V1 and V2 units run about $400-$450. The little monitor for these units runs about $150-$200. Installing one is like installing a fuel controller such as a VAFC, it's not difficult and can be done in a few hours if you are experienced with working with automotive wiring.
I believe it has been invaluable in protecting my engine, especially in the early stages when I was still learning how to tune the setup properly and safely. On my monitor I can clearly see when the unit is pulling timing for something that it has heard. If this event is repeatable and then disappears when I back the timing off, then I know what the cause was. In this sense it has been a helpful tuning tool.
I might be buying a used J&S from SuperSH, but am curious about how much better the current version is from this version...someone please check the description and give me some info...i am running a turbo at about 7psi using the vafc hack and just need to know if I might need the extras of the newer J&S version...
Description from classified ad:
J&S Safeguard, it has boost timing control but no map limiting. Includes wiring harness (3ft.) and contol box itself, no instructions but is easy to wire up. Some scratches on blue box. $300 shipped
J&S Dual Monitor, Black face with retard lights and a/f lights. In good condition. All wiring included. $100 shipped.
SuperSH has a "V1" unit. The only significant difference between the "V1" and the "V2" is that the V2 has a voltage clamp to limit the MAP sensor signal for setups that need this, while the V1 does not have this feature. If you don't need a MAP limiter, you can use his unit.
He's offering the unit and monitor for good prices, BTW.
That's a good question...although I'm guessing the map limiter of the J&S is supposed to do just about the same thing that the hack is supposed to do regarding the map sensor. But to add to PreludeSH157's question, would the map limiter of the J&S enable you to go above 9 or 10 psi which the hack isn't capable of doing by itself?
You wouldn't want to use the J&S MAP limiter if you are using the hack. With the hack, the reason you get away with running boost without the stock ecu freaking out is because you are cutting the MAP voltage down below the threshold for the trouble code. The limiter wouldn't help you run more boost, you would just have two devices cutting MAP voltage (and in turn, fueling).
If you have an SH, you might want to consider using the limiter for the MAP signal to the ATTS computer. I don't know if it would be necessary with the hack, but it would make sure that no "boost" MAP signal reaches the ATTS computer at all.
Originally posted by sharkcohen If you have an SH, you might want to consider using the limiter for the MAP signal to the ATTS computer. I don't know if it would be necessary with the hack, but it would make sure that no "boost" MAP signal reaches the ATTS computer at all.
^^^Edit: you will have to do this. I forgot that the ATTS computer gets its MAP signal directly from the MAP sensor on a seperate wire than that fed to the ecu.
Since you've already cut the ATTS MAP wire for the JR "ems" installation, you will encounter this wire again upon removal of the "ems". The wire is number 20 on the ATTS computer connector. You want to feed the MAP sensor side of this wire to the J&S MAP limiter input, and the ATTS computer side of this wire to the limiter output.
You still need to prevent the ATTS computer from seeing an overvoltage from the MAP sensor, or you're ATTS will shut down and throw the ATTS light. The MAP signal wire to the ATTS computer is seperate from the one to the ecu.
Originally posted by Coodawg I also have an SH, but my V1 J&S doesn't have the map limiter. Is there another way of preventing the ATTS ecu from seeing an overvoltage?
What exactly is your setup? I ask because you may not need to, depending on what you are using.
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