99spec 4-channel ABS?
06-21-06, 01:27 AM
#29
Originally Posted by FDNewbie
DaiOni, would you mind getting the prices on the lines and the computer? Cuz the pumps do pop up used every now and then... it's the other parts that I can't find.
canadaisintexas, would ya mind askin Jimlab about it? Him and I aren't exactly on speaking terms, so he wouldn't reply if I asked him
Thanks
~Ramy
canadaisintexas, would ya mind askin Jimlab about it? Him and I aren't exactly on speaking terms, so he wouldn't reply if I asked him
Thanks
~Ramy
How much are we talking for a 99 pump/modulator in USD?
06-21-06, 02:00 AM
#32
Wankler
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FD brake section of yahoo is here: http://search1.auctions.yahoo.co.jp/...ale=0jp&acc=jp
adding 'ABS' to the search: http://search1.auctions.yahoo.co.jp/...ale=0jp&acc=jp
to find a newer version, look for...
version number - V (or 5) or VI (or 6)
or
year - most likely to be in the japanese dating system, so 11 (99) - 14 (02)
or
kouki - which I have to put in kanji, it looks like this: ??
adding 'ABS' to the search: http://search1.auctions.yahoo.co.jp/...ale=0jp&acc=jp
to find a newer version, look for...
version number - V (or 5) or VI (or 6)
or
year - most likely to be in the japanese dating system, so 11 (99) - 14 (02)
or
kouki - which I have to put in kanji, it looks like this: ??
06-21-06, 03:14 PM
#34
Lives on the Forum
Fabbing brake lines is easy but without the 4 channel ABS computer, 4 channel ABS pump and complete 4 channel ABS electrical harness you're just pissing in the wind. Even this ***umes the wheel speed sensors and their toothed wheels on the spindles are the same as earlier cars (and it wouldn't surprise me in the least to find that they are not).
I wouldn't bother to start buying parts until I'd compared part numbers between '99 and US cars as well as studied some schematics.
I wouldn't bother to start buying parts until I'd compared part numbers between '99 and US cars as well as studied some schematics.
06-22-06, 01:52 AM
#36
Originally Posted by DamonB
Fabbing brake lines is easy but without the 4 channel ABS computer, 4 channel ABS pump and complete 4 channel ABS electrical harness you're just pissing in the wind. Even this ***umes the wheel speed sensors and their toothed wheels on the spindles are the same as earlier cars (and it wouldn't surprise me in the least to find that they are not).
I wouldn't bother to start buying parts until I'd compared part numbers between '99 and US cars as well as studied some schematics.
I wouldn't bother to start buying parts until I'd compared part numbers between '99 and US cars as well as studied some schematics.
I WOULD be surprised to see Mazda change the tooth pattern on the assembly though it is possible. A finer tooth pattern mike step up the frequency of AC generation, and therefore the sampling rate could be increased etc.., but it would also make the teeth narrower and more susceptible to damage from road debris. I don't see this as something that they would change, again I could be wrong. This would all certainly need to be verified before anyone starts ordering parts from japan.
Last edited by wanklin; 06-22-06 at 01:55 AM.
06-22-06, 03:56 AM
#37
Rotary Freak
The vehicle in Carbon Man's thread (which I believe is a 2000 year car):
https://www.rx7club.com/rx-7-audio-visual-lounge-143/rx7-circuit-car-photos-550325/
prior to the Alcon and dual M/C installation, was running what you would term 99 spec brakes. His wheel speed sensors interchange without problem to a 92 model car, the toothed wheels look identical to my untrained eye. I have both early and late ABS computers, at this stage haven't tried either on the harness, the only visible difference I can see are the part numbers on the case.
Interestingly, the race car was re-engineered to accept the earlier ABS pump and computer (primarily for parts availability on a weekend) so I would be surprised if there is any overwheming advantage to the system - at least on the track!
https://www.rx7club.com/rx-7-audio-visual-lounge-143/rx7-circuit-car-photos-550325/
prior to the Alcon and dual M/C installation, was running what you would term 99 spec brakes. His wheel speed sensors interchange without problem to a 92 model car, the toothed wheels look identical to my untrained eye. I have both early and late ABS computers, at this stage haven't tried either on the harness, the only visible difference I can see are the part numbers on the case.
Interestingly, the race car was re-engineered to accept the earlier ABS pump and computer (primarily for parts availability on a weekend) so I would be surprised if there is any overwheming advantage to the system - at least on the track!
06-22-06, 08:34 AM
#38
Lives on the Forum
Originally Posted by wanklin
I WOULD be surprised to see Mazda change the tooth pattern on the assembly though it is possible. A finer tooth pattern mike step up the frequency of AC generation, and therefore the sampling rate could be increased etc..
I have no idea if the '99 toothed wheels are the same or not but for the reasons above I wouldn't be surprised if they are in fact different and for these reasons I wouldn't spend a big pile of money purchasing a '99 ABS computer, pump and harness and then spend a big chunk of personal time fitting all of these components to the car until I KNEW.
Originally Posted by wanklin
This would all certainly need to be verified before anyone starts ordering parts from japan.
Last edited by DamonB; 06-22-06 at 08:43 AM.
06-23-06, 01:14 AM
#42
Wankel Kid
Join Date: Jul 2005
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Originally Posted by FDNewbie
Anyone know anything about it? Advantage of a 4-channel (vs. our 3-channel) unit? Anyone switch over (which I'm guessing would require the pump, lines, and computer)?
~Ramy
~Ramy
Four-channel, four-sensor ABS - This is the best scheme. There is a speed sensor on all four wheels and a separate valve for all four wheels. With this setup, the controller monitors each wheel individually to make sure it is achieving maximum braking force.
Three-channel, three-sensor ABS - This scheme, commonly found on pickup trucks with four-wheel ABS, has a speed sensor and a valve for each of the front wheels, with one valve and one sensor for both rear wheels. The speed sensor for the rear wheels is located in the rear axle.
This system provides individual control of the front wheels, so they can both achieve maximum braking force. The rear wheels, however, are monitored together; they both have to start to lock up before the ABS will activate on the rear. With this system, it is possible that one of the rear wheels will lock during a stop, reducing brake effectiveness.
Ok, so our target is the rear wheels in the upgrade. Since absolutely no changes will occur to the front brakes you must consider common knowledge, majority of your braking comes from the front brakes, hence why most cheaper or non-performance cars have front disc brakes, rear drums. Before I made this post I was interested exactly how much braking the front did vs the back, and found this on Edmunds.com-
"Combined with the fact that between 60 and 90 percent of a vehicle's stopping power comes from the front wheels, it's clear that a well-designed, modern drum brake is all that's required for most rear wheel brake duty."
That being said, Im not really sure what you guys are after here? You still have ABS functioning on the rears, but its only possible for ONE tire to lock. I know you guys know that there is no way 40% of the braking occurs at the back of our 7s, so lets take somewhere in between 10 and 40%, 25% is fair right? So say 25% of your braking is occuring at the back of your 7, and you are braking in such a manner that you cause one of your tires to lock(Possibly around a curve?). Now remember, a locked tire is still causing you to slow down, just not as well. But we will be nice for the cause of this thread and ignore that. Now you are only getting half the braking power of the rear. 25/2 is 12.5%. If take 12.5% 131ft (Only 60-0 FD Stat I could find!) you will get ~17ft. That may seem like alot, and it is, but remember a locked tire isnt just scooting along no problem. Now you can argue that that could be life/death accident/near miss, but so could a .1 second difference in reaction time. IMO this is way to much work and money for way to little of a benefit, but like Ramy said earliar, to every man his own.
06-24-06, 03:45 PM
#46
Originally Posted by RaPtOr-T
Howstuffworks.com says
Four-channel, four-sensor ABS - This is the best scheme. There is a speed sensor on all four wheels and a separate valve for all four wheels. With this setup, the controller monitors each wheel individually to make sure it is achieving maximum braking force.
Three-channel, three-sensor ABS - This scheme, commonly found on pickup trucks with four-wheel ABS, has a speed sensor and a valve for each of the front wheels, with one valve and one sensor for both rear wheels. The speed sensor for the rear wheels is located in the rear axle.
This system provides individual control of the front wheels, so they can both achieve maximum braking force. The rear wheels, however, are monitored together; they both have to start to lock up before the ABS will activate on the rear. With this system, it is possible that one of the rear wheels will lock during a stop, reducing brake effectiveness.
Ok, so our target is the rear wheels in the upgrade. Since absolutely no changes will occur to the front brakes you must consider common knowledge, majority of your braking comes from the front brakes, hence why most cheaper or non-performance cars have front disc brakes, rear drums. Before I made this post I was interested exactly how much braking the front did vs the back, and found this on Edmunds.com-
"Combined with the fact that between 60 and 90 percent of a vehicle's stopping power comes from the front wheels, it's clear that a well-designed, modern drum brake is all that's required for most rear wheel brake duty."
That being said, Im not really sure what you guys are after here? You still have ABS functioning on the rears, but its only possible for ONE tire to lock. I know you guys know that there is no way 40% of the braking occurs at the back of our 7s, so lets take somewhere in between 10 and 40%, 25% is fair right? So say 25% of your braking is occuring at the back of your 7, and you are braking in such a manner that you cause one of your tires to lock(Possibly around a curve?). Now remember, a locked tire is still causing you to slow down, just not as well. But we will be nice for the cause of this thread and ignore that. Now you are only getting half the braking power of the rear. 25/2 is 12.5%. If take 12.5% 131ft (Only 60-0 FD Stat I could find!) you will get ~17ft. That may seem like alot, and it is, but remember a locked tire isnt just scooting along no problem. Now you can argue that that could be life/death accident/near miss, but so could a .1 second difference in reaction time. IMO this is way to much work and money for way to little of a benefit, but like Ramy said earliar, to every man his own.
Four-channel, four-sensor ABS - This is the best scheme. There is a speed sensor on all four wheels and a separate valve for all four wheels. With this setup, the controller monitors each wheel individually to make sure it is achieving maximum braking force.
Three-channel, three-sensor ABS - This scheme, commonly found on pickup trucks with four-wheel ABS, has a speed sensor and a valve for each of the front wheels, with one valve and one sensor for both rear wheels. The speed sensor for the rear wheels is located in the rear axle.
This system provides individual control of the front wheels, so they can both achieve maximum braking force. The rear wheels, however, are monitored together; they both have to start to lock up before the ABS will activate on the rear. With this system, it is possible that one of the rear wheels will lock during a stop, reducing brake effectiveness.
Ok, so our target is the rear wheels in the upgrade. Since absolutely no changes will occur to the front brakes you must consider common knowledge, majority of your braking comes from the front brakes, hence why most cheaper or non-performance cars have front disc brakes, rear drums. Before I made this post I was interested exactly how much braking the front did vs the back, and found this on Edmunds.com-
"Combined with the fact that between 60 and 90 percent of a vehicle's stopping power comes from the front wheels, it's clear that a well-designed, modern drum brake is all that's required for most rear wheel brake duty."
That being said, Im not really sure what you guys are after here? You still have ABS functioning on the rears, but its only possible for ONE tire to lock. I know you guys know that there is no way 40% of the braking occurs at the back of our 7s, so lets take somewhere in between 10 and 40%, 25% is fair right? So say 25% of your braking is occuring at the back of your 7, and you are braking in such a manner that you cause one of your tires to lock(Possibly around a curve?). Now remember, a locked tire is still causing you to slow down, just not as well. But we will be nice for the cause of this thread and ignore that. Now you are only getting half the braking power of the rear. 25/2 is 12.5%. If take 12.5% 131ft (Only 60-0 FD Stat I could find!) you will get ~17ft. That may seem like alot, and it is, but remember a locked tire isnt just scooting along no problem. Now you can argue that that could be life/death accident/near miss, but so could a .1 second difference in reaction time. IMO this is way to much work and money for way to little of a benefit, but like Ramy said earliar, to every man his own.
The point of the upgrade is to be able to control the rear wheels independently instead of causing both rear brakes to react identically when only one needs modulation.
ex. You are coming into a corner at decent speed, and your left rear wheel passes over a wet spot as you apply full breaking pressure. Since the left rear wheel has a lower coefficient of friction due to the wet surface there will no longer be enough friction between the tire and road surface to allow the brake transfer 100% of its energy in opposition to the kitetic energy of the car. The braking force will outweigh the current FF and lock up the wheel, prompting the ABS system to step in.
The right rear wheel, on the other hand, is on a dry contact surface so the force of friction between the wheel and road surface is enough to keep the wheel from locking up despite the full braking force being applied to the right rear rotor via the caliper.
RESULTS
3CH System
The ABS computer detects wheel lockup in the left rear wheel as it sees the frequency of the incoming wheel speed AC signal decrease to zero. Since the computer has no means of modulating the left rear wheel alone, it will send a signal that will instruct the ABS modulator to begin rapidly modulating pressure to both right and left rear brakes through one feed which is T'd off in the rear of the car. This scenario will prevent the car from spinning, but it will decrease the amount of braking force available to the right rear caliper, which did not need to be modulated in the first place.
4CH System
Computer reads both wheel speed signals independently. It recognizes that the left rear freq has dropped to or near zero so it sends a signal to left rear dedicated modulation circuitry only. Meanwhile, the computer does not see any fault in the signal coming in from the right rear WSS so it allows that wheel to continue to be braked directly from the driver's pedal allowing maximum net braking force.
In summary, I think the net braking force of a car coming into a turn is greater is the rear wheels are allowed to operate independently.
06-24-06, 05:36 PM
#47
Ramy,
Don't waste your time and money on this... I'm sure this also requires 99 calipers and such to take full advantage of the ABS set up.. If you are really interested doing this conversion.. it might be worth it for you to just import a 00+ parts car and convert it over to yours... I personally think FD braking system is good enough for my level of driving.. I thought about going Big brake kit, but its will be just for show... maybe when I get my 20B in..
Don't waste your time and money on this... I'm sure this also requires 99 calipers and such to take full advantage of the ABS set up.. If you are really interested doing this conversion.. it might be worth it for you to just import a 00+ parts car and convert it over to yours... I personally think FD braking system is good enough for my level of driving.. I thought about going Big brake kit, but its will be just for show... maybe when I get my 20B in..
And I feel you...but see, I have a line on some Spirit R brakes...
06-25-06, 07:01 AM
#49
The ABS pump is going to be on the wrong side of the engine bay so you're going to need to fab all of the bay lines and shorten the harness at minimum. I'm interested in doing this, but I have 15 other one-off projects that I have to clear off the punch list before I take this one on.I look forward to seeing what you get going on this.
Last edited by wanklin; 06-25-06 at 07:04 AM.
06-25-06, 04:34 PM
#50
Ok here are the US part numbers:
FD ABS Parts; 94, 95, 95 after #5401
Complete ABS Hydraulic Unit; FD04-43-780F, FD31-43-7A0A, FD31-43-7A0B
Control Box; FD03-67-650, FD31-67-650, n/c
(Rear Wire Harness) w/o sunroof; FB15-67-650, FD31-67-050A, n/c
(Rear Wire Harness) w/ glass roof; FB18-67-050B, FD34-67-050A, n/c
Wheel Sensors FR; FD05-43-70XB
Wheel Sensors FL; FD05-43-73XB
Wheel Sensors RR; FD04-43-71YC
Wheel Sensors RL; FD04-43-72YC
FD ABS Parts; 94, 95, 95 after #5401
Complete ABS Hydraulic Unit; FD04-43-780F, FD31-43-7A0A, FD31-43-7A0B
Control Box; FD03-67-650, FD31-67-650, n/c
(Rear Wire Harness) w/o sunroof; FB15-67-650, FD31-67-050A, n/c
(Rear Wire Harness) w/ glass roof; FB18-67-050B, FD34-67-050A, n/c
Wheel Sensors FR; FD05-43-70XB
Wheel Sensors FL; FD05-43-73XB
Wheel Sensors RR; FD04-43-71YC
Wheel Sensors RL; FD04-43-72YC
Last edited by Julian; 06-25-06 at 04:36 PM.