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Integrator
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Discussion Starter #1 (Edited)
Has anyone any comments/experience with S&J Electronics Safeguard module?
J&S Electronics SafeGuard Indivdual Cylinder Knock Control

Originally introduced in 1991, the J&S SafeGuard is still the world's only standalone individual cylinder knock control ignition.
Pre-1989 Federal Esprits don't have any anti-knock protection, therefore installation of the SafeGuard may be a good precaution when correcting OE remote waste gate boost limit from 7psi to 9.5psi..

It is very very interesting how it works:
Individual Cylinder Knock Control for Distributor Ignition
Features include:
• Two Rev Limits (Staging and Top End)
• Cranking Retard: Knob allows up to 20° retard. Re-advances one dgree per spark event.
• Nitrous Retard: Knob allows up to 20° retard when activated by 12v.
• Boost Retard/Vacuum Advance with Start and Rate control
• Individual Cylinder Knock Retard
• High Energy Inductive ignition with variable dwell
• Knock sensor sensitivity adjust
• Triggers from points, OEM electronic, magnetic pickup, Hall effect.
• Can trigger MSD or other CDI box

• How it works:
The system makes a spark, then decides if there was knock. If knock is detected, software "knows" it had to come from the cylinder that just fired, and that cylinder won't fire again for two revolutons.
When that cylinder comes up to fire the next time, software dials in the calculated amount of knock retard. It does this as each cylinder goes by, building up a different timing curve for each cylinder if knock is detected.
The unit retards in steps, a total of ten steps are possible. Each step is one or two degrees, depending on a user mode switch. When knock is detected, software retards in proportion to knock intensity.
The unit responds to inaudible knock, and retards quickly enough to prevent knock from becoming audible. The re-advance rate is one step every twenty revolutions. Note that the unit will not advance beyond stock timing. Of course, you may choose to bump the timing a bit after installing the unit.
Articles on knock:
http://www.streetrodstuff.com/Articles/Engine/Detonation/
http://www.avweb.com/news/pelican/182132-1.html
 

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I've seen it used in race applications for it's ability to look at individual cylinder spark knock vs. one sensor looking at overall knock as is standard on my most 1990+ OEM turbo applications. I haven't had any experience with it on a distributor based systems like my 1988, but it already has an upgraded ignition module already, so I'm sure it wouldn't be too hard to adapt the J&S system to that. I don't know if it's really necessary for upping just a few psi though, in other applications, unless you had a really bad tank of gas, it didn't come into play til at least 17psi.
 

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Integrator
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Discussion Starter #3 (Edited)
A single channel Vampire unit would also work, price is $539.95. With the Vampire version, the existing inductive ignition (Pertronix in my case) does most of the work, the Vampire is active only when it retards. You can unplug the Vampire while the engine is running, and it keeps running.
The Vampire has no rev limiters, but nitrous retard and boost retard are included with individual cylinder knock retard.

http://jandssafeguard.com/VampirePage/Vampire.html

Pretty neat!
 

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The problem with a generic knock retard add-on modules is "teaching" the software to recognize the sound of knock on an individual engine. I have not used the J &S system, but I have used the Motec add on module with a Motec M800 ECU and I never was able to get pasted the complexity of teaching the knock sensor the characteristics of my specific engine. Maybe the software is more self learning in the J & S units.
 

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Integrator
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Discussion Starter #5 (Edited)
After consultations with John from J&S, I got custom tailored dual channel Waste Spark "Vampire" processor with augmented sensitivity range and expanded (adjustable) Nitrous Retard (0-20 degree) for my 88' CIS Esprit.

For cars with OE single coil/distributor ignition, a single channel unit would be prescribed, as in posting #1
 

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I've got experience with the J&S Safeguard on a completely different application (high performance Corvair). it worked pretty well - does what it says on the label, and tells you what it's doing. Once you get good at reading the display, you can also tell how many cylinders are getting how much retard - rather handy for telling if you have a cylinder running lean, ignition scatter, or just too much spark advance for the conditions.

In the Corvair's case, it did a great job of dealing with a hot intake tract (hot idling at a stoplight after working the engine hard). It'd pull 8 degrees out until the carbs and manifolds cooled back down again, and then would go back to no retard. Normally you'd have to baby the throttle or hear a lot of clatter from the engine until things normalized.

They do tune the knock sensor bandpass algorithm to cope with different engines - it's definitely not a one size fits all device.
 
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