When I removed the "Red" vacuum line from the end of the wastegate i got considerable more throttle response and i believe a faster pressure buildup in the turbo, my question is do i need to adjust the waste gate rod? I still here the woosh sound when it dumps the excess air, so is it still doing its job? Or just doing its job differently? THx



ps Stock tunes

 

anyone......?

 

Do you have the 6637?
If so, the woosh you're hearing is from the excess air flow coming back out of the intake, no the wastegate.

 

Ya i have the Kwik filter, and ccv so then is the wastegate not doing anything? when you unplug the vacuum line, does that leave the wastegate all the way open or just to the setting on the rod?

 

Check out the thread below. You'll have to put up with a little chatter, there, but there's a good explanation of what the wastegate is for and how the mod works.

https://www.ford-trucks.com/forums/5...ight=wastegate

 

Thanks pete, kris-strokin tried to explain it to me a while back but that explanation is better. So When boost pressure nears its threshold the diaphram will open anyway as to not hurt the turbo, and one guy said the pcm will defuel im sure at around that point also, so in a sense there are two safeguards as long as you dont tighten the rod to much or just leave the rod alone.
Reason i bring all this up is that ive heard that the function of a wastegate is actually to protect the intake manifold from building up to much pressure and i was concerned for blowing a boot or hurting something more major inside the top of the motor. your thoughts?

 

Benny, I'm going to have to let that question pass as it is getting beyond my meager understanding of things.

I try to keep track of good threads with excellent technical info, but am still sort of new to the inner workings of these diesel monsters myself.

Someone like Kris (strokin_it7.3), Kwik (Kwikkordead), Alan (amiller93), and many others can offer a much more valuable answer than any opinion I can develop on this issue. If you PM any of those guys directly, they won't hesitate to give you excellent input.

 

The stock wastegate actuator is a fairly weak unit. So unplugging the red line that leads up to it will delay opening a bit, but it will still be forced open by the exhaust backpressure at higher boost levels.

Also F250 is correct about the woosh sound. You cannot hear the wastegate opening whatsoever. The wastegate is on the exhaust side of the turbo, so any noise that it might make is drowned out by the engine.

As for your last question, the function of the wastegate is to relieve backpressure in the exhaust. The stock turbine housing size on our trucks is .84 A/R. That's fairly small for the size engine that we have. The benefit of a smaller housing is a quicker spool and less noticeable turbo lag. The downside is a loss of power at higher rpm's and boost levels. The smaller turbine housing does not allow as much exhaust gas to pass through, so a wastegate is incorporated to create an effective exhaust leak to bleed off the gasses and reduce the exhaust backpressure. Too much backpressure will cause a huge imbalance on the turbo, and you will kill the bearings in no time and greatly shorten the service life.

The general threshold of the stock turbo is 25 lbs of boost. If you go any higher than that, then you have now forced the turbo out of it's map range. The exhaust backpressure is too high, and the turbo is beginning to become inefficient. Since your truck doesn't have a chip or tuner, you won't come close to that threshold. The highest boost levels I could ever get on my truck in stock tuning was 18 lbs. Most trucks in stock form peak at around 16 lbs.

 

Thanks for jumping in on this, Curtis. Great explanation... helps me in my understanding as well.