It's been a week since I changed the dwell settings - I really think my hot starting is better now !!!

Does not make much sense (given that Oltman says the start up dwell is not from the main dwell table) but it just is - did nothing else .

 

what kind of hot starting problem have some seen?
Just takes a little longer to start?

. What I do know is that when cranking an engine, most 12 volt batteries drop down to about 10 or so volts, coils have to be designed to make full output voltage from 9-10 volts with the correct dwell. Once the engine is running, the voltage rises up to 13 or more and dwell has to change/drop or the coils will over heat ( to high of a duty cycle).
Now at a certain point we get a little over 14 volts in the system meaning that the dwell once again has to shorten.
Now the oem coils will not take much increase in dwell before overheating, but the aftermarket ones can? Why?
Most of the coils start out at about the same dwell at 12Volts and the lower rpms--give or take a fraction of a ms, but as voltage/rpms increases the gap between the rx8's coils dwelland the others broaden? Why? Is it because of a difference in the coils resistance? Maybe? If so then shouldn't that also be discussed? Or does the oem system tolerate this different resistance without problems?
I apologize that i am using this thread to try and learn something.


NEVERMIND- I DID SOME MORE RESEARCH AND FOUND MY ANSWER CONCERNING THE COIL DIFFERENCES.
It has to do with coil inductance and resistance per their design. I guess the oem computer can handle the differences ok.

 

Ok--just had a long conversation with MSD tech ( who was familar with the rx8--somewhat)
looks like I will be changing my dwell tables in the higher rpms.
We only have that one table for dwell?

 

Regardless, its the only one you have any direct access to for making any adjustments

 

well cant do crap--locked out of the tune. I get the no license widow pop up.
)*&^%@#$%^&(*).
Message sent to Steve Kan.

 

Steve Kan impressed me. E mail sent last night and I already have a reply! He will mod my map this w/e.

 

not nearly as impressive as doing it in 5 minutes yourself including starting up and shutting down your laptop ....

 

true--but tuners lock down their tunes and you cant do anything with it.

 

exactly ...

 

learn something all the time. Through some rather intense guided study and conversations with people that know a LOT more than I do-- I seems I have just been running around in circles.
Jeez.
It seems that there is no magic dwell number and the coil duty cycle needs to be talked about more. I will let others explain this as I am still very much a noob with electronics.

 

Is my table now safe to use or will i get some problems ?

----- 1000 2000 3000 4000 5000 6000 7000 8000 9000
------------------------------------------------------------------------
06,50 2706,06 2142,00 1696,46 1270,92 1016,74 849,66 728,28 635,46 564,06
07,75 2410,46 1902,10 1667,90 1270,92 1016,74 849,66 728,28 635,46 564,06
09,00 2170,56 1725,02 1506,54 1270,92 1016,74 849,66 728,28 635,46 564,06
10,25 1992,06 1577,94 1378,02 1256,64 1016,74 849,66 728,28 635,46 564,06
11,50 1844,98 1456,56 1278,06 1168,10 1016,74 849,66 728,28 635,46 564,06
12,75 1725,02 1368,02 1199,52 1085,28 1011,02 849,66 728,28 635,46 564,06
14,00 1577,94 1278,06 1120,98 1016,74 945,34 849,66 728,28 635,46 564,06
15,25 1339,46 1206,66 1059,58 968,18 892,50 842,52 728,28 635,46 564,06
16,50 1159,54 1116,70 1002,46 913,92 849,66 799,68 728,28 635,46 564,06

its the whole OEM Map multiplied by 1.45
will it be safe in the lower rpm with the BHR Coils ?
I don't want to melt them down or damage my car.

br

 

You did read the thread ?....Right

 

Trying not to say what I really think. I use it instead of being more "direct" like Team

 

yes i read the thread, but I'm going more confused then before.

So are the numbers safe and will not melt my ignition coils ?`

 

Children shouldn't play with matches. If you downloaded Oltmanns zip file and can't comprehend it then you have no business making your own changes.

 

I have downloaded the file, checked the times but they seem pretty high at lower rpm and voltage from 12v upwards . I just want an Info of the coils can handle the longer Times or not . Thats all.

 

i am not the expert--but I will try and save you some grief here. Oltmans table should be "safe" with the bhr coils. For the best info --just e mail Charles at Black Halo racing--he has the expert knowledge concerning his kit.
It really is not wise to make changes in these maps unless you understand how one seemingly simple change can affect a bunch of other parameters.

OK I AM GOING TO PUT MY FLAME SUIT ON HERE..........
I have been studying and speaking with different people concerning our type of ignition and how a rotary engine responds to ignition changes. All in all like many of us have repeatedly said "the oem system just sucks" at longevity and performance.
The coil pack location exposes it to extreme engine heat. the coils are fragile, the oem sparkplug wires are a joke and just LOOK at them.
Now better options are available that a lot of us are familiar with. But like Team has pointed out the limits of the wiring harness may come into play as the dwells(and amps) are increased. Look how small that supply wire is. But you have to have power in to get power out.
Now increasing the dwell also cuts down on the amount of recovery time the coil has ( increases its duty cycle) which also makes for more heat production which increases resistance in the harness and coil etc.
There is another variable that hasnt been mentioned and going there is the reason i put my flame suit on.
The other variable is increasing the volts/amps to the supply side while keeping the dwell time shorter. Kenne Bell has a product that has been around for many years with a good reputation. It is called "Boost a spark". I hate that name--makes it sound cheap--but it isnt. Now this is something that probably would not help the engine that doesnt have forced induction. But the FI guys may waht to take a look.
This unit plugs in to the coils supply line and then increases the power to the coil ( which can be controlled by owner with an adjustable input) by up to 20volts! It also comes with a hobbs switch that allows the unit to only come on board after 4 psi of boost. That is a sweet option.
Now increasing the voltage /amps to the coils increases its out put without having to increase the dwell. So you can run the oem dwell table with aftermarket coils sand still get the increased output you want. I have been told that just increasing the volts to 16 ( from the 14 we now see in the higher rpms) would be the same as increasing the dwell to the currently proposed levels.
Now this may be advantageous to some. First no worries with the oem wiring harness, 2nd- its easier on the coils as you only push them when you need too, 3nd the start up is unaffected. and forth --its easily tunable.
Its not really expensive--less than $300 and they resale very fast.
thoughts--insults--just another crazy OD idea?

 

Definitely an option Denny....another level of complexity...but if it fails it will likely quit working so not likely to lead to detonation events and cause further problems

To the OP....the Yukon coils are smart...they have a built in charge limiter...so they wont melt And you are far from pushing them too hard with your table

Like Team said though...you need to learn up before you play with stuff that can cause you boom boom typpe expensive problems

( and just for Charles...I left out the winky face so he doesn't get the wrong idea )

 

I don't run less than 5.4 mS dwell with the Yukon coils, and only then because my rev limiter is set at 10k ....

 

Limiter or not, if you set the dwell too high you will know it immeditately from the misfiring and other bad detonation type noises and hopefully not blow the engine in the process ....

 

its interesting that we have a condensor in our ignition system--i just took apart an engine harness-
its sad.

 

Sad? Explain???

 

I'm not an EE, but I think the charging supply is transistorized, and any capacitors are there just to suppress transients. Not an LC circuit.

 

What's sad is that teh baby jeezus weeps every time you post something dumb

Condenser = capacitor

 

need to look at the manual--its called by Mazda a "condensor". And yes--that does not make any sense. I realize it must function as a capacitator.
It is not present on the S2 model and I would THINK the ignition system didnt change on that model.
Whats sad is there are a total of 3 pigtails in the ignition system wiring and they reduce the systems capacity The power supply to the coils via the con/cap thing is particulary sad pigtail for those that want more amps to the coil.
From the pcm there is an obvious bigger wire (little smaller than the normal 18 gauge) that runs to the con/cap carring the voltage/amps. This wire has a pigtail that then branches off to the individual coils with a much smaller wire--smaller than the normal 20ga wire. If anyone intends on increasing the power to the coil by increasing voltage or increasing dwell those wires coming off that pigtail, imho ,need to be bigger.