Splitfire Spark Plug

[AdrianNg]

Hi all

I have a friend traveling to US and I am thinking of asking him to get for me the Splitfire Spark Plug

http://www.splitfire.com/

Has anyone in this forum came across ths plugs.... if so, appreciate your comments.

Cheers
Adrian
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[littleblackalfa]

er... u can buy splitfire plugs at McWell Ventures in Paya Ubi...

 

[explorer4000]

er... u can buy splitfire plugs at McWell Ventures in Paya Ubi...

Tried those before & my car drank a lot of petrol. After about 1 mth, replaced them with stock plug & the consumption 'normalised'. :verysad:

 

[AdrianNg]

Thanks for the input....

Was told that it is selling less that S$50 for 4 pcs in US and my friend is willing to pick it up for me.

more concern on the petrol consumption..... I might be wrong technically but how would the petrol comsumption become higer when the selling point of this spark plug is that it is supposed to get give better combustion to the engine chamber ?

Cheers
Adrian
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[stevenwu]

Hi all,

These plugs causes mis-firing at high rpm so please think twice. I have my car verified in PML after exhibit some engine rough feel at high rpm

These plugs don't come cheap too.

Use iridium la.......safer since most of us have tried it.

 

[Whisky_Tango]

Question is: Why some spark plugs cause high fuel consumption?

My answer: Is it because these plugs produce higher & brighter sparks and thus the piston head runs much hotter?

As I know the ECU will dump fuel to cool down the head. So could this be the reason for higher fuel consumption?

Cheers!

 

[Shaun]

These plugs are a gimmick.

The fork in the ground strap only put more in the way of the kernel, slowing propogation of flame front to the ends of the cylinder. The spark is not larger or hotter. Spark jumps to either side of the fork, not both. Same goes for the other multi ground strap plugs.

For purposes of unshrouding the kernel, I see more benefit in side gapping single standardly ground plugs.

 

[Tanzy]

Shaun,

By that you mean bending the spark plug terminal to the side?

 

[Shaun]

not bending but cutting the ground strap so that it does not cover the electrode, but leaves at least half of the electrode exposed. You can go further to fully expose the electrode, but there is next to, or no power gain and service life is shortened disproportionately.

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side note.. indexing plugs.. if the chamber is a standard 4 valve pentroof chamber, and plug goes straight down into the chamber (i know of no modern production 4 valve exception), then have the gap open towards the exhaust valves as a detonation prevention step.

 

[Tanzy]

Shaun,

What about spark plugs with 4 ground terminal leaving the central electrode exposed? Are those equivalent to cutting the the ground strap?

 

[Shaun]

not quite..

the bosch platinum 4 plug is a semi-surface gap plug but the thing is if the plug is not meant for the chamber type (surface gap often used for high compression where the piston really needs to come up close to the head in which case standard spark plugs would get in the way - like in F1), then there is not much sense to use it since being closer to the head and less exposed to the cool incoming air-fuel charge, it has to have a more specific operating temperature less it foul or overheat.

the spark though more unshrouded is still not as unshrouded and does not go as deep into the chamber as a sidegapped standard-ish plug that does not have the 3 other redundant (cept for service life - where the electrode itself will wear out before all 4 group straps do..negatiing this plus point) ground straps.

We have not found any power in a whole range of extremely high performance applications in any of these fancy plugs on the market currently. This is also why don't find these plugs in unsponsored competition. It matters even less in stock-ish NA street cars. I would get what has been tested to be reliable and not expensive. Then I would side gap them, index them, and that would be that.

(PS the index direction advise in previous post was not a cheap carry over from common writing about 2 valve head indexing. The vast majority of those articles are wrong with regards to maximum power and we instead position down into the cylinder, not the exhaust valves. With a 4 valve head the plane is always horizontal , so the next best thing is to index towards the exh. valves. )

 

[Tanzy]

Shaun,

Ok, so we get some good plugs of the correct temperature and just file the ground strap to expose half the electrode. What is the recommended gap if you do that?

 

[Shaun]

Every specific system is unique, but assuming stock BMW ignition system and nickel-alloy main electrode plug, then 0.037 - 0.048", start small and inch up on the larger gaps to find the limit. Give enough testing time between increasing gaps to allow for wide range of load and RPM - across which there should be no misfire. Be watchful and patient.

For platinum plugs, start out at higher gaps 0.049 - 0.070".

Finding the absolute optimum gap you will end up wasting a set of plugs as you inch past the target, but they are relatively cheap. If you do not want to waste a set, then be conservative and as long as the engine runs good, just leave it. The unshrouding and the indexing should bring a noticeable gain in smoothness if done right. Gain in power will not be discernable by butt, and barely measurable (if even) on a chassis dyno with its large variances

*gap measurement is closest point between main electrode and ground strap. If you cut the strap to fully unshroud the electrode, then the feeler gauges have to go in diagonally, not flat on top of the electrode.

 

[Racebred]

just regap to 0.8mm lah. tested to be good enough liao.

stock denso iridiums come at 1.1mm

 

[Shaun]

oh yah, if you are pushing the limits and looking out for misfire or intermittent misfire (very hard to pick up at the lower levels), I am sure this generation of BMW ECUs has a measuring block or two for misfire detection - usually by sensed crankshaft speed and/or lambda anomalies.

reason #917481 that a diagnostic tool is useful and worth the money.