Jump to content
SAU Community

Recommended Posts

]mines actually on +5 on idle...(auto) and jumps to 20 when i rev out its a mechanical cobalt series boost/vac gauge i just tap'd it into the line at the front of the manifold like described in a step by step posted on here i know its wrong coz my stock gauge sits in the - and jumps accordingly.. post-84025-0-70170300-1306822304_thumb.jpg

Edited by nismo07

any idea's?

Hmm, not sure. I've always tapped boost gauges directly off the plenum itself. Never really tried to tee it off an existing line. It definitely should be reading somewhere in the negatives on idle though.

Edited by GT32

Hmm, not sure. I've always tapped boost gauges directly off the plenum itself. Never really tried to tee it off an existing line. It definitely should be reading somewhere in the negatives on idle though.

Was thinking maby trying it at the rear where the stock line goes in from the little box right near the brake booster? if i was to pull that off and run the gauge straight in be fine right? doesnt matter if i disconnect the stock gauge at all does it??

Hmm, you could be right. Possibly a faulty gauge. I used to have an Omori boost gauge on my old 32. The gauge looked ancient! Was a mechanical type and I remember it was always 1-2psi out. When I had the car dynoed a few years ago, their dyno chart always displayed 1-2psi higher than what the boost gauge in the cabin displayed. It was probably due to wear and tear though. Is the gauge you're using brand new or second hand?

Hmm, you could be right. Possibly a faulty gauge. I used to have an Omori boost gauge on my old 32. The gauge looked ancient! Was a mechanical type and I remember it was always 1-2psi out. When I had the car dynoed a few years ago, their dyno chart always displayed 1-2psi higher than what the boost gauge in the cabin displayed. It was probably due to wear and tear though. Is the gauge you're using brand new or second hand?

Brand new from autobarn was a cobalt autometer so thought it was quality rofl...

Hmm, could be faulty. Bring it back and exchange it for another one to see if it still does the same thing. I'm not even gonna bother using a conventional boost gauge this time around in my new car. Once my AVC-R goes in then I'll just rely on that from now on to show me how much boost I'm running. :).

also shouldnt the gauge reset to 0 when the ignition is off? it sits on 15+ ??

Sorry, didn't see this. Yes it should revert back to +-0 when the ignition is off. If it sits on +15 then there definitely is a problem lol.

definitely was the gauge lol... funny on the phone to them were trying to blame installation but once they actually looked at it they said "yea its stuffed"... lol dont know how it could be my fault when the needle resets to +15psi and wont go below 5+ anyways yea overnight delivery :)

kool on another note what should the boost be reading on idle?? -7 like the stock gauge?

Different units, the stock gauge reads in mmHg x100 for both positive & negative pressure.

Most aftermarket boost gauge will read in inHg for negative & either PSI or Bar for positive pressure.

15 - 20 inHg is the norm for idling pressure with the car stationary, anything lower than 15 inHg & you may have a leak somewhere.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Looking at the photos, you could easily just drop this pipe and dump into atmosphere  Just 1 or 2 quick hits for data acquisition - if have a heat shield material and/or sheet metal, maybe just use wire/metal cable ties and attach it in a way to deflect heat from melting nearby wires.  
    • 2025 PRP GTR Festival - A Massive Thank You from SAU NSW! On behalf of SAU NSW, I want to extend a huge thank you to our incredible committee for all the hard work and dedication behind the scenes. You are the engine that keeps this club running smoothly! (hopefully an RB lol馃槅) To all our amazing volunteers who helped make the GTR Festival Sydney such a success, thank you for giving your time, energy and sacrificing your weekend sleep-ins. Your efforts did not go unnoticed and were absolutely appreciated by everyone. We also want to give a big shoutout to the workshops, trade stalls, and the awesome VIP's we connected with over the weekend. Your support means the world to us, and we鈥檙e so proud to be part of such a passionate automotive scene. We are looking forward to collaborating with you at our future events.  SAU NSW had our marquee up for two full days at GTR Festival, packed with merchandise, a sizzling members BBQ, and a chance to chat with the committee, sign up, and check out some hot Skylines on display from our members. It was incredible seeing so many smiles and genuine conversations, that's what we're all about! SAU NSW is more than just a car club... we鈥檙e building a community where you can make friends, share stories, and talk about anything RB related or not. 馃摳 Please post any cool pics you took at the GTR Festival in this thread! 馃摳 To our current members, thank you for your ongoing loyalty, and to all our new members... welcome to the family! We鈥檙e beyond excited to have you on board! Please ensure you are involved as much as possible within the club, and make the most of our exciting upcoming events. Here鈥檚 to more future events, thrilling drives, chill meets and good feeds! Let鈥檚 keep building something special. 馃挭馃殫馃挩 Matt Zoumpoulis, President SAU NSW
    • Yes, well, keep in mind that the air is intake air, which equal boost + possible oil. If there is a fine deposition of oil/scunge that then gets hot and carbonises, it could look just like that. Probably shouldn't be leaking. Might just be normal for that product. Hard to know if it is relevant.
    • Wrapped up putting the motor back in today. I have a stainless flex turbo drain pipe like you see on cummins and that funny enough PRP started selling. I generally prefer these but sadly they come with a finite amount of times they can be bent before they snap. Took well over a week for a replacement to arrive.  I was able to prime the pump but I will more then likely wait until next friday to take it on its madden voyage. I also installed the nozzles for my direct port WMI setup but plugged the nozzle holders for now. I'll tube it with Swagelok SS tubing and fittings next chance I get. No rush, i'll be breaking it for a week or two anyways. 
    • I could definitely do some logs without the VCT enabled for sure. I believe we tried it on the dyno and it still spiked but wouldn't hurt to try again and have the logs    I might be able to use some metal cable ties and hold the gate open entirely, I'd need to see about that one.   What do we think about these marks on the cap of the actuator? This is where the two parts push together where the diaphragm spring is. To me they look like air has been sleeping past?? Specifically talking about those black stains above the lower rim/lip. They can be rubbed away as if it's just an exhaust stain.  
  • Create New...