300E economy gauge for 300D
 

Anyone done any mods with a economy gauge from a 300E for a W124 300D (or SE to SD)?? Would like to modify one as either a boost gauge or economy gauge.

Boost guages are cheap enough............but I have heard soembody here did that.........but don't remember which member.

Sixto did it for a W126. Search threads under his name for the details. I'm not sure if it ever got finalized, however.

Just did it the other day on my '87 TD. Reads from 5-15 psi between the posts. No increments, but the red zone begins at ~10psi. The car is still up on blocks receiving an intercooler among other maintenance items, but the mod has been completed, so I'll report how well it performs later. I used the bourdon tube assembly from an '89 300E and the gauge face from an '86 190E 2.3 (no "Premium Unleaded Fuel Only" script). I have no intention of tweaking the boost level beyone stock, but may use the boost controller to maintain proper pressure at the manifold to compensate for losses through IC/plumbing.

I installed a bourdon unit in my OE cluster several months ago. Involves drilling 2 holes at existing marks in pressure cluster to allow needle base to pass through. Needle swings CCW between 9:00 and 3:30 o'clock for 0-13 lbs. of boost (checked with another boost gauge). Unit has two attachment bolts that pass thru to back for nuts to fasten. Boost hose extends from unused fitting of intake manifold through rubber vacuum hose manifold on firewall to interior behind instrument cluster. Once you aquire the donor and take it apart, it's quite a simple and gratifying project.