You could look at every single part we run on our cars under a microscope and say how some rules make sense and some don't. Bottom line, why would you want to run an aftermarket part? Specifically a coil, distributor cap, or rotor.
If it is for a performance advantage, then that is why the rule is written that way. If it is for reliability, then submit an RCR.
-Michael Mosty
CMC #11 Mosty Brothers' Racing
Director - TX Region
I appreciate the discussion.
The whole reason this came up for us in the first place is that we have what seems to be an intermittent spark issue. It's been odd to try and track down, because I would have said it was a throttle position sensor problem, but the sensor checked out just fine previously. At idle everything is good and the engine runs smooth. At full throttle, we have full power. During a race, we have an intermittent condition during throttle tip-in where the engine doesn't quit, but it sort of stumbles or misses and only produces partial power. A split second after the accelerator reaches the floor *BAM* you have full power again. It's a crappy thing to deal with as it can be unexpected and lead to some power induced oversteer on corner exit when the throttle acts like an intermittent on/off switch.
Dave had a qualifying race last weekend where the condition was NOT intermittent and any accelerator depression much above idle led to a continuous severe stumble that didn't clear up at full throttle. We previously had an issue where the spout jumper wire was grounding out on the alternator bracket. This wasn't that, but in desperation Dave wiggled all the ignition wires, harness, and pulled off and replaced all the plug and coil wires. Things were magically *fixed* after that with no good explanation of why.
In the process of *fixing* things, we did notice the little male connector end on the coil where the coil wire from the distributor cap connects to the coil was loose. The connector wasn't a screw-on type, so it couldn't be tightened. We don't think this was the cause of our issue, but it surely didn't help. That's when we started discussing the replacement of our coil and possibly other components in our ignition system that are several years old. This includes the 30+ year old factory wiring harness and connectors that lead to the TFI module and coil. I suspect something in the OEM harness may actually be where our problem is originating. At the very least, we'll be replacing the connectors to those components that are available with wiring pigtails along with any other wires that appear to be of sketchy condition.
The discussion of what to replace the older components with led us to a discussion of what would be considered legal and where our current stuff stands with regard to legality after using it for nearly a decade.
It appears, as the rules are currently written, while any plugs and wires may be used (some of which surely have a performance benefit), the cap and rotor with brass inserts we've used for nearly a decade are actually illegal. I think we may need to request a rules revision here as I'm not sure there is any "performance" benefit with our current cap and rotor, but instead more of a "reliability" and "longevity" benefit as those components still look like they are in pretty decent shape for never having been changed the whole time we've run the car. Wouldn't any performance gain realized by a mild performance coil be accounted for on the dyno and similarly be more in the realm of reliability and longevity by potentially being constructed of higher quality base components? I actually have no problem with any coil folks choose if it remains in the same form factor as the OEM coil. Basically, I think anyone should be able to use any coil that is the same size and shape as the OEM coil, not just the same output as the OEM coil. Nearly every OEM replacement and cheap mild performance coil fits that requirement. Only the seriously hot, huge, and very expensive racing coils would be excluded. I've actually tried to find out what the output specifications of the OEM coil are, but I haven't been able to find them listed anywhere, and I have no idea how to go about testing that. The only specs I have found with regard to the OEM coils are the resistance values of the windings. The Accel coil we were looking at meets those values. Accel also publishes their coil output values, but without any OEM values to compare them to, I actually have no idea how much, or even IF those values are any different. My gut feeling is if they are different, they aren't by very much. But without the OEM values to compare it to, I have no idea.
Here is another possible request for a rules change I've had on my mind for years. How about allowing the relocation of the TFI module from the distributor to a remote location on a fender well with a heat sink. This would remove it from a very hot location that can lead to it's degradation thereby increasing it's longevity and reliability by keeping it cooler with no gain in actual performance.
So, in the mean time, I guess we all now know what we can protest on our competitors cars at the Championship Events this year that actually have a field of CMC cars. Have the tech inspectors check the Fords for non-OEM replacement coils along with coils, caps, and rotors with brass components instead of whatever silver colored metal Motorcraft uses in their OEM components.
Last edited by MHISSTC; 09-08-2017 at 06:40 PM.
Hands-down the most reliable ignition set up I've ever used is OEM, every aftermarket ignition system I've dealt with has been problematic
i had accel coil packs on my car for the first couple weekends after we built it and they actually made the car run leaner. Plus i found they were illegal so i sold em on ebay and bought new oem ones. never looked back or had a problem after that. It's the typical aftermarket hype. "Run our coils for more power". It's a crock!
“A man with no enemies is a man with no character.”
― Paul Newman
For many of the cars in the series, you can't actually get "OEM" equipment anymore. They haven't made the stuff in a decade or more. When you get it in a box that implies OEM, you pay more but it's the same junk that everyone else is selling...Originally Posted by mach1
Richard P.
Dave/Scott my truck exhibited the very symptoms you describe. Guess what happens when you go WOT? You get WOT fueling. Try new O2 sensors first or better yet, datalog the ones you have and see what you find. Mine threw no codes but would peg full lean. When I'd floor it, the WOT fueling would add enough to make the engine act normal.
RM CMC Director
I feel you, I’ve done extensive research trying to find good parts, ironically enough I have the stock 150,000 mile ignition module on my car because the Motorcraft replacement was junk. That being said I was more referring to aftermarket performance ignition products when it comes to problematic components
I believe at wide-open throttle the eec-iv computer is fueling from the predefined open loop tables, not sure the o2 sensors will help much in this case.
You're forgetting that WOT fueling is richer than cruise or tip in fueling.
RM CMC Director
This -- every parts store distributor and TFI module I've put in my car has caused some sort of dumb issue. Old OEM stuff seems > new parts store junk.
Daniel Records
CMC # 34
It is a context question and it should be a driver/mechanic preference not a rule preference.
If I want the ability to run an Accel coil, or an MSD optispark that yields no performance advantage, why can't I? Make the notation on the dyno sheet and risk re-dyno if something changes.
Reliability can also be described in terms of dollars - i.e. small block Ford cranks. One invisible intent of the rules is to NOT have to pull the motor every couple of races to check the crank.
If OEM is so good for reliability, let's roll the brake rule back.
#39 CMC Camaro
Orange is Fast!
CMC-NT01 FTW!
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