GReddy boost pressure dial

[Dash Rendar]

Hi all

I'm afraid I'm quite new to the Supra scene and I don't know much about this stuff, so my apologies if this sounds stupid!

I have a GReddy boost pressure dial in my Supe. The dial shows 0 at the horizontal and goes up to 2.0kg/cm² moving clockwise round the dial. Moving anticlockwise from the horizontal, the dial shows up to 760mmHg.

The dial remains on the horizontal 0 when the turbos are spinning. When I let off and the BOV dumps, the needle moves clockwise and shows me the pressure. It never moves anticlockwise past the 0.

The thing is... a few years ago I had a Renault 11 Turbo. The boost gauge on that car showed boost *while* the turbo was engaged, not when I let off.

But this gauge is doing the opposite.

Is that correct, or has it been installed incorrectly?

[SimonB]

Nope, definitely wrong! You should get negative boost while at idle and positive while the turbos are producing boost. How it's been installed so it only works on lift off I don't know! It should be plumbed in to one of the hoses on the intake side, see www.mkiv.com technical articles for a fitting guide.

[Dash Rendar]

Thanks for that.

[Dash Rendar]

FYI, a friend of mine reckons that for the dial to behaving this way, it must have been rigged to the dump valve hose instead of where it should be.

[Ian C]

Sounds plausible.

A search on here will show up a few discussions and piccies of boost gauge plumbing locations :)

-Ian