J&S Vampire

Stupid Canuck

Registered User
I know our ECU does it's best and a lot of us have custom SCT tunes, but I was wondering if this might help or even if it could be wired in. Apparently, all it needs is a separate negative for each coil. The adjustability is nice change and it has optional guages, including a dual knock/AFR.

http://www.jandssafeguard.com/VampirePage/J&S_Vampire.html

Price is normally $545 but he is offering a $10 discount for 3 channel version and a 10% discount for a group buy of 5.
 
cool find, i've never seen that before. i don't think it will work with our cars. it says not for cdi, and i believe thats exactly what we have.
 
Hmm, interesting. I haven't heard of how you can retard timing by extending dwell. That's the part I'm not clear on. How does it retard timing without some sort of input into something.
 
I think it retards AND extends dwell. Even more curious is how it works in parallel.

The fact is, it works. I've done some more research and they've been around for quite a while and are recommended by Kenne Bell and Snow. Not well known but less mysterious with ricers and supercharged Mustangs. If it works properly, you won't notice it.

Think of it as insurance. Expensive insurance, but how much do head gaskets or pistons cost. There are many other ways to kill an engine that the J&S doesn't prevent. I'm not sure how much the ECU retards timing but I doubt the 20 degrees that the J&S is capable and not as quickly or selectively per cylinder. I've read where many factory ECUs can't filter out the background noise from the knock sensor above 4000 RPM and ends up ignoring both. Even a conservative tune on the dyno can't compensate for conditions like bad gas or the fuel pump dying.

Compared to the MSD retard systems, it's adaptive instead of manual and not expensive.

I quickly learned how succeptable even a mildly modified SC is to detonation and, thankfully, it only cost my hg's (and another $2500 in extras). I'm also 4 hours and a border away from a SCT dyno, which ain't cheap either.

The basic monitor guage is $99 and the dual (not wideband) is $175, but don't quote me on that.
 
You would need to the outputs from the DIS in our case as it has the drivers for what coils fire. Keep in mind also you'd be monitoring only 3 coil packs as our system is paired, so in affect you would be changing the timing of the main event as well as the waste fire event on the opposite cylinder at the same time.

Better double check it would work on our system first before purchasing.
 
Hmm, then i wonder they do with the signal. Drop it to ground? They appear to be just tapping into the control lines. Thus unless they take things to ground, they can't really change when the signal starts.

The MSD6 (?) does it's changes by actually taking over control. The dis goes into the MSD box and the MSD box has outputs for the coils.
 
FTurner: Wasted spark systems are fairly typical of all makes, including GM and Chrysler, so I assume that's taken into account.

Mike: Can't go to ground, that would be a continuous, unswitched circuit.

Does anybody have an official wiring diagram/schematic of the SC ignition system that I can pass along to J&S to confirm if it will work? Right now, my car is stripped down to the block at a friend's carport, waiting for parts.

All I was able to find was:
http://www.bgsoflex.com/mjl/mjl_edis_summary.html

On the EDIS6 diagram, the 3 wires labeled "coils A,B,C" are where it would tap into. The ground on the other side of the coil pack is just for the suppresion cap. So, the DIS module is actually just a set of switches. If the coil pack has 4 wires, the only question is if Ford managed to reverse the polarity in the early versions, which doesn't seem likely. If my car was together, it would take 2 minutes to meter out.
 
Our cars use a "waste spark" ignition system.

This product looks very good. It would be useful for guys who have power loss due to knocking, and would also lead you right to the cylinder(s) causing the knock (it might help you troubleshoot and eliminate the cause).

Another plus is the way it's tied into the OE system. If something goes wrong you simply unplug it.. No OE wires are cut (interrupted) and this type of design is often more reliable.

Mike8675309 said:
Hmm, interesting. I haven't heard of how you can retard timing by extending dwell. That's the part I'm not clear on. How does it retard timing without some sort of input into something.
It's really quite simple, and this method is the great part of their design.

First, lets review some basics. The coils are driven from the DIS module, but the grounds are what are "switched". All three coils have +12V wired to their + side at all times.

Dwell is how long the coil winding has current flowing through it (switched on by the DIS by grounding the - wire). This causes the core in the coil to build up a high magnetic field (flux). When the DIS module wants to fire the spark plug, it disconnects the - wire at the right time. This causes the high magnetic flux to collapse and dump its energy into the secondary winding (and fire the plugs).

What this device does to control the spark timing is continue to maintain the ground for a specific amount of time beyond the DIS time. The later the device "lifts" the ground, the later the spark plugs will fire, thus retarding the ignition timing.

My only concern with this system would be the knock detection circuitry. Different engines produce different knock signals and I wonder how they addressed that. The knock sensors Ford uses are tuned to some extent (they have a resonant frequency where they are most sensitive), so using the OE sensor would be preferred over their "generic" sensor.
 
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Good grief guys, I ain't that dumb, I know our cars use a waste ignition system :cool:.

Because of the system we have, you will actually be tapping into 3 wires, so you will not get per cylinder protection that you think you will :rolleyes:.

The signal goes out and fires cylinder 1, which actually fires cylinder 4 at the same time... THAT same signal will also be activated to fire cylinder 4, which will fire cylinder 1..... so which one is causing the actual problem???

It may be "better" than the single system we have built in, but I could see engine virbrations coming up when a couple of cylinders start detonating so those are "backed" off, but the others are still getting the full power timing command. Unbalanced cylinder power at that time. At least with the default system, everything remains "balanced" so to speak, and heck with the issues we have with a naturally unbalanced motor....

I'd rather spend my money on something else and make sure the tune I get is good, instead of covering up issues that could bite your a$$ cause your covering something up..... or is that the way things are now because its "computerized" :D

Me step down from soap box.....
 
From what I understand, the knock sensor is a piezo-electric device that is tuned to a specific frequency, mainly based on cylinder size. I've read that GM has 3 versions. It sends out a voltage spike at a specific frequency but also at various harmonics, to lesser degree. Apparently, it takes quite a bit of processing to filter out the spurious signals.

The factory ECU, I believe, uses a ten count of spikes, before reacting and retarding timing. It also has many more functions, including fuel injector timing. I would be willing to bet that a dedicated unit, like the J&S, has far more processing power than the factory ECU. It seems that many of us have had severe (audible) detonation problems and that indicates the ECU isn't compensating adequately, particularly when modified.

I'm not trying to sell this product. It just seems more obvious the more I think about it.
 
But again I ask, what is causing that detonation that you are saying you are getting....

I'd be more curious as to find and fix that problem than just cover it up with an electronic gizmo, because if that gizmo craps out and you don't know it... you could have a crapped out motor anyway.

Besides, I hear alot of people are saying the knock sensors in cars are too sensitive, which is opposite what your saying.
 
My PLX hooks up to KS wire @ the EEC and uses headphones.
Attached interesting article on Detonation.
 

Attachments

  • Detonation1.pdf
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thanks for the clarification Paul, I wasn't aware that it worked like that. That does explain how it could fully impact timing.

Knock sensors are tuned to a specific frequency. What frequency that is has nothing to do with the number of cylinders and has more to do with the actual noise the engine makes when it is running. The manufacturers load the motor, identify knock, then figure out what frequency that is at at that point to catch knock when it will help most to catch it.

My guess on their knock sensor is that it senses across a wider range and their software is highly attuned to weeding out the noise from an actual knock detect.

It would be a fun device to try out.
 
The signal goes out and fires cylinder 1, which actually fires cylinder 4 at the same time... THAT same signal will also be activated to fire cylinder 4, which will fire cylinder 1..... so which one is causing the actual problem???
Quite simple really... the device keeps track of which of the three coils fired (when it detected knock), and then applies spark retard to the second pulse from the DIS to the same coil (which happens to be 720 degrees crank rotation, or two revolutions). It doesn't matter to the device which plug it is... it will be the same cylinder firing every second pulse. So, as you can see, it's quite easy to control knock on a single cylinder :)

Mike8675309 said:
Knock sensors are tuned to a specific frequency. What frequency that is has nothing to do with the number of cylinders and has more to do with the actual noise the engine makes when it is running.
Yes, it looks for a set of frequencies that characterize knock on that particular engine block. Even the location for the knock sensor is critical to detecting knock. To complicate matters further, the level of unwanted noise (harmonics and other crap) rises with engine RPM as well, so it's tough to "hear" the knock at high RPMs. Ford uses a floating threshold noise floor to compensate for this anomaly.
 
We have had excellent results on a number of different vehicles, beginning in '91.

Heard back from a Ford tuner and his customer yesterday.

Customer installed an eight channel Vampire a couple months ago on his '04 Mustang Cobra with KB blower and 17 psi pulley. Adjusted sensitivity to about mid point, and unit would briefly detect at the gear change, then go out.

Customer trailers the car 600 miles to his tuner. Sort out a problem with the boost bypass system, then make a clean pull on the eddy current dyno, no knock detections, senstivity unchanged.

Tune is for 93 octane, 17 psi, 18° timing, A/F was high 11's.

Change to 19 psi pulley and 105 octane, bump timing to 21°, set A/F to 12.0.

Unit now detects at torque peak. Experienced Ford tuner declares it must be false knock, since they are running 105 octane.

Tuner sets J&S sensitivity to minimum, no detections, car makes 590 rwhp, tuner and customer happy.

I contend that J&S reacted to inaudible trace knock. Maybe not be enough to damage the engine, but it's there.

I've heard many people disparage our system. "Oh, it has to knock before it does anything, and by then it's too late." I doubt these people even use a set of headphones to tune with. Even if they did, the J&S reacts to knock they can't hear in the head phones.

I know a tuner that uses our system, and his day job is an electrical engineer. He built his own knock amplifier with Bose noise cancelling headphones.

Here's a quote from a post he made:

Now moving on to the headphone users... I've personally built a couple units myself for use with noise canceling head phones and have added various levels of filtering and so forth. Simply put, the JandS id'ed and corrected detonation well before it was ever to a point of being audible and distinguishable to my ears. In other words, it was typically much higher level detonation. Keep in mind that by the time most detonation is audible a considerable amount of high level detonation has already taken place. Apparently John's algorithm is sensitive enough to detect it based on my experience. For those that will immediately jump on me to cry wolf that the JandS was false triggering... an adjustment of 3-4 degrees of timing on my EMS eliminated all triggers from the JandS and when added back in yielded the same response from the JandS. Again there was no hope or prayer of hearing this detonation through the head phones by any stretch. I tried quite a bit and ran numerous experiments to see if I could hear the detonation. So again, while headphones may work great (and do!) for hearing detonation in some cases, the underlying fact is there is considerable detonation occuring at high levels that are inaudible amidst the engine noise that the JandS is identifying successfully.

The above was from post 27 of this thread:

http://forums.nasioc.com/forums/showthread.php?t=831718

JohnP
 
John found this thread while googling. He also returned an email after I asked about the group buy for SCCoA members. I've seen some of the other forums and I hope our little group has a bit more vision. We should, we have to work harder at finding power with our limited parts.

"J&S detection strategy is proprietary. Developed while working in signal processing lab at Hughes Aircraft (now Raytheon). Excellent results across a broad range of vehicles."
 
I am considering a purchase of it. I have other parts I simply must purchase first, so a J&S would likely be a good year or two out for me unless something came up to motivate me to re-allocate funds now. (i.e. a meaning full discount to buy now)

I gained an understanding of the function of the unit, so I am seeing value.
 
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