Rotor Arm Mod

[ttelracs]

Anybody done anything like this before ?  The theory being a fatter, higher voltage spark with all of the associated benefits.

I used this mod a couple of years ago when I was running a V70 T5 and I noticed smoother running and better economy and so thought I'd try it on the valver.  In essence you are removing the resistor part of the rotor arm and replacing it a non resistive conductor such as solder or copper wire and then covering it with a non conductive insulator of some type such as a silicone sealant used for bathrooms etc.

I came across the idea first on a 'Tuning the C20LET' website and thought I had little to lose.  I've attached a link below giving the full details and some pics.

http://www.max-boost.co.uk/max-boost/ignition.htm

I did it earlier today and in total including removing the distributor and replacing it all back took less than an hour.  I would recommend having a spare 'new' one to use if you cock up the old one as that way you will not be immobile through 'fettling'.  We've all been there !  I noticed a smoother tickover and it appeared to pull better through the gears but it is all subjective of course as not properly tested on a dyno with a before and after.  Also, I couldn't drive too quickly in this weather and will wait to add some real mileage whilst monitoring the mpg too !

I will not accept any blame of course if it goes 'tits up' but the worst I can imagine happening is that you will need a new rotor arm and distributor cap.

Any thoughts good or bad and I'll update this thread in the coming weeks with feedback.

[Khare]

Interesting. Worth chucking on the dyno I reckon 

[itavaltalainen]

Am sure this will make some improvements to running but might shorten coil life as it will draw more current.

Won't be dieing in coldish weather (I refuse to call just about freezing "bitterly cold" as the said on the BBC news this eve) but could just push an old coil over the edge during a hot summer day when you give it the beans 

[ttelracs]

Good points.

Regarding the dyno, I'm too tight / skint to stump up the cash for this and so will wait for someone else, Khare? to try it and post the results.

Regarding pushing an old coil too hard and prematurely killing it off, mine has 160k on the clock and looks to be the original so if it does go, it'll be replaced.  Tempted to replace it anyway and I could always pick up a second on ebay !

My next mod will be to shorten my HT lead as I'm sure I can reduce it's length by half and benefit again by a lower voltage drop since it is shorter.  Not going out tonight to try, maybe wait until tomorrow lunchtime. It can't do any harm...

[Khare]

I'm done finding power on this car 

[thai-wronghorse]

Some good reading in the link you posted above,  some particularly amusing and bang on the money.

[Ess_Three]

I can understand the need for a stronger spark on a forced induction engine with high boost which gives the spark a harder job to do.
But NA?

Does anyone believe they have a weak spark or need a stronger one?

Even a high compression 2.1 16v at 8500RPM and above, seems to run just fine on a standard coil, dizzy cap, rotor arm and plug leads...so I ask again, if you are getting good combustion (as measured and verified by the lambda sensor) why is a stronger spark required?

Just wondering...

I've tried many of these so called 'performance' ignition products...Hotwires, bigger coils, additional earths, fancy plugs that promise bigger sparks...and you know what?
No provable gains...only the placebo effect of what you sense you should feel after having your wallet emptied.

[Wayne]

As Glen said on a turbo yes but I can see little or no point with the mod on a n/a engine

[ttelracs]

I can't argue with you Glen and Wayne as I've read many of your threads especially regarding the airbox mod and the 200 bhp Holy Grail you've been after so I must respect your point.  I see it as a 'freebie' since I had all of the bits needed to do this and it cost me an hour of a Sunday which would otherwise be watching dull tv.  If it results in slightly smoother running, albeit subjectively through the seat of my pants AND I can yield another 1-3 mpg, I'll be happy since I'm not chasing big power and this is my daily. If anyone else gives it a go and sees / feels an improvement then all the better as it is a cheap, easy and lkow risk mod in my opinion.

I've now shortened the HT lead which was almost twice as long as required and I had foolishly tie-wrapped around my metal strut brace, which probably weakened the current from the coil through it coming into contact with a nice conductive lump of material. Very silly in hindsight !

Thanks for the feedback though as always good to hear.

[javalin]

Personally I wouldn't bother, but yes I think thats where Ford and others have gone by doing DIS or coil-on-plug ignition where there is effectively a coil per plug.  Having an extra jump for the spark is just silly and old hat.

James