coils

[mattallac]

have a jen 2 turbo motor in my rx2 the coils are huge any good coil options you guys know of that are small and have good quality

[RETed]

I don't know what you're looking for, but the general rule of thumb is that the bigger the coil...the bigger, better the spark.
Going with a small coil usually means less spark.

You can try and mess with LS-series coils taken from Chevy V8's?


-Ted

[Raksj04]

I heard gen 2 coils were the most reliable coils mazda put in a rotary. Are they dead or are you trying to get smaller ones to clean up the engine bay?

[mattallac]

trying to clean the engine bay up ,the rx2 has very little room in the engine bay i found that the coils from the gen 2 has igniters on them i dont know this for fact if so that could be a factor . i am using a haltec sprint re ecu and bigger coils dont mean better spark .

[TitaniumTT]

Originally Posted by RETed

I don't know what you're looking for, but the general rule of thumb is that the bigger the coil...the bigger, better the spark.
Going with a small coil usually means less spark.

You can try and mess with LS-series coils taken from Chevy V8's?


-Ted

I wouldn't waste your time with the LS1 coils, I still have yet to test the LS2 coils, however, you do need to be careful; certain versions of the LS2 coil have circuitry built into them that allows them to auto ignite. Those I would stay away from.

I'm running a set of Bosch motorsports coils and LOVE them. Small, powerful etc etc. I will say though that the Quicksilver ones the C Ludwig offers impressed me. They're larger, more difficult to mount, but they are the most powerful inductive coil I have ever put on my car.

[Raksj04]

Originally Posted by mattallac

trying to clean the engine bay up ,the rx2 has very little room in the engine bay i found that the coils from the gen 2 has igniters on them i dont know this for fact if so that could be a factor . i am using a haltec sprint re ecu and bigger coils dont mean better spark .

I have heard of a FB guy who did a super clean 13B-T swap. I think his coils were mounted under the dash. I didn't see the car but my friend james talks about it all the time. I think is AFM is after the turbo mounted behind the front fascia.

[WE3RX7]

I run LS2 on mine at stock dwell times with no issue. It's the D585 series. The Bosch are good as well. I have a set sitting on the bench not sure what to do with, lol...

[RETed]

Originally Posted by mattallac

trying to clean the engine bay up ,the rx2 has very little room in the engine bay i found that the coils from the gen 2 has igniters on them i dont know this for fact if so that could be a factor .

Yes, the FC coils have an integrated ignitor built into the bases.

i am using a haltec sprint re ecu and bigger coils dont mean better spark .

Be careful with this statement...
It is true that the Haltech is able to adjust (i.e. lengthen) the dwell signal duration, but this fact should be kept independent of this discussion.
You can just lengthen the dwell duration and get a longer spark before you get to the point where you fry the coil, but this just means that you able to apply this fact to any coil you install in there.

If we isolate the coil by themselves, my statement still stands: physically larger coils will, in general, fire a better spark.
The coil is just a (step-up, DCV) transformer.
As long as it gets the minimum charge voltage and time, it will fire a spark that's dependent on circuit resistance and windings ratio...pretty simple.
Coils are typically rated by primary resistance, secondary resistance, coil ratio, current (and sometimes "work" - i.e. Joules), and max output voltage.

The easy answer would be to use some kinda CDI box for your coils, and just run the smallest coils you can find.
The CDI system negates most of the limitations from input charge time and minimum voltage.
Adding a CDI box just adds complexity and eats up space though...

One downside to running a smaller coil is that heat can sometimes become a problem.
If this is a race-only vehicle, then you just need the coil to stay cool for the duration of the race.
If you're going to street this vehicle, you gotta watch out, as most of the "race-only" coils are not made to run for long periods and can fry from overheating.

With all of that crap said, check out the MSD Blaster SS coil...
http://www.msdignition.com/Products/...r_SS_Coil.aspx


-Ted

[mattallac]

still dont agree bigger is not hotter spark/better spark ,with the epoxy / oil filled coils all the advantage can be is cooling.all coils are not the same , resistance ,saturation time etc.oil filled is old hat for coils and epoxy filled are compact and stay cooler .most of the cars made in the last 20 years that came with crank fire systems stock have enough mv to cook a man from the inside out,they are not large coils.they are coil over packs (small).i would like to know what the output voltages are on those huge coils that came from the 2nd jen(made in the 80's) and are they oil or epoxy filled,my bet is i can find smaller coils with the same if not more output voltage and less saturation time .

[mattallac]

p.s. spark plugs and theyre resistance have alot to do with spark energy and when the plug fires at a set voltage. i work at a dyno shop in the bay area so if i get some coils i can test and see a difference between stock and aftermarket coils and maybe play with some colder plugs than stock ,all factors in the spark debate.aem high output coils with igniter are looking like my choice for the moment.

[C. Ludwig]

What engine management system are you using?

Normally, I'd say the LS truck coils are what you're looking for, but, IMO they require an ECU that is capable of direct-fire ignition. They do not work well with wastespark systems, due to dwell time limitations. The AEM/Mercury IGN-1A coils are one of the best inductive coils on the market right now, but they're a little larger than the LSx coils, and are difficult to package on top of the engine like you will want to do to clean things up.

[RICE RACING]

Stop playing with old tech and toys.

Go full CDI, Dynatek is very small coils (bike stuff) and CDI boxes are not large at all and very simple system and reliable and cheap too.

I have been running the above for many years and 10's of thousands of covered real world miles. You can run any tuning you like, any fuel, any ratio, it will burn the lot. and unlike MSD (My Spark Disappeared) you wont have any reliability issues.

If you are in any doubts about Inductive V's CDI go rent a lab scope and test your secondary voltage @ 2k rpm increments to 8k rpm then post back, you will be shocked how much voltage you drop as rpm increases!!!

If you need some help for parts PM me or search my threads.

[mattallac]

the aem coils are a little large but doable for my space situation the haltec ls1 coils are a little smaller .i have limited space and a cdi (from dynatek or haltec) is a great idea but want to make it clean .see i dont need the MOST powerful thing on the market ,its a street car .all i was looking for was a smaller coil with the same if not better spark and over all performance .the fact sheet for the aem coils are what i was searching for .cdi is a better system (to me and the dyno )lol but rx2s can be a tight fit for a turbo setup .my car is a 13b turbo with a street port, super t4 turbo at 10 psi and it runs mid 11 in the quarter.that is with the stock coils. as long as that stays the same im good .the next project is changing the turbo to a t3 t4 hybrid ,the boost starts spooling at 4800 with the t4 ,i would like to lower that #,any suggestions are greatly appreciated

[C. Ludwig]

Skip all variants of the LS1 coil all together. Their output is far from impressive. The only LSx coil I would recommend is the truck coil (the one with the heat sink).

The LS truck coil will output around 115 mj peak @ 6ms charge. The AEM/Mercury can make that at 3 ms charge. If your EMS allows you to throttle the coil charge relative to demand (most do not) and supports direct-fire, you can really lean on the Mercury coil. They'll develop 250 mj at 6 ms charge time! That's more than any street capable CDI with a much longer spark duration. But, like a race CDI (M&W Drag boxes for example), you can't run the Mercury coil at that much dwell for extended durations on the street. If it's a drag only setup, then you can get away with running them that hard.

Inductive technology has come a long way over the last decade. The need for CDI has diminished as that technology has improved. We now have inductive coils that provide the same levels of output, with fast charge times, and none of the electrical noise associated with CDI. They package more neatly and are less expensive as well.

[RICE RACING]

You will never ever get ANY inductive ignition that will not drop output as a function of rpm *fact*

You will never ever get any inductive ignition that will run a true race spark plug of the coldest heat range from cold start *fact*

You will never ever get any inductive ignition that will fire 50% excess fuel as required in a turbo car, let alone any type of water injection system *fact*

CDI DO NOT create "electrical noise" unless it is a very poor install or fitted by someone who has no idea of CDI systems

If you want a real ignition system for a turbo car, you want CDI, inductive is a pure waste of time, effort, energy to try and make it work, if you HATE changing out warm up spark plugs for race plugs, hate needing to tune to suit the ignition system rather than the engine, then dont waste your time trying to follow poor advise to run inductive ignition systems.

No matter how many decades or centuries pass electrical theory does not change and inferior slower less energy of magnetic induction will always be vastly inferior to using the coil as a step up transformer Rotary engines have ALWAYS made more power on CDI v's Inductive, all experienced people know this for a fact.