Mods Face Off Result: Shorty Spark Plug Wires

**CoolVanilla** · 10-17-2006, 02:19 AM

Mods Face Off Result: Shortie Spark Plug Wires
This test consisted of testing shortie spark plug wires on a stock 5.7L.

Mod Tested: Shortie Spark Plug Wires
Date: 10/12/06 - 10/13/06
Dyno Location: SVS R&D, Sacramento CA

***Remember to always review and keep in mind the Mods Face Off Testing Methodology Q&A while reviewing these results.***

The Good:

They look gooood!

The Bad:

There's no denying it; on a 2005 5.7L MDS engine, those shortie wires have a negative effect on performance, although minimal.

*NOTE: We tested this previously and showed similar results. We've retested these again due to significant request.

The Numbers:

The Graphs:

These two pulls closely follow the averages for the entire set. This is average vs average, not worst vs best.

**Ozzie** · 10-17-2006, 02:23 AM

Interesting. I wasn't around for this. Did anyone figure out why the negative effect?

**Scarbs** · 10-17-2006, 02:27 AM

Well thats not what i was expecting.
Is it the same for the 06's?

**CoolVanilla** · 10-17-2006, 02:28 AM

Originally Posted by scarbrs

Well thats not what i was expecting.
Is it the same for the 06's?

The 06's dont have the "rats nest" up top. Hmmm... I wonder if we went the other way... tested the rats nest on an 06? MFO6?

**RobAGD** · 10-17-2006, 02:42 AM

humm what is with that weird dip, I have seen that before....

yea my pre header dyno runs had that dip I would be willing to bet it is at the same rpm's

Have we found out anythingabout that dip ? I think its a bit weird that its there with the shortie wires and not with the stockers. But that same dip was on my ( Cat back and Ram Air SC 87 tuned car ).

/me scratches his head on that one

-Robert

**Banshee** · 10-17-2006, 06:11 AM

Originally Posted by Ozzie

Interesting. I wasn't around for this. Did anyone figure out why the negative effect?

Maybe it is the quality of the wire it's self. All plug wires are not created equal.

**magnum375** · 10-17-2006, 07:18 AM

Well, I dont know much about reading the graphs, but i did watch the videos and the guys were running the dyno in 3rd and 4th gears, so the dip maybe a gear change

Son of M375

**RobAGD** · 10-17-2006, 09:11 AM

te huge dip is the gear change, look just a tad past that and you will see a dip that looks very much like the one on my graph.

-R

**CoolVanilla** · 10-17-2006, 12:43 PM

These were Taylor wires. AFAIK these are among the best money can buy. True?

**CoolVanilla** · 10-17-2006, 02:08 PM

After some quick searching, I found this from a year ago:

Originally Posted by fnkychkn

in theory, this mod will accomplish.......................absolutely nothing.

from FSM:

a "wasted spark" system is used on the 5.7L engine, combining paired, or dual-firing coils, and two spark plugs per cylinder.
each cylinder is equipped with 1 dual output coil. meaning one coil mounts directly over one of the dual spark plugs for 1 high-voltage output. a second high-voltage is supplied directly from the same coil (using a plug cable) to one of the dual spark plugs on a corresponding (paired) cylinder on the opposite cylinder bank.
each coil fires 2 spark plugs simultaneously on each of the cylinder banks (one cylinder on compression stroke and one cylinder on exhaust stroke). EXAMPLE:when the #1 cylinder is on compression stroke and ready for spark, the #1 coil will fire one of the dual spark plugs on the #1 cylinder (directly below the coil). the other dual spark plug on the #1 cylinder will be fired by the #6 coil. at the same time, the #1 coil will fire a "wasted spark" to one of the dual spark plugs at the #6 cylinder as #6 coil also fires a "wasted spark" to the other spark plug at #6 cylinder.
the firing order is paired at cylinders 1/6, 2/3, 4/7, 5/8. basic firing order is 1-8-4-3-6-5-7-2.

in simpler terms:
both spark plugs fire at compression and exhaust strokes. the lenght and resistance of the spark plug wires snaking over the intake manifold delay spark by milliseconds. not 100% sure but i think they do it this way to prevent 2 equal flame fronts colliding in center of combustion chamber and causing detonation (spark knock/ping).

And then

Originally Posted by fnkychkn

had a few minutes to spare today. so i experimented with '05 and '06 hemis. here is what i found:
on '05 with ignition wires, all coils fire twice per cycle. once on compression, once on exhaust.
on '06 without ignition wires, all coils fire once per cycle.
hopefully, i'll have more time to research/experiment soon.

So, this seems to confirm the 06's fire a cylinders 2 plugs only during compression, not exhaust. And the resistance in the longer wires of the 05 might actually be a good thing, as fnky points out.

**MattRobertson** · 10-17-2006, 07:53 PM

Dangit. I have to call SVS and hope my wires are still there.

**Meister** · 10-17-2006, 07:57 PM

Bummer. But I'll bet they're still there. (Referring to your original stockers, I presume?)

**RandomAccess** · 10-17-2006, 09:17 PM

I don't really want to start a full on debate on this... (maybe I do) but I still disagree with the conclusion.

Since you somehow lost 6 HP between run 119 and 120... on the same setup...

How can we conclude that this loses HP? When the loss is in the the 2 HP ragnge???

I draw this conclusion.... These will not have any affect on your performance positive nor negative.

They're perty... and I'm a keepin em on my ride!!!

(that is an odd dipp RobAGD... The only think I can think of is Operator error, does it occur in more than one file?)