Truck Coils MYTH PROVEN INSIDE
10-26-2009, 02:51 PM
#61
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yes indeed,there comes a time when more ignition is demanded.Very high compression engines,n2o engines and forced induction engines can cause spark blow out which causes misfires.When this is the case,more ignition is clearly needed.
10-26-2009, 02:56 PM
#62
I never tested the MSD coils, but I had them bench tested for output and they fell behind the truck coils.
I wonder if you need an engine that is struggling to see the gain. My truck engine had no audible misfire with the f car coils, seemed fine on the dyno. The truck coils picked it up starting just a bit before peak torque (3900rpm 900+ft lbs) all the way out to peak power (5200rpm-900hp) and slightly beyond power peak. My engine now is 100,000 miles and sounds like a diesel! One coil did go bad at about 80,000 miles, but they have generally been good.
Kurt
I wonder if you need an engine that is struggling to see the gain. My truck engine had no audible misfire with the f car coils, seemed fine on the dyno. The truck coils picked it up starting just a bit before peak torque (3900rpm 900+ft lbs) all the way out to peak power (5200rpm-900hp) and slightly beyond power peak. My engine now is 100,000 miles and sounds like a diesel! One coil did go bad at about 80,000 miles, but they have generally been good.
Kurt
If anything, I'd bet specifically in a setup like that, you'd be able to get away with less spark advance under boost once you went to the stronger coils and still make the same, if not more power...could probably get away with a little more plug gap too, and possibly pickup more power and necessitate LESS advance.
If you can light off the mixture really well...you don't need to light it off so early to get max cylinder pressure at the optimal time...if you're having trouble getting it lit off well, you need to ignite it earlier so that your max cylinder pressure happens at the right time...and that max pressure is probably ever so slightly lower (as evidenced by your increase in torque when going to the D585's).
I'd bet you saw little to no difference before the turbo spooled, and then as it spooled, if you had enough resolution in the dyno, you probably saw it gain proportionally to the total torque (torque is an excellent indiactor of how much total charge there really is in the chamber) until peak boost was achieved, and then as torque started to drop off (if it did) you probably saw the gain begin to diminish as well.
Shawn, wouldn't you agree that your last post seems to agree with this?
Anyone else care to debate (rather than just make angry BS posts)? It's the best way for us all to learn.
10-26-2009, 03:05 PM
#63
fuel air and spark makes fast cars go vroom vroom, so i should get a bad *** intake badass fuel injectors, and leave spark alone?
and a cam is a cam? **** it i'm going back to stock...
10-26-2009, 03:32 PM
#64
Thanks again GENIUS......exactly what I said before which is why you shouldn't take the OP's results and expect the same outcome ...we should all know by now that there are many variables to consider when reading dyno results and dynos can be manipulated to read higher or lower...not trying to get into a pissing match not argue with stupidity ....back to the subject at hand please
10-26-2009, 04:34 PM
#66
I'm not sure what your getting at with the comment that dynos can be manipulated to read higher or lower comment but I can tell you that I was there and helped swap out the coils and there was nothing done to manipulate the dyno. Just so you know.... we were hoping to see some gains.
And the truck coil "MYTH" has not been proven as there has not been enough r/d to say what works and what doesn't...simply put if you have an application such as Shawn mentioned and are still running stock coils it may benefit you to give it a try, for you bolt-on guys it may be best to wait and make sure the rest of your system (plugs, wire, etc..) are in optimal condition before you add these expecting some sort of tremendous gain
10-26-2009, 06:07 PM
#67
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Simply pointing out that some dynos (different types of dynos, different areas {DA,weather,temps,altitude,etc..}) read higher or lower than others because there are a few "tricks" that people do to get their dyno to read higher so customers will be super pleased with their combo (not getting into that) Not saying that this dyno was or wasn't manipulated because I wasn't there and don't know all the details (nor does anyone else except for those who were there), the only info we have is what the OP posted...Thank you Shawn for chiming in and answering the question directly And the truck coil "MYTH" has not been proven as there has not been enough r/d to say what works and what doesn't...simply put if you have an application such as Shawn mentioned and are still running stock coils it may benefit you to give it a try, for you bolt-on guys it may be best to wait and make sure the rest of your system (plugs, wire, etc..) are in optimal condition before you add these expecting some sort of tremendous gain
And the truck coil "MYTH" has not been proven as there has not been enough r/d to say what works and what doesn't...simply put if you have an application such as Shawn mentioned and are still running stock coils it may benefit you to give it a try, for you bolt-on guys it may be best to wait and make sure the rest of your system (plugs, wire, etc..) are in optimal condition before you add these expecting some sort of tremendous gain
10-26-2009, 07:01 PM
#68
Let me first put up a disclamer because another member is salty with me because supposedly I gave out bad 'adise' (as he spelled it) and he went and bought a set of truck coils for $200, then drove an hour to have his car dyno'd and he only gained 5hp and he was pissed at me.
With that said. I went and picked up a set of d585 coils because the way I look at it, it's a better factory peice than the stock ls1 coils. I went in and bumped up my dwell time a little bit and have noticed a good amount of decrease in misfires at idle and low rpms as well as better tip in throttle response. I didn't dyno the car because, A: it's been 7 years since it was last on a dyno, B: I don't have the time to drive my car much less take it and get it dyno'd, C: I would rather compare actual data on the road than worry about dyno graphs.
I did notice about a 2-3mpg gain in mileage as well, which could be a result of better light off and reduced misfires at low rpms.
Fact is, the truck coils or ls2 coils are better than the original ls1 coils that gm tossed onto these cars 10-12 years ago, so for less than $200, it's a decent preventative maintenance item.
With that said. I went and picked up a set of d585 coils because the way I look at it, it's a better factory peice than the stock ls1 coils. I went in and bumped up my dwell time a little bit and have noticed a good amount of decrease in misfires at idle and low rpms as well as better tip in throttle response. I didn't dyno the car because, A: it's been 7 years since it was last on a dyno, B: I don't have the time to drive my car much less take it and get it dyno'd, C: I would rather compare actual data on the road than worry about dyno graphs.
I did notice about a 2-3mpg gain in mileage as well, which could be a result of better light off and reduced misfires at low rpms.
Fact is, the truck coils or ls2 coils are better than the original ls1 coils that gm tossed onto these cars 10-12 years ago, so for less than $200, it's a decent preventative maintenance item.
10-26-2009, 07:20 PM
#69
I like how you sidestep the question.in other words you can't tell me how more spark is going to make more power if your ignition system is working properly with no misfires.
you're the one who said you can feel more spark,just trying to figure that out.Maybe you should read what you typed.
plugs and wires aren't going ot make more power-unless they are bad.if they have more resistance than the coil can overcome you will start having misfires.The main reason for aftermarket plug wires is to prevent spark leakage.If an engine is running rough that is a misfire.the main reason for having different spark plugs is to have different heat ranges and electrode designs to reduce detonation.
The only way possible for more ignition to help is that if you can widen the plig gap and have a better flame kernal.and that is pretty iffy.
You need to quit reading what these companys say to sell their products.This is what i do for a living-i have tested all of this stuff-where do you get you info from-the internet,if you havn't done it personally it's just hear say from another person.
you're the one who said you can feel more spark,just trying to figure that out.Maybe you should read what you typed.
plugs and wires aren't going ot make more power-unless they are bad.if they have more resistance than the coil can overcome you will start having misfires.The main reason for aftermarket plug wires is to prevent spark leakage.If an engine is running rough that is a misfire.the main reason for having different spark plugs is to have different heat ranges and electrode designs to reduce detonation.
The only way possible for more ignition to help is that if you can widen the plig gap and have a better flame kernal.and that is pretty iffy.
You need to quit reading what these companys say to sell their products.This is what i do for a living-i have tested all of this stuff-where do you get you info from-the internet,if you havn't done it personally it's just hear say from another person.
Seriously and from experience, if you grab a hot wire with twice the current of the last one you grabbed, you can generally "feel" it
though I was (again) referring to the measured results in the video.Seriously, these *companies* is referring to what? I see no "company" selling exactly what we're discussing here, unless I missed it. It may complement their business but there is no direct gain that I see at this point. These guys, ostensibly at Megasquirt, measured and compared the output of the various LS coils using an o-scope and other tools of the trade. I didn't read the site at all, only watched the video. Did you even take the time to look at the video and see the output results? Based on your response, my guess is "No."
Intuitively, a hotter spark burns the fuel/air mixture more quickly and more completely. Simple physics. This results in more power and more efficiency. Is it measurable? Obviously yes it is at times, not so much in others. Does it require tuning or other adjustments? I guess time will tell as results are logged with different combinations and different variables. So far, it seems to make a small positive gain a slight majority of the time. Another way to look at it is - how much unburned fuel is being sent out the exhaust? If the car is running rich, say only burning 98-99% of the fuel, a hotter spark will enable more combustion of the fuel. It's pretty easy to see that could be 1-2% more power potential. Simply put, more electrical energy has the clear potential to burn more fuel more quickly. Otherwise, why would EVERY manufacturer continue to upgrade ignition systems? Why did GM choose the hotter coils for vehicles that see high loads? Why do all the FI guys seem to like these higher output coils?
Again, and you seem to have missed this or just didn't respond because it's not consistent with your view - plugs can be worn out but not cause misfires. Guys with a serious tune/electrical REPAIR background know this. (This basic knowledge is often lacking in speed shops who are good at making cars faster but not always at troubleshooting basic issues. I'm not saying that's you but I've seen it MANY times.) Put in new plugs and wires, and bang! more power even though there were zero misfires. Same principle applies with a hotter coil. Simply put, you can have less energy getting through the wires and to the plug, but it can still get there regularly enough to not cause any misfires. Weak but completely unbroken flow of current. This concept should be pretty clear to someone with an extensive electrical and tuning background.
Aftermarket wires are also used for other reasons - including to block out EMI noise, to allow more energy through the wires, to make a shop money, and for aesthetic appeal. Fact is, GM wires are typically excellent and not prone to leakage under anything approaching normal applications. LOTS of fast LS cars out there on the completely stock ignition system, showing the LS platform has been endowed with a robust ignition system. LS cars and trucks have LOTS of fuel issues when it comes to driveability, and a few air-related also - but PRECIOUS few when it comes to spark/ignition. This is why I was a bit skeptical about truck coils at first, but the concept is sound and I am anxious to see more results and know more of the back story on each.
I'm still open on the flame *kernel* issue though.
I didn't sidestep a thing - I took the time to answer each of your questions/comments in several ways, some direct and some by related example, some by both....again, though you've not yet done the same in return.
By the way, this is fun! Interested to hear more...and see more dyno results and details.
10-26-2009, 07:28 PM
#70
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I love how people have said that 375 is a "weak h/c stalled" car. No one mentioned if the car had a 9inch or was on a mustang dyno. In that case 375 is not that weak. Not everyone runs a 10 bolt,t56, on a dyno jet.
10-26-2009, 07:29 PM
#71
No expert by any means sir but in regards to the subject at hand I have taken the time and researched these claims and info that was in 15+ page thread that originally started the "myth". I apologize if you are disappointed in me not letting one person's/shop's results be the "end all" of the truck coil theory. You ought to know that there are people who see the info on this site, immediately try to duplicate or discard the info without further investigation....
10-26-2009, 07:45 PM
#73
Fact is, GM wires are typically excellent and not prone to leakage under anything approaching normal applications. LOTS of fast LS cars out there on the completely stock ignition system, showing the LS platform has been endowed with a robust ignition system. LS cars and trucks have LOTS of fuel issues when it comes to driveability, and a few air-related also - but PRECIOUS few when it comes to spark/ignition. This is why I was a bit skeptical about truck coils at first, but the concept is sound and I am anxious to see more results and know more of the back story on each.
Regarding the fuel issues versus spark issues...you're right again, ESPECIALLY with 99-2000 cars where the injectors are smaller, and basic bolt ons get the duty cycles up too high. The LS ignition is indeed very very robust, especially evidenced by the fact that people retrofit the coils from LS1's and other gen3/4 engines to all sorts of other vehicles...but everything eventually has it's limitations...and the stock LS1 coils start to be limiting when cylinder pressures get very high, and plug gaps don't come down...decreasing the plug gap to nothing to get the thing to spark under high load, is working backwards, beefing up the strength of the coils instead so that you can keep the plug gap up high despite the higher cylinder pressures is working in the right direction...and the D585's ARE stronger coils and they DO show benefits in the right applications.
10-26-2009, 07:54 PM
#75
I am NOT saying dyno's lie...but comparing one number from one dyno, to another number from another dyno, is pointless...comparing time slips from different tracks in different parts of the country on different days is equally pointless, and since we're not all in the same place at the same time racing on the same track and tuning on the same dyno...there's no sense in arguing about the empirical number at all...it's just a number, it doesn't mean anything...but if the car is strapped to the dyno, and makes a few pulls, the coils and tune are changed, and a few more pulls are made and the dyno shows a new number...THAT is absolutely NOT a dyno lieing, and that gain DOES mean something. The fact that the OP showed no real gain, means that his setup didn't need it...and it also shows that he's probably not actually making a whole lot of power, and thus his cylinder pressures aren't all that high, and his stock coils are more than capable of making a healthy spark at whatever plug gap he's running. The fact that Kurt picked up power, means he IS making a lot of power, has a lot of cylinder pressure, and coils that weren't D585's were not strong enough to create a healthy spark...at least not as healthy as the D585's are creating on his setup.
I'm sure there are thousands of cars on this board, and in general, that would gain nothing from D585's, but there are also quite a few others that are making good power...that could make even more by just swapping the coils and flashing the correct dwell tables into the PCM and making some minor adjustments to the tune.
10-26-2009, 08:57 PM
#76
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I am curious if others have gotten that good of an increase in mileage that The Alchemist received.
10-26-2009, 09:05 PM
#77
I have not seen any change in MPG...but my engine is stock, so the stock cam is very happy at the 1750ish RPM that I spend an AWFUL lot of time at in 6th gear...if I had a larger cam and thus unhappy/unstable chambers at lower RPM, I'd expect to see an MPG gain from a better ignition...just like the people seeing gains at full throttle, not all setups will...but not all won't either 
...and although I've currently seen no appreciable gain from my free upgrade to D585's...I do know that any future upgrades, will not find my ignition being the weak link in keeping the setup optimized.
...and although I've currently seen no appreciable gain from my free upgrade to D585's...I do know that any future upgrades, will not find my ignition being the weak link in keeping the setup optimized. 
10-27-2009, 05:17 AM
#79
Am I wrong somewhere?
10-27-2009, 05:59 AM
#80
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My truck is turbocharged, I like it that way!!
This thread has degraded to a pissing contest for some reason. I just wrote my findings with my 6.0 in my truck, this has caused me to use the truck coils in many cop engines because they produced more power with no ill effects. One thing I think most will agree with is that the truck coils won't hurt performance and they are long lasting parts at a reasonable price. If you need coils on a new build it would be foolish not to use the truck coils, and if you have any other coil and your engine does not misfire rock on if you so desire!! I have shared information I have on my testing which was done back to back in my favorite A-B-A method, it has me convinced the added amperage is helpful.
Kurt
This thread has degraded to a pissing contest for some reason. I just wrote my findings with my 6.0 in my truck, this has caused me to use the truck coils in many cop engines because they produced more power with no ill effects. One thing I think most will agree with is that the truck coils won't hurt performance and they are long lasting parts at a reasonable price. If you need coils on a new build it would be foolish not to use the truck coils, and if you have any other coil and your engine does not misfire rock on if you so desire!! I have shared information I have on my testing which was done back to back in my favorite A-B-A method, it has me convinced the added amperage is helpful.
Kurt
Kurt, Isn't your truck turbocharged? I bet the spark was weak...not completely out...but weak under boost, with the stock coils, and was therefore not misfiring, but was having trouble initiating combustion.
If anything, I'd bet specifically in a setup like that, you'd be able to get away with less spark advance under boost once you went to the stronger coils and still make the same, if not more power...could probably get away with a little more plug gap too, and possibly pickup more power and necessitate LESS advance.
If you can light off the mixture really well...you don't need to light it off so early to get max cylinder pressure at the optimal time...if you're having trouble getting it lit off well, you need to ignite it earlier so that your max cylinder pressure happens at the right time...and that max pressure is probably ever so slightly lower (as evidenced by your increase in torque when going to the D585's).
I'd bet you saw little to no difference before the turbo spooled, and then as it spooled, if you had enough resolution in the dyno, you probably saw it gain proportionally to the total torque (torque is an excellent indiactor of how much total charge there really is in the chamber) until peak boost was achieved, and then as torque started to drop off (if it did) you probably saw the gain begin to diminish as well.
Shawn, wouldn't you agree that your last post seems to agree with this?
Anyone else care to debate (rather than just make angry BS posts)? It's the best way for us all to learn.
If anything, I'd bet specifically in a setup like that, you'd be able to get away with less spark advance under boost once you went to the stronger coils and still make the same, if not more power...could probably get away with a little more plug gap too, and possibly pickup more power and necessitate LESS advance.
If you can light off the mixture really well...you don't need to light it off so early to get max cylinder pressure at the optimal time...if you're having trouble getting it lit off well, you need to ignite it earlier so that your max cylinder pressure happens at the right time...and that max pressure is probably ever so slightly lower (as evidenced by your increase in torque when going to the D585's).
I'd bet you saw little to no difference before the turbo spooled, and then as it spooled, if you had enough resolution in the dyno, you probably saw it gain proportionally to the total torque (torque is an excellent indiactor of how much total charge there really is in the chamber) until peak boost was achieved, and then as torque started to drop off (if it did) you probably saw the gain begin to diminish as well.
Shawn, wouldn't you agree that your last post seems to agree with this?
Anyone else care to debate (rather than just make angry BS posts)? It's the best way for us all to learn.