Maybe im just out of the loop. I cant even find a boost gauge that shows negative on google. Vacuum sure, negative PSI, nope. Or maybe its alien technology hahaha.

6.5inHG sounds awfully low. Even with not running things off of vacuum a healthy motor still creates it with the throttle closed. I think the numbers are just a placeholder for things to come.

Maybe it is a placeholder and they will change it when a ZR1-like version comes out.

I think you can make any boost gauge show -PSI if you connect the reference tube to something that reads both boost and vaccum. I'm using an AEM TruBoost, so that's pretty common. If you hook it up directly to the turbos then you only read boost. If you hook it up to the manifold it will read both boost and vaccum. We hooked mine up to the manifold because I installed a vacuum pump and it gave me an easy way to adjust the vaccum I was pulling without installing another gauge in my car. Once I got that dialed in I just left it like that.

I know you can get it to read vacuum. What im saying is that -12 is not a number you will see on a gauge reading just PSI. 12inHg maybe since its reading vacuum but not -12PSI. The "-" on your boost gauge is just there to show you that the gauge is reading vacuum now. So -15 on aem truboost gauge is saying you have 15inhg. The positive number is psi obviously. I have never delt with those directly but have been told thats how it functions. Since its just leds and does not actually say "PSI or inHg" on the gauge. If it really was reading -15psi that would be a very unhealthy engine with very little vacuum.

Which brings me back to why the C7 gauge says PSI but yet have a negative number. Its probably just a placeholder though ya.

It could also be a software thing for future. Why not use the same software for all models, even though there's no use for it in a NA car, a boost gauge could have a use in future vehicles.

Also what options did that car have? It looks like either a 2LT/3LT Z51 car with carbon fiber interior package.

Woo supercharged or turbo motor coming??

Possibly Z06 and ZR1 both going forced induction?

i hope the Z06 or ZR1 will be a revolution.
they should have DCT or at least Tapshift automatic in them.
the low volume sell of Z06 or Zr1 now because the lack of DCT or Auto..

What were his impressions?

Great pics. The boost gauge on the ZL1 is formatted the same way; reads vacuum in hg at idle and psi when in boost.

BTW - How does this site always get the cool pics first, hmmm?

Ya but what Im saying is that the one in the C7 does not read inHg. Its just PSI, which is not correct. Even if the -12 was supposed to stand for 12inHg thats pretty low vacuum.

Good point. I didn't see the negative by the lower 12. Mine start at 30 in hg and goes to 15 psi for boost. Though I did set up a pid in my scan tool to log boost (only in psi) and it shows a negative boost number in psi at idle even though it's technically not negative boost.

Ya I mean there is a formula to figure out what "negative" PSI would be in vacuum terms(inHg) but -12 is only like 5 or 6inHg. Its probably just there as a place holder for bigger things to come. Im just looking into it too much probably hahaha :smiling1:

-12 in hg converts to -40 kPa which is definitely not correct. You're probably right, it's probably there for another model. Perhaps the rumored twin turbo big brother motor for the top of the line C7?

OK, what do I need to do to have GM give me a prototype to test and drive??? Talk about hitting the lotto. I can test a car year round without any hint of snow or ice. Good pictures even if they are taken with a cell phone.

LMAO - I'll sacrifice myself and do some altitude testing as well if they need it. Maryland International Raceway (such a grand name for a dragstrip) has an elevation of a whopping 80' ASL :smiling1: It's only 80 miles from my front door and then I have Capitol Raceway outside the Beltway for verification ;) I will need to make multiple passes naturally, to validate the results....