VDO boost gauge vs stock

[Swede2]

Hi!

I did go out in the garage today to fix my leaky VDO gauge. I found the leak, and now it works ok.

But... there is some difference between the stock and VDO gauge.

I have connected the VDO to the FP vacum hose line. Up to 10-15 psi both gauges read the same. But then the stock gauge turns up to 20 psi, and the VDO is just on 18... Is this normal and in that case wich gauge shall I trust ?

Daniel

 

[Razor]

VDO

 

[Swede2]

So I just run 18 psi now... and with about 2 KR... I think I have to start use your alky kit Julio, hehe. Can the difference be because the gauges are connected to different places ?

Btw, Andreas sent me his MSD50:s... they will be here tomorrow Monday I guess.

Then I will get a chip at Eric. Will be fun to see what times I can acomplish.

Daniel

 

[Razor]

What you turned it off?

Ohh boy.

See when you put the alky kit on you were instructed to remove an adapter between the harness and the 3 bar MAP sensor. This will throw the factory guage off, but allow the 3 bar sensor to adjust up to 29.4 PSI. With the factory plug, the 3 bar could only adjust to about 25 PSI. If you put that plug back on, the TTA guage should match the VDO. Unless the 3 bar sensor is off in calibration, factory guage is off.. or VDO is off. Either way if the car runs clean.. make it as fast as possible at whatever boost level your at without detonation.

I never use my factory boost guage. Its been getting pinned for years now. My buddy always said my car only ran 20 PSI cuase thats how high my boost guage read.

Needle is bad I tell em..