Hot weather tune up?

[TC]

When you are comparing CDI coils (Capacitive Discharge) to IDI (Inductive Discharge) coils, you don't use "millijoules" because the CDi coils discharge their energy into a shorter time period. It's apples to oranges... but TC apparently doesn't know that. I've tried explaining this to him before but it's apparently way more information than he's ever going to be able to understand. Some people reach their limits of understanding early, the worst of them do not understand and carry on looking like fools. As we see here. lol.

Anywho, your best method of comparing coil power when comparing these two different designs, is to compare amperage draw. A single IGN1-A can draw 20+ amps per spark event. Got a news flash for you, a set of 16 of those will kick the crap out of a pair of magnetos only capable of 44 amps continuous apiece.

Not to be outdone by "specs" - I've already run a set of IGN1-As in a coil test chamber against a 44-amp mag. The IGN1-As are capable of lighting the same mix as the 44-amp mag. This is widely known. There are turbo cars making the same power per cube as the highest output BLOWN nitro engines, guess who's coils they run? IGN-1a.

So anyways, let's get back to the tuning discussion, you know, a chat by people who are experienced at tuning engines? lol

You do realize that 950mj is measured at the Sparkplug "Gap", right??......

Not sure what that has to do with CDI or IDI ignitions..........

You need to think, 1.3:1 AFR, it's nothing like tuning for gasoline..... Way Way Way Wetter environment.....

[dieselgeek]

Not sure what that has to do with CDI or IDI ignitions..........

Yes, we all understand that you are NOT SURE what anything has to do with CDI versus IDI ignitions. How about starting your own thread about it, so Scott and the rest of the TUNERS here can have a discussion uninterrupted by you? thanks, sunshine!

[TC]

Yes, we all understand that you are NOT SURE what anything has to do with CDI versus IDI ignitions. How about starting your own thread about it, so Scott and the rest of the TUNERS here can have a discussion uninterrupted by you? thanks, sunshine!

The mj's are a measurement of Spark Energy at the sparkplug "gap"...... Not sure how a CDI or IDI igntion would make a differences since it the measurement of the End Product.......... Seems to me IDI ignitions can put out of hell of a lot of Spark Energy........ Maybe CDI isn't so great after all.........

[38P]

Laughing at a joke on you?

Just wait until Brian gets the bill for infringing on TC copyright.

[TC]

Just wait until Brian gets the bill for infringing on TC copyright.

I would never do that to a friend............

[38P]

I would never do that to a friend............

The "friend use" copyright doctrine.

I'm just glad that DG's c-note is safe. Carry on, Gentlemen.

[dieselgeek]

The mj's are a measurement of Spark Energy at the sparkplug "gap"...... Not sure how a CDI or IDI igntion would make a differences since it the measurement of the End Product.......... Seems to me IDI ignitions can put out of hell of a lot of Spark Energy........ Maybe CDI isn't so great after all.........

I'm pretty sure you were intending to poke fun at the IGN1-A ignitions since you are swinging from the MSD Magneto's nuts. Meanwhile, just a little primer for you, the mag is CDI (capacitive discharge) and the IGN1-A is IDI (inductive).

Marketing hype on ignition systems is huge - it leads guys like you to think you can look up the ignition with the "highest number" and have something awesome. I'm sure that's how you ended up with the absolutely horrible set of replacement LS packs on your 4th gen camaro. Newsflash bro, those are sad pieces that drastically reduced your peak power potential as compared to the stock LS coils. But I bet the marketing said "higher millijoules than stock!" (guess you haven't noticed that there is no "time" function in that marketing)

Same goes for the IGN1-As. I already know how they stack up against a Top Fueler's ignition system because I've seen them tested in a pressure chamber against the best magnetos and also the best distributorless ignitions, with my own eyes. Lance Nist covered this ground already.

What I stated earlier, still goes. A set of IGN1-As would have no problem firing his A-Fuel engine. There are some downsides though, which I'll share with Scott privately because I'm kinda tired of having TC follow me around and making me re-explain everything over and over again.

And besides, Gene Adams and Dan Miller were setting up a distributorless ignition on one of their customers' cars, before Danny passed away. I know it was either a junior or A-fueler motor, as those are the engines they build and tune for a number of very successful/winning customers. I'm sure if they were convinced it'll work, that should be enough for pretty much anyone in Nitro land.

[Barry Donovan]

When you are comparing CDI coils (Capacitive Discharge) to IDI (Inductive Discharge) coils, you don't use "millijoules" because the CDi coils discharge their energy into a shorter time period. It's apples to oranges...

hey, it pays to read threads. I just started one asking a Q about coils for CDI.

thanks, i needed this info.

[TC]

Yap totally got that mixed up didn't I, hate being in a rush when I'm posting.......

Anyway I still say the IGN1-A's won't fire it......

The popular MSD Super 44 magnetos are so powerful that they deliver 1.2 amps of electrical energy across the spark plug gap each time a plug fires. This is four times the electrical energy delivered by a hot street ignition system at 300 milliamps (0.3 amp). Think of those MSD magnetos as the equivalent of an engine-driven arc welder and you get the idea.

Read more: http://www.carcraft.com/techarticles...#ixzz20pqfrs4q

[dieselgeek]

Why doesn't that article talk about millijoules and instead talking in amps? Please explain Alex.

[A/Fuel]

I would be intrested in reading about those coils if there are some links out there. I'd like to be a little more informed before I bring something like this up in one of our meetings.

[dieselgeek]

I would be intrested in reading about those coils if there are some links out there. I'd like to be a little more informed before I bring something like this up in one of our meetings.

There's not much worth reading.

Talking about milliamps and millijoules is just marketing bullshit for morons to talk about. The real way to compare ignition coils (my opinion based on experience) is to observe the specific output they can support. Right now I have guys making as much as 12hp per cubic inch on Alcohol having zero problems with these coils, running them at 50-75% of their capacity. You control their power by controlling how long the coils charge (dwell time).

We could do some experimenting with some loaner parts if you want. Just let me know.

[A/Fuel]

Not to be outdone by "specs" - I've already run a set of IGN1-As in a coil test chamber against a 44-amp mag. The IGN1-As are capable of lighting the same mix as the 44-amp mag. This is widely known. There are turbo cars making the same power per cube as the highest output BLOWN nitro engines, guess who's coils they run? IGN-1a.

I have no doubt that you've had success in these applications, I guess it just comes down to electricity is electricity, and I'm sure the plug can't tell the difference where it's comming from. Since we don't dyno our type of engine what would be your approach be to an honest experiment? Would you just leave a basic "get down the track" type of tune up in and only change the ignition?
Can you change how long the spark occurs in individule cylinders, or just change how long it occurs perriod?

[dieselgeek]

I have no doubt that you've had success in these applications, I guess it just comes down to electricity is electricity, and I'm sure the plug can't tell the difference where it's comming from. Since we don't dyno our type of engine what would be your approach be to an honest experiment? Would you just leave a basic "get down the track" type of tune up in and only change the ignition?
Can you change how long the spark occurs in individule cylinders, or just change how long it occurs perriod?

The downside I was talking about earlier is, you'd have to rig up a new crank position sensor and cam pickup - not hard to do, ask CDMBill! - then we'd have to run a box to control the coils themselves, it'd be a pretty simple megasquirt set up for just ignition. Also, you'd have to run a battery as these need power - they're happy at 16v, and they wouldn't need anything more than what the guys who run batteries for their MSD ignitions. Ron Pratt won 5 CHRRs and ran a 16v battery and MSD 7AL ignition on his nitro engines, so I know that part works. But if weight is an issue, it might be a showstopper for you.

So you'd have 8 of these coils with short wires mounted on the valve covers, or nearby with longer wires. Then you'd have a megasquirt box, and a battery. If that works, I'd loan you the megasquirt, do the wiring, help with the crank and cam sensor setup (might as well do an EDIS wheel).

In my mind, a valid test for you is going to be "run it down the track" but we can fire it up in the shop first to get you comfortable with it.

The megasquirt has a tach output that can drive your Racepak's tach input. Although, you could use the megasquirt for all the datalogging you need, maybe save some weight?

[CDMBill]

I wouldn't say that we are adding power in the heat, it's just that it takes more timing to make power in the heat.
At 60 degree weather we've smoked the tires with 48* timing....at 100 degree weather it could take 60* lead just to get it to move out of it's own way.
That track was really greasy at 151 degrees, wheel speed was pretty high at .500 sec.......it was hanging at around 2000 for a 1/4 of a sec. Very close to going up in smoke, the g-meter takes a dive there, so if I had to do it again I'd take a few (like 2 or maybe 3 degrees out there) and see if it hooked a little better. My luck, it probably would have shook then, lol.
It's close enough though, that adding a 1/2 lb of air to the tires or raising the wheelie bar a turn might make enough difference to leave the engine alone.

Given the facts presented and assuming (loaded word I know) that the blower drive and the fuel quantity is the same in the 60 degree weather and the 100 degree weather, and spark lead is the variable then the conclusion I reach is that the variance is driven by the difference in ambient air density (quantity of oxygen) and the therefore the relative proportion of ambient air (oxygen) vs. that released by the nitro and that cahnge in proportion accounts for the change in net effecetive burn rate and the need for more timing in hot conditions.

I didn't read anything about water grains but I suspect the humidity level has an impact as well.