Need some education on brakes please

[stuntman]

It sounds like with a 4 channel ABS you are in fact adjusting bias on the fly in a rather crude manner. But certainly it is better than a system with poor bias without abs. Essentially, the fine tuning of bias matters more on a 2 channel system on the older NSX and on cars without ABS. This is the info I was looking for. I suppose even adjusting the bias on a car with any sort of ABS is problematic. You can't quiet lock up to see where you need to back off and which wheel.

Billy you mentioned dual master cylinder. Why do race cars use that? Is it a pressure thing or is it for more control? What is each master cylinder doing is what I am asking.

Pretty much ever real race car has a twin master non-boosted setup. 1 master is for the front brakes, the other is for the rear. The master cylinder sizes can be changed out for bias, then the adjustable T-bar uses a worm-screw that's driver adjustable to slightly change the pivot point of the brake pedal relative to the F&R master cylinders.

Every racecar in Grand-Am CTSCC uses ABS and some sort of proportioning. Like I said, its better to have a good inherent bias and have the ABS modulate from there. ABS pulsates and prevents lockup but does not affect the inherent bias of the brake system.

For your Stoptech brakes, i'd just let the ABS do what it does. I'm not sure how the ceramic brakes will work, if they need temperature to have any sort of useful friction, etc... for street or track use or how the ABS will react to the characteristics of the ceramic rotor.

 

[NSX-Files]

I think your car has the 2nd generation modern 4-channel ABS system while the Pre (2000?) cars have an archaic, terrible 2-channel system. Your ABS system is very good and modulates/pulsates the line pressure to each individual wheel as needed to prevent lockup.

Ideally you want your bias to be correct and have the ABS modulate as needed rather than being overworked by constantly adjusting for an improper brake setup. I forget, do you have a 4 or 2 wheel ST BBK? Either way, I wouldn't mess with it. From where you're at now, the only way to really improve your braking performance is to ditch the entire setup, go to a non-boosted twin master cylinder setup with a proper bias adjuster, remove ABS (and be perfect with your applications) or going with a $10-15K programmable race abs system.

According to the 1991 Service Manual, even the early NSX had a 4-channel ABS system with 4 solenoid valves to independently modulate each of the 4 wheels.

 

[TURBO2GO]

Thanks billy. Very useful info. What is the "pivot point" of the pedal?

 

[Shaylord]

All Nsxs have a four channel abs. The Nsx was the first production car with a four channel abs system.

 

[docjohn]

Wow Dave you will be really out in uncharted waters with a composite bbk.....you might want to talk to Detlif whether movit had such a system,or whether honda racing in Europe gave it a look.

 

[TURBO2GO]

Yes, Movit has a system. No one has had them on an NSX before.

 

[DDozier]

Yes, Movit has a system. No one has had them on an NSX before.

Things to consider with Carbon Composit Rotors:
1. Pad choices are few
2. Pads are expensive
3. Rotors will last three to fours times longer than the average two piece rotor
4. Rotors must be weighed and tracked to know true rotor wear rates and life left
5. Rotors are delicate and can be damaged by uneven pad wear, debris, or mishandling
6. Did i mention the pads are expensive

I have based this info on my expierence maintaining Corvette ZR1 and Z07 Brake Systems, these use the Brembo Carbon Ceramic Rotors and Brembo Pads, they are still super cool.

Dave

 

[scammy]

Dave have you upgraded to the NSX-R ABS it has different bias setup for more aggressive style suited to track work. Adnan has them listed at present

 

[stuntman]

According to the 1991 Service Manual, even the early NSX had a 4-channel ABS system with 4 solenoid valves to independently modulate each of the 4 wheels.

I vaguely remember reading that a long time ago. Thanks for the correction.

Thanks billy. Very useful info. What is the "pivot point" of the pedal?

The rod that goes from the pedal to the master cylinder (on a stock car) would go in the middle of a "T" joint between two master cylinders. As the worm gear is rotated, the center rod from the pedal would move closer to either the F or R master cylinder -adjusting the bias.

Dave have you upgraded to the NSX-R ABS it has different bias setup for more aggressive style suited to track work. Adnan has them listed at present

Do you have to replace the entire module to an NSX-R one?

 

[Shaylord]

Do you have to replace the entire module to an NSX-R one?

I have looked into this some and from what I have found I believe the only difference is in the actual programming, it activates the abs later than the regular modulator assembly. Unfourtantly honda does not split up the parts for the modulator it is one preassembled piece. I am probably going to get one and investigate further the differences between the two.

 

[TURBO2GO]

Dave have you upgraded to the NSX-R ABS it has different bias setup for more aggressive style suited to track work. Adnan has them listed at present

I know about it, I am just bot convined there is enough of a difference to justify the cost. I don't have any real data. "More aggressive" is a pretty vague term. It's not cheap what if the difference is minimal?

- - - Updated - - -

Things to consider with Carbon Composit Rotors:
1. Pad choices are few
2. Pads are expensive
3. Rotors will last three to fours times longer than the average two piece rotor
4. Rotors must be weighed and tracked to know true rotor wear rates and life left
5. Rotors are delicate and can be damaged by uneven pad wear, debris, or mishandling
6. Did i mention the pads are expensive

I have based this info on my expierence maintaining Corvette ZR1 and Z07 Brake Systems, these use the Brembo Carbon Ceramic Rotors and Brembo Pads, they are still super cool.

Dave

Dave I am aware of the pad costs, and I am getting 3 sets included with my purchase. They assure me the rotors last 5 times porsche PCCBII and about 10X porsche PCCBI. I asked if I needed to remove and weigh, they said no, a thickness measurement will give an accurate enough wear rating. The rotors can be "retreaded" up to 5X, the cost is about $2800 for the 4 to bring them back to factory spec.

 

[Shaylord]

Interesting combine this with the NSX-R modulator I wonder if it would be a marginal improvement or the sum of the two together to would make quite the difference in braking.

 

[Stook2003]

I have no first hand information with movit CCB myself, but a guy I met at the track had a couple sets on his Carrera GT and eventually went back to Porsche PCCB and later steel brakes.
His explanation was that while driving on the track, you can not actually keep them hot enough to work properly. He even blocked all the cooling ducts and they would still get cold. Hes a good driver too and does club races and stuff. Just something to consider or ask the Movit engineers about it.

 

[DDozier]

Dave I am aware of the pad costs, and I am getting 3 sets included with my purchase. They assure me the rotors last 5 times porsche PCCBII and about 10X porsche PCCBI. I asked if I needed to remove and weigh, they said no, a thickness measurement will give an accurate enough wear rating. The rotors can be "retreaded" up to 5X, the cost is about $2800 for the 4 to bring them back to factory spec.

I am only basing my expierience off the Brembo Carbon Ceramic setup, they say with their product the only way to know rotor wear is to weigh the rotor. It was explained to me that the rotors do not wear on the surface that they decay from the heat created in the braking process and the mass is lost from the inside out. Not sure if this is correct but the Brembo sales rep gave me the info at last years PRI show. Interesting idea about retreating the rotors, Brembo says discard and replace at min weight stamped on the rotor hat.

Of course I would follow your manufacturers recommendations as they should know what should be best.

Dave

 

[ryneen]

I agree with the others..at some point you spend too much time chasing small theoretical hardware issues when all you need is more attention to the fleshy software that drives the car.My suggestion for next season is no more messing with car and just hire a good coach.

Wonderful advice! I've been tracking my car for 9 years.
- Year 1 = Bone stock car. No instructors (too dumb and prideful to hire one).
- Year 2 = I added almost all of the mods/changes that I currently have now during year two. These were all carefully selected to make the car quicker, easier to drive and more reliable. BBK, replaced all hoses, non compliance everything, Penske coilovers, sway bars, upgraded radiator, baffled oil pan, accusump, R Comp tires, I/H/E.
- Year 3- Hired my setup person whom is a phenomenal driver as well, to drive the car and coach me to make sure the car setup was well balanced and to teach me how to drive it better.
- For the last 5 years, I have essentially changed very little other than adding a harness, proper seat, aftermarket steering wheel, short gears, rear view mirror air freshner and a gurney flap from Billy Johnson.
- My car is very predictable since it is very well setup and has been mostly unchanged for nearly 5 years. This has allowed me to focus on improving my skills and lap times as opposed to chasing setup changes. I do adjust my dampers a click or to depending on the track. Another huge benefit was hiring Billy Johnson for his professional coaching services. He is far better and more articulate than any coach I have encountered. I got a lot quicker from him.

Note: My NA1 ABS failed a few years ago so I replaced it with the NA2 ABS. It is better, but I don't think it made a big difference in lap times or driveability.

 

[docjohn]

..........you share my philosophy and setup!......

 

[stuntman]

Wonderful advice! I've been tracking my car for 9 years.
- Year 1 = Bone stock car. No instructors (too dumb and prideful to hire one).
- Year 2 = I added almost all of the mods/changes that I currently have now during year two. These were all carefully selected to make the car quicker, easier to drive and more reliable. BBK, replaced all hoses, non compliance everything, Penske coilovers, sway bars, upgraded radiator, baffled oil pan, accusump, R Comp tires, I/H/E.
- Year 3- Hired my setup person whom is a phenomenal driver as well, to drive the car and coach me to make sure the car setup was well balanced and to teach me how to drive it better.
- For the last 5 years, I have essentially changed very little other than adding a harness, proper seat, aftermarket steering wheel, short gears, rear view mirror air freshner and a gurney flap from Billy Johnson.
- My car is very predictable since it is very well setup and has been mostly unchanged for nearly 5 years. This has allowed me to focus on improving my skills and lap times as opposed to chasing setup changes. I do adjust my dampers a click or to depending on the track. Another huge benefit was hiring Billy Johnson for his professional coaching services. He is far better and more articulate than any coach I have encountered. I got a lot quicker from him.

Note: My NA1 ABS failed a few years ago so I replaced it with the NA2 ABS. It is better, but I don't think it made a big difference in lap times or driveability.

Thanks Ryan

You really need to come out to BW this weekend! I'd love to see your car again.