Hey everyone,

I drive a 2000 F250 7.3 PSD with 140k it. I am hesitate to put a chip in the truck because of the mileage and the horror stories which i heard. Therefore, i am trying to develop some more naturally aspirated power. Recently i installed a turbo back dual 5 inch exhaust and im in the process of purchasing an AFE stage 2 intake system. However, i keep seein wastegates that claim they help build boost, so now im interested. Can you upgrade your waste gate without doing any modifications to the turbo or the turbo housing?

 

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What horror stories? I've got 100K miles and my truck has never run better.

Let me explain how the wastegate works, then I'll tell you how (and if) to modify.

A wastegate is used on turbo applications where exhaust backpressure must be kept in check. On the stock 7.3L's, the turbine housing is only a .84 A/R. This is great for low end boost and a quick spool, but due to the small size, the exhaust backpressure can more than double the boost when boost pressures reach 25 psi. With a larger turbine housing, you can safely boost to higher pressures and still keep exhaust backpressures lower, but you sacrifice on the low end with excessive turbo lag. The wastegate opens up under higher boost levels to relieve some of that exhaust backpressure and keep the imbalance of drive and compressor pressures under control. If there is too great of an imbalance, the thrust bearings in the turbo are stressed and you end up with premature turbo failure.

On the 7.3L, the wastegate actuator is controled by the wastegate solenoid (and to the PCM). When the MAP sensor reads about 5 psi of boost, the PCM commands the wastegate solenoid to apply air pressure to the wastegate actuator, and the wastegate begins to open. As you increase boost pressure, the wastegate continues to open up, bleeding off more exhaust gas. This basically creates an exhaust leak, lowering the amount of drive pressure, and it helps limit boost pressure as well. In stock form, most 7.3L's will see a max 16-18 psi of boost.

If you disable the wastegate from opening, or tighten the actuator rod to delay or limit opening, then you can gain a bit of extra boost, usually peaking at 18-20 psi without a chip (a few have gone higher without adding a chip). For most people, there is no harm in doing this, and you may feel a very slight difference. Once you start adding power via chip or tuner, then boost pressures can quickly exceed 25 psi and the wastegate is necessary to regulate pressures until you replace the turbo with an aftermarket unit, or increase the size of the turbine housing.

There are several things you can do to the wastegate actuator. One method is simply pulling off the red tube leading to the actuator and sticking it on one of the intercooler boot clamps to keep it from leaking air. This prevents the wastegate solenoid from applying air pressure to the actuator and delays the opening. However, the stock spring inside is still very weak, so the wastegate will still open up on its own as turbine pressures increase.

Another way is to remove the clip that holds the actuator rod to the wastegate arm, then tightening the rod a few turns and re-attach. This limits how far the wastegate will open, and also delays opening a bit.

Or do a combo of both.

The last option without replacing the turbo is to simply replace the wastegate actuator. Banks Big Head and TurboMaster are the two aftermarket replacements that are currently available. The Banks version is a much beefier version of the stock unit, and the TurboMaster is an adjustable-on-the-fly version (so to speak, just tighten or loosen the nut to adjust).

Sorry for rambling, but hope this helps.

 

well that is a great deal of information, most of what I did not know. I have to mow back over it and really take it in. I greatly appreciate the information on the wastegate and will continue to do research on the subjet. As far as the chip goes, ive heard of a few people blowing up trannys from the different change in shift points. Once again i am new at this so i continue to do my research. Thanks

 

The transmission is the weak point on these trucks, stock or chipped. If you baby it, the trans will last a while. Work it or abuse it, and it's toast. With mine chipped I did some harsh things to it, and it made it nearly 100K miles. Not that great, but better than I expected with the way it was abused and the power that the motor was putting out. There are supporting mods like a valve body that you can do to prolong the life of the transmission when you add a chip. However, the torque converter is very weak to begin with, and that's a very common failure point.