Night Fury Posted April 8, 2014 Report Share Posted April 8, 2014 They aren't different. Were they used coils? Quote Link to comment Share on other sites More sharing options...
l67ss Posted April 8, 2014 Report Share Posted April 8, 2014 Yup, all under 80k. Ive compared like 15 sets. Had a new set of 3100 coils on my old engine, when i swapped to some high mileage l67 coils i still noticed a big dif Quote Link to comment Share on other sites More sharing options...
Night Fury Posted April 8, 2014 Report Share Posted April 8, 2014 I don't buy it Quote Link to comment Share on other sites More sharing options...
RobertISaar Posted April 8, 2014 Report Share Posted April 8, 2014 if non-L67 coils were less effective, there wouldn't be guys running 300+HP out of a 60V6 using 150K+ mile factory coilpacks from a 3100. all of the DIS ICMs current-limit and sense for coil saturation, so any coilpack is going to be limited to the primary current of whatever the ICM likes(i want to say near 5 amps), so there certainly isn't any more current making it into the primaries. if the primary:secondary wind ratio were different, then peak voltage and current would be effected, one would be raised while the other is dropped, there isn't any way around that. if the transformer core were different..... then there might be a difference, but you would have to disassemble the packs and actually know what you're looking for. also, HHO: Quote Link to comment Share on other sites More sharing options...
GP1138 Posted April 8, 2014 Report Share Posted April 8, 2014 : Quote Link to comment Share on other sites More sharing options...
Turbocharged400sbc Posted April 9, 2014 Report Share Posted April 9, 2014 if non-L67 coils were less effective, there wouldn't be guys running 300+HP out of a 60V6 using 150K+ mile factory coilpacks from a 3100. all of the DIS ICMs current-limit and sense for coil saturation, so any coilpack is going to be limited to the primary current of whatever the ICM likes(i want to say near 5 amps), so there certainly isn't any more current making it into the primaries. if the primary:secondary wind ratio were different, then peak voltage and current would be effected, one would be raised while the other is dropped, there isn't any way around that. if the transformer core were different..... then there might be a difference, but you would have to disassemble the packs and actually know what you're looking for. also, HHO: x2 on browns gas rofl there is a difference. while our ICM's are current limited GM does and makes different coil packs for the SC cars. and yes they do have a difference in the winding cappacitance...but the main thing is to find a good coil....while all will fire a stock engine many have unknown shorted windings/manufacturing defects that can reduce peak output. the primary headache is that one plug fires negatively and as a result is firing at a lower kv than the other. you can double yer plg life by switching your plug wires on the secondary terminals to equalize electrode wear. but even the l67 coils have bad ones...went through a dozen and dozens of street/track runs before i found 3 immaculate coils that wouldnt blow out spark even at 13.4to1 AFR if they werent different or didnt make any difference then i wouldnt have 3 OEM replacement GM "blue" coils without any cylinder numbering....if would be the std yellow/gray/black std/NA coils spent hundreds on plugs for the TR...its likes the 1.69$ copper autolites. as far as plugs...its not worth the hype...cheap and effective is the name of the game...far better things to blow $ on.... Quote Link to comment Share on other sites More sharing options...
Schurkey Posted April 11, 2014 Report Share Posted April 11, 2014 (edited) What's the best Non Resistant Sparkplug and can the gap affect performance or emissions on a normal plug? WHY are you still looking for non-resistor plugs? Too large of a gap will stress the secondary insulation, and if (when) it misfires, power goes down and emissions go up. Give up the idea that an overly-large gap improves power. It doesn't. My Dad had a Mercury Marine six-popper outboard with surface-gap plugs. I think I still have a couple of plugs for it out in the garage. For those of you who haven't seen surface-gap spark plugs: Surface Gap averages to about a 5mm gap. Back in the 80s theyd break the ground strap off and grind the electrode down to match the surface. Haven't made an actual measurement, but the gap between center electrode and the side of the plug shell appears to be about .050, not the 5mm previously claimed. Note the extended width of the plug shell at the firing end. "Breaking off" the ground strap of an ordinary spark plug to simulate a surface-gap plug is friggin' crazy. Note the total lack of porcelain "cone", these spark plugs are C-O-L-D. I am now abandoning this thread. Edited April 11, 2014 by Schurkey Quote Link to comment Share on other sites More sharing options...
Michael Savage Posted April 11, 2014 Author Report Share Posted April 11, 2014 The one I was saying 5mm was the cheap home made ones from the 80s just grinding the electrode down to the surface and the strap broke off and ground down. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Imp558 Posted April 11, 2014 Report Share Posted April 11, 2014 x2 on browns gas rofl there is a difference. while our ICM's are current limited GM does and makes different coil packs for the SC cars. and yes they do have a difference in the winding cappacitance...but the main thing is to find a good coil....while all will fire a stock engine many have unknown shorted windings/manufacturing defects that can reduce peak output. the primary headache is that one plug fires negatively and as a result is firing at a lower kv than the other. you can double yer plg life by switching your plug wires on the secondary terminals to equalize electrode wear. but even the l67 coils have bad ones...went through a dozen and dozens of street/track runs before i found 3 immaculate coils that wouldnt blow out spark even at 13.4to1 AFR if they werent different or didnt make any difference then i wouldnt have 3 OEM replacement GM "blue" coils without any cylinder numbering....if would be the std yellow/gray/black std/NA coils spent hundreds on plugs for the TR...its likes the 1.69$ copper autolites. as far as plugs...its not worth the hype...cheap and effective is the name of the game...far better things to blow $ on.... I stop paying attention as soon as I see brown gas, Do you have or could you get resistance and/or inductance readings off coils you've noticed to be better performers? I'll carry my LCR to the wrecking yard. Quote Link to comment Share on other sites More sharing options...
Turbocharged400sbc Posted April 11, 2014 Report Share Posted April 11, 2014 (edited) so far the only real option is trial and error/stress testing at leaner afr's (pull timing to protect the motor and get spark closer to TDC/max cylinder pressure) its the only way to run em hard/hot enough to show any failures....the 3 for the TR are forever with that car...they are the first parts off and the last parts on, i even have a foam filled box for the fuckers. to be clear i still have the 9 other coils...3 are on my 97 gtp daily, 3 more on a locals car, run fine...just dont reach the cylinder pressures that the TR can.... you could do kv measurements using the same arc gap/plug/wire for all coils and see if you can spot the really shitty ones.... back in the day my Vantage meter had the simulator board that would be great to generate the 3x signal for base ignition on an ICM "coil testing" offboard too bad it disapeared long ago... Edited April 11, 2014 by Turbocharged400sbc Quote Link to comment Share on other sites More sharing options...
Imp558 Posted April 11, 2014 Report Share Posted April 11, 2014 It should be possible to test them the same as anything else with windings, a megger and an LCR Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.