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Hello folks,

I'm going to try a small shot with a friend on a Dodge Dakota 2009 where we don't have option for a time retard.

A coleague said we could compensate this lack of timing retard with a coulder spark plug but I don't see a correlation between them.

We do timing retardingbecause nitrous increase burn speed avoiding the peak cilynder pressure right? How a colder spark can compensate that?!


Thanks and Br,
 

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If you can't retard the timing, are you able to enrich the fuel?
 

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This is coil on plug with coils that have a two pin connector? If so, you can use the J&S Vampire unit.


In addition to nitrous retard, it also features individual cylinder knock retard. I just upgraded the design and incorporated an adjustable rev limiter. You can set the rev limiter to arm with either 12v or ground, so you use it as a staging limit.
 

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Looking at the coils on rockauto dotcom, it looks like this is waste spark. Four coils, two plug wires per coil? The Vampire controls one coil per channel, so the four channel version is all you need.


To install, no wires are cut or intercepted. The Vampire has a "control wire" for each coil, that connects to the coil negative wire. It retards by extending the dwell pulse. The unit senses when the stock ignition is firing the coil. If it wants to retard, it instantly grounds THAT coil, preventing the spark. The coil is released to fire at the end of the retard angle.

The stock ignition does most of the work. The Vampire goes active only when retarding or rev limiting. You can disconnect the unit while the engine is running, and it continues running on the stock ignition. No bypass plugs or tach adapters are required.


The rev limiter is set by a knob on the front panel. The associated test point is calibrated in volts/thousand RPM. Resolution is 50 RPM. For example, if you want to stage at 3250 RPM, set the knob so the test point reads 3.25v.
 

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The retard is proportional to the amount set by the knob on the front panel and a 0-5v signal. The range is 0-16° retard.


For example, with the knob at midrange, you would get 8° retard when anything over 5v is applied to the input pin. Apply 2.5v and you would get 4° retard.
 

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The rev limiter has a soft touch, skipping every third cylinder at the selected limit, resulting in a 33% drop in power. If the engine goes 100 RPM above the limit, it skips as many cylinders as necessary.


For six cylinder, this strategy would result in misfiring the same two plugs, so the program fires three, skips two, etc, resulting in a 40% drop in power.


The number of cylinders is set by two mode switches on the front panel.
 

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The unit includes an onboard 2.5 bar MAP sensor for boost retard or vacuum advance. The Boost Retard "Start" knob sets at what psi boost retard starts (adjustable from 0-10 psi), while the "Rate" knobs sets the amount of retard per psi above the start point (adjustable from 0-2° retard per psi).
 

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Most any modern engine will have the timing set close to optimal from the factory....This means that it will hurt itself quickly if you add nitrous.

Other methods of trying to slow combustion (cooler/fatter) are a patch, retard the timing to the proper level for the amount of nitrous used and your bank account (and ET) will thank you.
 

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We add a good bit of spray, with A/Fs set in the 12s, as long as we run straight C-16

You must avoid detonation. lower timing or more octane.
If you add more than 10hp per cylinder, I recommend retard a couple degrees per 10hp per cylinder and run straight C-16
 

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I'm a user of the J&S Vampire unit. I thought I'd chime in.

I'm guessing that the timing issue has come up since the owner of the truck doesn't have the ability to tune his truck and doesn't want the added expense.
You need some way to retard timing or things are going to get really expensive really fast.

I'd seriously consider the J&S knock sensor system. It works, and your application is probably perfect for this unit. Cost wise, its probably still your best solution (Other than blindly spraying).

Some guys somehow manage to do these junk yard builds and cheap out with success.
My experiences have not gone so good, and I tend to blow stuff up unless I do it properly.

You need to get some timing out somehow when your spraying, period. Look at your options. I'm sure the J&S unit will come out as a great solution for you.
Before I bought mine, I did all kinds of research and messaged owners of the product to get their first hand thoughts.

Once you start going power adder on motors, you need to spend money on getting control of your motor timing. How you do that really needs to be the question.
 
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