Also while you are under the hood check the mapp line
for restriction or leak.

Bill

 

Pray it is a mapp line or intake leak. You will have to remove the turbo to replace the exhaust donuts on the up pipe. Its a PITA.

 

but a 5psi drop is alot for a donut leak, if it was a donut he should hear it in the cab and/or see lots of soot. as madvan said, check the map line, and if thats ok try unplugging it and driving the truck with the map sensor wire unplugged.

 

ok no abnormal sounds, and definately no soot, so i'm pretty sure it's not exhaust. I rechecked all of my connections and found a cracked piece on the tee setup. so i fixed that, and now i'm back to seeing 15 psi, and the power i had lost is back.
So is 15 psi still too abnormal? or am i not the only one with a stock truck that peaks there?

 

15 psi is good.

Bill

 

thanks bill.
I have heard as much as 18-20 stock, but at 15 psi it runs great so i'm under the impression that it's fine.
6637 got here today. how much boost should that add???
Thanks guys! your help is invaluable.

 

I was cruising down the road yesterday and here are my numbers how do you guys compare?

75mph, 2500Rpm, 800-900egt, boost at6psi, I have got my boost up to 15 before but not often.

 

That's about what i'm looking at, only more like 3-4 psi. but i'm stock other than the gauges.

 

Splitshot motors will build more boost than singleshot. (oem tune).
Average is about 13 psi.

Bill

 

Average for single shots? wow. that makes me feel a little better about the 15 i'm seeing.

 

the official ford spec for our psd's is "12 psi minimum" the avg that i always see on stockish trucks is 14-15 psi, i have seen them get up to 17 and 18 on 49 state trucks but not too often.

 

oh, and the 6637 wont add any boost unless your cuurent filter is plugged up. lol. what you will get is more turbo noise and the awesome "wastegate" sound under de-pressure

 

this video has poor quality but its taken with my digital camera while driving... on the gauge you can see an inner set of numbers in red, the first line is 10 psi and the second line is 20 psi.

YouTube - 1800-limiter boost levels