August Fastrack

[Andy Bettencourt]

http://www.scca.com/_FileLibrary/File/05-0...08-fastrack.pdf

------------------
Andy Bettencourt
New England Region, R188967
www.flatout-motorsports.com

[RSTPerformance]

no comments???

Looks like people are working hard, but I must admit I think the rule for alternate crank pullies is a bit much... I remember a discussion before on this website, but I did not have enough time to keep up. Can anyone explain why this was made a rule??? what is the point??? Who gets the advantage besides the wealthy???

Thanks;

Raymond "not keeping up with everything off the track " Blethen

[turboICE]

I don't know all the ins and outs of crank pulley discussions or the change to the rule.

However, it makes sense to me in a way that I wish they would do more often. Depending on the car it sometimes is easier and less expensive to underdrive the accessories at the crank rather than the accessory. So it benefits those who race those makes not necessarily the wealthy IMO.

------------------
Ed.
240SX ITA

[its66]

I'm not sure I like the clarification on the ecu/harness rule. With it, adding a resistor in the harness is illegal, but modifying the sensor with the same resistor is legal. It is much simpler to splice a resistor into the harness, than to add it to the sensors (in most cases). This reminds me of the threaded body shock issue in that the simply solution wasn't allowed, but the more complex answer was.

Jim

[Knestis]

...but once the harness-modification floodgates are open, it becomes 200 little cases of interpretation, rather than one simple observation. Is the harness modified? Yes - not legal. No - legal. Sometimes simple is better.

K

[its66]

Kirk,
I see your point,and agree. There would be liberal interpretations that people would try to include "Super AFC" units, etc. as a resistor. If the rule were worded in a manner that permitted a single, fixed resistance to be added in line, then it is greatly simplified. No Pot's, No AFC controllers, etc. fixed units only.

The ECU rules are getting more "muddy" everytime they change. I can add a Motec, as long as I can stuff it in the factory case. I can add a resistor, as long as I don't put it in the place that is simple to install. Instead, you have to try to solder it to the pins on sensor, or disasemble the sensor and install it internally. Then, you have to hope the sensor didn't react negatively to the heat of soldering, and that the whole deal will clip back together. It seems like a twisted way to ensure that a resistor is legal, when a completely different ecu is-as long as it uses the stock harness.

Think about the logic of this. Any ECU as long as it fits in the stock case, and uses the stock harness. Why is the stock harness such an important piece, when the "brains" of the car can be changed? Stock brake calipers, sure. Stock harness, silly. What if I have an injector clip break? I purchase a replacement pigtail, and "modify" the harness so the replacement will fit. I know this is an extreme example, but it is still modified--even if it actually a repair.

I guess I should have been more carefull with what I asked for.

Jim

[Renaultfool]

And what about "free" ignition that may require you to modify the harness to hook it up. Will that still be ok under the "you can't change it unless you must to do a legal modification" interpretation?
Renaultfool

[nlevine]

The note about disabling traction control by disconnecting or removing all wheel speed sensors has me a bit concerned. It's similar to the letter of the disable ABS rule. The problem is, if I remove all of the wheel sensors from my car, the computer puts it into "limp home" mode and I can't rev past 5,400 RPM. Put ONE rear-wheel sensor in, and it runs fine (ABS was disabled by removing the pump relays), but I'm not sure if I'm technically illegal..

I see a letter to Topeka asking for clarification in my future...

-noam
#18 ITA BMW Z3
NER

[This message has been edited by nlevine (edited June 27, 2005).]

[lateapex911]

Noam, That's an interesting predicament. I imagine hooking up a front sensor wouldn't do much for you.

Do you know what your ECU needs the signal for?

Good call on the letter, I am sure a solution can be acheived.

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

[924Guy]

Ah, good point on that. Seems to me this is a classic specification issue. Due to the variances across different cars and types of technology, the GCR (IMO) should specify that TCS should be disabled; it should be a little less specific about how. Wheel speed sensors are only one way, not the only way. Perhaps in your case disabling the ABS unit and/or disrupting communications between the TCS ECU and the ECM is ideal, and easy to achieve (simply pull the right pin from the wiring harness... AT the ABS/TCS ECU!)

------------------
Vaughan Scott
Detroit Region #280052
'79 924 #77 ITB/GTS1
www.vaughanscott.com

[nlevine]

Originally posted by lateapex911:
Do you know what your ECU needs the signal for?

On the schematic, there's a signal line going from the ABS computer to the Engine Control Unit (with no label). My little aftermarket code reader spits out a "speed sensor" fault if all sensors are not there. Guess the engine needs to know that the brake system is at least minimally alive before it lets the car run properly. The other speed sensor - located in the diff - is there, works fine, and drives the speedometer before it, too, gets routed to the ECU.

[924Guy]

Typical BMW - overengineered. Ick.

The direct line between the ABS/TCS ECU and the engine ECU is most likely a direct RPM line; other lines of communication are via the controller network (CAN, Class 2, whatever, car-specific) and sometimes direct hardwires for communication of engine requested and delivered torque or the like (depending on specifics, again).

There's no real good reason (IMO) that the engine shouldn't run right without ABS functioning; other OEM's don't tend to shut everything down like that. Just that German bloodymindedness at work again...

------------------
Vaughan Scott
Detroit Region #280052
'79 924 #77 ITB/GTS1
www.vaughanscott.com

[nlevine]

Originally posted by 924Guy:
Typical BMW - overengineered. Ick.

(some stuff deleted)

There's no real good reason (IMO) that the engine shouldn't run right without ABS functioning; other OEM's don't tend to shut everything down like that. Just that German bloodymindedness at work again...

I agree completely.. I miss my first BMW race car - a '71 2002. I think it only had 10 wires in the whole car, and 8 of them were for lights!

[gsbaker]

Originally posted by nlevine:
...I think it only had 10 wires in the whole car, and 8 of them were for lights!

But that only leaves two spark plug wires.

G