OK, got boost gauge is installed... pyro next on my list.

I don't want to babysit my boost gauge which depends on my attention to it, with my foot ready to come off the pedal, or twist the key off to kill engine. Why do this when I can hook up a control that does that all day long?

Anybody got answers about the best way of adding your own automated overboost control, as per previous post? ...on the wastegate, or on the intake manifold.

__________________
Cheers!
Scott McPhee

1987 300D

Use the stock overboost switch and a loud 12V buzzer from radioshack.

..not getting how a buzzer automatically reduces boost. This idea fits the babysitter solution list, analogous to the idiot light on the dash for check-engine. It might be good to have the boost gauge and the buzzer... to wake you up to look at the gauge to ..... take your foot off the pedal or shut off the key. Looking to automate this.. blowoff or wastegate?

__________________
Cheers!
Scott McPhee

1987 300D

This is no idiot light. When you hear how loud those buzzers are, they are impossible to ignore and you'll know there is a problem.

A blowoff is the last thing you want when overboosting the engine. The turbo is already spinning 155,000rpm loaded with pressurizing air, releasing that load will only make it spin faster. The risk of blowing a headgasket or cracking the head is peanuts compared to grenading the compressor wheel and feeding it to your engine.

Well if it's unanimous then that blow-off is not the solution, what about the other end and hooking up something to yank the wastegate open? Or hook up an auxiliary wastegate and just operate it separately. I haven't looked at the turbo plumbing to see if/who/where there'd be room to bore another hole in the exhaust prior to turbo.

__________________
Cheers!
Scott McPhee

1987 300D

Whats wrong with a buzzer? It costs $4 and 15 minutes to install.

Nothing, I like the idea, but it just requires an idiot like me sitting between it and what needs to be done next with the car. I wanted to take myself out of the equation.

Anybody play with wastegate controllers on a 87 300D? Don't know which turbo I've got KKK or Garrett, off hand.

I also wondered about the simple little push on plastic hose managing the stock wastegate actuator. Jeez... it's amazing that thing is trusted enough to do the job. I feel like scaling up the quality of materials and maybe putting hose clamps on the thing... I think it's just shoved on.

__________________
Cheers!
Scott McPhee

1987 300D

Another thought, rather than just a buzzer... Hook up the stock 1.2 bar switch to a vac switchover valve that applies suck to the stop solenoid... choke the car off. That should do it! Got all the parts.

But I want to explore the wastegate thing a bit too..

This is so not ALDA removal anymore... I'd be happy to take this conversation somewhere else.

__________________
Cheers!
Scott McPhee

1987 300D

The ideal setting is where there is no further improvement in off-the-line power. Beyond that point is useless. Typically this point results in a small puff of smoke when leaving a stop... not a cloud, and not a steady stream of smoke as the engine revs increase (the latter symptoms typically indicate it's too rich).

If you're not sure if it went too rich, lean it out a bit (half turn or so) and see if you can feel a power loss. Keep going leaner until you feel the power loss, then go 1/4 turn richer. That's pretty much the ideal setting. And then the whole question about overboost protection, etc is irrelevant.

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I recently replaced the head on my 603 and found the 15psi pressure sensor totally clogged. If I were to rely on the sensor, I would clean and test it. The EGR really makes a mess of the intake manifold.
Where did you mount your gauge?

You're right, we're trusting the orifice in that 1.2 bar sensor, I haven't looked to see the size of the pressure pad / opening. It should be cleaned and tested... after 20 years.

..I plugged the EGR with a thin shim plate, it was a leaky EGR valve so unplugging the vac line did not finish the deed. This helps reduce soot build up, and it sure smoothed out my cold starts not having bad in the mix from the get-go.

I mounted the gauge under my wiper arm, on its flexible tubing. Right beside the mityvac under the same wiper. I thought things were fine until a light mist came along and unthinkingly I used the wiper on instinct. Doh! When not in use, I tuck instruments in under the hood near the brake booster.

I'm still looking for the right boost gauge. I don't want this 2 5/8" monster whole in my dash, have of the gauge is "vac". I want a pure boost only gauge for diesels... then I'll get out a drill and find a spot. Although, a stack of pods up the A-piller might be the way to go. A little ricey, gotta be careful with that one.

__________________
Cheers!
Scott McPhee

1987 300D

Ya, I'm thinking the ALDA might work it's way on again, shimmed up, to keep the richness down. I don't want to crack the top off and twist the screw, I'd rather shim.. somewhere I saw a comparison of what one oil plug shim (same diameter and everything!) is equal to in turns-of-the-screw.

You're right, the ALDA is the correct overboost protection. Test that sensor, putting the overboost vac switchover back in, and its tubing, and making sure those tubes stay un-sooted.

__________________
Cheers!
Scott McPhee

1987 300D

As mentioned in the first post, 0.75mm equals one turn of the screw. Just measure the thickness of the shim. If you don't have a mic, a cheap caliper like this one also works well.




Here's a pic of my gauge setup - additional photos are located here.

Attached Thumbnails

 

Bringing this back from the dead.... quick question: with the ALDA installed stock, does flooring the throttle actually do anything? I cant start mine due to a leaky IP, Im thinking of removing the ALDA and flooring the throttle, then lots of cranking to get it running....
or does the ALDA only restrict fuel when the engine is already running?

The governor already "floors" the "throttle" when the pedal is depressed once prior to the start. The ALDA has no effect on this "flooring"..............

Clearly, you've got gassers on your mind.