Speedster fuel gauges

The fuel gauge sender used by most Porshce replica builders is the stock VW unit, VDO part No.221-012 or 1-551-001-209D. Unfortunately the Brazilian VDO replica temp/fuel combo gauge's fuel gauge is not built to match this sender's impedance (sender is 180 ohms empty, open at full).

With the Brazilian gauge and VW sender you usually get readings of full for a L O N G time and then the fuel gauge needle drops like a stone to empty; at least that's the way my "D" gauge works.

I found all of this out while having some custom gauges made by Palo Alto Speedometer (North Hollywood Speedo is also good) for my new IM Speedster. So, if you have the same fuel gauge problem, you can send your Brazilian combo gauge to north Hollywood or Palo Alto Speedometer and have them replace the coil in the fuel gauge to match the sender.

George, as you know my IM '55 will be completed about the same time as yours. I was wondering if Henry has addressed this issue with his more recent instrumentation installations.

Scott, you'll have to ask Henry, but I doubt it. I think he just builds them with the available parts. Whey not call Henry and ask him to send your Brazilian gauge to Palo Alto or North Hollywood for modification before it gets installed?

My experiance with the sender from VS is that it doesn't read the tanks capacity. The tank in the VS is angled down, the tank used in the Beetle is flat. Because of these angle differences the sender has to travel further in the VS to read correctly. This causes the sender to read empty when the tank has a couple of gallons left.

If you want more fuel capacity out of your VS simply pull the sender out and adjust the rod to get it to read right. It will take some time but I can tell you it's worth it as now it takes me nine gallons to fill up. My wife still needs a rest stop at five gallons left though!

J-P

Jean-Paul, Henry at IM told me he adjusts the senders such that they read empty with one gallon reserve. The problem is that the coil in the Brazilian VDO replica gauge is wound to a diiferent impedance than the VW sender (which is 180 ohms), so even with the float arm adjusted to the tank, the gauge tends to read much higher for a long period of time and then drop quickly. Different cars may or may not have this problem depending on the sender and gauge used.

Your probably right about that, even though my sender now sits correct in the tank (so I think) the fuel reads full for a long time then dumps to E in sixty miles or so. One thing to think about though is that since the tank sits at an angle and since the sender is located in the middle of the tank then sender can only read what's in the the middle of the tank unless adjusted.

If Henry adjusts the rod so that the bob can dip down the the front bottom of the tank (bob can register almost empty) then when the tank is filled the sender bob hits the top front of the tank thus limiting the bobs travel. With this limitation of the angled tank the bob can only read where it's positioned. Bassically the bob will read full when only half filled. This is only my experiance with the VS, your IM may be different.

I'm just happy that the car let's me know when it's close to empty.

J-p

I thought about the arc of travel... may have to modify the assembly so that the float traverses at an angle from the high point to the low point.

If you find out how let me know.

J-P