When do you need MSD 6AL?

[DammitBobby]

I have been pondering wether that is something I need to consider for future upgrades. What would be reasons to upgrade? I have JWT so I don`t need it for retard timing.

1. Reach certain HP level

2. Would it allow more boost better spark less chance detonation.

3. Only if you see problems in Dyno Tune.

Really didn`t see any good articles when researching that explained why someone needed it.

[S13FX]

Well first of all Detonation doesn't happen because of a poor spark, it happens when it get so hot in your cylinder the fuel actually ignites with out the spark creating combustion at the wrong time of the pistons cycle like forcing it down when its suppose to go up. Now if your running for a better stronger spark jsut simply get something like the MSD Blaster SS Coil.

But from my understanding, the stock coil is good for around 500rwhp.

[nissanfanatic]

I needed the MSD 6A when I hit ~320ft/lbs of torque. I was making 338whp. I installed the MSD 6A and made 353whp at the same boost level..

I would say don't upgrade until you start blowing out spark.

[Craving4Boost]

Well first of all Detonation doesn't happen because of a poor spark, it happens when it get so hot in your cylinder the fuel actually ignites with out the spark creating combustion at the wrong time of the pistons cycle like forcing it down when its suppose to go up. Now if your running for a better stronger spark jsut simply get something like the MSD Blaster SS Coil.

But from my understanding, the stock coil is good for around 500rwhp.

Ivan from AMS says the msd blaster SS coil doesn't do much really. It's good to have but you won't have a dramatic change in spark power. Who has made 500hp on stock coil? That seems a tad high....

[Chris@AMS]

I have a completely stock ignition system on my car. I have made over 400whp with the plugs gapped somewhere in the 20's.

I am interested in seeing where I run out of ignition, as it has not happened yet...

[nissanfanatic]

My stock coil died at less than 5psi. Its definitely car specific. Spark break up is the only indication of when you need to upgrade ignition. Upgrading when current spark is not blowing out is a foolish modification.

[hannibal]

Well first of all Detonation doesn't happen because of a poor spark, it happens when it get so hot in your cylinder the fuel actually ignites with out the spark creating combustion at the wrong time of the pistons cycle like forcing it down when its suppose to go up. Now if your running for a better stronger spark jsut simply get something like the MSD Blaster SS Coil.

But from my understanding, the stock coil is good for around 500rwhp.

From what Ive learned, detonation is caused by mistimed spark, which I think 'could' be caused by weak or slow spark. Splitting hairs, yes, but thought I'd mention it.

[DammitBobby]

MSD offers another ignition SCI PN 6300. I wonder why I haven`t heard anybody using it instead of the 6AL.

Definition of Detonation:a condition, in which, after the spark plug fires, some of the unburned air-fuel mixture in the combustion chamber explodes spontaneously, set off only by the heat and pressure of air-fuel mixture that has already been ignited. Detonation, or "knock", greatly Increases the mechanical and thermal stresses on the engine.

A better spark should help with eliminating unburned air-fuel misture in the combustion chamber. Therefore allowing more boost and timing.

[S13FX]

Ok then this definition kind of contradicts that running on the rich side is safer. I understand why running rich might be safer, but at the same time it could be dangerous since the spark has to be stronger to ignite the fuel.

[WDRacing]

I disagree with that definition. Although it may be true in some cases, the point FI guys run into is usually related to octane deficiency. By that I mean we run cylinder pressures to high for the current octane rating of the fuel. This causes the fuel to ignite prior to the spark. Thus causing the piston to be forced downward far ahead of schedule and snapping lands. It also occurs when the spark plug ground strap becomes so hot it ignites the fuel without the actual spark, with the same end result. Or you get mutiple flame fronts. This is why higher octane fuel is used for higher boost. The higher the octane, the more its resistance to detonation.

It also has to do with why we retard ignition timing on boost. The higher the cylinder pressure, the more retard needed. For the obvious reason, the NA timing curve would be trying to ignite the spark plug far to early in the compression stroke. With that much additional cylinder pressure, the flame front will develope far to quickly. Again, trying to drive the piston the wrong way to early in the stroke.

So Mike was pretty much correct. Will a better ignition system prevent detonation...I don't know. I suppose if you blow the spark out on one compression stroke, then there will be residual fuel and air left in the cylincer...but then you'd already know you were blowing out the spark

WD

[C-Kwik]

MSD offers another ignition SCI PN 6300. I wonder why I haven`t heard anybody using it instead of the 6AL.

Definition of Detonation:a condition, in which, after the spark plug fires, some of the unburned air-fuel mixture in the combustion chamber explodes spontaneously, set off only by the heat and pressure of air-fuel mixture that has already been ignited. Detonation, or "knock", greatly Increases the mechanical and thermal stresses on the engine.

A better spark should help with eliminating unburned air-fuel misture in the combustion chamber. Therefore allowing more boost and timing.

You're interpretation of this is wrong. Ultimately, detonation occurs because of heat. Several other factors such as pressure, hot spots and early spark will contribute to heat or other factors that can cause detonation. When they say unburned fuel, it is refering to the fuel that has not burned yet. Say, if the ignition was too far advanced, it would cause the mixture to ignite sooner. The pressure as the piston reaches TDC would be higher for a given crank angle. Instead of burning all the fuel through normal combunstion the excess pressure which in turn causes excess heat, can detonate whatever fuel hasn't burned yet.

Personally, I'd recommend an ignition amplifier in any boosted car if you can afford it. It's not going to be critical for most, but might allow one to run a larger gap which can lead to a better combustion (read: more power).

[WDRacing]

Damn, I was going to mention that as well Chano. The increased spak energy will allow for alot greater gaps. Running a gap in the 20's isn't really ideal. Having one in the mid 30's would be perfect. The bigger the spark, the better the ignition process will be.

Thx Chano

[DammitBobby]

I disagree with that definition. Although it may be true in some cases, the point FI guys run into is usually related to octane deficiency. By that I mean we run cylinder pressures to high for the current octane rating of the fuel. This causes the fuel to ignite prior to the spark.

Actually I think we are talking about 2 different problems. This relates to pre-ignition not detonation.

Pre-ignition- Another condition that is sometimes confused with detonation is "preignition." This occurs when a point within the combustion chamber becomes so hot that it becomes a source of ignition and causes the fuel to ignite before the spark plug fires. This, in turn, may contribute to or cause a detonation problem.

Instead of the fuel igniting at the right instant to give the crankshaft a smooth kick in the right direction, the fuel ignites prematurely (early) causing a momentarily backlash as the piston tries to turn the crank in the wrong direction. This can be very damaging because of the stresses it creates. It can also localize heat to such an extent that it can partially melt or burn a hole through the top of a piston!

I don`t think that MSD box is going to do anything for pre-ignition but possibly detonation. By the way I pulled these definitions off of google.

[eazye2000]

Not that I know alot about anything at all. But it was my understanding that a lower octane fuel, has a lower flashpoint. Therefore making it more unstable for higher cylinder pressures...? Also making it more succeptable to detonation and pre-ignition...?

If that's wrong I'll delete it, but that's my $.02 like usual. Gotta be involved in everything it seems huh? LoL

[WDRacing]

Nope, thats correct. Another reason high compression engines or forced induction engines aren't able to use 87 octane.

[WDRacing]

Preignition and Detonation are basically hand in hand. Lets keep it simple and say that they both are a flame front of some type that occurs other then when the spark plug ignites. I know for a fact that I've had audible detonation, and no preignition to speak of.

Reguardless, the main issue here is spark. As with anything else in the system, whether it be cooling, lube or ignition, if there is a way to make it better, you WILL see improvements. That goes without saying. More spark will give a better flash in the combustion chamber. Which will yeild a more complete burn.

Bobby, a MSD Super coil or Ignition box is a good upgrade. Its one of those things like a radiator. Does the stock unit work? Yes it does, but does it work well? Given the chance, I'll improve every aspect I have the chance to.

WD

[nissanfanatic]

I always go by pre-ignition being caused by cylinder conditions being out of control(hot spots, too low of fuel octane, excessive cylinder temps, ect) and detonation being caused by prolonged conditions mentioned above and too much timing advance.