Has anyone had any experience with the Vararam VR-4 VR velocity stack ? I have seen some of themF-Bodyguys with 5.7L TB use them as well as some 4.3L S-10 guys use them. I spoke with the owner today and verified it fit our throttle bodies. He said "it is a great compliment to other intake mods such as K&N CAI, etc. I didnt ask about throttle body spacers, but don't see why it wouldn't.The Vararam will Streamline the air intake flow to reduce power-robbing turbulence over the AIR and PCV valve while maximizing the factory throttle body's diameter."It seems to be a valid item, the way I interpreted it is that it basically funnels the airin a streamlined fashion to give betterand more consistent airflow speed/power/psi over the throttle blade! They are only $29.99 on Summit.

www.vararam.com

What do you guys think?

 

Their description is a little off... The IAC (idle air control) valve pulls its air from the horn of the throttle body (the port you see on the back wall of the TB when you pull off the duct work). This would cover that opening... The AIR (air injection reaction) can basically be likened to a smog pump and has nothing to do with the intake tract at all. The PCV valve on the SCFI 4.3L v6 (96+) pulls directly off of the upper intake plenum, no where near the 'velocity stack' insert.

Now, I'm not saying that this won't work if designed properly, but I am skeptical. I can't explain the proper application of a velocity stack any better than this: Velocity Stack - Wikipedia

BTW, which one would you choose? Both the VR3 & VR4 are listed for v6 truck/suv applications. Their site and applications listing leaves a lot to be desired.

 

Kyle,

agree on the website, I thought the same thing to myself. I also see what you are saying about the AIR and PCV valve. I have a message into them on the VR-3 vs. VR-4 and will let you know. I had this in mind when I gave my lamens terms description but didn't explain. With our application it would just give a better streamline flow of ram air entering over the throttle blade. I bet it will help with a smooth idle and WOT from stop on the low end torque range byabout 5-10lbs but almost be a give-and-take on the HP side of things. I might just give it a 30-day gurantee trial next week, afterall both JEGS and SUMMIT sell these. I like torque! and more mpg too!

 

Knowing the design of our throttle bodies and the design of the intake ductwork and throttle body, I would expect more gain from a different duct 'hat' than on any modification to the inlet of the throttle body. Just knowing how the air flows through the factory 'hat' (the plastic piece directly on top of the throttle body), I would expect more gains from a better designed 'hat'. K&N makes a nicely flowing 'hat'.

But any gain would mostlikely be not noticeable even on a dyno.