First Experiences with a Boost Gauge

[AndyL]

I installed my boost gauges today. I wasn't confortable tapping a new hole in the intake so I tee'ed off the Air Inlet Temperature sensor(prety sure that what it was, towards the drivers side of the MAP sensor) and installed it there.

My boost seemed to wander all over the place, usually from about 5 to 11 PSI while at 100% throttle, towards 11 PSI when in top gear with the converter locked. I also did a quick break torque and the boost spiked to about 14 PSI.

Is all of this normal? How about my placement?

Thanks, Andy.

[James Schaack]

andy,

i also recently installed a boost gauge on my '93 and i get the same readings. cruising at highway speeds i stay at a constant 5psi, and i will spike to about 11psi when i lay the pedal down. i am also curious if these are normal readings. i currently have 2.5" exhaust, how much increase in boost could i expect w/ 3" exhaust no muffler or cat?

thanks,

james

[pannhead]

AIT sensor should stay in the hole by itself,the tip should be in the air stream for it to be accurate...dont know for sure if its a HUGE deal or not though or if its relevent

[gmctd]

Intake Air Temperature (IAT) sensor must be in air stream for correct PCM measurement of compressed air temps.
Pcm pulls boost first, then fuel when IAT becomes excessive at higher boost levels.
Boost temps can rise dangerously even at lower levels under sustained demand, such as towing.
Moving sensor out of factory location can result in burned pistons, siezed engine.

It is important even if vehicle has charge air cooler (intercooler) installed.

Both of your boost levels are normal in these cooler Fall temps.

[ 12-12-2003, 03:47 AM: Message edited by: gmctd ]

[rjschoolcraft]

To install the pressure tap, remove the upper intake manifold. Usually, the kits come with an adapter that has 1/8" NPT thread. Drill and tap for that. Be sure to clean all machining debris out before reinstalling. It is really quite easy.

[AndyL]

Is there a gasket between the upper and lower intake pieces?

[gmctd]

Factory installed paper gasket will tear - you'll need another.
I used grey RTV on both surfaces to prevent tearing while I was experimenting.

[BuffaloGuy]

Hey GMCTD I checked out your link. Cool truck! What did you use for an intake air temp. gauge? I've got an old stewart warner oil temp gauge. The kind with the bulb and the cable and I'm thinking of drilling and tapping my pleneum with it. Should work, don't you think?
Ken

[gmctd]

Thanks, Buffalo.

I used the Isspro 100 - 280 deg oil temp gage. Machined the end off the brass probe to expose the sensing element which greatly improved response time.

The mechanical temp gage should work, but response time will be very slow.
Oil temps do not change quickly - I wanted to see rapid changes that actual intake air temps would respond to.