Trial Balloon - Retaining ABS?

[Knestis]

I'm planning on writing to request a rule change allowing IT cars to keep ABS sytems intact.

Having used it all year on the SSC Golf, I've only had reinforced my belief that it is indeed true that anti-lock systems do not shorten braking distances, compared to a skilled foot.

Call this an inherent disadvantage of ABS over a correctly - if manually - balanced system. In addition VW's programming goes into what is called "ice mode" if it senses a prolonged lock-up, at which point the scale shifts down to something like 20% of the nominal brakin force. THAT'S fun, I can tell you...

ABS brakes DO however, (a) make it possible to put your right side tires in the wet grass under braking when a Spec Miata moves over on you without looking, ( keep you from flatspotting expensive tires due to driver error, and © modulate heel-toe downshifts with crappy pedal placement. Call these advantages in the real world.

Given the option, I'd prefer a correct non-ABS system with proper proportioning valves but that is a real engineering job. Simply disconnecting the sensors to meet the rule is rumored to leave the Golf with a really awful balance, although I won't know until August what really happens and I don't have any information on which to base statements about IT cars in general.

At the end of the day, the most valuable aspect of a rule allowing drivers to keep ABS might be a practical one: One less thing to have to screw up during a beginner's IT build.

I'm tempted to write my proposed rule change such that it deletes the rule requiring ABS to be removed; and amends the existing language about proportioning valves to (a) allow ABS removal/disabling, and ( allow prop valves ONLY if on cars without functional ABS - whether it has been removed or was never there in the first place.

This is an example of the kind of challenge that we are going to be facing as more cars come with what used to be considered exotic and forbidden technology. ABS has found its way onto the cheapest of hatchcraps so maybe it's time for a rethink.

Opinions?

K

[Geo]

Originally posted by Knestis:
Opinions?

I think everyone who has pulled out their ABS is going to think it's rules creep and unfair to them because they already had to pull out their ABS. But I could be wrong.


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George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com

[lateapex911]

Originally posted by Knestis:
......, keep you from flatspotting expensive tires due to driver error, and ........Opinions?

K

Or another different, but equal statement could be, "...let you maximize traction without consideration of driver error"....

Interesting points, but anything that takes a skill set away is, IMHO, to a degree "dumbing down" the sport to the lowest common denominator.

Geo makes a good point, as well.

And lastly, unplanned consequences could include changes in a cars behavior that would affect the final performance potential, post classification, which is always a bad thing....

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

[This message has been edited by lateapex911 (edited July 11, 2004).]

[Banzai240]

One thing to consider is that, as long as the ABS is connected, and with open ECUs, it is possible to use the ABS as a form of Traction Control... As a matter of fact, I believe that there are several newer models out there that work exactly this way...

I DO think that ABS adds some advantage to the car, especially in the rain... I've totally removed mine, including the wheel-speed sensors, mostly because it adds over 20lbs to the car...

Not sure how I feel about allowing it to remain in IT, because I haven't given it much thought... It's not legal now, and I don't really see any need to change that...

Sounds like something that could be made to work well, however, in the new class that our club is thinking of implementing...



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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX

[dickita15]

darin has a good idea about trying it out in the new faster high tech IT class. we need to be very carefull about unintended consequences.
dick patullo

[Knestis]

Okay - valid points all. But speaking theoretically for a moment, what happens down the road a few years when every newly classified car in IT comes only with ABS?

It's also interesting how many of the arguments against ABS are predicated on the first principle that it is going to be faster. I've learned that it's a relatively common SS cheat to disable ABS systems - the belief being the opposite.

Thanks for the input.

K

[ITSRX7]

Originally posted by Knestis:
Okay - valid points all. But speaking theoretically for a moment, what happens down the road a few years when every newly classified car in IT comes only with ABS?

It's also interesting how many of the arguments against ABS are predicated on the first principle that it is going to be faster. I've learned that it's a relatively common SS cheat to disable ABS systems - the belief being the opposite.

Thanks for the input.

K

Then they can remove the systems too! IMHO, ABS is only an advantage in the wet. They last thing I want to do as an ITAC member is have to deal with a weather-specific factor when classing a car. This is why AWD is such a red-hearing - ABS is much more so.

Currently, like on the Neon, the systems are a performance disadvantage in certain situations. If the system doesn't have enough 'channels', the car can sense lock-up on a lifted wheel and engage the ABS when it isn't needed, adding a TON of feet to stopping distance.

AB

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Andy Bettencourt
ITS RX-7 & Spec Miata 1.6
New England Region R188967
www.flatout-motorsports.com

[Banzai240]

Originally posted by Knestis:
Okay - valid points all. But speaking theoretically for a moment, what happens down the road a few years when every newly classified car in IT comes only with ABS?

That's simple... they can remove the fuse and learn to threshold brake like the rest of us have had to do!

As for the comment on ABS making you "faster"... What I believe is that it makes an average "braker" better... allowing them to be "better" with less actual skill involved...



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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX

[Greg Amy]

There is one serious safety factor that the ITAC and the Comp Board will have to consider in regards to disabling ABS, especially as we move into classifying later model cars.

This is that today's cars are not designed to run *without* ABS. Prior to the widespread use of ABS engineers would design the braking system with brake system components sized appropriate to the vehicle. Then, to make sure that the bias was maintained, a mechanical bias system was added to keep the cars from swapping ends under varying loads and braking conditions (remember the Chevy Citation rear wheel lockup fiasco?)

Today, however, there is not *near* as much engineering going into making sure the systems are tuned as well. Manufacturers are tossing in larger components that are somewhat matched but then rely on the electronics of ABS to accomodate for any major issues. Now, don't take that to mean that there's no design going on, but they are doing away with things such as mechanical brake bias adjustments, especially in cars where ABS is not an optional component.

The ramifications of that to Improved Touring is that by disabling ABS (e.g., pulling the fuse) you are adding a significant unknown to the equation. In some cases an ABS fault will result in a significant reduction in rear braking pressures, and thus in braking performance (tilting the tables on a performance value that was considered when classifying the car); or it could result in a significant imbalance of the braking system resulting in an ill-handling car.

Granted, the IT regs allow you to add manual brake bias adjusters, but I'd hate to get into a situation where we are *requiring* drivers to install a modification in order to be safe and/or match the original performance, especially when such a modification can be a engineering nightmare for the uninitiated. Modern ABS uses separate lines to all four corners, with only two outputs from the master cylinder. Do you tee one line out one side of the MC and put in a single line to both rear wheels? If you do that, which port of the master cylinder do you come out of? Are the two ports of the MC the same size? What do you do about the front; tee that too? Again, which side? We're talking about completing re-lining a modern vehicle's hydraulic brake system.

As you can see, it's a potential hornet's nest. I don't necessarily condone the idea of allowing ABS, but nor do I reject it. However, I strongly urge the club to consider the effects of disabling ABS in modern vehicles, and consider alternatives to requiring disabling modern electronic ABS systems in Improved Touring cars.

GregA

[Banzai240]

Originally posted by grega:
This is that today's cars are not designed to run *without* ABS.

I can appreciate what you are saying, having dealt with this myself, but these same cars aren't designed to run with Hawk Blues either... We all understand that we will be throwing off the balance of our brake systems in preparing them for racing... Finding that balance again is one of those performance parameters that separates the winner from the rest of the pack...

Basically what I am saying is that what you descibe is no different than if someone put Hawk Blues on the rear and stock organics on the front (or something to that effect)... I don't see either as inherrently "dangerous", and when you swap ends or experience premature brake fade, you know you got it wrong... Either system, however, WILL stop the car just fine... just not as efficiently as it could have...

In my opinion, at this moment, I think we have a lot of changes happening in the SCCA in regards to Safety requirements. I'd hate to see us start manufacturing reasons to create more... I'll keep an eye out for more information concerning this to see if it truely needs attentions, but right now, I just don't see it...



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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX

[Greg Gauper]

Any thoughts on this idea.....

Since 'racing' master cylinders i.e. Tilton, AP, Wilwood, etc. are relatively inexpensive, maybe we could allow these to be fitted in place of the OEM ABS master cylinder. The racing units are about 1/3 to 1/5 the price of the OEM units in some cases, and are a lot cheaper to rebuild.

Allow the pedal assembly to be modified to allow racing M/C's to be fitted with balance bars. To be fair, the mod should be allowed for all cars, not just those with ABS.

[Banzai240]

Originally posted by Greg Gauper:
...maybe we could allow these to be fitted in place of the OEM ABS master cylinder... Allow the pedal assembly to be modified to allow racing M/C's to be fitted with balance bars. To be fair, the mod should be allowed for all cars, not just those with ABS.

Let's seeee.... where is that "fingers sticking out in front of me in the sign of a cross" emoticon... ( )

I would really hate to go down this road... Would be a great idea for "Club Challenge Touring/GT"...



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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX

[Eric Parham]

Hey, how about an IT class with *no* computers allowed (either by not including cars that came with any computers, or *requiring* removal of all)... Seriously

[Banzai240]

Originally posted by Eric Parham:
Hey, how about an IT class with *no* computers allowed (either by not including cars that came with any computers, or *requiring* removal of all)... Seriously

Already exists... It's called "Vintage"...



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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX

[Knestis]

Greg does a great job elaborating on the concern that got me thinking down this road.

Generally, I am Mr. Anti Rulescreep but allowing technology that comes on cars that can be classified in IT just doesn't seem to fall into that catgory. Club racing finally got past the idea of requiring all Production cars to run carbs, after all.

Other thoughts?

K

[handfulz28]

Is there a possibility of talking with the ABS system designers and various manufacturers' engineers to see what REALLY happens when you pull the fuse, or otherwise hack a perfectly good brake system?
I don't know what the current state of SCCA's relationship with manufacturers is, especially when we start talking about 5-year old models.
Just a thought.
Michael

[dickita15]

Originally posted by Banzai240:
Already exists... It's called "Vintage"...
already exists... It's called nascar.

[Greg Gauper]

A quick glance thru the Pegasus catalog shows the cost of a M/C to be $70-99 each (Tilton vs Girling) and a balance bar can be had for another $60. So you are talking roughly $200 for race hardware. Heck, I just spent $150 on a new set of brake pads for my Civic because 'good' race brake pads are getting harder to find for 20 year old cars, despite their popularity.....

Rebuild kits are about $20.

Originally posted by Knestis:
Greg does a great job elaborating on the concern that got me thinking down this road.

Generally, I am Mr. Anti Rulescreep but allowing technology that comes on cars that can be classified in IT just doesn't seem to fall into that catgory. Club racing finally got past the idea of requiring all Production cars to run carbs, after all.

Other thoughts?

K

[This message has been edited by Greg Gauper (edited July 12, 2004).]

[GKR_17]

Originally posted by Banzai240:
One thing to consider is that, as long as the ABS is connected, and with open ECUs, it is possible to use the ABS as a form of Traction Control... As a matter of fact, I believe that there are several newer models out there that work exactly this way...

If that is true, then they can argue that they should be able to leave it on, since traction control is allowed.

Grafton

[gsbaker]

Where's Vaughan? He works with ABS and should be all over this.

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Gregg Baker, P.E.
Isaac, LLC
http://www.isaacdirect.com