Guys,
A little bit of background: My boost is set to 10-11psi using a bleeder valve (Turbosmart) I have stock IC, ECU. I have an exhaust, POD, CAI, usual stuff....
I found that if I increase boost to say around 12-13psi, when under load at about 3000rpm, the car will jolt violently for like half a second, then resume accelerating.
I have since then wound the boost back down to 10-11psi and when in 5th gear, cruising under 3000rpm on the freeway, it's fine. As soon as I put my foot down, and boost climbs to 10psi.... at about 3000rpm the car will jolt violently then continue.
I've worked out a few things:
It's not detonation, as the boost _really_ isn't high enough to cause a problem.
I'm 90% sure it's not misfiring, as I've had that before with bad plugs, and is fixed. I have copper plugs gapped to 0.75
Similarity: I've had the exact same jolty feeling if I've got under a 1/4 tank and hammering the 'go' pedal around a corner, Obviously the fuel isn't getting in there somehow, but then again It's coz i'm low on fuel
One more thing:
When boost climbs to 13psi it SCREAMS (the noise I mean) gets really loud... very loud induction/turbo spool noise. Is this normal?
Does anyone have any ideas?
-Kym.