Boost Question

[timlavxr6t]

hey guys,

I have an 04 ba m1 xr6t auto 140k on the clock. when the car is on less than a quarter of a tank of fuel boost comes on 6 psi steady all the way to when the auto shifts to the next gear and boost spikes to nearly 10 psi between shifts but no torque control from the ecu, just wondering if that's normal or not, oh and the only mod is a k&n panel filter.

cheers tim.

[xr6t 4.0]

I know there is a problem with them when they run under a 1/4 of a tank they have a tenancy to run lean. Might be the problem?

Everyone says not to run them with less then a 1/4 of a tank of fuel for that reason.

[timlavxr6t]

I heard that was more of a surging under acceleration rather than a boost spike

[BensXR6T]

Never took any notice, but mine does the same thing with 10psi map. Stays nice and steady at 10psi, but builds up to 12 after a gear change then tapers down. Pretty sure it's a normal thing in an auto as the throttle doesn't get closed for the BOV to release pressure before the next gear loads the engine up.

I'll flash it back to std tomoz and give it a go if you want.

Cheers,

Ben