For a project which adds absolutely no performance to the car whatsoever (just allows you to see whats going on), there is a major MAJOR amount of work needed to set these pesky things up. Alot of it due to the design of the W116 itself. Lets just say this is a one-off, and anyone contemplating the same upgrade should save themselves the headaches below and install them in the cabin like a normal hoon.
1. The W116 scuttle panel doesn't lend itself to mounting external gauges. Ideally you want them directly in front of the instrument cluster which would mount two on the chrome trim covering the wiper motor.
To achieve this:
I had to make this:
(on another angle):
It doesn't look straight but its straight relative to the driver, and the reason it looks crooked is due to the curvature in the scuttle area.
Here's a shot with the cup-straps on:
I chose VAC (because as a born tuner, I like vacuum gauges), Oil Temp, and Fuel Pressure. ALL race cars should have a fuel pressure gauge, even if you omit everything else. The strong Aussie dollar meant that I was able to buy these expensive AutoMeter Sport-Comps from a stockist in the USA, including freight for $200 less than it would cost to buy locally. In addition to the three gauges, I also needed 3 chrome gauge cups and a braided fuel hose.
Gauges mounted:
and wired up:
At this point we're only about 1/2 way. To install the oil temp sensor, you need to remove the lower sump. I did that previously and installed the temp sensor at the time, however if you were installing the sensor its a disgusting job which requires an expensive sump gasket, new oil, mess everywhere.
To install the fuel pressure gauge I needed a brass T-piece to put in the fuel line, but the rest of the hardware comes with the A-M fuel hose kit. Don't forget the teflon tape. I did, because I'd mislaid my teflon tape and the thing leaked, so I had to stop being lazy and go buy some.
The Vac gauge I just piped it directly into the hose coming from the intake manifold that normally operates the central locking/heater. Since I don't care for either it worked fine.
2. NOW THE BIG DRAMA... one the guages are in place you can't open the bonnet! Thats because the trailing edge of the bonnet enters the area which the gauges now inhabit! I thought for a while and the only solution which had any merit (to me) was to cut a gap in the trailing edge of the bonnet to clear the gauges when the bonnet it open.
The ploy works:
But admittedly this solution isn't for everyone, and naturally this car lives in a garage and is not exposed to the elements often.
Finished job and the race car taking shape:
Do they work? Oh yes... here's the video... its only short because no sooner had I started the engine that my camera ran out of memory, but you get the idea: http://www.youtube.com/watch?v=RUG24xvYiBQ
You see the fuel pressure rise when you hear the D-jet fuel pump prime, and when the engine start the vacuums reaches 17 inches when the car is fully warmed up and idling in Reverse or Drive. Oil temp there's not much to see as yet. My car is fitted with the oil cooler and since its working properly, the oil temp for normal Melbourne winter driving it probably sits around 65C. Since the oil temp gauge starts at 60C I've bearly seen it move. It will be a different case racing in summer on a 35 degree day.
Any questions (other than costs), I'm all ears and more than willing to answer.
I.
1. The W116 scuttle panel doesn't lend itself to mounting external gauges. Ideally you want them directly in front of the instrument cluster which would mount two on the chrome trim covering the wiper motor.
To achieve this:

I had to make this:

(on another angle):

It doesn't look straight but its straight relative to the driver, and the reason it looks crooked is due to the curvature in the scuttle area.
Here's a shot with the cup-straps on:

I chose VAC (because as a born tuner, I like vacuum gauges), Oil Temp, and Fuel Pressure. ALL race cars should have a fuel pressure gauge, even if you omit everything else. The strong Aussie dollar meant that I was able to buy these expensive AutoMeter Sport-Comps from a stockist in the USA, including freight for $200 less than it would cost to buy locally. In addition to the three gauges, I also needed 3 chrome gauge cups and a braided fuel hose.
Gauges mounted:

and wired up:

At this point we're only about 1/2 way. To install the oil temp sensor, you need to remove the lower sump. I did that previously and installed the temp sensor at the time, however if you were installing the sensor its a disgusting job which requires an expensive sump gasket, new oil, mess everywhere.
To install the fuel pressure gauge I needed a brass T-piece to put in the fuel line, but the rest of the hardware comes with the A-M fuel hose kit. Don't forget the teflon tape. I did, because I'd mislaid my teflon tape and the thing leaked, so I had to stop being lazy and go buy some.
The Vac gauge I just piped it directly into the hose coming from the intake manifold that normally operates the central locking/heater. Since I don't care for either it worked fine.
2. NOW THE BIG DRAMA... one the guages are in place you can't open the bonnet! Thats because the trailing edge of the bonnet enters the area which the gauges now inhabit! I thought for a while and the only solution which had any merit (to me) was to cut a gap in the trailing edge of the bonnet to clear the gauges when the bonnet it open.
The ploy works:

But admittedly this solution isn't for everyone, and naturally this car lives in a garage and is not exposed to the elements often.
Finished job and the race car taking shape:

Do they work? Oh yes... here's the video... its only short because no sooner had I started the engine that my camera ran out of memory, but you get the idea: http://www.youtube.com/watch?v=RUG24xvYiBQ
You see the fuel pressure rise when you hear the D-jet fuel pump prime, and when the engine start the vacuums reaches 17 inches when the car is fully warmed up and idling in Reverse or Drive. Oil temp there's not much to see as yet. My car is fitted with the oil cooler and since its working properly, the oil temp for normal Melbourne winter driving it probably sits around 65C. Since the oil temp gauge starts at 60C I've bearly seen it move. It will be a different case racing in summer on a 35 degree day.
Any questions (other than costs), I'm all ears and more than willing to answer.
I.