Boost Pressure Problem??

[BMH95]

So I just installed an Isspro 60 lb boost gauge, and am a little disturbed by what I'm seeing. I spent time replumbing the gauge, and putting new compression fittings, teflon tape, etc trying to ensure it wasn't my install that's the problem. I also tightened down all the intake hoses, and checked for boost leaks. I can't find anythign wrong with any of that. Here's the issue: I only see MAX quick spikes of 30 lbs before the waste gate opens, and then pressure settles back around 26 or so. It will typically not exceed 26-28 lbs under WOT, then the waste gate opens and settle down at 24-26 lbs. Would the waste gate be opening at that low of pressures? The reason for that question, is: Is my gauge reading low, and the map is reading 32ish and opening the waste gate like it's supposed to? Is there something wrong with my truck? If it only gets to 26 or 28 lbs under WOT, would it open the waste gate? I've also heard that boost foolers are supposed to hold the waste gate shut, and I should be seeing close to 40 lbs using one. I borrowed a boost fooler, and it will only get to 34 lbs with that on. I tried it just to test this problem - my truck is TOTALLY stock as far as the engine controls and such. I removed the intake baffles, and that's it - other than analog Isspro gauges and 285's. The truck is a 2005 with 56K on the clock.



Thanks for the input!

 

[RobertP]

where are you reading the boost pressure from? it doesnt sound like there is a problem with the numbers you are seeing.

 

[231jasonS]

those numbers sound correct for a stock application. But a box on it or put it under a heavy load towing and they will go up.



With a BDDL and no boost fooler my 04 would see about 34-32 WOT for a second or two. Stock it would spike at 29-30 for a second.

 

[mattymac]

Way back when my rig was stock I would see a spike of about 32 lbs then settle to about 26-28.

 

[BHolm]

Those numbers sound normal to me too. I found the only way it would sustain 30 psi was with a big load on. Otherwise mine would spike at 30 and drop to 26 when empty, no matter how hard I drove it.

 

[BMH95]

Interesting. I was wondering if the truck alone is just to light to make it sustain high boost readings. I'm going to be towing a 27ft Zinger from Northern IL to Estes Park at the end of the month, and I didn't want to find a problem ON the trip.



It's reading out of a boost bolt.



So I guess I don't need to jump off a bridge then?

 

[BHolm]

Interesting. I was wondering if the truck alone is just to light to make it sustain high boost readings. I'm going to be towing a 27ft Zinger from Northern IL to Estes Park at the end of the month, and I didn't want to find a problem ON the trip.



It's reading out of a boost bolt.



So I guess I don't need to jump off a bridge then?

Nope, I had the same concern when I first installed a boost gauge. If you are pulling against the wind in Nebraska, which is like always, it will sustain higher numbers pulling that trailer. With a 28' car enclosed hauler into the wind between CO and MN mine ran 30 psi for hours. When I got done with the trip I noticed a milage increase when empty too

 

[BMH95]

I'm kinda hoping for the same thing. I'm gonna work the snot out of it out there in the middle of Nebraska - aka "nowhere". It should have some work cut out for it, as I have a tonneau cover. That should be a good sail to load up the engine. There'll be no carbon in my motor after that round trip!



How was your fuel mileage while towing on that trip?