My limited understanding is that the increase would be because of a better burn or more complete combustion in the cylinder. I guess I don't understand why only in the mid range this would occur. Does anyone have any ideas?
I've heard that and it makes sense. Especially if you are going to buy 6 new stock coilpacks there is no reason to not upgrade IMO. When mine start to go I will be upgrading I think...my only dilemma is my m4 delphi packs have a lifetime warranty. Maybe I will just replace them once a month until I have a full set and then resell.
That's my understanding too, especially judging from the dynos and my own experience with upgraded coils.
As to why? I'm not 100% sure, but I'm sure taking a closer look at the detailed posts PR made would offer a little more insight. Its obvious our stock coils aren't the best option when running higher boost, ethanol etc - I agree it's strange it only happens in the mid range though considering dwell times and spark power are even more important at higher RPMs. Maybe BMW's multispark method makes up for the generally sub-par coil performance at higher RPMs but just isn't ideal in comparison to the rest of the powerband?
I think that was VTT. Claimed a pretty significant torque increase due to stronger combustion and higher cylinder pressures after installing PR coils, if memory serves.
Yep, I think both me and Torgus knew VTT was the vendor to first post those kind of results. But AFAIK no one else (especially just a consumer) has paid for dyno time just for swapping coils and made a forum post which is what I figured he was looking for since he found the VTT results suspect, but I understand why he'd want more info even if VTT and PR aren't related in the slightest.
There's been a few dynos, Robert from PR would know better. Tony put them on and dynos, didn't believe it so took them off and lost power and then put them back on again. His gains were unexpected for sure, he was maxed out wgdc but was making an extra psi with coils. Most cars seem to gain around 30ft.lbs or so, but all situations are different.
I didnt even realize Tony was consistently making an extra PSI during those pulls with maxed WGDC, very impressive. I assumed the gain was just from the superior burn in the mid range that most experience, good to know there's "scaling" gains as well though!
Hmm pretty odd that yours are red. I have the PR Coils and they have been running flawless. Ive had missfires at the beggining due to the plug not sitting all the way down but now that they are all pushed down i havent had missfires or timing drops. Could it be a bad/faulty coil or something?
His are red because they're custom made due to his issues, PR only offers the blue ones.
As for his issues, like he said it was likely in part due to the aluminum valve cover or just age. If he happened to have received the batch that had ill-fitting plug wires it likely would've made things worse too.
