turbo question

[ScottWA]

Ive been reading on a couple posts for a cheap replacment turbo is to use a newer 04. 5 turbo on an 03 motor. Seems straight forward except what do I do with the wastegate solenoid on the 04. 5 wont it effect boost?

 

[cerberusiam]

Just put a boost elbow in the reference line and use that to tune the WG opening. The WG solenoid defaults to full boost when bad or unplugged.

 

[Prairie Dog]

If you don't hook up the waste gate, it will never open so it wont dump any boost. Of course you could then overdrive it and have other problems.

 

[cerberusiam]

If you don't hook up the waste gate, it will never open so it wont dump any boost. Of course you could then overdrive it and have other problems.

Nope, see my previous post.

 

[ScottWA]

well I have it installed the 04. 5 but now im getting about 24 pounds max boost where as my 03 stocker would tap out at 36. I checked connections no boost leaks. The 04. 5 charger has 36k on it. And I work w the guy who had the truck before he upgraded. Im only changed the turbo because it was making noise under a hard load. Until I upgrade later with twins

 

[cerberusiam]

well I have it installed the 04. 5 but now im getting about 24 pounds max boost where as my 03 stocker would tap out at 36.

That is because the WG solenoid defaults to full boost when it is not powered and controlled by the ECU. This limits boost to 24-26 psi. A quick fix is just clamp the boost referene hose with a pair of vice grips to get full boost and control it with your right foot. I have been running over a year like that with Smarty on 5-6 and just control it with the throttle input. Depending on how much fueling your 03 engine is doing you may just need to crimp the line.



From the FSM:



When the command valve is not actuated (no current supplied to the valve), a passage in the valve allows the

wastegate signal line to be supplied with boost pressure. This allows boost pressure to be mechanically regulated

by the wastegate as in a conventional wastegated system.

When the engine control module (ECM) provides a pulse width modulated (PWM) signal to the command valve,

boost pressure is bypassed away from the wastegate signal line through a drilling in the turbocharger compressor

housing. The internal drilling bleeds boost pressure back to the turbocharger compressor inlet (low pressure). Actuating

the command valve and bypassing the boost pressure signal to the wastegate allows the engine to operate at

a higher boost than would be achieved if the wastegate were allowed to operate normally.

 

[Prairie Dog]

Nope, see my previous post.

Ya, it does help if I actually read post's doesn't it :-laf

 

[CToney]

The wastegate spring on the 351 is weaker. Swap over your 341 spring and shorten the rod to get <35psi and all is good.