vdo boost gauge connection

[Mark Frietchen]

Where is the do I connect the boost gauge for accurate boost reading? I've got a VDO with a 9/16 male motor fitting.

 

[stickybones]

I just "T" into the factory boost line that runs from the vacuum block on top of the throttle body to the MAP sensor on the passenger side fender.

 

[Mark Frietchen]

Just spliced into the hard plastic line from the throttle body to MAP and took a test drive to see if it was working correctly. According to the new VDO boost gauge, the stock turbo was able to produce 20 psi on a partial throttle trip. I have an ATR knock detector that beeps when experiencing knock and it was beeping a bit. 20 psi seems way up there for an essentially stock car. Is this normal?

 

[stickybones]

Originally posted by Mark Frietchen
Is this normal?

I'd say no. Seems quite high for part throttle.

 

[Mark Frietchen]

Thanks for your other comments!
I've got an old ATR Pit Bull Chip and looks like the waste gate arm has some adjustment mechanism. I'm guessing I need to try and reduct the boost autill I can get the Knock under control. Where to start? Go back to stock chip? What Numbers should be on my turbo to ensure its the OEM unit?

 

[stickybones]

Yes, get your boost under control. If you have an adjustable wastegate rod (which sounds like you do based on your description), lenghten the rod to reduce boost.

The ATR pit bull chip I believe is pretty agressive for street tune (timing wise). Probably acceptable, but you'll have to turn your boost down probably below 15psi max if you're only running 93 octane gas. I don't think it matters what chip you're running. Need to get boost under control first. You should also check the three little vacuum lines controlling your boost for cracks. One line comes off your turbo compressor, one line comes off the wastegate actuator and the third line is on your boost solenoid (if you're still running with it). The 3 lines are connected together with a "Y" fitting. If these lines deteriorate and crack, it too can cause boost to run out of control.

Can't say about the stock turbo. I've upgraded to a TA49 years ago so I no longer have access to the stock turbo for reference. I believe if nothing else, it should say Garrett on it and will probably have a .63 marking on it too somewhere. Doesn't mean it's stock, but it's a sign it could be.