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  #1  
Old 06-25-2018, 01:26 PM
monkeh monkeh is offline
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Default Removing the overboost indication and EGR

Got a 940 d24tic on its way, Its got EGR. I have a non EGR manifold, and intake Tee piece, but I understand it all ties into the overboost valve? I intend on elevating boost with a manual boost controller at one point so I would like to make it ready for boosting. Do I also need to set up the wastegate?
Ive had 2 years off from the forum/d24's in general so my knowledge is a little rusty.
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Old 06-25-2018, 09:59 PM
ngoma ngoma is offline
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Not familiar with the D24tic EGR plumbing, but I removed all the EGR pieces from my D24t. All the narrow vacuum line and microswitch pieces were easy, then made two crude blockoff plates for the intake and exhaust manifolds.
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Old 06-27-2018, 01:57 PM
monkeh monkeh is offline
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What is the purpose of the microswitch? I can replace the manifold with a non egr version, I have a spare and same with the tee piece for the inlet.
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Old 06-27-2018, 03:47 PM
v8volvo v8volvo is offline
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There appears to be an overboost pressure relief valve in the front of the intake manifold on the TIC motors similar to the non IC TD motors. This is probably the piece you are referring to?

The purpose of the microswitch is to turn on the warning light on the instrument panel if that valve is opened by excessive boost pressure, since it assumes if this happens the turbo wastegate or its hose have failed and the engine might be threatened. Increasing the boost with a manual controller should push that valve open and trigger the light when the blowoff valve set to its stock opening pressure. But, you can adjust the screw in the valve to increase the spring preload and the raise valve opening pressure. This should enable you to keep the valve shut and the light off at higher boost pressures, as long as you have a gauge so you know what's going on.

You could also plug or eliminate the relief valve if you decide to run boost pressures high enough that even with the screw turned all the way in it's still blowing off air and turning on the light. But the screw adjustment gives you enough range to run up to around 15-17 psi and the stock turbo and intercooler are close to their limits by that point anyway, so depending on your plans it might give you enough range unless you are going to do other upgrades.

Look forward to hearing how it goes and seeing some photos, those late IC motors are always fun for us to see.
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Old 06-28-2018, 02:06 PM
ngoma ngoma is offline
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The microswitch I was talking about was the one on the throttle arm bracketry.
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Old 06-30-2018, 09:17 AM
v8volvo v8volvo is offline
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My mistake. Since the OP mentioned the overboost valve I assumed his question referred to the valve position switch inside it. I overlooked your mention of the throttle switch in the previous post.

To avoid any confusion, on the overboost valve the bottom line is you can try leaving it in place and adjusting its opening pressure as much as it permits, that should allow for some boost pressure increase without it bleeding off some of your intake air. If you end up going for a boost pressure beyond what it can handle, you will know because you'll hear it pop open and see the dash light, and then you can disable it through a few different methods.

As for the idle microswitch and other EGR-related electrical and vacuum components on the IP, those are the primitive control system for the EGR that regulate under what conditions EGR is active. No need for them if you want to disable or remove the EGR system, which is a good idea.
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