Curious to understand the purpose and functionality of the red needle. I am about to pick up an '88 930 that has this in place of the clock.

Thanks!

 

The red needle is a pointer to show the highest level of boost achieved - it should be able to be moved back to -0-. When the boost needle swings up, it pushes the red needle with it so you can see how high it went. These are usually used along with an adjustable boost control, thus you can change your setting to what you want.

 

Great. Thanks

 

Hey Dave,
My partner in TrackVision has one of these in his 930-based GT1-R car. Neither of us can figure out how to reset the red marker before a run. Dumb question, but would be helpful if you happen to know.

 

If you look at the center of the gauge there is a triangular shaped reset that uses a key that came with the gauge to reset it.

 

The key may have come with the gauge, but it sure didn't come with the car. Guess we'll need to find one from a VDO source.
Thanks!

 

Tony,
Before you fork out like 40$ for that key, there is an alternative solution:
You take an aluminium pop rivet, remove the center rod, then put the rivet in your electric drill's mandrel. Then you tighten with the mandrel key, hard. The 3 indents will make a perfect triangular shape for that VDO gauge center.
I have done that for my 2 same gauges, works a treat.

 

You would think that VDO would have just designed the gauge so that there was a manual adjustment attached to the center axis...

 

Don't even use the stupid thing, it will load down the needle and give you a false reading.

 

We have one at the shop. It's a very smart looking gauge.

 

I bought a replacement key from North Hollywood Speedometer.

 

Brent, yours is misadjusted. YOu can play with the resistance of the telltale needle if you take it apart. On mine the needle goes to the same level when I take the telltale over at 2 bars.

 

That's cool, didn't know that but I have since sold it for what I believe is a better responding one and to monitor EGT's.

 

I had the same question with the same gauge in my '82 935 DP, and wasn't sure what the red needle was or how it worked. For a while, I thought it represented the setting from the manual boost **** between the seats, and I thought it was broken because it wasn't changing with the **** twiddling.

Thanks for the info!

 

FYI, just talking to North Hollywood Speedometer (http://www.nhspeedometer.com) and they're shipping up my new key as we speak. $20, and sent in regular mail.

I'd spend more than that just driving to the Home Depot to buy some rivets to try and build a replacement! Great tip, by the way.