After reading several threads here, I usually see some comments relating EBP to Boost, usually with EBP similar but slighter higher. My truck, which I got 7 years ago used from a dealer where they got it from a contractor with 180k on it, had some cold start/white smoke issues and then developed a black smoke issue when goosed. Eventually I replaced the injectors with stock remans (all problems went away), and then the next year I had a battery / glow plug issue which gave me cold start / white smoke issues again, and now I'm back to some small puffs of black when goosing it on the highway, but easily avoidable with sane driving.

Anyway, I've noticed that my EBP is pretty much above 20psi during normal driving in town, and can get as high as 30 or so when at WOT - where I get noticeable black smoke. I really don't know what good "normal" boost readings are, but I get around 5-8 in town, and maybe 10 under normal highway driving. At WOT, maybe 15-18psi. Wondering if I might have a plugged CAT - it's an e99, and the exhaust looks stock, so I think it's original.

I can rationalize how a restricted exhaust can reduce turbo efficiency, thus lowering boost, creating smoke, and causing the CAT to plug up even more. Do you guys think this is possible, and know of any way to make some checks w/o removing it?

 

Here's a screen shot of one my runs. Fortunately MAP and EBP are side by side to make for easy comparison.

 

I just noticed...my boost gauge must not be working too gut, it never reads above 26...

 

What are the readings key on engine off?

 

Mark, boost really doesn't look that bad. Your kicking above 30 which means boost was probably around 17 or 18 PSI, at least that is the way I read it.

My question is why is EBP so low? It should be at least the same as atmospheric boost, usually 3-4 PSI higher with the engine running.

 

Aha, you got caught up like I did at first. MAP and EBP are scaled different, you have to look at the numbers on the side there to see where it stands.

And...hmmm...you're right, that 30 would have to be reduced by about 14.2 to give boost but I do get boosts of 26 peak.

 

AH, ya got me on that one. Sorry for the confusion. Those graphs can be confusing for sure.

 

From the Ford manual...

EBP and Boost Tests.pdf

 

You need to set the scale factor on your FIPW to 10, then you will see accurate FIPW in ms.

Stock EBP should get over 20 PSI above BARO on a "proper" WOT run, and stock boost should sneak up on 18 PSI.