating characteristics, pedal modulation, etc... but that is for another post.
Stop-Tech’s front BBK reduces stopping distance by utilizing a smaller piston area than stock. Yes, the Stop-Tech front caliper has less stopping torque than the stock caliper. Stop-Tech BBK's are the best available. But "brake balance" can be achieved by lessor brake companies.
The proper question to ask is the size of the pistons and the rotor. I’ll explain.
First, all brake kits operate on the same principals. Hydraulic fluid is pushed through a line that compresses a piston which pushes the pads on the rotor.
Second, total piston area determines the torque of any given caliper. For example, the stock caliper on a 2005 6MT has two 1.75 inch pistons. Do some math and the total area is 4.8 inches. This calculation uses the pistons on only one side of the caliper. So, a six piston caliper’s piston area would be based on 3 pistons. Strangely, the stock sliding calipers brake as if they had identical opposed pistons (why? Ask a physicist).
Third, the number of pistons does not affect torque. I doesn’t matter if you get 4 inches of piston area with one big piston or 9 tiny pistons.
Fourth, rotor diameter effects brake torque. For example, if the only modification you did to your stock brakes was increase the front rotors to 14 inches then front brake bias would increase 2%. A 13 inch rear rotor would reduce front bias 2%. That rear rotor upgrade is starting to look pretty good now...
Fifth, our cars come from the factory overly front brake biased (74% front/26% rear). Although this increases stopping distance, a front biased vehicle is easier to control.
Therefore, reducing front brake bias will balance the car and decrease stopping times. However, shift the bias too far and the rears may lock up before the front. VERY DANGEROUS!
Stop-Tech has determined that magic amount of brake bias to magically balance a 350z/G35. I would love to know the piston area of the Stop-Tech front BBK.
So you want to know the effectiveness of your specific BBK. Get a ruler and measure the piston areas and rotor diameter.
Then use a brake bias calculator like the one at http://dsr.racer.net/brake_bias.htm. If the ratio is the same as stock, then your brake distance will be unchanged. If the ratio is more front biased you will take longer to stop and unnecessarily burden your front brakes.
If you are going front only, make sure the total piston area (and front brake bias) is slightly less than stock. A general rule of thumb is no more than 5%. Also, search the forums and call the distributor to determine if there are any problems with that specific BBK locking the rears.
For example, I have Wilwood 6 piston calipers on 13 inch rotors. The total piston area is 4.06 or .74 inches less than stock resulting in 72%/28% bias or 2% more rear bias.
A Wilwood 6 piston superlight BBK with a 13 inch rotor will stop in a shorter distance than stock.DOMO
Of course different BBK's will have better heat dissipating characteristics, pedal modulation, etc... but that is for another post.
So all you've proven is what we've said all along, and thats that the reason to choose stoptech is because they keep the brake bias similar to stock. No other kits provide piston sizing information or explain how they go about setting bias. Many offer the same kit for the front whether you purchase a rear kit or not. They offer the same kit for all 03-06 models regardless of rear brake setup. You just happened to luck out with your kit because infiniti decided to increase the rear brakes on the 05+ g35's. The arizonazcar kit was designed around the smaller 03-04 brakes and actually INCREASES the front brake bias. So much for great engineering right? BTW, using your calculator you provided, your brake bias calculations appear to be incorrect, I get a stock bias of 66/34. and the 05+ front piston size is only 1.69".
#37
01-27-2010, 01:52 AM
Cont..
Yes, this is a perfectly valid way of determining brake bias if you have the information beforehand. The problem is that every time someone who has a kit other than stoptech is asked if their kit addresses brake bias or if they knew how it affected it, we never get an answer. Stoptech is the only company that has addressed this to the Z/G community publically. This is the reason why many of us recommend stoptech. How many other kits do you know the piston sizing for without having the kit in front of you? Are you going to just guess and check by purchasing multiple kits until you get one that has better brake bias? That is the the big picture you have to look at.
#38
01-27-2010, 02:19 PM
I'm not sure who you are trying to force a "lesson" upon - but I know I have no interest in the rhetoric...
I have a BBK f/r and am not affected by the subject... I know plenty of ppl that have had bbk in front and not in rear and have had absolutely no negative consequences...
No matter how much "stuff" you post - those facts wont change.
So to the question(s) of using BBK in front and not in rear = it's been done many times without problems.
The end - bu-bye
I have a BBK f/r and am not affected by the subject... I know plenty of ppl that have had bbk in front and not in rear and have had absolutely no negative consequences...
No matter how much "stuff" you post - those facts wont change.
So to the question(s) of using BBK in front and not in rear = it's been done many times without problems.
The end - bu-bye
#39
01-27-2010, 02:25 PM
No Mike. Just stating that people have used them w/o problems w/o any clarification on WHAT kit they have and WHAT specs they have is flat out the WRONG way to assess the issue of having a properly designed brake system. They might have a properly biased system or they may not.
Either discuss the issue of brake bias on a techncially sound level or just leave the conversation. Because that logic process is borderline asinine IMHO.
The only real fact there is although I'm far from a brake expert, relatively speaking, you have no idea what you are talking about here.
Either discuss the issue of brake bias on a techncially sound level or just leave the conversation. Because that logic process is borderline asinine IMHO.
The only real fact there is although I'm far from a brake expert, relatively speaking, you have no idea what you are talking about here.
Last edited by Jeff92se; 01-27-2010 at 02:30 PM.
#40
01-27-2010, 02:48 PM
Jeff, you are one strange guy... I mean really strange...
We are in a thread about non-brembo OEM 06 Z brake upgrade (which might as well include 05+ G)...
A guy asks this:
and you respond with this (who the hell knows why, because its inaccurate, there is nothing wrong with using 05 front with existing rear - which is what the guy was asking... the rear on the 05+ isnt going to change anything about brake bias that the pre 05 have)
Then someone asked this:
and I responded with this:
Now - what part of your blabbering changes any of this?
As usual, you take the entire subject in a completely different direction that has nothing to do what the posts that have been made - then you get mad when no one is interested in getting into that crap - because it's not relevant to what has been discussed.
Again - nothing you have posted changes any of the FACTS that I listed.
We are in a thread about non-brembo OEM 06 Z brake upgrade (which might as well include 05+ G)...
A guy asks this:
and you respond with this (who the hell knows why, because its inaccurate, there is nothing wrong with using 05 front with existing rear - which is what the guy was asking... the rear on the 05+ isnt going to change anything about brake bias that the pre 05 have)
You want to do both. Most of the braking IS up front but it's the bias ratio you want to balance. Too much front makes it easier to lock them up and nets you more front end dive.
I've experienced too much front bias when I put 13" rotors and Z32 calipers on my maxima. It would lock and dive pretty good. When I upgraded my rears (happens to be a simple bracket and larger rotor upgrade) the braking was MUCH flatter and it locked up much less.
I've experienced too much front bias when I put 13" rotors and Z32 calipers on my maxima. It would lock and dive pretty good. When I upgraded my rears (happens to be a simple bracket and larger rotor upgrade) the braking was MUCH flatter and it locked up much less.
lol yeah i know about bbk's, idk why I brought them up
my friend put some altima front brakes on his 96 g20 and if u aren't careful it will lock up the brakes pretty nicely with the back going in a slightly different direction, but the car defiantly stops better if you are careful.
I would think in the case of an 03-04 G35 which has abs(the g20 is supposed to but it doesn't work) and the rear calipers are the same on 05-06 G's just with different brackets, the only difference is the size of the rear rotors so it seems like it wouldn't be a huge issue to drive around like that until it was time to do the rear brakes.
the question is has anyone actually tried it and is their G currently upside down at the bottom of a ravine?
my friend put some altima front brakes on his 96 g20 and if u aren't careful it will lock up the brakes pretty nicely with the back going in a slightly different direction, but the car defiantly stops better if you are careful.
I would think in the case of an 03-04 G35 which has abs(the g20 is supposed to but it doesn't work) and the rear calipers are the same on 05-06 G's just with different brackets, the only difference is the size of the rear rotors so it seems like it wouldn't be a huge issue to drive around like that until it was time to do the rear brakes.
the question is has anyone actually tried it and is their G currently upside down at the bottom of a ravine?
Now - what part of your blabbering changes any of this?
As usual, you take the entire subject in a completely different direction that has nothing to do what the posts that have been made - then you get mad when no one is interested in getting into that crap - because it's not relevant to what has been discussed.
Again - nothing you have posted changes any of the FACTS that I listed.
#42
01-27-2010, 03:01 PM
No Mike. The 05+ rear brakes use the same caliper but larger rear rotors. Why? Because the 05+ FRONT brakes have more bias. More bias in the front means you need more bias in the rear (everthing else being the same).
Your statement is false:
Yes it will. If you put a rear 05+ system on the 03-04 and 05 AWD, it WILL change the brake bias. That is a fact and it's not disputable.
AGAIN, the issue is proper brake bias. And that's the issue front and center. PRECISELY what the links address and clarify.
Your statement is false:
the rear on the 05+ isnt going to change anything about brake bias that the pre 05 have)
AGAIN, the issue is proper brake bias. And that's the issue front and center. PRECISELY what the links address and clarify.
#44
01-27-2010, 03:07 PM
No Mike. The 05+ rear brakes use the same caliper but larger rear rotors. Why? Because the 05+ FRONT brakes have more bias. More bias in the front means you need more bias in the rear (everthing else being the same).
Your statement is false:
Yes it will. If you put a rear 05+ system on the 03-04 and 05 AWD, it WILL change the brake bias. That is a fact and it's not disputable.
AGAIN, the issue is proper brake bias. And that's the issue front and center. PRECISELY what the links address and clarify.
Your statement is false:
Yes it will. If you put a rear 05+ system on the 03-04 and 05 AWD, it WILL change the brake bias. That is a fact and it's not disputable.
AGAIN, the issue is proper brake bias. And that's the issue front and center. PRECISELY what the links address and clarify.
The posts I responded to were has it caused problems and can it be done?... the answers are "no" and "Yes"... no matter how much you want to change those facts.
Now - if you are trying to indicate those statements are not fact - why not just post the reference of people having problems?
Its funny because I've known people that have actually tracked their car and not had issue (much less just street driven cars)... hey, but maybe there's a hidden incident that hasn't been widely reported - do us all a favor an proved details on that please.
#45
01-27-2010, 03:08 PM
The issue ABS shouldn't even be mentioned at all. It's a non-factor. So let's move on to this:
1) The larger rear rotors is the SOLE reason these rears have an increased brake power. And the use of bigger rotors is a very effective way of increasing brake power to that side of the car. Actually the use of a larger rotor is a bigger brake power adder than the use of larger pistons or # of pistons. (master cylinder issue)
2) HUGE issue? Perhaps not because in this PARTICULAR case, the bias isn't going off that MUCH. BUT the question is why? You aren't doing yourself any favors doing so. In all likelyhood, you aren't decreasing your stopping distances and probably have a better chance it increasing them (tech discussion about bias again)
Probably not, but again, running 4 lugs vs 5 won't net me that result either. I still wouldn't do it from a technical standpoint.
would think in the case of an 03-04 G35 which has abs(the g20 is supposed to but it doesn't work) and the rear calipers are the same on 05-06 G's just with different brackets, the only difference is the size of the rear rotors so it seems like it wouldn't be a huge issue to drive around like that until it was time to do the rear brakes.
2) HUGE issue? Perhaps not because in this PARTICULAR case, the bias isn't going off that MUCH. BUT the question is why? You aren't doing yourself any favors doing so. In all likelyhood, you aren't decreasing your stopping distances and probably have a better chance it increasing them (tech discussion about bias again)
the question is has anyone actually tried it and is their G currently upside down at the bottom of a ravine?
Last edited by Jeff92se; 01-27-2010 at 03:21 PM.