Coil Dwell Settings with ProTuner & AccessPort
It seems for me on a personal level this past year has been a huge leap knowledge and application wise. And by application I don't mean all the silly android apps I've been spitting out
probably because more and more cars are out of warranty, even their engine core extended warranty, so more and more people are willing to take more *risk* than ever, thus making the progress that this community has been dying for.
Not really, Brett, and your name came up a couple nights ago while having dinner with a prominent member of this forum when we were discussing this very thread. We thought it remarkable how tuning progress has continued (and maybe even improved as a result) even though we are now missing a member who was once thought to be irreplaceable around here.
That is not dwelling, that is moving forward.
That is not dwelling, that is moving forward.

There were times i actually enjoyed an argument with that missing member , although it often led to him becoming abusive, making it quite unpleasant for me .
Although I initially felt we lost someone who had a lot to offer us , I now feel that maybe we are much better off without him.
Just a point of order. Current across an ignition coil secondary is dependent on dwell time. As it is an inductor its resistance starts high then drops as it saturates until it is just wire resistance (which is what you read with a meter). I'm playing with coils that dwell about .2ms at 30volts. The only issues I have with them is that if my code hangs for even fraction of a second it fries the drive transistor.
I would not worry about setting high dwell at high rpm, since you can't over dwell the coils in the time available, however I don't know if the ECU is smart enough to make sure the coils have enough time to fire, and that could also lead to excessive dwell/coil failure.
I would not worry about setting high dwell at high rpm, since you can't over dwell the coils in the time available, however I don't know if the ECU is smart enough to make sure the coils have enough time to fire, and that could also lead to excessive dwell/coil failure.
which reminds me - A few years ago I stated that I had found some success in increasing the dwell on the STOCK oem coils . Was told at the time I was dreaming but I know for a fact that it enabled me to increase boost safely past a certain level ( around the 320whp mark ).
I didn't bother arguing about it back then but in the light of recent revelations it might be worth revisiting for those that have not upgraded their coils.
What I did back then was increase dwell (above 5000rpm) 10% initially but then eased that back to 5% and still got good results from that.
I didn't bother arguing about it back then but in the light of recent revelations it might be worth revisiting for those that have not upgraded their coils.
What I did back then was increase dwell (above 5000rpm) 10% initially but then eased that back to 5% and still got good results from that.
Last edited by Brettus; Oct 20, 2012 at 11:20 PM.
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How much dwell increase is safe with the stock coils? Just curious...
I remember the tuner referred to in this thread said that the dwell settings for the BHR ignition will quickly melt the stock coils, is that indeed the case?
I remember the tuner referred to in this thread said that the dwell settings for the BHR ignition will quickly melt the stock coils, is that indeed the case?
i would say he is correct there . I ran at 5% more than stock above 5000rpm for a good 50000kms and the coils were still fine when i replaced them. I did always have good quality leads which i believe made a difference as well.
Harlan ( and others if they wish) --what do you think about keeping the dwell table intact and just boosting the supplied voltage in a controlled way to the coils at an elective point?
Boosting the voltage decreases the dwell time. It's almost linear. If you had a HV power supply you could decrease the dwell. The problem in this application is that you would have to make the table identical for every voltage so that it would only change with rpm. It would however allow you to run a shorter dwell at all rpms. I think the stock table tapers off at high rpms to prevent frying the coils, but with better coils you should be able run full dwell on the coil even at 9k. Ideally with perfect coils and a stable power supply you could only use one value for dwell.
if you can't understand what is going on here then you shouldn't be doing this yourself:
https://www.rx8club.com/engine-tunin...5/#post4260808
https://www.rx8club.com/engine-tunin...5/#post4260808
Ok... post 108 was golden.. 
I am an NA application just wanted to make sure my BHR GM Coils are running properly but I can see how the simple Multiplier is not correct.
Thanks guys.

I am an NA application just wanted to make sure my BHR GM Coils are running properly but I can see how the simple Multiplier is not correct.
Thanks guys.
Last edited by WreakLoosE; Jan 30, 2013 at 06:33 PM.


