Electronic traction control and ABS

[rgn]

Hi all, just a quick question, I'm primarily interested in motorcycle applications, but I guess the question is relevant to all LSR vehicles (other than thrust powered).

Is the use of electronic traction-control and ABS common in LSR vehicles?  Cheers.   

[McRat]

On cars, it's normally packaged as "stability control", or Active Handling for the vette folk.  It requires digital injection and throttle (fly by wire).  Otherwise, the engine output cannot be reduced smoothly.

Nearly all new cars and some motorcycles come with it.  By law all Euro cars have it, IIRC. 

First car I drove that had it was about 15 years ago.  If you have not tested a modern car so equipped, you really need to give it try.  A Cadillac CTS-V is a good testbed.  Do it on a rainy day, or at a roadrace track, and get stupid. Dive into a corner too hot, then chop the throttle violently and jerk the wheel.  Normally you'll loop it in a heartbeat.  SC/AH will stop it from happening.

A good question is if stability control would stop LSR spins, I'd guess the answer would be yes.  It will stop most oversteer spins while roadracing, or in the dirt.

Stability control has accelerometers that detect the beginning of a spin, and apply the brakes in each corner individually to resist it.  The latest systems are very effective.

If money is no object and safety is important to you, start with a vehicle so equipped.  However, roadracing with it on will increase your lap times.  It has no effect on dragrace ET's though, so it should not affect LSR speeds either.

[SPARKY]

it is amazing stuff but it cannot defy the laws of physics---ie it cannot make traction!

[dw230]

TC is allowed, ABS not needed. Most of us sit on our TC, I cannot get my head around the "reduce power - go faster" concept.

DW

[rgn]

Ha... no, no I can't see any electronics package making traction     but perhaps they could help prevent the loss of it.

I've been watching a couple of Ack-attack vids (amazing) and on one of them after the push out the bike gets quite sideways.  I imagine wheel spin is something that works against effective acceleration also?  Most of the systems available do a partial ignition cut when wheel speed anomalies are detected, and some detect engine rpm changes via ignition pick-up.  

I've spent a fair bit of time reading post here and on the Aussie DLRA site, and (the pursuit of) traction is something that is mentioned a lot.  ABS I think less important, but i was interested to know if it was something that is commonly in use.

I build and road race pre-90 superbikes, and are looking at traction control for my machines.  I think in the future I will build a single engined streamliner, though I have never been to a Land racing event!  I had thought I would drive over to Lake Gairdner this year as an observer, but it seems weather is being unkind to the community here.

Thanks for your replies!  

[John Burk]

Is discrete EFI injector non firing used as TC . As closed loop or slope control that ought to be a a nice form of TC .

[johnneilson]

wouldn't it be nice to use an auxillary input to read wheel rotation and tie it into the rev limiter circuit with a calculated slip factor?

been accused of calculating the rev delta before..........

J

[McRat]

Old Schoolers:

Have front wheel speedo cable (aka VW style) and a normal trans speedo cable.  Put a planetary gear assy under the backing plate of the distributor, with both cables feeding it.  When rear over-runs, then the timing plate gets retarded, reducing the HP output.  When the front over runs, then it dials 911 for you.

Seriously, ABS is always a good idea.  It's not for reducing stopping distances, it's for adding options to your driving choices.  In fact, it increases stopping distances.  It's not for ice, or sand, or mud.  It's for driving fast.

ABS permits you to fk'g BEND the brake pedal while swerving left and right.  ie - If a kid darts out on an ATV at 2/3's track, you could nail the brakes and steer around him.

Try it.  Get in your family car (if it was made sometime after Fred Flintstone was working the line at Ford), and try it.  Take it up to 50mph in a parking lot, then hit the brakes and turn.  Don't "squeeze" the brake.  Try to damage the pedal.  If your seat doesn't creak or pop, you're not doing right.  Now swerve violently, like a timed slalom.  If your car isn't a POS, it will behave itself pretty well.  Now pull your ABS fuse and try again.

If you drive a car, and you HAVEN'T tried to bend the brake pedal in half, or swerve wildly, you are a threat to other motorists.  How do you KNOW what's going to happen when things get bad?  OPPPPSSS!!!  That made me go head-on into oncoming traffic!  OPPSSS!!  I just spun and killed 4 pedestrians! 

And like it or not, the same applies to trailers and motorhomes.  If you don't know what hitting the brakes does, you should not be driving it.  Period.

There are very, very few "accidents".  There are a lot of "the car got away from me's".  They aren't the same thing.

[jl222]

Is discrete EFI injector non firing used as TC . As closed loop or slope control that ought to be a a nice form of TC .

  MSD came out with a slope control on one of their didgital ignitions that allowed the 10 1/2'' tire drag doorslamers to get the 1st 200 mph times.

  You can input how fast the engine will rev, so many rpms per sec.

  We have the ignition on the 222 Camaro but have not used it for purist reasons, but not saying never

                JL222

[DallasV]

A '32 grill makes for great ABS

[Stan Back]

Everyone should try what McRat has suggested.  If you encounter any problems, ruin your vehicle, hit something -- give me a ring -- I've got his address so you can start legal proceedings.

[4-barrel Mike]

The average ABS-equipped car is rather small.  I was thinking about trying it with my Ford SuperCrew.   

I suspect that I wouldn't be singing along with B.B.King doing "The Thrill Is Gone."



Mike

[McRat]

Everyone should try what McRat has suggested.  If you encounter any problems, ruin your vehicle, hit something -- give me a ring -- I've got his address so you can start legal proceedings.

Remember a couple years back when a Porsche GT3 crashed at Cal Speedway on an Open Track Day?  IIRC it was sponsored by the Ferrari Owners Club?

Anyhow, a guy went into the wall because he sucked at driving, and killed his passenger.

Porsche was successfully sued for $$$$ because the GT3 did not have Stability Control.

So today, if you can't drive, it's the car's fault.  So they would have to sue their car maker, not me.

Worst thing?  The passenger wasn't a lawyer, so it was a total loss.

[hotrod]

ABS and stability controls are not flawless, each system has quirks and under some conditions they will get you in serious trouble.

One of the ABS systems uses what is called "hold low" as the breaking algorithm, if it detects one wheel skidding it lowers the brake effort on all wheels to the same effort that will prevent skidding on the wheel with no traction.

That sounds like a good idea on an icy street but does lead to some interesting issues if on dry pavement you come up to a stop where you need to apply strong braking and happen to hit a bump in the road, a wet manhole cover, a RR track or a bit of sand with one wheel just at the moment you hit the brake peddle. That wheel locks and the ABS decides you really don't want to apply a lot of brake force and basically turns off your brakes until you lift the peddle (the thing they tell you not to ever do with ABS). I know several people (myself included) that have nearly had major accidents due to that quirk. NHTS investigated it but the manufacture talked them out of a recall and just did a "customer satisfaction" optional re-flash of the ABS system to minimize the risk of that problem. I used a more effective solution I pulled the ABS fuse. The car stops much harder without the ABS (even without wheel lock) much firmer peddle and much better brake feel, and most of all no ugly surprises as you are trying to stop as someone steps out in front of you or a left turn arrow changes at a bad time as you are changing lanes and one wheel is on the sand and grit between traffic lanes.

Some studies have shown that ABS does not really reduce accidents, it only changes the type of accidents people have. Without ABS the driver slides straight off the road because he entered a slick curve too fast, with ABS he is able to turn the car and almost gets through the corner before he runs off the outside of the curve and rolls the car or hits a tree.

As you mentioned ABS in several circumstances actually increases braking distance, so instead of being able to stop but ending up a bit sideways, now the driver under full control shortens the trunk of the car in front of him at the red light by about 2 ft because of the longer stopping distance. Especially in special circumstances like dirt, or gravel roads and deep snow, locked wheels stop faster than wheels at thresh hold braking at incipient skid point.

No computer can replace a driver who evaluates conditions and makes intelligent choices about when and how to apply power and brakes.
ABS and stability control will keep most idiot drivers safe most of the time but can get in the way of many special situations where the programmed behavior does not mesh with what the driver needs to do.

Even on very high dollar computer assisted systems you have these failures. In one case an airplane decided the pilot really wanted to land when that was not the case, and caused a crash by skillfully flying the plane into the trees at the end of the runway with a perfect touch down just before the plane turned into a ball of scrap metal.

Larry

[Heand1987]

Hi all, just a quick question, I'm primarily interested in motorcycle applications, but I guess the question is relevant to all LSR vehicles (other than thrust powered).

Is the use of electronic traction-control and ABS common in LSR vehicles?  Cheers.   

obviously its common for safety for all motor riders. ABS is enough. TC is only a secondary...