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Congrats. Awesome.
 

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Nice. What are the rules for Coyote stock? I wish the car was on a bye run so we could really hear it. Sounds good.
 

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Hard work.... Not to mention the butt suckin weather conditions they had to deal with to get there. GREAT JOB!
 

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Hard work.....
yup same way any heads up racer is going fast lol

Ed your old ass coming down for world cup? or can you not handle the cold at your age lol
 

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yup same way any heads up racer is going fast lol

Ed your old ass coming down for world cup? or can you not handle the cold at your age lol
Nope - too many imports. My ears can't handle that racket.

>:)
 
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Nope - too many imports. My ears can't handle that racket.

>:)
It would almost be bearable if it was confined to the track. But the endless revving in the pits............................what am I missing?
 

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G-Force G101A four speed with a "tweaked" Black Magic clutch assembly.
Not asking for trade secrets so understand if you can't say, but since by rule it has to be a min 10" disc and a diaphragm style clutch, is the pp long style, borg and beck or oem style? Organic, ceramic, sintered iron?

Doing a clutch this winter, and just trying to get the most out of my humble Mach 4V.
 

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Not asking for trade secrets so understand if you can't say, but since by rule it has to be a min 10" disc and a diaphragm style clutch, is the pp long style, borg and beck or oem style? Organic, ceramic, sintered iron?

Doing a clutch this winter, and just trying to get the most out of my humble Mach 4V.
Per the NMRA rules, the units we run are a diaphragm pressure plate configuration and utilize a 10 or 10.4 inch diameter disc. Materials vary as we will change the disc based on track conditions. We haven't tried every combination of the discs or pressure plate diaphragms we have in the queue due to time constraints but suffice to say, what may not work today doesn't mean it won't work in another situation.

We have also used in competition a clutch assembly that was custom made for us and looks nothing like what others use. It wasn't in the car at this event and is currently on loan to a Factory Stock racer for testing with a radial tire combination. We're going to be comparing notes for the 2017 season. In Coyote Stock, there is no stone left unturned.

If you want to use something similar to what's currently in the Cobra, I can help you obtain one but be forewarned, it's not the cost of the off the shelf SPEC or RAM. With all the options required to make it perform under nearly every condition, it'll be close to $2500 but it does allow for incredible amounts of flexibility.
 

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Per the NMRA rules, the units we run are a diaphragm pressure plate configuration and utilize a 10 or 10.4 inch diameter disc. Materials vary as we will change the disc based on track conditions. We haven't tried every combination of the discs or pressure plate diaphragms we have in the queue due to time constraints but suffice to say, what may not work today doesn't mean it won't work in another situation.

We have also used in competition a clutch assembly that was custom made for us and looks nothing like what others use. It wasn't in the car at this event and is currently on loan to a Factory Stock racer for testing with a radial tire combination. We're going to be comparing notes for the 2017 season. In Coyote Stock, there is no stone left unturned.

If you want to use something similar to what's currently in the Cobra, I can help you obtain one but be forewarned, it's not the cost of the off the shelf SPEC or RAM. With all the options required to make it perform under nearly every condition, it'll be close to $2500 but it does allow for incredible amounts of flexibility.
Thanks for sharing Ed. Yes, I'm aware that custom clutches can produce considerable sticker shock. I've had conversations with custom clutch shops that build 7 and 8" sintered iron long style super adjustable super lightweight systems and they are in the price range you mention. In my situation, bracket racing vs heads up, making easily 125 hp/tq less than your Cobra, it's a cost/performance ratio I can't justify. Our race weights are very close, I'm at about 2950. Right now, still using my stock Mach 1 clutch, which is a Valeo 11" organic and according to Ford Racing techs is very similar to the no longer available King Cobra in clamping force. I have well over 200 6K launches on Hoosier stiffwall 26x8,5x15's and she will still sixty a very consistent 1.51-1.53. 2.97 first gear in my T56 (which I know is a boat anchor). So to pick up potentially a tenth on my sixty and therefore potentially 2 tenths on the big end for $2500 is just a bad investment, especially bracket racing. Actually my sixty foots have improved gradually as the stock clutch started to wear, giving me a little more slip, and less bog on launch. Funny. Almost the opposite of what some folks would think about a new vs well used clutch. At this point due to the performance of my stock clutch, I've been investigating similar clutches, and had a good conversation with an Exedy tech. Their Mach 400 11" organic would give me about 10-12% more clamp than the old King Cobra. I would pair that with their billet chrome molly lightweight flywheel which is 7 lbs lighter than my stock flywheel. At this point, if I have to replace the disc once a season, no biggie. I was concerned about breaking in an organic disc on a race only, trailered car, but the Exedy tech said if I could get about 150 normal clutch engagements in my driveway, pits, return lanes and first test and tune I should be fine.

Good luck with your plans for next years campaign.
 

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When everybody's making the same power, it can be especially sweet when you get the clutch tune just right. When the clutch hits too hard, it either pulls the engine down too far or knocks the tires loose. Hitting too soft is also counter productive, but there's a sweet spot in between where things work amazingly well. Basically you want to match the clutch's clamp to the engine's power, as this can effectively raise the engine's average rpm, which in turn allows the engine to produce more power in a tighter time frame.

Here's a simplified example to help explain why you want to keep average rpm as high as practically possible-

Lets say a car has the power to gain speed at an average rate of 6000 rpm per second in 1st gear. Let's also have the clutch slip until .5 sec into the run with the tires remaining dead hooked. If the car launches at 6k and the tires are stuck, the clutch will pull engine rpm down to 3k by the .5 sec mark. Then from .5 to 1.0 seconds rpm will climb from 3k back up to 6k, as the engine regains the lost rpm. What all this boils down to is that during the initial 1 second after launch, the engine's average rpm was 4500 rpm, which means the engine made 75 revolutions over that 1st second of the run.
...Now suppose that same car launches at 6k, but now the clutch slips just enough that the engine does not lose any rpm over that same 1 sec period. Now the engine's average rpm was 6000, which means it made 100 revolutions during that initial 1 second period.
...Here's the thing- both left from the same rpm, but the launch that didn't lose any rpm actually packs 33% more revolutions of WOT power production into the same 1 second time period. If the clutch also slips just right after the shifts, you can pick up some power production there as well.

When you understand what you need to do, you can likely make things come together on your own. Here's a few things you can do to an overly aggressive clutch to tweak it closer to that sweet spot...
1- less aggressive friction material
2- smaller diameter disc
3- reduce effective diameter of the disc (trim away some of the friction material's face without reducing overall diameter)
4- reduce clamp pressure either by swapping to a weaker PP/spring, different fulcrum, or shimming your existing PP away from the flywheel
5- temporarily hold back some clamp pressure with your foot, basically ride the clutch out for 5-10 feet. Adding an adjustable spring loaded pedal stop can make it easier to consistently find the sweet spot in the pedal travel
6- temporarily hold back some clamp pressure with a timed mechanical device (this is what my device does)

Grant
 
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