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Thread: STx Ignitions

  1. #1
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    Default STx Ignitions

    9.1.4.G.7
    "Ignition system components may be replaced freely provided the type of ignition remains the same as stock."

    I hate this rule. I read it as the installed motor's stock ignition system must remain, but you can throw whatever plugs/wires/coil(s) at it that you want.

    1 - Since the class is weighted by displacement, why wouldn't swapping to COP or waste spark from a mechanical distributor be allowed? theoretically, this simply brings everyone closer to the potential of their swept volume, similar to the allowed removal of AFM/MAF etc...

    2 - Regardless of #1 , does this rule allow for the instalation of non-stock pickups on the crank/cam for purposes of fuel and spark timing, or only the changing ("replacing") of sensors in stock locations?

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    Quote Originally Posted by Chip42 View Post
    9.1.4.G.7
    "Ignition system components may be replaced freely provided the type of ignition remains the same as stock."

    I hate this rule. I read it as the installed motor's stock ignition system must remain, but you can throw whatever plugs/wires/coil(s) at it that you want.

    1 - Since the class is weighted by displacement, why wouldn't swapping to COP or waste spark from a mechanical distributor be allowed? theoretically, this simply brings everyone closer to the potential of their swept volume, similar to the allowed removal of AFM/MAF etc...

    2 - Regardless of #1 , does this rule allow for the instalation of non-stock pickups on the crank/cam for purposes of fuel and spark timing, or only the changing ("replacing") of sensors in stock locations?
    #2: Well, it says, "replaced" so. I'm thinking you can take a bendix crank sensor and replace it with a Motronic. But replace doesn't mean "add"

    I hate that they said "freely". That word adds nothing, except confusion.
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  3. #3
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    Quote Originally Posted by Chip42 View Post
    "Ignition system components may be replaced freely provided the type of ignition remains the same as stock."
    Define "type of ignition" and you have your answer. Is it "crank fired" versus "distributor"? "COP" versus "single coil"? Or maybe nothing more than "spark" versus "compression"?

    I don't know the answer, just directing the question.

    GA

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    tGA - that's how I read it regarding type. my question is more based on philosophy - "why?". there are too many limits regarding stock engines for a displacement based weight system to work.

    [RANT]
    removing the restriction on ignition type might add cost (not a lot these days) but it also removes one of the barriers to equality. ditto the allowance of a crank trigger where none was present from stock (assuming jake's answer is correct, I think it probably is).

    with stock TBs, intakes, heads, rotating assemblies, etc... there will never be perfect parity between all motors, that's understood. but the restrictions to such basic tuning modifications really only serves to further limit potentially competitive combinations. it's not good for class diversity.

    in prod, 2 motors of the same displacement and same drivetrain layout (neon, sentra SER, etc...) could be spec'ed with the same cam allowance and have very different weights with no seemingly obvious reason for it, other than the inherant inequality between their motors by design. STx is effectively the same rule set (as the example cars, not the category overall), but adds additional restrictions to modifications (i.e. ignition) and makes NO allowance for the disperity of design between various mills. The evidence from production is that the CRB recognizes the effects of different designs that appear to have the same characteristics, and it should be expanded to the principles that formulate ST (though the instability of the production category rules is not desirable).

    I don't "want" speclines for each allowed vehicle, but I do think that removing barriers to potential power should be a basic requirement in a class with this classification system.
    [/RANT]

  5. #5
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    If my acme 2 litre had a distributor in it originally, than no COP, or coil pack??
    But, I can remove the AFM and replace it with a MAF??!?!
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    Quote Originally Posted by DoubleXL240Z View Post
    If my acme 2 litre had a distributor in it originally, than no COP, or coil pack??
    But, I can remove the AFM and replace it with a MAF??!?!
    correct. makes no sense. write a letter!!!!

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    Quote Originally Posted by DoubleXL240Z View Post
    If my acme 2 litre had a distributor in it originally, than no COP, or coil pack??
    But, I can remove the AFM and replace it with a MAF??!?!
    No, I don't think so. You can add the MAF but I don't think you can remove the AFM. All the intake air still has to pass through it.
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    Quote Originally Posted by DoubleXL240Z View Post
    But, I can remove the AFM and replace it with a MAF??!?!
    Yes. The limiting factor is the "air throttling device" (e.g., throttle body/carb). Everything outside of that is fair game.

    See Jan Fastrack for the latest clarification.

    GA

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    Quote Originally Posted by Greg Amy View Post
    Yes. The limiting factor is the "air throttling device" (e.g., throttle body/carb). Everything outside of that is fair game.

    See Jan Fastrack for the latest clarification.

    GA
    Oops, I should pay closer attention to which forum I'm in.

    Greg, I can't find that FT reference (although I do remember it). Seems like it was STx specific. Is there reason to think that it also applies to IT? I hope not, because if it does I think I just found some HP.
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    Quote Originally Posted by Eagle7 View Post
    Oops, I should pay closer attention to which forum I'm in.

    Greg, I can't find that FT reference (although I do remember it). Seems like it was STx specific. Is there reason to think that it also applies to IT? I hope not, because if it does I think I just found some HP.
    I was about to post just to remind you that you're in the ST sub-forum. What you stated would apply if you were in the regular IT side. The FT reference is for ST not IT.
    STU BMW Z3 2.5liter

  11. #11
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    I went ahead and submitted a letter on this topic - it's a two parter.

    #4328:
    Quote Originally Posted by Letter 4328
    9.1.4.G.7:
    "The ignition system components may be replaced freely provided that the type of ignition remains the same as stock."
    9.1.4.G.8:
    "Engine calibration (spark and fuel) is free. A programmable ECU is permitted."

    Please expand these rules to allow the addition of crank trigger wheels or the explanation that they and other engine sensors are legal to ADD or replace for the purposes of providing signals to the ECU allowed in 8. I believe this to be the intent, but there is no rule (at least none I can find) stating as much.

    Allow the use of aftermarket ignition in place of the factory TYPE of ignition. (i.e. allow coil on plug, waste spark, etc.. on mechanical distributor ignition engines). This fits with the category structure of displacement to weight as it is a further limit on potential power for a given engine that is not consistant accross the years and makes listed. such systems are not prohibitively expenive, particularly when ECUs that may control them are already allowed.

  12. #12
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    Thumbs up STL Ignitions

    Chip: I agree with your letter. However, as I interpret the rules we already have the ability to use a crank sensor with or without a distributor. Let me also provide some clarification of my interpretation. 1.) The true definition of a crank trigger ignition is one without a distributor and the sensor at the crank triggers electronics to fire spark plugs. 2.) The other ignition system uses the stock distributor in its stock location and uses a crank sensor/pick-up to replace the sensor inside the distributor to provide the needed signal for the ignition to work. In short you have not changed the stock ignition components only re-located a sensor. Another way of looking at this is to take the stock pick-up inside the distributor and move it to the cam/crank. The components are the same, the functioning is the same, only the configuration of the sensor has changed which the rules already allow. You are commended for your advanced thinking and creativity.
    Last edited by racermr2; 08-30-2012 at 03:42 PM. Reason: misspelled words

  13. #13
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    That's an old letter; notice 2011 date.

    Ignition are now "unrestricted" in Super Touring. See GCR 9.1.4.G.7, p468 in September 2012 PDF.

    GA

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