alright so my jrsc has been detonating like a **** whenever i floor it. i retarded the timing but i dont drive in boost that much so it killed the drivability. i was driving the other day and came up with something

if i left a vacuum line uncapped like i had a vacuum leak it would make less peak boost right? so instead of having 6lbs id have maybe 4 or 5. i tried it and the car definately felt weaker (boost gauge got stolen) so the question is would a big vacuum leak damage the engine under normal driving?

 

how much did you retard the timing? Sounds like 'tipin' detonation.

i'm not sure about the vacuum thing because I'm not sure how the bypass valve in the JRSC works.

 

its not tip in detonation. i think it has to do with my fuel pump leaning out because i get detonation after i floor it for a couple seconds. i retarded the timing more than the recomended 8 degrees because it was detonating so much. i think its at 6 or 5 now. im talking about leaving the vacuum line that once went to my boost gauge unplugged so it leaks boost and doesnt put out the full 6 pounds.

 

When you say 8 degrees Im assuming your using the Boost Timing Control **** (BTC) that connects to the JR EMS - correct? Have you verified the timing is actually in fact retarded with a timing light? Im thinking perhaps your EMS is not wired up correctly.

Are you using a FMU? Have you tried increasing the fuel pressure?

You could also try 1 step colder spark plugs. And gapping them closer .035" ~.040" range.

And if you want to leak boost you could possibly leave one of the vac/boost nipples unplugged on the base of the supercharger. It has to be after (below) the blower. But by doing so your avoiding the problem rather than solving it.

 

the kit didnt come with a jr ems. i have the fmu hooked up. and a resistor in the air temp sensor. the point is to avoid the problem and give the car a little more driveability until i can afford a wideband o2. the vacuum line that i left uncapped was the one going to my boostgauge so it read boost. so itll leak boost. i dont have an adj fpr.