01 ACR ABS FAILURE

[99t1]

When I mean failure I'm referring to applying pressure on the brake pedal and having NO BRAKES for close to one second during hard braking on a bumpy or uneven track surface...a factory Viper test driver called this "bump logic" and it is an unwanted but apparently normal characteristic of the ABS system.

Another failure (in my opinion) is locking up tires and flat spotting which has now happened twice under heave braking on a very smooth surface.

What's up...???

 

[PMUM]

I had the same problem with my '01 ACR on the track but it had nothing to do with bumps. It was totally heat related (I did it enough times to verify). After the brakes got too hot the ABS would wait about a second before coming in even on the pit road at 30 mph after my excursions. Definitely below average.

Anybody who road races an '01 better get a good brake kit or pull the ABS fuse pronto!

 

[treynor]

Hrrrm, this is disconcerting -- I'm going to be taking my '01 on the racetrack (roadrace, not dragrace

) in about 6 weeks. Do either of you two have ducting kits to send cold air to the front brakes? I'm very interested to hear what you've tried, what worked/didn't work, and what you do about the problem.

 

[PMUM]

I had Porsche deflectors and race pads in the front (street in the rear) so the fronts were running hotter than normal. The problem doesn't rear until very high temps, but when it does you better hope there's room to run off because you will. You've gotta be VERY aggressive on the brakes and be on a track that isn't brake friendly.

I made it through the weekend at Willow Springs (easy on brakes) with no problems, but at Buttonwillow (tough on brakes) when the temps would come up (sometimes in 3 laps or less) there would be no warning, just a rock hard pedal and a trip through the weeds. It does it for about a second, which if you're heating up the brakes to those temps means you can't spare a second in a braking zone, and the pedal pulses.

Morgan, I know it didn't happen to you earlier so this time do you think the brake temps were higher? That's 100% what caused mine. I'd say 90% of the driver/track combos won't cause it, but I was fortunate to be at a place with no walls.

Ben, where are you going? If it's Laguna (HUGE brake temps) or Sears (walls & ditchesamania) I'd pull the fuse and go old school. My solution is a big-*** brake kit with big-*** ducting. Haven't tried the new setup but will let you guys know how/if it works.

 

[99t1]

I run Hawk HT9 pads, Porsche deflectors, Archer duct kit.

I had the bump logic problem at Nelson Ledges in a bumpy uneven braking zone but the lock up was at Limerock in a very smooth zone and the ABS was working fine except for a single lock up during a 30 minute race.??? It continued to work fine after the lock up???

I doubt the temps got to @1100 degrees where Paul has apparently had his failures.

 

[treynor]

Paul,
I'm sticking to Buttonwillow, Willow Springs and Thunder Hill precisely because they have lots of run-off and nothing much to hit if I take an off-track "excursion". Still, both T-hill and BW have some hard braking points, and I'd hate to lose my brakes going into, say, turn 1 at T-hill.

I'll be very interested to hear how your braking upgrades proceed. I may well copy the parts that end up working

 

[GTS Dean]

That "bump logic" thing sounds like what my Ram 2WD has at the rear. Get into a rutted, bumpy braking area approaching a red light and the back end just gives up for a moment. Very disconcerting and not worth a darn in anybody's book.

Just gimme plain-ol' full-manual analog brakes. That way, it's either pad fade (almost never) or fluid boil (very rarely) - no electronics to worry about.

 

[JonB]

'01 Owners: Have you found a REAR PAD FITTMENT?

I have stabbed around the rumored "T-bird solution" ....but I had no luck. Anyone have a rear bad upgrade???

 

[99t1]

I have been using the Porterfield AP599 with the R-4 compound (secret Thunderbird work around by Mumford) but I will have Hawk HT9s made by Carbotech in the near future. http://www.carbotecheng.com/

 

[jimandela]

JonB,
I dont know if you will consider this an upgrade? I do
(less dust, no squeak) my 2001 rear EBC green stuff brake pads
should be here within 2 weeks....at that time will switch out the fronts and rears on my 2001 for the new pads.

also do you think that the 2001 abs could fail on a regular street drive under a panic stop condition?

 

[99t1]

probably not...it works well overall except if you are punishing it on the track

 

[SEASNAKE]

I had the rears lock up on my Ram 3500 Van. They were not hot and I was only going about 30. The road was kind of rough though.

 

[JonB]

UPDATE - StopTech has been doing some stainless line testing, and found an interesting tech-tidbit when studying video of the same car without, and then WITH SS lines----

1) Rubber lines: Brake lites on, wait a tenth, see car squat.

2) Stainless lines: Brake lites on, car squats simultaneously.
No perceptible visual delay.......

Advanced drivers have been saying this for years, as buttt-feel.

Does this "help" ABS cars? Maybe it would "start the ABS computer clock" faster?

 

[wmw1]

Installing StopTech S/S brake hoses as an upgade(BY A TRAINED TECH) to your brake system with or with/out ABS-Brakes, should be a number one upgrade for your safety and towards others on the track and on the street.As to ABS systems and operations on 2001 Viper model years,the system works the same as it does on any other,DC,GM,Ford,orImports lines.What DC needs to do is get some real-time feed back from track drivers using ABS-systems.Performing dia-system checks of the system,and seeing if any codes are being set and stored in the ABS-ECU.Wm