I just picked up an Ultra Safeguard V2 and am wondering about the MAP limiter function. The limiter value is adjustable, and you can set it to clamp at any voltage you want. But I know with the AFC hack you WANT the MAP to send boost voltages.

Is anyone with the hack using a J&S V2? If so, how did you set up the limiter?

Am I correct in assuming that the S/V-AFC needs to see boost, so it can modify the signal, but NOT the ECU. So if I put the J&S MAP limiter AFTER the AFC (i.e. MAP out) and before the ECU, it will pass the modified AFC signal (unchanged by the J&S), but clamp it in the rare case that the voltage was modified too high by the AFC.

Right?

Also, what value should I clamp the voltage at? I've heard a few different values - 2.80, 2.85, and a few others - but does the ECU actually THROW a code at 2.90? I would think I want to set it a few tenths below that value to be on the safe side.

Thanks for any help,
- Slater

 

No, do not limit the voltage at all. The vafc decrases it enough so that it would not throw a code. Dont have time to type, but just leave it at that.

 

...ANYTIME the voltage goes above 2.8x the ECU will throw a code? Sure, the Map limiter may never actually have to clamp the voltage, because the VAFC will always keep it lower; but that ONE time the limiter does clamp it, you will save your engine.

I think installing it the way I described will not interfere with the AFC hack in any way - it will just prevent it from going over the limit in the case that it ever did.

I was hoping to hear from someone that has tried it and had a bad experience...have you?

- Slater

 

BUT, when the J&S does clamp the voltage, it will prevent it from throwing a code, but it will also cease to increase the fuel. It would be so much safer to have the ecu just go into safe mode (excessivly rich, retarded ignition) than have it just stop increasing fuel. Please do not limit the voltage with the vafc mod.

 

...that makes sense. Thanks for the clarification.

Dammit, why did I get the V2 then? I want to use SOME of these extrs features ;0)

- Slater