89 upper and lower intake manifold
04-22-03, 11:52 AM
#26
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the question to use the switch or not has come up and I believe I may have caused confusion among some people wanting to do this mod (I have reread some of my posts and they are a little strange)
The ONLY reason I was able to do the mod WITHOUT the switch is because of my exhaust system. Because I removed the ACV and Air pump I no longer had a air source to be able to open the ports or VDI. So by doing the Pochinko method the only reason we were able to do this without the switch is because the exhaust back pressure only reaches 3.5 psi and higher above 5000 rpm, which is a reasonable time to open. We were just basically lucky that it doesn't open any sooner. If you do this swap, and still have your air pump and ACV, then you use the ACV for port activation and air pump to the solenoid, with the RPM switch. you need the switch for this setup because the air pump is constantly pumping the required air that would open the VDI actuator at all times, thus redering it useless. So thats where the solenoid and rpm switch come into play. You set the switch to whatever setting you want and then the solenoid opens thus letting air open the actuator. In my case it would have just been a redundant system seeing how if I set the RPM switch to lets say 5200 or so, my car only produces enough of the backpressure to start opening the VDI at 5000 anyways, so why not just let the car decied when it wants it open.
I hope I have cleared up the reason for needing and not needing the switch.
P.S. I called summit when trying to do the swap and the RPM swictch is not water proof, you shouldint mount it in the engine bay.
The ONLY reason I was able to do the mod WITHOUT the switch is because of my exhaust system. Because I removed the ACV and Air pump I no longer had a air source to be able to open the ports or VDI. So by doing the Pochinko method the only reason we were able to do this without the switch is because the exhaust back pressure only reaches 3.5 psi and higher above 5000 rpm, which is a reasonable time to open. We were just basically lucky that it doesn't open any sooner. If you do this swap, and still have your air pump and ACV, then you use the ACV for port activation and air pump to the solenoid, with the RPM switch. you need the switch for this setup because the air pump is constantly pumping the required air that would open the VDI actuator at all times, thus redering it useless. So thats where the solenoid and rpm switch come into play. You set the switch to whatever setting you want and then the solenoid opens thus letting air open the actuator. In my case it would have just been a redundant system seeing how if I set the RPM switch to lets say 5200 or so, my car only produces enough of the backpressure to start opening the VDI at 5000 anyways, so why not just let the car decied when it wants it open.
I hope I have cleared up the reason for needing and not needing the switch.
P.S. I called summit when trying to do the swap and the RPM swictch is not water proof, you shouldint mount it in the engine bay.
04-22-03, 11:55 AM
#27
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Originally posted by Bruce
I know this is a stretch but there is always vaccum source running to the power brake booster. I just dont know how strong it is.
I know this is a stretch but there is always vaccum source running to the power brake booster. I just dont know how strong it is.
well the thing is for you, since you are planing to keep the ACV and AP might as well use those as your vacuum sources. If you mean for someone that has removed ACV and AP and has no exhaust backpressure to use as boost source (I realize I've been using Vacuum and boost interchangibly) then test the brake boost with a gauge. If it does provide more than 3.5 psi then use it in accordance with the switch.
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trickster
2nd Generation Specific (1986-1992)
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