Stock Skyline Boost Guage

[ossie_21]

I have a 33 gtst, don't have a a/m boost guage as yet, but I just had a question about the stock one in the dash. The psi readings are +7, 0 & -7, and under normal conditions (cruising 100kph in 5th) it sits at about what I would say is -4.

It dosen't go above 0 very much unless I hit full boost in 2nd or 3rd, and even then it gets to maybe +4 or 5. I was just wondering if this is normal, because the fuel economy seems a bit too good for a turbo car & I am wondering if maybe it has been tuned to a lower boost level.

Any help will be appreciated.

[WazR32GTSt]

firstly, why do you say "i don't have an aftermarket gauge yet"? you don't need an aftermarket gauge.. the stock one works fine. its just hard to read, that's all...

now to your problem: the gauge does NOT read in psi, it reads in mmHg

how does this convert to psi?

well +7 on your gauge equates to approximately 14psi.. so in your car you would expect to see full boost as +3.5 uness the boost has been turned up, or the car modified eg with an exhaust

and lastly, if you aren't under acceleration then you don't have a positive manifold pressure, and so that is why you don't see boost in cruise

The good news?

Everything you described is perfectly normal for an unmodified R33!

cheers,

Warren.

[R33S2]

As he said

[ossie_21]

Thanks for that Warren, I couldn't see anything that says what reading it was but knowing skyline is 7psi I just assumed that. I will be getting an aftermarket one that will be easier & in a better place to read when I get a ebc, but at least I know what's going on now. Cheers.

edit - I typed this at 3:30 am, there is the mm/hg reading but I had no idea what it stood for.

[WazR32GTSt]

no worries

[gts25t4door]

My stock boost guage is in 100 x HG not PSI. That way when the needle reaches the 3.5 mark it is actually about 6-7 psi. If that helps