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+--- Thread: Switchover valve (/showthread.php?tid=2111)
Switchover valve - Walkenvol - 01-03-2011
'82 300sd OM617 has been pulled for a repower project in front of a manual transmission.
I'm trying to eliminate all the vacuum lines not required with the elimination of the EGR system and the auto trans. Is there any other vacuum I need to maintain under the hood besides the brake booster and the shut down switch on the IP? Can the white plastic vacuum unit that is next to the IP (above the shutdown switch) be removed completely?
There is a hose running from the intake manifold to a switchover valve bolted to the firewall and then onto the alda. In my reading of the factory service manual, this switchover valve was to protect transmission overload. Since the auto trans is leaving, can I eliminate the switchover and run a line straight from the intake manifold to the alda?
Thanks in advance.
RE: Switchover valve - winmutt - 01-03-2011
HVAC/locks/brakes/shutdown. Everything else can be tossed. Bay looks so cleaner when its done...
RE: Switchover valve - Walkenvol - 01-03-2011
Thanks Winmutt.
Are you familiar with the alda supply from the intake manifold? Can the switchover valve be eliminated when going with a manual transmission?
RE: Switchover valve - ForcedInduction - 01-03-2011
No. The valve is a crucial engine safety device.
RE: Switchover valve - willbhere4u - 01-03-2011
I've removed them in the past with no I'll affects It's an over boost protection valve if you build 2 much boost it limits fuel! more than 13-14 psi?
If you have a boost gauge it should be fine with out it!
RE: Switchover valve - Walkenvol - 01-04-2011
When adding a boost guage, is the preferred method to put a "T" in the line feeding the alda and measure the pressure there or to tap a new hole in the EGR block off plate (EGR system removed)?
RE: Switchover valve - tomnik - 01-04-2011
(01-04-2011, 08:55 AM)Walkenvol When adding a boost guage, is the preferred method to put a "T" in the line feeding the alda and measure the pressure there or to tap a new hole in the EGR block off plate (EGR system removed)?
first option is easier to do and gives you the additional information that pressure is reaching the ALDA.
Tom
RE: Switchover valve - winmutt - 01-04-2011
(01-04-2011, 10:03 AM)tomnik(01-04-2011, 08:55 AM)Walkenvol When adding a boost guage, is the preferred method to put a "T" in the line feeding the alda and measure the pressure there or to tap a new hole in the EGR block off plate (EGR system removed)?
first option is easier to do and gives you the additional information that pressure is reaching the ALDA.
Tom
It also means another potential leak in a crucial part of the engine performance. I am personally split on it. It is essential to know psi at ALDA yet its also essential to make sure there are no leaks
My next gauge I will be using the vac lines ala om60x boost lines instead of the nylon ones on the 617.
RE: Switchover valve - willbhere4u - 01-04-2011
I removed the over boost sensor on my car and attached the gauge there towards the back of the manifold
RE: Switchover valve - led-panzer - 01-04-2011
Does the valve do anything other than limit over boosting? Ive removed my alda (much happier with it gone) but I have the vacuum amplifier that connects to the trans to give firmer shifts with boost, I just took both the lines from the alda and connected them, seems to still shift fine.
RE: Switchover valve - Walkenvol - 01-04-2011
Forced - would you be comfortable removing the switchover valve if you have a boost guage to monitor over boost?
Willbe - How does your alda get its pressure?
led-panzer - Why are you happier without an alda? I'm new to this and trying to learn more.
I understood the alda adjusted the fuel level to the amount of boost from the turbo at a rate to ensure proper fuel burn. Without the alda it would appear you would pump more fuel into the engine than it can burn and therefore fuel out the tailpipe.
What am I missing?
RE: Switchover valve - tomnik - 01-04-2011
(01-04-2011, 12:22 PM)Walkenvol Willbe - How does your alda get its pressure?
led-panzer - Why are you happier without an alda? I'm new to this and trying to learn more.
I understood the alda adjusted the fuel level to the amount of boost from the turbo at a rate to ensure proper fuel burn. Without the alda it would appear you would pump more fuel into the moter than it can burn and therefore fuel out the tailpipe.
What am I missing?
nothing!
when the car feels better with ALDA removed then the full load adjustment is wrong.
With correct adjustment the ALDA allows full fuel (like with LADA removed) but limits fuel without boost to prevent smoke.
Tom
RE: Switchover valve - led-panzer - 01-04-2011
Eliminating the alda gets rid of the uneven throttle response, no more push the pedal........ok now were moving. Now the car moves right with the pedal, and doesn't smoke at all. And before I took it off I had it maxed out. It's not hard to put on and off, try it out and see how you like it, I promise the moon won't collide with the earth if you take it off.
RE: Switchover valve - tomnik - 01-04-2011
full load adjustment should be done without ALDA until the car starts to smoke at full pedal.
Then normally the quantity is too much without boost and you will get partial load smoke. This is then the job of the ALDA to reduce quantity (smoke) when there is not enough air.
The governor has a spring capsule that adapts fuel to rpm respecting less efficient high rpm range.
What I want to say is that you need an ALDA if you want to get max performance (without excessive smoke).
Tom
RE: Switchover valve - ForcedInduction - 01-04-2011
I like it better off. As led-panzer said, it gives a linear throttle response instead of that "rocket booster" feeling as the turbo builds pressure.
Quote:What I want to say is that you need an ALDA if you want to get max performance (without excessive smoke).Once you learn the car's capabilities that can be done with your foot easily. The ALDA is made for people that like to drive with their foot to the floor all the time.
RE: Switchover valve - tomnik - 01-05-2011
I agree but the fuel delivery curve has to match the air flow.
This is not the case with the stock spring capsules.
With the stock turbo charger the air flow is more of "rocket booster".
To avoid over fueling at partial load you might have too much air when boost comes up.
For sure different with VTG.
Tom
RE: Switchover valve - willbhere4u - 01-05-2011
On my car I ran the line from the manifold directly to the ALDA! and have it adjusted nearly maxed out about an 1/8 turn from max! and its a rocket off the line with the k26 turbo!
no smoke at Idle but a nice puff if you put your foot in to it!
RE: Switchover valve - Walkenvol - 01-05-2011
Still interested in opinions concerning adding a boost guage.
Since I've got the egr removed, it would be easy to tap into the block-off plate or I could "T" into the line running to the alda.
Is there any down side in accessing the boost pressure from the alda line?
RE: Switchover valve - led-panzer - 01-05-2011
None that I can think of. Easiest place to do it really
RE: Switchover valve - ForcedInduction - 01-05-2011
As with any hydraulic system, pressure is pressure anywhere. It doesn't really matter where you tap in the gauge.