Guest mosupra Posted April 15, 2007 Share Posted April 15, 2007 Has anyone tried the Ford style COP coils? They could be plugged directly onto the plug with no short plug-wire and with the short boots from the Taurus SHO wouldn't need brackets to hold them. Are they fired the same as the GM coil, could my LS6 use ford coils? Link to comment Share on other sites More sharing options...
z-ya Posted April 15, 2007 Author Share Posted April 15, 2007 Has anyone tried the Ford style COP coils? They could be plugged directly onto the plug with no short plug-wire and with the short boots from the Taurus SHO wouldn't need brackets to hold them. Are they fired the same as the GM coil, could my LS6 use ford coils? Do you mean that they are fired with the exact same dwell time? If so, yes they should work fine. If the dwell is different, and you are using the stock computer, the dwell might be too high for the Ford coils. You really need to put a scope on it to be sure. To hig a dwell will cause the coils to overheat and become intermittent. Link to comment Share on other sites More sharing options...
Guest mike_robert Posted August 6, 2007 Share Posted August 6, 2007 Excellent thread! I'm a little late but thought that I could contribute some info re Ford COP coils. http://msextra.com/viewtopic.php?t=25451&highlight= has some scope shots from Ford COPs and a non-currrent limited IGBT. BTW, these things can charge to a decent amount (~90%) in 0.9 ms given enough current availibility. -Mike Link to comment Share on other sites More sharing options...
twoeightythreez Posted November 30, 2008 Share Posted November 30, 2008 The infiniti Vh41 coils (1997-2001) also have an ignitor built right in, maybe I should use them instead of the ford coils with my setup (once I actually get the motor mounted in, lol) Link to comment Share on other sites More sharing options...
z-ya Posted February 20, 2009 Author Share Posted February 20, 2009 OK, thanks to BRAAP I have an Yukon coil to mess with. This is the good part. The bad part is I no longer work for a Scope maker, so no more $40k+ scopes to mess with. So I made these measurements with my 200MHz SDS USB scope. I also no longer have a current probe either, so I improvised by measuring voltage across a 1 Ohm resistor in line with the ground lead of the coil (so I didn't have to float the scope). Ohm's Law: I = V/R So here is the setup: - Megasquirt with Extra code to control Dwell. - Channel one of scope looking at control signal from Megasquirt to the coil - Channel two of scope looking across 1 Ohm resistor (current) - 12V power supply providing power to coil - Separate 15V supply powering the Megasquirt - NGK BPR6ES gapped to 34 thousands Measurement #1: determine minimum dwell (charge time) that sully charges coil. Top trace is control, bottom is current going into the coil. Notice how the coil fully charges. LS1: 1.9mS Yukon: 1.6mS Measurement #2: determine minimum coil discharge time. Look at the current trace, you can see that when the coil starts charging, it starts from a non zero value because the coil had not fully discharged from the previous firing. If I increase the RPM more, it will exaggerate the effect. I adjusted the RPM so that it was just on the hairy edge to show the minimum discharge time. LS1: 1.5mS Yukon: 1mS Measurement #3: Effects of increasing dwell beyond minimum. If the charge time is increased more, the coil will go into a mode where the current is limited by rapidly firing the coil on and off. The control module in the coil pack is doing this to prevent damage to the coil. The effect of running more dwell is multiple sparks. Too long a dwell will effect you max rpm depending on how many coils you run. Both the LS1 and Yukon coils do this. In summary: The Yukon coils are a better coil design for many reasons: - Shorter minimum dwell increases RPM potential - Shorter minimum discharge increases RPM potential and allows a longer max dwell to be run. - Physically smaller, and has cool heatsink - Although I could not measure it, the spark energy "sounds" stronger at the plug. I can't confirm this because they both use about the same amount of current (about 2A peak). Now comes the weird part. The LS1 measurements I previously made did not show the current limiting/multiple spark mode that I've seen with in these measurements. Yes, I made the measurements differently, with different equipment, but I still don't understand it. I will try to borrow the same scope I used in my previous measurements. Anyway, I'm going to sleep on it.... Pete Link to comment Share on other sites More sharing options...
z-ya Posted February 20, 2009 Author Share Posted February 20, 2009 I think I will re-run my tests with different gaps. The gap I had the BPR6ES set to was 0.034" (I think). What might be happening is that the gap is small enough where the spark jump quicker. So what happens is the coil goes into current limit mode sooner because it has less distance to jump, which means more voltage, and a longer coil charge time (dwell). In my earlier tests I may have had the gap set much wider. I'll re-run the test and post the results. Pete Link to comment Share on other sites More sharing options...
ktm Posted February 23, 2009 Share Posted February 23, 2009 Pete, I am not familiar with scopes, but on your tests showing the minimum charge time it appears that the LS1 coil is charging to a higher state than the Yukon coil. I am looking a the hash mark closest to the peak and for the LS1 coil it is 1.5 hashes above the x-axis whereas the Yukon coil is less than 1 hash above the x-axis. Assuming they both started at the same origin. Could it be that the LS1 coil is storing more charge than the Yukon? This would impact its charge and discharge times. You can see this affect in your discharge plots. The LS1 coil looks like it is starting at a higher charge state if you compare the hash marks again. Link to comment Share on other sites More sharing options...
z-ya Posted February 24, 2009 Author Share Posted February 24, 2009 Yes you are correct, the LS1 coil draws a bit more max current (charging current). I'm not sure if this really gains you anything as it appears that the spark energy is about the same. The Yukon coil may be a bit more efficient. To show the min discharge time, I set it low in Megatune (0.5mS), so that the Megasquirt would not change the dwell at high RPMs. Then I adjusted the RPM just to show the discharge time on the waveform. If I set the discharge time to 1mS on the Yukon coil and try the same test, the Megasquirt will change the dwell to prevent the coil from getting into a state where it never fully discharges. As far as trying different gaps, there is very little difference with a wider gap (ran up to 0.045). So I am convinced that the optimal charge times are correct above. Running any more dwell than that will just generate heat and reduce the life of the coil. Pete Link to comment Share on other sites More sharing options...
ktm Posted February 25, 2009 Share Posted February 25, 2009 I was thinking more along the lines of the charge and discharge times. The LS1 coil has to discharge more current than the Yukon coil and therefore would have a longer discharge time. Once discharged, it would then charge more current and consequently have a longer charge time. Link to comment Share on other sites More sharing options...
z-ya Posted February 25, 2009 Author Share Posted February 25, 2009 Maybe... It really depends on the design of the coil. Just because it draws more current, doesn't mean that the coil part of module holds more of a charge. Some of that current is used by the coil driver circuits. The newer Yukon coil design may use more efficient electronics making it appear to charge less. The fact may be that the Yukon coil is just a more efficient design. Also the design of the coil itself can effect it's efficiency (materials, windings, etc.). Pete Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted July 6, 2009 Share Posted July 6, 2009 Pete, on the LS1 coils you stated earlier that the max dwell is 5-6ms or so, then later state around 2ms. I wasn't sure which you had determined to be the ideal dwell. Thanks man. Great information. My RB is running these now. Evan Link to comment Share on other sites More sharing options...
z-ya Posted July 7, 2009 Author Share Posted July 7, 2009 Evan, I still don't understand how I got 5ms for a charge time before. as far as I can tell from my most recent measurements the LS1 dwell should not be larger than 1.9ms. The later truck coils should have a dwell of 1.5ms. Just an FYI: I confirmed my measurements on my turbo car which uses a Wolf 3D ECU where I can vary coil charge time. Using the same scope and series resistor on a running engine, anything more than 1.9ms on an LS1 coild will just create heat and decrease the life of the coil. What ECU are you using on your RB motor? Pete Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted July 7, 2009 Share Posted July 7, 2009 Pete, thank you for the clarification. I am using the coils with an Apexi' PowerFC plug and play ECU.. .which for all intensive purposes from the ign. side is a stock RB computer. I do have the ability to change my dwell though.. this is a series 2 m otor and had no external ignitor from the factory so wiring was very simple. Link to comment Share on other sites More sharing options...
z-ya Posted July 7, 2009 Author Share Posted July 7, 2009 Nice job mounting them. Do you think the LS1 coils are better than the Nissan COP coils? I'm putting an RB25DE NEO engine in a 71'. Pete Link to comment Share on other sites More sharing options...
Evan Purple240zt Posted July 7, 2009 Share Posted July 7, 2009 The reality of the COP setup is that most of us have coils that are the better part of 15 years old. I know the spark is stronger from the LS coils because I was out last night and recorded a WOT pull at afr's in the high 9's with absolutely no misfire. It would have cut out and sputtered badly if I had the stock coils on there. This was before changing plug gap and dwell too. IMO, well worth it. Plus you can get a new coil from the parts store which is a huge plus since I daily drive this car. Evan Link to comment Share on other sites More sharing options...
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