As far as I know, the VVEL system essentially replaces the conventional throttle with a throttle on each cylinder. Limit the air at the cylinder and you don't need to limit it anywhere else right? So why do we have a pair of throttle bodies? Aren't they just added restriction in the intake, or do they still serve a purpose?

 

From what I know, the VVEL actually replaces the Intake cams on traditional engines with a mecanism that varies the valve lift and duration electronically. The optimum lift and duration are chosen from certain tables in the ECU based on two inputs: engine rpm and throttle body % opening (which is basically why a throttle body is needed)

http://www.youtube.com/watch?v=a8P2VwEe0FY

 

Found this a few minutes ago.

http://www.nissan-global.com/EN/DOCU...AL/VVEL_EN.pdf

I assume that http://www dot nissan-global dot com is Nissan's official website, so directly from Nissan, "We increased throttle response by directly controlling the intake valve rather than using the traditional method of controlling intake with the throttle valve." Looks like our intake is controlled directly by the intake valves, not at the throttle valve.

ugh, I should have just finished painting instead of looking up VVEL stuff. I'm more confused now than I was before It seems as though there's alot of confusion about VVEL floating around the world wide web.

 

Funny I was thinking if we could replace the 2 small tb with larger diamiter ones, to improve volume of air flow.

While back when I had a 5.0 I replaced the stock tb 60mm with 65mm.

Huge gains from just that mod.

Sice vvel loves more air, wondering if this could be done for the g.

 

What do you mean by VVEL loves more air?

 

Edit:
Larger diameter tb allowing more air / fuel to be introduced for combustion.

 

^ Interesting point. I have always been around the V8 scene, and have recently since getting the G been around V6 etc. As he said, throttle bodies are very common with V8s but I have yet to hear about them with these motors. Curious why?

 

Considering the high compression motor loves high velocity airflow, im kind of surprised it has not been made.
Plus if you could do some porting on cylinder head (say just 0.30)to accept larger amount of the a/f mixture.
Not anything to drastic, maybe a 5mm increase on each tb.
Can anyone with a tt set up chime in, curious if any of the tt kits have this already.
Im out of warranty, so I may start with internals anyway.

 

It's got to be a combination of speed of the airflow and the amount of flow, right? If you increase the amount of flow (larger throttle bodies) normally that will slow down the air flow won't it? I know there is a sweet spot for any engine, not really sure what they may be though.

 

You kind of answered yourself, larger throttle bodies means that air will flow in slower at a given rpm and load.

Where did you get "high compression loves high velocity" from though?

 

Look how well the vhr responds to boost.
Like I mentioned earlier, I have done the tb swap on another vehicle.
As far as velocity, that is why the gen 3 works so well.
Not just increasing the volume of air, thr speed in wich it enters the intake.
We dont have big block engines, but we do have very restrictive tb as far as emmisions.