This weekend I had to make a fast trip to Chicago area. I noticed when running at 70 my boost pressure was running about 9-10 Lbs. Is this normal boost on flat road at cruise?<br>Chuck

 

Its about right if your on flat land about 70-75 MPH with out a load.

 

Mine runs with about 5 to 8 psi on flat freeway no headwind. With the 3000# slide in camper it runs with about 10 to 14 psi.<br><br>Did you have a headwind?

 

That sounds a tad high to me too.... <br>At that speed I'd see about 4-6 psi steady boost. Have you got any restrictions in the air in/air out system??<br>Is your tranny slipping causing you to need more throttle than should be?<br>Bob.

 

I agree withthe 4-6# with no headwind. Pulling my 29' Airstream, the boost is still less than 10 most of the time.<br>george

 

There was no headwind I noticed. The only change I made to the intake system is I replaced my BHAF with a MHAF (AH1141). <br>Chuck

 

Part of the answer may be that you have a smaller exhaust housing than me, you have a tight TC/shiftkit as well. <br>For each housing you go up in size you have roughly 2psi less boost for given fueling. So, you may not be that far off with the mods you've done and the turbo your running. How's your EGT's? Mileage? Anything out of the ordinary??<br>Otherwise, you may be about were you should be with your setup/fueling/turbo/load/speed etc.<br><br>bob.

 

I too run about 9-10 psi remember also that a boost guage isa mechnical device and mechanical devices are not always 100% accurate. I'm not saying that your boost guage is unreliable but even most speedometers are off by a mph or two. ;D ;D ;D