Ah, ok - you seem to be confusing the inductive (or charge) and release (or fire / discharge) wires with completing a circut. One of those two wires "filles up" the coil with the current for the spark. The other wire tells the coil when to let the spark fire. The plug and/or coil wire(s) complete the circut.

To be honest I can't remember if the coil is triggered like a capacitor (merges the circuts) or keeps the "release" circut seperated from the "inductive" circut. I'll have to check my Evo manual when I get home. You are right about electricty flowing in loops, though.

 

But trying to pick out 4HP(assuming thats where you got that claim) on a car that puts out well over 200, when you are using a GTech, would be pretty tricky. There are so many unaccounted for environmental variables, that you can't accurately say thats where you got the 4HP from. Dynos provide much more consistency, but even they can be tricky to use to measure such a small difference.

Brad

 

Actually it was easy - did everything the same night. I undid my main ground for the kit and pulled 3 base runs and then re-connected the kit and did 3 more runs. Took all of about 15 minutes - same temps, track, gas, tires, etc.

 

I am not confusing anything with anything else, I can assure you that.
The coil is like a transformer, with 2 big inductors in it. The primary side with 2 wires is fed with 12V on one side, a switched ground on the other. The secondary side of the coil, is a much higher impedance, with 2 outputs as well. One end of the secondary going to one plug, the other end of the secondary goes to the other plug. The secondary floats, and has no ground connection.

I'm right about the rest of it too. Let me know when you figure that out

Brad

 

And that is how you determine its accurate? How close were the cylinder head temps from one run to the next? How much gas did you use? Roll on at the exact same RPM? Use the exact same stretch of road, traveling in the same direction? Like I said, lots of environmental variables. Its hard to get that accuracy on a dyno, which doesn't have nearly as many variables.

Brad

 

That's exactly what I'm saying. The high voltage side of the coil completes it's circut by crossing the gap in the plug and grounding to the head. Improving the head's grounding = better spark. That's why I added a grounding cable to the head. I'm willing to bet that's also why the kit puts one there also.

As for the switched ground on the on the coil, thats (probably) the trigger for the spark to jump from the coil to the plug. Where that grounds to (it is a "switched ground") can also impact spark quality. If it's less than optimal the spark could be slow or weak due to a poor signal quality.

I'm heading home and will try dig up the details in an hour or two.

 

Sigh - Ok. This is sooo painfull.

First - the car was fully warmed up and had been running at highway cruising speeds for about an hour. I pulled onto the test pad and popped my added grounding wires from the neg battery post and secured them aside. Then I got back into the car...

The first three (baseline) runs where done in quick sucession: do the run, brake, turn, cruise back to the start point, repeat.

Got back out of the car and re-connected my added grounding wires to the neg battery post.

Then the next three (w/grounding kit) runs where done in quick sucession: do the run, brake, turn, cruise back to the start point, repeat. All on the same road, within 5 minutes of the first set of runs.

I added up the peak HP of my 3 baseline runs and then added up the peak HP of my 3 grounding kit runs. When I subtracted the total of the baseline runs from the total of the grounding kit runs I ended up with about 12 HP. Divide 12 HP by 3 runs and you get about 4 whp per run. Not perfect, but more reliable than my "butt dyno".

I've used the same or similiar techniques for a number of other things, too, with decent results. Like which gas to buy, do my new brake pads stop more quickly, (not initially, but they are slightly more fade resistant), etc. It's actually a handy tool for verifying what a change does if you're willing to take the time and work out a testing plan.

 

You still arent getting it. Its not completing the circuit to ground. In order for that to happen, one side of the coil secondary would HAVE to be tied to ground as well for there to be al loop. BOTH sides of the coil secondary are tied to a spark plug though. So there is no other connection to ground, and when you ground the head, you aren't creating a loop for the current to flow through. Draw it all out.
Improving the heads grounding gets you nothing. Since you are so insistent on this, lets make it into a bet?

Brad

 

Well, the weight of the vehicle changed as the runs went on(less gas). The weight is used to calculate the HP. Thats one thing that changed definitely, and would result in higher readings for the second set of runs. You have no idea exactly how consistent the intake temps were from run to run, or the cylinder head temps since you never measured either. I'm sure you want to believe its a gain, but a 1-2% gain under varying conditions using the Gtech would get you laughed out of just about any legitimate shop. So how about that bet? Got $1000 laying around?

Brad

 

Finally; I think I get what you're saying.

You are wrong. Each spark plug fires at a different time; the coil completes two different circuts at different times. Both plug wires are not charged and released at the same time.

Hmm - let me re-state that. For a circut to complete from the coil to the same coil (down one plug wire and up the other) both plugs would need to fire at the same time. You would also need to discharge spark as well as draw current up from the head back into the coil at the same time you were releasing the same energy from the same coil.

That would make a loop with essentially no input, no output, and no battery.

You could argue that new energy is comming through the coil, and old energy is being lost through spark, but you still haven't overcome the need to fire both plugs at the same time, or the fact that the base of the plugs are connected to the head, which is grounded wheather you like it or not.

Time to get some food

 

So you got that $1000 laying around? You are sure of yourself, right? It should be a quick grand for you right?

Brad

 

It doesn't matter that the head is grounded, nothing flows to the battery ground from this circuit. If you go back and reread my earlier posts, I said that both plugs fire at the same time, and explain why the head being grounded is irrelevant.

How about that bet? Come on... you seem sure of yourself, otherwise you wouldn't continue arguing this right? Its easy money right? I obviously don't know what I am talking about right?

Brad

 

Interesting. Brad, what triggers the spark(s) in both plugs that are in the same loop? Is this circuit actually in the owners manual? (I will go look now).

 

I am not sure about extra HP, but in theory, extra/better grounding does contribute to better/smoother idle. This is plowed ground and there was plenty of discussion on this matter from about 5-6 months ago. About that time, I posted some info I learned from our in-house electrical engineer. Happy searching...

 

Its a single transistor that is built into the coil . Its right in the manual where it clearly explains the simultaneous sparks pgs 16-32, and 90-30. On earlier 4G63s, they had an external "power transistor", but they switched to an internal one for the Evo(I have one of the Evo coils I was evaluating on my desk). But don't tell erioshi that, I want my $1000.

Brad