Pontiac Solstice Forum - View Single Post - Shortened wastegate rod mod

I sent the info to Lyndon Wester, he says pretty much the same as Dave. He just explains a few things sort of. Here is his comment.

"Limiting boost pressure is accomplished by the ECM controlling the
turbocharger wastegate solenoid and maintaining the duty cycle at 0 percent.
"

This would be the same as leaving the wastegate solenoid electrically
disconnected, so this statement is true.

"This means that the ECM will not actively close the wastegate during
greater engine loads."

True.

"The system at this point is limited to mechanical boost. Mechanical boost
means that the wastegate will move, but the amount of motion is limited by
mechanical properties of the return spring within the actuator, the
pneumatic properties of the actuator."

True.

"In this mode of operation the manifold pressure will attain a max pressure
of 140kPa."

In its' stock adjusted form--true.

"During normal operation, if a wide open throttle were to be requested at
lower engine speeds, the ECM will command the boost control solenoid with a
duty cycle of 100% to minimize any turbo lag."

Yes, more boost would be allowed. True.

"During engine loads in the middle and upper RPM ranges, the ECM will
command the boost control solenoid, with a duty cycle of 65-80%. Manifold
pressures for up to 240 kPa are possible."

Possible, yes...attainable for any length of time longer than 1-3 seconds,
not in the stock form. At this point, it doesn't matter what the wastegate
does, or what the solenoid does...the ECM commands the electronic throttle
closed.

"The turbocharger wastegate actuator assembly has a threaded rod and nut
that connects the diaphragm of the actuator to the wastegate. This rod is
adjusted to Borg-Warner factory specs and is not adjustable."

I think we all know the answer to this one.

Lyndon

__________________
Red Bull Drift Team 2008
Solo Mach and High Flow Cat
Dejon Intercooler, Intake Elbow, BOV spring
Wester's Garage RACE tune II
JPM custom shifter.
Barney Juice with Militec-1
GM Auto-dimming mirror with OnStar and maplights
Rhys Millen Racing, RMR Style Bar.
Peak RWHP 286.3, Peak Torque 313 ft/lbs.
SSR Type C wheels, Bridgestone Potenza RE-01's
DDM Works PINK Breastplate

NASSOA In Great Company! Founding Member

	lil goat Senior Member Join Date: Nov 2005 Location: Objects in mirror will soon disappear!	I sent the info to Lyndon Wester, he says pretty much the same as Dave. He just explains a few things sort of. Here is his comment. "Limiting boost pressure is accomplished by the ECM controlling the turbocharger wastegate solenoid and maintaining the duty cycle at 0 percent. " This would be the same as leaving the wastegate solenoid electrically disconnected, so this statement is true. "This means that the ECM will not actively close the wastegate during greater engine loads." True. "The system at this point is limited to mechanical boost. Mechanical boost means that the wastegate will move, but the amount of motion is limited by mechanical properties of the return spring within the actuator, the pneumatic properties of the actuator." True. "In this mode of operation the manifold pressure will attain a max pressure of 140kPa." In its' stock adjusted form--true. "During normal operation, if a wide open throttle were to be requested at lower engine speeds, the ECM will command the boost control solenoid with a duty cycle of 100% to minimize any turbo lag." Yes, more boost would be allowed. True. "During engine loads in the middle and upper RPM ranges, the ECM will command the boost control solenoid, with a duty cycle of 65-80%. Manifold pressures for up to 240 kPa are possible." Possible, yes...attainable for any length of time longer than 1-3 seconds, not in the stock form. At this point, it doesn't matter what the wastegate does, or what the solenoid does...the ECM commands the electronic throttle closed. "The turbocharger wastegate actuator assembly has a threaded rod and nut that connects the diaphragm of the actuator to the wastegate. This rod is adjusted to Borg-Warner factory specs and is not adjustable." I think we all know the answer to this one. Lyndon __________________ Red Bull Drift Team 2008 Solo Mach and High Flow Cat Dejon Intercooler, Intake Elbow, BOV spring Wester's Garage RACE tune II JPM custom shifter. Barney Juice with Militec-1 GM Auto-dimming mirror with OnStar and maplights Rhys Millen Racing, RMR Style Bar. Peak RWHP 286.3, Peak Torque 313 ft/lbs. SSR Type C wheels, Bridgestone Potenza RE-01's DDM Works PINK Breastplate NASSOA In Great Company! Founding Member