I just installed the Stewart Warner electronic oil pressure and egt (didn't have time to mount the probe) and mechanical boost gauges. I just have some concerns/questions about the readings (and yes I did searches but just about everything is in metric).

The boost gauge peaks at about 21-22 psi and tapers to about 17-18 psi (I have the Buschur 3" Turboback and so I believe that is why it is higher than the factory 19 psi) and then reads 20 in Hg at idle and 28-29 in Hg under cruising speeds. This is all normal right?

My oil pressure gauge is what gets me. It idles at 20-30 psi, cruises around 60 psi, when driven hard its about 80-90 psi, it drops and comes back between shifts, and flucuates if you are in neutral and rev it up. Is this normal? I though oil pressure was supposed to be pretty constant.

I had two sets of instructions for it. One from the vendor (42DraftDesigns) and one that came with the gauge. The directions from the vendor say to just ground the gauge where you are grouding the others and the ones from SW say to run it to a ground on the engine.

I can't see there being a giant drop in potential between these grounds where it would interfer with the gauge. I have a grounding kit and according to my digital voltmeter, I get a more constant and higher voltage now so the ground I have should be pretty good and equal throughout the car. Should I run a ground to the engine for the oil pressure gauge? Where did everyone else ground their gauges? Thanks for your help guys.

 

no worries man. you are ok.

 

i have the same set up also.my oil pressure was going crazy at one point also.check,and tighten the sender again.it works fine for me now.idle 20,goes to 60,step on gas,it goes to 80-90.do you have a mbc?if not,it will spike to 21-22 with the turboback exhaust on.

 

thanks for the help guys. should i tighten the sender itself (cause its pretty tight already) or the nuts that hold the crimp rings onto the sender bolts (at the sender and the gauge)? should i even bother trying to see if running a ground to the motor will work more accurately? also, i've got a walbaro fuel pump waiting to go in. as soon as that goes in, i'll be getting an XEDE to control boost. oh and one last thing. what method/technique did you guys use to mount the egt probe? i'm planning on mounting it on the number 2 runner because it gives clearance for my cusco ss manifold cover. i'm also planning on drilling the hole with the manifold still on the car because its a ton of work to remove the manifold just to drill one hole.

 

tighten the nut,not the sender.don't bother with the ground,it should be good.
my egt is in #2 about 2 inchs away from the head.i have to cut out a little of my manifold cover.just drill/tap it on the car.i did it that way also