DIY: Removing VFAD
#51
#53
ok i am slightly confused. I have studied jons diagrams and seen the video and have a question. Does simply caping off the nipple behind the throttle body keep the vfad open since it needs vaccum to close it?
#54
As long as you don't introduce vacuum back into the line, the valve will stay open.
Now... if you only remove the hose behind the throttle body, the valve will stay closed because the VFAD solenoid is closed and keeping vacuum in the line to the actuator.
Two easy ways around this.
1) When you drive your car and take the RPM above 5500, the solenoid will open and release the remaining vacuum in the line.
2)Remove the line connected to the solenoid (line going to the actuator) and you'll hear the vacuum escape. Then just reinsert the hose onto the solenoid so its not dangling.
#56
Its totally up to you.
Nice thing is, if you cap the nipple behind the throttle body to keep the VFAD open at all times and you find out a few days later that you don't like it, just remove the cap and reinstall the hose.
Very easy to go back as long as you don't remove anything like the solenoid, vacuum chamber, and the one-way valve.
Then if you do like the "mod" and want to remove the components (to make it look cleaner), you can do that.
Nice thing is, if you cap the nipple behind the throttle body to keep the VFAD open at all times and you find out a few days later that you don't like it, just remove the cap and reinstall the hose.
Very easy to go back as long as you don't remove anything like the solenoid, vacuum chamber, and the one-way valve.
Then if you do like the "mod" and want to remove the components (to make it look cleaner), you can do that.
#57
ok, i went out to do this and my throttle body does not seem to have the nipple or hose running down as shown in you're pics/diagrams. Very strange, as theres just nothing there on that side. I will try to post pics tom of my throttle body. I have a 05 if that helps at all.
#62
#63
gotcha. however, when i hit 4,300 rpm (automatic) it definitely gets alot louder and revs quicker. is this some variation of vfad or is that just the nature the 4 port renesis. i have always been told thats the vfad opening
edit: ok so i have a fad, not vfad. does this mean since its not "variable" it's always open?
edit: ok so i have a fad, not vfad. does this mean since its not "variable" it's always open?
Last edited by pistonkilla; 07-05-2009 at 10:44 PM.
#64
If you have an '05 auto, you don't have a VFAD.
The VFAD normally opens at 5500rpm (if you have it), the SSV (secondary shutter valve) opens at 3250rpm which is on all models.
The VFAD normally opens at 5500rpm (if you have it), the SSV (secondary shutter valve) opens at 3250rpm which is on all models.
Last edited by Jon316G; 07-05-2009 at 10:45 PM.
#65
#66
#71
Well today I removed the hose going to the intake and capped it with a rubber grommet (looks like a plastic valve cap) I don't notice any difference in sound but I notice that there is no hesitation around the 5500 RPM mark. Some have said that it should be louder. Just curious if others are noticing the same thing.
#73
keep in mind you have butterfly valves in the intake manifold that open around 5k as well. thats where the stumble is. but when you get rid of the vfad it might help a little to provide less vaccum resistence so it gives the perception of more responce to the motor due to less piping. its like a short ram, works better for top end, cold air long tube works for the bottom end of the range more.
and as for the rb duct, you have 2 full 90 degree bends before it goes into the intake pipe. but if you use a straight forward duct it will help alot more. exspecially on the k/n intake with a surround to provide positive pressure.
and as for the rb duct, you have 2 full 90 degree bends before it goes into the intake pipe. but if you use a straight forward duct it will help alot more. exspecially on the k/n intake with a surround to provide positive pressure.
Last edited by notorque; 07-21-2009 at 12:57 PM.
#74
The in-motion "ram air effect" of the RB duct easily overcomes the slight resistance of the two bends. But intakes are more about suction than intake pressure anyway, in that the engine will take all it can get. Yes I know we talk about FI in terms of "boost" (increased air pressure to achieve denser oxygen rich air) but our, and most other, engines run starved for air as stock.
Also keep in mind the 2nd set of injectors that come into play around 5k rpm. Removing the VFAD won't of course have any bearing on those, but again removing it does eliminate the VFAD shutter transition lag.
Also keep in mind the 2nd set of injectors that come into play around 5k rpm. Removing the VFAD won't of course have any bearing on those, but again removing it does eliminate the VFAD shutter transition lag.
#75
You really just need to cap the nipple behind the throttle body.
This is the "beginning" of the vacuum line for the VFAD.
Attachment 136611
Autozone sells a pack of vacuum caps of various sizes.
This is the "beginning" of the vacuum line for the VFAD.
Attachment 136611
Autozone sells a pack of vacuum caps of various sizes.
Last edited by Collier's Ride; 07-23-2009 at 04:24 PM.