Pertronix Second Strike

[cvair4life]

Has anybody ever used or heard of the Pertronix Second Strike multi spark box... supposedly it double sparks through the entire RPM.
http://www.pertronix.com/prod/ig/strike/default.aspx

[miniman82]

If your fuel isn't igniting on the first strike, it's not gonna do you much good to have 'second strike'...

Think about it: the second spark is always going to be some measurable amount of crankshaft degrees after the first, so that means if your timing is set correctly the second spark is always going to produce less power than a correctly timed one anyway. A much better idea is having a hot enough spark to ignite the mixture the first time every time, the rest is just marketing gimmickery.

[Trip]

If your fuel isn't igniting on the first strike, it's not gonna do you much good to have 'second strike'...

Think about it: the second spark is always going to be some measurable amount of crankshaft degrees after the first, so that means if your timing is set correctly the second spark is always going to produce less power than a correctly timed one anyway. A much better idea is having a hot enough spark to ignite the mixture the first time every time, the rest is just marketing gimmickery.

I agree, get a really good "single strike" ignition system instead!

[cvair4life]

If your fuel isn't igniting on the first strike, it's not gonna do you much good to have 'second strike'...

Agree'd

Think about it: the second spark is always going to be some measurable amount of crankshaft degrees after the first, so that means if your timing is set correctly the second spark is always going to produce less power than a correctly timed one anyway. A much better idea is having a hot enough spark to ignite the mixture the first time every time,

Agree'd - How hot is hot enough?

the rest is just marketing gimmickery.

So why do electronic ignitions exist with multiple-spark discharge? I assume that the Megasquirt EFI you use is also an electronic ignition controller?

[Trip]

So why do electronic ignitions exist with multiple-spark discharge? I assume that the Megasquirt EFI you use is also an electronic ignition controller?

Lot's of stuff exists because it sounds good and sells.. like those silly splitfire spark plugs and all that variety of stuff.

What you want is a high quality electronic ignition that has the features to suit your needs. For a simple upgrade from stock a Pertronix eliminates the points, a Pertronix II goes with the stronger 12V coil and gives a stronger spark for better performance (not neccesarilly faster, but better). If you are looking for something programmable (for a really high performance app) then you might want to get into the fancier stuff.

just my 2cents,

[miniman82]

Think about it: the second spark is always going to be some measurable amount of crankshaft degrees after the first, so that means if your timing is set correctly the second spark is always going to produce less power than a correctly timed one anyway. A much better idea is having a hot enough spark to ignite the mixture the first time every time,

Agree'd - How hot is hot enough?

Hot enough that you don't experience misfires under any driving condition, only experimentation will be the judge. Stock systems are only good for completely stock engines (or in the case of the 150 or 180 engine not good enough), the second you make a change that increases the volumetric efficiency of the engine, you need a better ignition (speaking in terms of what Corvairs have from the factory). Better exhaust? Upgrade the ignition. Portwork to the heads, or better cam? Get an ignition upgrade. YMMV.

the rest is just marketing gimmickery.

So why do electronic ignitions exist with multiple-spark discharge?

Because unsuspecting Honda owners who don't know any better will make what they believe to be a logical conclusion based on what the company is telling them, and shell out their money to buy the system. One spark is good, more must be better. In fairness, it's not that systems such as MSD have multiple spark capability, it's that their INITIAL SPARK is so much hotter than just about anything out there. You would do just as well to buy a capacitive system without multiple sparking; in the end a strong AND ACCURATELY TIMED spark is what it's all about. Light the mixture off under any adverse condition, put it at the right time, and you won't care how many strikes come after the first one. One will be enough.

That's why I love the EDIS system. It's got a wicked hot spark, and digital crank referenced timing makes it the system for me. All I need to do is figure out how to get knock sensing incorporated, and it will be at least as good as Safeguard at half that cost.

I assume that the Megasquirt EFI you use is also an electronic ignition controller?

It is, but there is only one spark. It's strong, and more accurate than any distributor will ever be- that's its selling point. I'll never use anything else, unless all those other companies suddenly decide to cut their prices by 75%.

[azdave]

"Second Strike"? Really?

Is that poor marketing or what? Sounds like they swung and missed twice already. :)

[cvair4life]

Thanks guys for the input. I had the same premonitions on that idea but wanted to hear what the real car guys have to say about it. With any luck I'll have a Megasquirt + EDIS combo sooner than later :)

[Greybeard]

On a big cammed, multi carbed engine with a single plane manifold as you might find in a 11-12sec V8 car, a multispark ignition has it's place. The cam creates low vacumm, the carbs don't mix well, and a single plane mani has poor distribution at low rpm. Hence, the idle we so enjoy. A large portion of that irratic idle we are all so found of comes from lean misfires because the mixture is so poor that it fails to ignite.
MSD created their multi spark ignition to try to combat the idle problems and help prevent loading up on drag engines. Their ignition just keeps throwing spark at the cylinder trying to fire it, even if it's late. That helps keep the plug from fouling when moving around the pits, and at the starting line. Standing behind many drag cars makes your eyes water, and the MSD stops much of that. MSD multispark becomes a single spark ignition above 3000 rpm because there is no longer an issue as the rpm goes up.
A two spark could help a Corvair at idle, but it is of no help once on the road. It's better to try to fire late than not at all, but once the engine has some load and rpm, it doesn't do anything for you.

[miniman82]

Not even multiple strikes will cure all of the problems. My machinist runs a glass body Camaro in the 8.90's on a 400+ inch small block using Digital 7 ignition. When he had a dual quad, it was a major pain trying to get the thing on trans brake because the carbs were just too big. That's all a memory now, but the ignition didn't cure it- fuel injection did.

[flat6_musik]

You never know....if a dyno shows an increase in power, it's hard to argue with that.

[Scott V]

That's why I love the EDIS system. It's got a wicked hot spark, and digital crank referenced timing makes it the system for me. All I need to do is figure out how to get knock sensing incorporated, and it will be at least as good as Safeguard at half that cost.

do the above & you will get as about 1/2 as good as safeguard - not anywhere near as good.

to be close to a safeguard youd need to do individual cylinder timing control - for starters. if you dont you are giving up at least 15% of your power. its not as ez as just getting a knock sensing incorporated into an edis system - that is not so hard to do. to get close to the safeguard has youd need to spend much more time developing lots of software & hardware & getting the knock detection working as it should.

get a eke system & copy that to make three systems. use 1 on each edis output. that will get you a simple knock sensor system @ a low cost to work /w your edis. or you can spend a few years developing hardware/sofware & try to do what the safeguard does.

-Scott V.

[Scott V]

MSD multispark becomes a single spark ignition above 3000 rpm because there is no longer an issue as the rpm goes up.

its single spark about 3K not because there is no longer an issue as the rpm goes up but because there isnt enough time to charge the cap to make multispark above that rpm.

-Scott V.

[miniman82]

That's why I love the EDIS system. It's got a wicked hot spark, and digital crank referenced timing makes it the system for me. All I need to do is figure out how to get knock sensing incorporated, and it will be at least as good as Safeguard at half that cost.

do the above & you will get as about 1/2 as good as safeguard - not anywhere near as good.

to be close to a safeguard youd need to do individual cylinder timing control - for starters. if you dont you are giving up at least 15% of your power. its not as ez as just getting a knock sensing incorporated into an edis system - that is not so hard to do. to get close to the safeguard has youd need to spend much more time developing lots of software & hardware & getting the knock detection working as it should.

get a eke system & copy that to make three systems. use 1 on each edis output. that will get you a simple knock sensor system @ a low cost to work /w your edis. or you can spend a few years developing hardware/sofware & try to do what the safeguard does.

If detonation can occur in one cylinder, the same conditions likely exist in the other ones as well. It would be a lot better to be globally farther away from detonation in the first place, there's less chance of damage. Plus, EDIS is still easily half the cost...

[Eurobilly]

Good discussion but don't over look the additional features of the safeguard: ignition amplifier, active dwell control, "nitrous" retard(I use this to warm the turbo at the strip.), cranking retard (easy starts for lots of static timing - such as turbo apps.), boost retard, vacuum advance (on turbos, no need for the can anymore) input trigger & output driver ( Rising or Falling), mag pick up trigger, dig. rpm limits, etc.
Good stuff - especially if you are running boost or high compression!

[miniman82]

don't over look the additional features of the safeguard: ignition amplifier, active dwell control, "nitrous" retard(I use this to warm the turbo at the strip.), cranking retard (easy starts for lots of static timing - such as turbo apps.), boost retard, vacuum advance

EDIS does all this as well. The EDIS module contains the coil drivers and does dwell control, where the Megajolt unit does the rest.