Yep it's meant to show higher pressure under higher load generally, that was the gist I got from reading earlier pages of the thread anyway.

I've solved my jittery pressure gauge by earthing it properly also, just used a plumbing earthing strip to wrap around the T-piece in the end.

 

Finally got my gauges fitted (by a local Subaru specialist) and after a bit of a search I'm pretty sure that there's something wrong with the boost gauge.

With the engine turned off the needle sits at about -15inHg (shouldn't it be on zero?), at idle it drops off the scale (beyond -30inHg) and at full boost in 5th it tops out at about 7psi.

My car is a pretty much standard (apart from exhaust and filter) UK spec MY99. Can anyone please confirm that this is not normal?

Could it be something as simple as the needle position needing adjusting? (don't know if this is possible but it reads lower than I'd expect in all situations) or is it more likely to be dodgy fitting?

Here's a pic of how it's connected under the bonnet:

 

Hmm ive got a MY00 uk turbo and fitted mine by unplugging the little rubber nipple to the right of where it is at the moment.This way i didnt need to use the t plug at all.

I do like what they done with your oil temp guage though, nice positioning compared to mine

 

Not sure why they didn't do it that way - what sort of readings do you see on your gauge with engine off, at idle etc.??

 

Expected boost gauge readings anyone?

 

Gauge should be at zero hen engine not running

 

0 when engine not running, About -ve 10psi on overrun, +ve on boost up to your boost limit (11+ psi depending on spec)

 

Thanks for the replies fellas.

 

Does anyone know if its possible to adjust the zero position of the needle on the boost gauge?

Don't want to take it apart only to find I've wasted my time.

 

Yeah you should be able to on all guages, on the back just remove the little sticker and theres a potentiometer to adjust it with.

 

SWPT, you have no choise but to open the case up. Mine was the same as yours, sitting on the 5inHg at rest. You will either have to cut the case all the way round about 19mm from the end or remove the bezal on the front. When your in there undo the three nuts on the back & the inards will fall out.
Have a look on the rear & you will see a half round brass tube about 32mm diameter, at one end its connected to a square block, at the other end theirs a little brass tag solderd to it, the tag has a kink in it like a dogs hinde leg, you will have to very carefully open or close the kinky bit make the needle sit on the zero mark. Mine now sits on zero, full boost is 14psi, on overun its 30inHg & tickover it shows 20inHg.Hope its of some use,

cheers Plym51

 

Thanks for that Plym51 - will give it a go.

 

Sorry to resurrect the thread but after finally sorting my boost gauge the oil pressure sender has now died!

Does anyone know what sort of sender is used and where I can get a suitable replacement? (apart from Xyberautos)