S5 N/A VDI Manifold Questions
04-21-08, 11:37 PM
#1
Rotary Kids
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Join Date: May 2007
Location: Rocky Mount, NC
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S5 N/A VDI Manifold Questions
I've been building an N/A S5 for about a year and a half now and everything has been doing pretty good so far. I do have a question about the Variable Dynamic Intake Manifold, though.
When I was cleaning and reassembling the manifolds on this motor, I was looking at the VDI valve and was curious about it's function. I do understand the basic principal of the pulses pushing one another into the motor and such but I'm wondering about the actual timing and settings for this thing.
I don't have the air pump any more and I've removed the aux sleeves. Since the actuator on the VDI used pressure as opposed to vacuum, I don't really have a way of making it function again.
However, I was thinking about possibly using some RPM activated switch linked to a servo of some kind that would turn the VDI valve at a desired point and turn it back at a desired point. The valve opens and closes VERY easily so it requires little effort and I was thinking about making a small bracket with maybe an R/C steering servo (with the voltage regulated to the servo and such) to do the job. I had toyed with the idea of the AFC Neo fuel computer I'm using to activate a relay to the servo by way of it's built in vtec settings and such.
Just how much of a positive effect does the VDI system provide? With an N/A motor, I'll take anything I can get but is it worth the trouble for any torque/power gains I might get? And if so, when should the valve open and close? And if not, should it remain open or closed if it's not to be used? Removing it completely looks as if it would cause crazy turbulence in the manifold and probably hurt more than help.
I've been trying to find out information on this for a good while but haven't been able to really find anything out much, even from the guy who built my motor (he's mostly an FD guy.)
Any help would be awesome. =]
When I was cleaning and reassembling the manifolds on this motor, I was looking at the VDI valve and was curious about it's function. I do understand the basic principal of the pulses pushing one another into the motor and such but I'm wondering about the actual timing and settings for this thing.
I don't have the air pump any more and I've removed the aux sleeves. Since the actuator on the VDI used pressure as opposed to vacuum, I don't really have a way of making it function again.
However, I was thinking about possibly using some RPM activated switch linked to a servo of some kind that would turn the VDI valve at a desired point and turn it back at a desired point. The valve opens and closes VERY easily so it requires little effort and I was thinking about making a small bracket with maybe an R/C steering servo (with the voltage regulated to the servo and such) to do the job. I had toyed with the idea of the AFC Neo fuel computer I'm using to activate a relay to the servo by way of it's built in vtec settings and such.
Just how much of a positive effect does the VDI system provide? With an N/A motor, I'll take anything I can get but is it worth the trouble for any torque/power gains I might get? And if so, when should the valve open and close? And if not, should it remain open or closed if it's not to be used? Removing it completely looks as if it would cause crazy turbulence in the manifold and probably hurt more than help.
I've been trying to find out information on this for a good while but haven't been able to really find anything out much, even from the guy who built my motor (he's mostly an FD guy.)
Any help would be awesome. =]
04-21-08, 11:50 PM
#3
I would say the gains from using the VDI properly are well worth it. It could be unfortunate that you have removed your aux sleeves. these systems were there for a reason - more high end horse power(when open) & more low end torque(when closed) I assume you have removed the vacuum rack, solenoids, air pump & acv? Well now you need to come up with a substitute. I've been there & done that.
Check out this link https://www.rx7club.com/forum/showthread.php?t=748570
I went from my *** to get to my elbow on this but am very happy & my ride pulls like crazy at the moment. You should consider making all of your ports functional as it makes a big difference. you will lose alot on either the top or bottom end or both with your current setup. Don't get discouraged...you can make it work... I did and i'm pretty happy right now.
Ramses666
Check out this link https://www.rx7club.com/forum/showthread.php?t=748570
I went from my *** to get to my elbow on this but am very happy & my ride pulls like crazy at the moment. You should consider making all of your ports functional as it makes a big difference. you will lose alot on either the top or bottom end or both with your current setup. Don't get discouraged...you can make it work... I did and i'm pretty happy right now.
Ramses666
