Has anyone fitted any aftermarket igition systems/components? I've read through this site a bit, dunno how people rates this (good/bad) but it talks about adding a coil and advancing the timing. http://web.tampabay.rr.com/redroby/3liter/ . Anyone done that after leads and gapping plugs?

Once you have soild state ignition, then you have pretty much the most efficient ignition setup. The old days when people used to buy crane setups and the likes, was only really to get a constant dwell. If you have ever had a car with points, and changed to a constant dwell setup you will know why they went to such lengths to do it!

But see'ings you have constant dwell/solid state setups, then your already ahead. Also unless your standard leads are faulty there is no need to replace them. The standard jobbies are better shielded and will cause less radio static and are generally far better than your cheap 8/10.5mm leads, thats why std replacements are more expencive.

But getting a better coil and gapped plugs is benefical Isn't it? I mean, your making a bigger spark and advancing the timing is pretty much the only thing you can do apart from cams and intake-exhaust mods... BASICALLY.. don't get all literal on me now.. I just wonder if anyone has done it and if it has made a difference..

I have never done it on a magna no, but I have installed splitfire coils and a crazy expencive ignitors on a RB20, and other than the original coils being faulty, there was no increase in power on a dyno run before and after, on the same day.

Was that turbo though? did you have bigger plugs and advance it? you didn't really tell me if I was right or not.. But from what i've read advancing the timing is a cheap hp boost.. and with using plugs with a bigger gap and having a bigger coil that means a fatter spark which means you can advance it more without the risk of detonation/burning out valves etc..

But from what i've read advancing the timing is a cheap hp boost

True, depending on RPM. The ecu is tuned to set the correct timing for low down and mid range SPOT ON. Peak torque happens at a specific degree, well away from where pinging will occur in mid range.


and with using plugs with a bigger gap and having a bigger coil that means a fatter spark which means you can advance it more without the risk of detonation/burning out valves etc..

I have never heard of that before, and it doesn't sound very true. Burning valves happens from either too hot a combustion or too late a combustion, so too lean or too retarded. Ignition is exactly that, it ignites the fuel and air. Having a bigger spark is only helpful for when the spark is having trouble arcing like with big boost applications or very high compression motors.

Advancing the timing is good for peak power yes, but unless you remap the ECU, spinning the dissy/CAS will be a trade off for peak power vs mid range torque. You dont need a fat spark to ignite a standard motor, and to minimise the risk of detonation/burning valves you need a consistant spark. The stock ignitor/coil/coils do this already.

Don't agree with the stuff on this site? It's pretty much what I'm using as my guide.

http://web.aanet.com.au/naa/tuningmitsu3l/

I put it on my own webspace cause i didn't know when the other guys space might just disappear. Check out the ignition link - hell - read the whole lot and tell me if there's anything you disagree with..

I dont think that its worth the time or money nah.

Advancing the timing a few degrees can help, mainly because peak torque timing can be off by a good 3 or 4 degrees and still produce 99% of the torque. So shifting the whole spectrum up a little will yield a few extra kw up top with little sacarafice to torque down low.

Its only what I think btw, and I dont know what sort of tests those lads have done to prove any of this.

My time on dynos shows that once the dwell is past a good solid spart, any more can just cause problems with secondary spikes in voltage and other wierd things.

All the effort of replacing coils and ignitors could only possibly gain max 1kw, if any, and for the price I dont think its worth it.

I have never done it on a magna no, but I have installed splitfire coils and a crazy expencive ignitors on a RB20, and other than the original coils being faulty, there was no increase in power on a dyno run before and after, on the same day.

What you say is dead right.
If your stock system is up to scratch and your plugs seviceable and gapped, A 60,000v coil and super duper muti pronged platinum / gold/ urainium spark plugs will not make any difference.
On a good system it only takes around 20,000v to get a spark to jump across the gap on a spark plug. As soon as the spark is produced the coil shut off (laymens terms) and gets ready to fire the the next cylinder. The other 40,000v of your 60,000v coil are not needed.
And once the fuel is ignited by the spark, the fuel charge is rapidly burnt.
Now it doesnt matter if your coil fires once or 25 times per cycle , it aint gunna burn any quicker or produce any more power.

Yeah but if i have a plug with a bigger gap could by system fire that plug just as efficiently?, i was told once, the bigger the gap, the cooler it burns so you can advance it more big the more power you need.. feels like my point just isn't getting across!

The thing is that the fuel mixture is sitting there compressed and waiting for the slightest reason to ignite. It doesnt need a bolt of lightning, only the smallest of spark and its away.
The biggest spark in the world is not going to make it burn any quicker.

Naturally as you open the gap in the plugs you will require more voltage for the spark to jump the wider gap. But I cannot see how making the current jump a wider gap is going to produce more power or run cooler.

I like you sigmaproject :cool:

If you interested in advancing your timing, I did mine for $20 and a dyno run and got 12hp extra at the wheels, it's all on Mitsubishi Club Australia aswell, in the magna section and performance mods section, oh I've done over 5000ks aswell with this mod and not a problem.

Was it Saab who bought out the twin sparkie engine a few years back? They seem to think having two sparks plugs is better than one!

Did they continue with it :P

A few manufacturers brought that out as a features, but none have kept the design.

It does suggest there is a benefit from having more spark, but the cost of producing an engine with 12 sparkies for a 6 cylinder it probably outweighed the benefit. As well as the cost of 12 platinum/iridium sparkplugs would hurt!

agreed with sigmaproject and turbo charade... making spark plug bigger wont help out with anything. wether your spark is big or small, it's igniting the same amount of air/fuel at a given point in time... producing the same heat. i cant possibly burn cooler from gapping a sparkplug alone. changing the timing affects how cool or hot the motor runs.

i was interested in aftermarket ignition stuff for mine, but found out that my dizzy is fully solid state anyways and dwell is not an issue with it.

when my choke is closed, the engine sometimes misses... that was the other reason for making my spark plugs bigger with an ignition kit.

Just want to add to this thread.. i should be trying this to the 6G74 in the near future.

On my 2.0 litre SR20, upgrading the coil to a Crane LX91 unit allowed me to run BKR7EIX-11 iridiums at a 2.0mm gap and 11:1CR with no misfires under various loads during the Aussie summer.

Couple with a 4psi increase in fuel pressure netted ~5wkw from 5000-7500rpm... and this wasn't a dyno variation because the curve clearly changed in those rpm. plus near upper rpms where ignition spark usually breaks down, you could clearly see the curve was perfect smooth where as on most cars you'll start seeing serated looking areas.. kinda like a knife clearly showing ign breakdown

On my 1.6l B16a2 Honda motor with 11:1CR and full headwork (cams,plenum/TB/valve job, etc) i was also able to run BKR7EIX-11 at 1.8mm gap

I'd expect to see some gains on the bigger 6G74 motor but the low static CR is a tad disappointing.


the only downside to running upgraded coils is that your leads will deteriorate quicker and you will NEVER see the advertised lifespan of iridium/platinum.... this is where the multi-core leads come in handy though.

***EDIT***
oh and your rotor contacts deteriorate quicker too. i had to upgrade to a rotor with a solid metal contact. most oem ones have like this circuitboard material as an insulant over a really tin metal contact point... this didn't last long. lookie at my B16 motor here:
http://www.youtube.com/watch?v=_a7zYLuZpwk


***EDIT AGAIN***

and on a side note, the MSD Blaster SS coil (cylinder model) had nothing on the Crane Cams LX91... started misfiring at 1.7mm gap on 3rd gear load (up a shopping centre carpark ramp where i liked to do my ignition testing)

Was it Saab who bought out the twin sparkie engine a few years back? They seem to think having two sparks plugs is better than one!

the twin spark engine was not for performance, but rather for emmissions. I cant remember the exact detail of the 2ndary spark system but there was a reason they had the 2nd bank of spark plugs and the 2nd bank, known as the exhaust plug was a different plug to the main igniton plug.

If i remmber correctly the first plug would fire, with a small gap, to make an easy jump and ignite the fuel/air mix. This would burn and expand as per normal, but at soem timed point the 2nd, larger gap plug would fire, possible 20degrees before bottom dead centre of the combustion stroke in an attempt to burn off as much stoichometric vapour as possible left over in the chamber. The 2nd plug had a big gap because the cylinder pressures were much smaller at this point then when at TDC of the igntion stroke so the same igntion system had more punch so to speak.

Yeah but if i have a plug with a bigger gap could by system fire that plug just as efficiently?, i was told once, the bigger the gap, the cooler it burns so you can advance it more big the more power you need.. feels like my point just isn't getting across!

Your point IS getting across . . . . but it's not accurate! Delete this information from your mind!!!

I'd love to run 5 cm gaps with a mega volt coil with 20 dgrees extra timing and get another 25 Kw at the wheels, but it isn't going to happen!

the twin spark engine was not for performance, but rather for emmissions. I cant remember the exact detail of the 2ndary spark system but there was a reason they had the 2nd bank of spark plugs and the 2nd bank, known as the exhaust plug was a different plug to the main igniton plug.

If i remmber correctly the first plug would fire, with a small gap, to make an easy jump and ignite the fuel/air mix. This would burn and expand as per normal, but at soem timed point the 2nd, larger gap plug would fire, possible 20degrees before bottom dead centre of the combustion stroke in an attempt to burn off as much stoichometric vapour as possible left over in the chamber. The 2nd plug had a big gap because the cylinder pressures were much smaller at this point then when at TDC of the igntion stroke so the same igntion system had more punch so to speak.

Correct! Twin plug heads were in vogue, briefly, to try to improve combustion efficiency thus reducing emissions and avoid detonation with higher compressions. Improvements in combustion chamber shape and plug location made the twin setup redundant. Catalytic converters came in at about the same time IIRC

Just want to add to this thread.. i should be trying this to the 6G74 in the near future.

On my 2.0 litre SR20, upgrading the coil to a Crane LX91 unit allowed me to run BKR7EIX-11 iridiums at a 2.0mm gap and 11:1CR with no misfires under various loads during the Aussie summer.

Couple with a 4psi increase in fuel pressure netted ~5wkw from 5000-7500rpm... and this wasn't a dyno variation because the curve clearly changed in those rpm. plus near upper rpms where ignition spark usually breaks down, you could clearly see the curve was perfect smooth where as on most cars you'll start seeing serated looking areas.. kinda like a knife clearly showing ign breakdown

On my 1.6l B16a2 Honda motor with 11:1CR and full headwork (cams,plenum/TB/valve job, etc) i was also able to run BKR7EIX-11 at 1.8mm gap

I'd expect to see some gains on the bigger 6G74 motor but the low static CR is a tad disappointing.


the only downside to running upgraded coils is that your leads will deteriorate quicker and you will NEVER see the advertised lifespan of iridium/platinum.... this is where the multi-core leads come in handy though.

***EDIT***
oh and your rotor contacts deteriorate quicker too. i had to upgrade to a rotor with a solid metal contact. most oem ones have like this circuitboard material as an insulant over a really tin metal contact point... this didn't last long. lookie at my B16 motor here:
http://www.youtube.com/watch?v=_a7zYLuZpwk


***EDIT AGAIN***

and on a side note, the MSD Blaster SS coil (cylinder model) had nothing on the Crane Cams LX91... started misfiring at 1.7mm gap on 3rd gear load (up a shopping centre carpark ramp where i liked to do my ignition testing)

Big plug gaps produce a fatter spark, if the ignition system is up to it, but of shorter duration. Car manufacturers use it to fire poorly vapourised fuel and poorly homogenised mixtures contaminated by ex gas and crankcase gases. Racers use it to also fire poorly vapourised fuel and poorly homogenised mixtures, usually due to bad engine design or hard to ignite fuels like methanol and nitro.

The bad engine designs typically have a big piston compression lump that masks flame travel across the combustion chamber. More spark advance helps get more HP but often the mixture far from the plug will preignite before the spark plug flame gets to it and the two flame fronts collide, bang goes the piston/head gasket if you're lucky! In the old air cooled Porsches we added an extra plug on the other side of the chamber. This didn't increase HP much but we could run with a lot less spark advance and seldom lost pistons. In the Chrysler Hemi it helps get more power and cuts bore wash from excess mathanol/nitro down past the rings.

A good engine design with compact chamber and flat top or dished piston should not need more than 0.6-0.9mm plug gap. If it does there is something wrong with fuel preparation and fuel/air mix.

Big gaps stress the whole ignition system. Everything is likely to fail sooner and the slightest insulation weakness means a HV flashover to earth when the engine is loaded. That means no spark, a mis-fire. Misfire= zero HP for that ignition event.

Same thing at high rpm. The system can't sustain sufficient voltage for sufficient time to get the spark going and keep it going long enough to start combustion. At high rpm theres a gale blowing through the plug gap and a weak short duration spark can't get enough heat into the gap to start a good burn.

Cheers,
Alan