93Cobra#2771

iTrader: (2)

I gotta check that out - have a new scangauge e that I won but haven't observed throttle angle. Not even sure it has throttle angle as an option. I know it has tps voltage but haven't played enough to know it all yet.

rancheroracer

Here's a video of boost during 1/4 mile run:

TheBundo

That explanation doesn't hold water to me, nothing personal. As to your last sentence, the EB has 90% or more of it's rated torque all the way from 1700-5000 rpm, making it less of a torque "curve" than 3-sides-of-a-square.

As RPM is increasing much faster, percentage-wise, than the turbos could (since they initially spin up so fast compared to the engine), the pressure has to go down.

TheBundo

This is as it should be. The upshift lowers the air volume flowing through the engine as the rpm's decrease, but the turbos are still spooled up, hence the pressure increase, and the repeated cycle as you've described.

TheBundo

While that may be the case, and possible because of "fly-by-wire" throttles, coming from the diesel world, the modulating was done, especially for purposes of auto tranny gear changes, done by controlling the direct injection (momentary de-fueling), not by moving the throttle blades. Much faster that way, as it is done in milliseconds. And we do have direct injection, not sure if the Mustangs did???

engineermike

Bundo, Diesels don't modulate the fly-by-wire throttle blade because they don't have one. "De-fueling" the diesel is the easiest way they could reduce power during the shift. What we are seeing, however, is dialed back throttle in the gear between shifts.

Also, in the vast majority of turbocharged gas engines, the wastegate holds boost pressure constant through the rpm range. This isn't a supercharger, where the boost isn't controlled. I've never seen a boost increase during and after the shift on any turbo vehicle until this truck.

p38fln

I wonder if the Ecoboost gives out more power if it's under load? That would explain a lot of the "it feels like nothing is there" comments when a trailer is attached to one.
I noticed on my cousin's Platinum the turbos spool up very quickly and are fairly loud if he has his boat hooked up, while you can't even hear them when it's empty, even pulling a grade.
My XLT doesn't see enough trailers to know if that's true on it too. It likes hills, though.