I seem to have spark break up in the high rpm range at times. Is it best to just get a new coil and ignitor. or upgrade to and aftermarket msd unit? I have my sparks plugs gap around 22 and these Oem distributor are used and old. Gsr motor on boost

 

https://honda-tech.com/forced-induct...tions-3191479/

A lot of good info in this thread.

 

At your power level it wouldn't hurt to at least upgrade a few components.

accel OEM replacement supercoil (or external coil)
ignitor delete
external ignition box

with that setup you'll be able to open your gap up a bit while still avoiding any blowouts and get a more aggressive and complete combustion cycle/fuel burn.

Although depending on your setup in regards to things like displacement, rpm, power level, boost pressure, and so on a coil on plug system definitely wouldn't hurt... you'd have much more flexible and precise control over spark events and things such as coil dwell, ignition timing, stronger spark, more complete burn with a larger plug gap, and so on.

typically with a coil on plug setup you can go a bit more aggressive in regards to timing since you won't be suffering from a weak spark production and possible blowout from plug gap and cylinder pressure, also cop cars tend to run a bit smoother at higher power than distributor cars and obviously you can get more power and economy out of the car over your current setup.

it just depends on your budget, goals, and current EMS and whether it supports any type of coil on plug system.

 

How much voltage does the accel OEM replacement supercoil outputs compare to the oem? or what is the output of a factory ignition coil? I'm running hondata s300 at around 20-25lbs of boost on a built gsr.

When trying on different distributor, why is that certain distributor have different base setting adjustment to another? I have one that base timing is right in the middle and when I try another one. I had to set the distributor all the way down to get the base timing of 16.

 

Small differences in the castings... like pickup positions, run out of the shaft, timing wheels aren't exactly identical from distributor to distributor.

I'll have to look up the accel coil.. I think it's like 35k to 50k volts,can't remember exactly. it would work best with the icm delete and an external box.

at your pressure and power level you need to invest in a stronger ignition system. you'll notice better drivability across the board as well as more mpg, more power, and more response. there really isn't a downside other than the cost of parts and the time to do the work.

 

The accel drop in coil replacement works great, I've used it personally and advised others to use it with great sucess. At your level its minimal fuss and is effective on extending the use of the OEM system without any other modifications. With that being said..... It is not the end all be all ignition upgrade but there are guys running way beyond 500hp on ALL OEM components (other than spark plugs) I have no doubt that it is the proper upgrade for you.

 

Yeah, I would like to stay oem as possible. Less wiring all over the engine bay. I will give the accel a shot plus a new oem ignitor and cap and rotor.

 

You're gonna keep going through ICMs. You may as well do it right and do it once. Get the ICM delete, an external box and upgraded coil. Can be had for ~$300 or less and it's worth the peace of mind IMO.

I know how you feel about the wiring but I'd rather have a bay with a little extra clutter and have it be reliable than have it look super hella jdm clean and constantly be replacing things. That's just me though.

 

Yea the ICM is definitely the weak link when making lots of power and running lots of boost/high cylinder pressures. when I got my new distributor the first thing I did was take the ICM out lol.

eventually you're gonna go nuts replacing the ICM all the time.

 

Higher cylinder pressures have absolutely no impact on ignitor life.

 

What causing the Icm to go out? The output votage of the aftermarket coil is too much compare to factory? Anyone know the Max output voltage of the accel coil oem replacement compare to factory? I can't seem to find the spec anywhere. It Jusy say 15% more than stock , but I don't know what the stock one outputs.

 

The output voltage doesn't seem to be specified anywhere.

Heat, current draw and vibration is what kills the ICM.

 

IIRC someone said/tested that since higher cylinder pressures make it harder to initiate a spark event for a given plug gap that it can stress the ICM. at least that's what I remember lol.

 

While that is true, the coil does not require any more current to charge.

 

Yea I mean the voltage/current won't change.. it's just harder to initiate the spark.. then you add in higher rpm, more vibration, more underhood heat, more aggressive driving, etc and it's not hard to see why components OEM or not fail.

 

That's not how a coil works. The spark is created when the voltage is removed.

 

I know, when current is removed it causes the voltage increase.

I'm not taking about the coil though.

 

And we don't use a points system so technically it's a bit more complicated

 

When there are break-up in the upper rpm, What can possibly be the cause? A weak coil or icm is going bad?

 

I guess I'm still missing where you feel the added stress is introduced, specifically. The function of firing the coil is the same regardless if it's done mechanically or through a circuit.

OP:
What is your plug gap? Fuel? AFR? Is it a specific RPM? What is the condition of your plug wires?

 

Plug gaps are 22, e85 fuel, break up varies after 7k up, ngk wires are 4 years old. I'm not sure on the a/f when the breakup is happening. I try another used distributor and the breakup went away. What parts can I replace when rebuilding a distributor? These distributor are 10+ year old and I have only replace cap and rotor. I was thinking coil and icm to fresh things up??

 

Coil and icm are good things to replace if the break up doesn't go away.

the only components that never really go bad are the vr sensor pickups.

 

Have anyone try the accel oem replace coil and have spark plugs gaps in the upper .020's?

 

I'm not sure, accel only says 10-15% increase in voltage over OEM. I would imagine that means it's at least a 30,000 volt.

The only real way to figure out what kind of gap you can run is just to keep opening the gap and doing a pull until you start to feel it breaking up then gap them down a bit.

I've also never really understood why honda/acuras have to run such a tight plug gap on FI setups. Maybe it's just the distributor design and it's limits or something random.

as an example my SVT Focus using the stock EDIS wasted spark coil near plug can run gaps as high as .065 while making 300hp and about 20psi, most stay around .060 regardless of NA or FI. This is also on a 10.2:1 static compression motor as well. I'm not sure what the coil on plug honda guys are running as far as coil gaps but I would hope it's at least .032 or so. I think then the gap mostly depends on coil strength.

that being said, while the accel coil is a bit better than OEM it's not perfect. Some people have had issues with random failures and what not. Just remember you'll still be limited by what the distributor can physically do, if you aren't close to that already, so at some point it would be beneficial to go COP

for right now (and i'll say it again lol) this would be your best bet and best bang for the buck...

ICM delete (turbo-ls sells a nice one)

External ignition box - the Summit box has proven to work well on our motors, also affordable

External coil - Crane LX92, replaced the older/weaker PS92

Distributor cap and rotor to support external coil - MSD cap PN82922 comes with a cap, rotor, and plug wire for external coil. MSD recommends drilling a small hole in the bottom of the cap to release ionizing gasses that cause misfires.


That setup would work better than just replacing the coil. You would be able to make more power/boost before having to step up to a COP setup. It would also improve drivability and reliability(as far as ignition component failure)

 

You already have an s300, so Hondata COP should be your best bet.
Get that for peace of mind and easily works with higher hp without anything else.