Even at low boost (5 lbs.) and the lowest sensitivity possible (8 o clock) I get 1-2 lights occasionally (2-4 degree retard). J&S will desensitize the unit if I want to send it back. Should I do it? Before the J&S install, I was running 7-8 lbs for over a year with no problems. I would like to run 10-12 lbs safely. Anyone know what the optimum boost retard start and rate settings might be? Thanks.

 

Good luck with it. I used a J&S Ultra for a while, realized how worthless it was, then sold it.

 

Why do say its worthless?

 

The map voltage limiter never worked 100% of the time. I would set it at 2.8v and the voltage would spike above that during boost and freak out my ecu. I ended up having to set the voltage to about 2.65v and it usually behaved itself.

Unless you have the sensitivity down to almost nothing, the J&S will probably pull GOBS of timing above 5k rpms. I set the retard to take out 0.5 degrees/psi, the J&S takes out 8 (or more) degrees more on top of all that at about 5k rpms. Then I set the retard to 1.0 degree/psi, keeping the sensitvity the same, and it still took out 8 degrees of timing. Retarding 15 degrees at 7 psi? The car doesn't even move! I played with the sensitivity alot and never really got anywhere.

So to sum all that up, the J&S was misdiagnosing engine noise as detonation. Keep in mind I had about $700 tied up in this thing that didn't even do its job in my opinion. I messed and messed with the thing trying to get it to do its job. I got fed up and sold it. Hondata 2b is about the same price...

I realize there are alot of guys that like it, that's great. I don't.

BTW, I do weekly compresson tests.