Turbo Gauge On A Stock R33

[Trav33]

I hope this question isn't too silly...

I've got a 33 GTS-T which has the little gauge on the tacho from -7 to +7 x100mmHg. I believe this is mm of Mercury, or Torr's, where 1 Torr = 19e-3 psi. So 100 Torrs = 1.9 psi. So each 100mmHg on my gauge will be 1.9psi, meaning the gauge of -7 to +7 is actually -13.3 psi to +13.3 psi. Is this right?

Secondly,... the needle on my gauge sits at -7 at idle, and goes to 0 at max boost. Is this normal on a 33?

Thanks for any enlightening information you can share with me!

[sloazr33]

+7 x 100 mmHg [0 °C] = 13.535 psi

standard max boost = 7 psi

so at standard max boost your stock gauge should read approx +3.5 x 100 mmHg

the standard gauges are not really accurate

if your gauge is only reaching 0 when on boost something is not right

could be a dodgy gauge

[RANDY]

Yer... shouldn't be -7 at idle... That's vacuum. Should only see that when backing off hard or coasting downhill.

Does your car actually boost and work properly? If so, it just sounds like your guage isn't right. Could check the piping to the sensor for leaks. It sits against the firewall on the drivers side (under-bonnet). Has one pipe, and one electrical plug... small black box.

[mad082]

the needle shouldn't site at -7 at idle. it should be at about -5.

if you are boosting and it doesn't go above 0 then there could be a major leak, or the turbo is stuffed, like its missing the exhaust wheel.

[Trav33]

Ooops, it does sit about -4 or -5 on idle, so that is ok?

Will have to take it for another drive and look a bit more closely at the gauge under full throttle, maybe it goes above 0.