BBK's and ABS

[JWillis]

Hey guys. When I bought my car, the previous owner disabled the ABS because it was leaving the puddle after driving etc. And so I went ahead and did the flush/excersize of the system. The car has stoptechs all around, and my question is, will the extra size and increased force of the brakes alter the behavior of the ABS system? I went out today and the car still locks the tires. There could be a few variables why the tires locked such as it was 10 degrees outside, but the roads were dry. I am still on street tires.

I have, and still will track my NSX as much as I can. As a matter of fact there is a local event next weekend. I was curious to know how many of you deleted the ABS altogether. That was my plan, but a part of me wanted to keep it around in case I come into a corner too hot. Any input is appreciated.

 

[FXMDBilly]

Do you know the Stoptech piston sizes front and rear?

What tires are you running and what's the size front and rear?

What suspension are you running?

When you locked it up, did you immediately unlock the wheel or did it skid for quite a bit?

Did the ABS pulsate your pedal atall?

Before knowing the above, I would probably suggest keeping the ABS system functional and active regardless. A brake proportioning valve and a lot of testing is a MUST if you don't keep ABS.

Billy

 

[JWillis]

Thanks Billy,

I am currently running 18/19" setup with 225/35/18's in the front and 275/30/19's in the rear. I will be making the switch to 17/18" setup in the spring.

As far as suspension I have the JIC coilovers. All set at 8.5" from the bottom perch to the top tower/plate. I still have stock sway bars.

When the wheels lock up it seems that it is just the front that lock up. They calipers are stoptech ST-40's all around with axxis ultimate pads. As soon as the tires lock up I immediately lift off the brake pedal. So far after I did the flush/excersize of the ABS system, the pump activates as soon as I start driving for no more than 10 seconds. However when the tires lock up, the ABS did not seem to activate. The pedal did not pulsate.

 

[Hrant]

How old are your tires? Have they hardened at all?

From my experinece, any of these two with cold weather may cause such lock-up.

 

[docjohn]

How old are your tires? Have they hardened at all?

From my experinece, any of these two with cold weather may cause such lock-up.

exactly you may have been locking up the fronts and not even have been getting into abs.I have found with my brembo indys depending on pads I never got into abs and was locking.

 

[JWillis]

exactly you may have been locking up the fronts and not even have been getting into abs.I have found with my brembo indys depending on pads I never got into abs and was locking.

The front tires are 4+ years old. Goodyear eagle F1's. The rears I had purchased new a few years ago. The front tires still have 60% treadlife left. I do recall the last track event I had attended was in early November. The temperature reached 55+ degrees that day, and I did get hard on the brakes a few times and they did not lock up. But come to find out the ABS relay had been pulled at that time.

 

[Hrant]

The front tires are 4+ years old. Goodyear eagle F1's. The rears I had purchased new a few years ago. The front tires still have 60% treadlife left. I do recall the last track event I had attended was in early November. The temperature reached 55+ degrees that day, and I did get hard on the brakes a few times and they did not lock up. But come to find out the ABS relay had been pulled at that time.

As I said, if your tires have hardened and the weather is cold, you will lockup. Does this happen also when you have driven the car for some 30 minutes - and in moderate to warmer weather. The fact that is didn't happen at the track might be your clue.

 

[NSXAMG996TT]

It is an uneasy feeling to have the front wheels lock up at the track even with Stoptechs and Carbotech XP10's (street tires). With the Hoosiers, there is definitely less locking up. I may still have to install ABS from an '02-up.

 

[FXMDBilly]

Try doing a few repeated stops. My car with the stock brake system but with good fluids and pads will also lock the tire for about 5-10 feet on cold tires and cold ground but the ABS will eventually activate. After one hard stop, it seems like the ABS activates a little quicker and won't let the tire actually lock like it did the at first.

Try braking a few times and see if it locks repeatedly or if it behaves like mine and works well the second time. Also try separately to warm up the tires (on the track) or on the street by doing a few fairly hard stops to put heat in the tire and soften them up/get more grip, then try locking them with a heavy brake application. A cold tire is very easy to lock up and maybe a hotter/grippier tire gives the ABS enough time to kick on the pump and pulsate the pedal/prevent lockup.

Billy

 

[JWillis]

Thanks for the replies everyone, I will definitely figure out if the ABS works this upcoming Saturday.

 

[titaniumdave]

An easy check is to un-plug the ABS at the pump, see what the brakes feel like in a 'panic' stop. Check how the car feels and how quickly the wheels lock up. Then go back and plug the pump back in and feel the difference. I thought my ABS was not doing anything with my first BBK. I did this test at the track and could not believe how active the stock ABS was! It was working all the time at threshold braking and I never sensed it.

Good luck,
Dave

 

[JWillis]

Well after today, my conclusion is to keep the ABS in! Without the ABS, the car under high speeds, cold conditions and street tires would skid for a while almost pushing the car way outside at times. After several fluid flushes, solenoid excersizes, I wondered why the ABS did not kick on aftter 20 feet of skidding. So I popped the hood just to make sure the fluid was not boiling over, and I discovered that the ALM/ABS 20 amp fuse was blown. After replacing the fuse, the car's behavior was alot different to say the least under braking. The ABS unit worked wonderfully and gave me more driving confidence. So even though a heavy unit it may be, the ABS is staying in.