TJPlatinumEB

I've spent far too many years building and tuning turbocharged Supras and am full of lots of generally useless knowledge. Occassionally some of that comes in handy

To answer your questions.

1. When a blow off / recirculation / bypass valve opens, the excess pressure is generally routed back into the intake piping. This is the way it has been done on many stock vehicles for years. Most are not vented to the atmosphere, because this will create a very rich condition as the air has already been metered and accounted for, therefore fuel is already being applied to compensate. When the air isn't there, of course this creates the rich problem. This is why 99% of factory turbocharge vehicles have their valves routed back into the intake.

2. At these low boost pressures, the wastegate really isn't doing anything at all. Most actuators that control these wastegates are controlled via vaccuum/boost. Vaccuum keeps it closed and boost opens it. Even those that are electronically controlled will have a vaccuum source of some sort. They will start to open as boost gets close to max pressure and allows the excess volume of air bypass the turbo into the exhaust to prevent it from overboosting. On these small hills, I would be surprised if you were seeing more than maybe 6-8psi at MOST. This low pressure would not cause the wastegates to open.

3. Also to note that turbos with internal wastegates generally do not make noise when they open or close. Most of the time you wouldn't hear anything as the action of opening and closing is enclosed in the turbo and exhaust and its only a flapper or puck about the size of a quarter that actually is moving around. External wastegates are a totally different story of course The noise is deafening on some of those.

4. Lastly yes, a blow off valve needs to be routed somewhere in the IC piping. Most aftermarket installs will do it post intercooler plumbing as opposed to before. This proves to be a more effecient method. As you get up in power levels up over 1000hp, I generally will have one post intercooler and one pre intercooler as well. Many people try to get them as close to the throttle plate as possible to evacuate the air at the plate as soon as possible so it doesn't have to go "backwards" to be evacuated. Please note I use that term backwards very loosely! It's more for illustration and explanation purposes.

mcfarmall

Thanks for the explanations. I did some searching for some kind of an animated "video" of what happens during various engine conditions and didn't find anything but I did find some pretty good written explanations.

Here is one link
http://www.turbochargerpros.com/about-turbocharger.html
and the site www.turbobygarrett.com also has a lot of good information, some of which is way over my head. I had heard that the turbos on the EB were made by Honeywell who "owns" Garrett.

I also found that Michigan Turbo is located in Wyoming which is about 1.25 hours from home. I'm not going to make a special trip there @$3.35/gallon but I will try to visit them if I'm in the neighborhood during business hours. I remember seeing their name when I used to attend superstock tractor pulls years ago

EcoBco

ford is aware of the issue and have already fixed it, there is a TSB out for an engine recalibration.

93lightning

what is the TSB # for the recalibration????

EcoBco

12-2-10

EcoBco

https://www.f150forum.com/f70/comput...uccess-138353/

this thread is about the update

93lightning

Thanks......