Ivoidwarranties

iTrader: (7)

No it's not. I read and used to think the same thing but there are some data logs posted on here by modme. You can see the signal to the throttle bodies going up and down in voltage the whole time he is driving. He was just driving around, up and down in speed and through the gears. It shows the throttle bodies do in fact throttle.

Whatnobeer

So I think the next logical question would be, if we ported or used larger TB's would that have an effect on a N/A car? I'm thinking not tremendously. Now on a F/I car, I know those work.

G37Sam

But if that were true (which I'm not saying it isn't), what would be the use of the 2nd throttle body?



Come to think about it, what's the point of a throttle valve anyways if it's going to be open all the time? An additional flow restrictor

Ivoidwarranties

iTrader: (7)

First question: Good question. Somehow the designers felt it was either a good way to go or a the right thing to do. Two throttle bodies have been used before by others and they obviously must have their advantages in some applications. Funny thing, two smaller throttle bodies allow for finer throttle control than one big throttle body does. That's a little odd considering some of the publications out there say the VVEL allows for the throttle bodies to be held wide open while the intake valves do the throttling.

Second question: Even if the throttle bodies fully opened during normal operation, which they don't if you look at modme's data logs, there are still certain situations which the VVEL probably couldn't handle, such as idle and cold start-up.

The video's about the VVEL when it first came out said (or in an animation showed) the throttle bodies would be full open while the intake valves do the throttling.

The VVEL is really neat and has potential, but it's not nearly as dynamic as some believe.

Mike

iTrader: (1)

Emissions.

Mike

iTrader: (1)

Nope. The throttlebody is not the restricting point on the intake side...

Mike

iTrader: (1)

Of course the voltage is varying. It doesn't mean the throttlebodies are moving. Do you know what the voltage threshold is for the throttles to be "fully open"?

Ivoidwarranties

iTrader: (7)

Around 4.5 volts for full open, around 0.5 volts for closed. It varies car to car. Are you saying the throttle bodies are full up at any signal? You do know how the throttle bodies work and what operates them, right?

Mike

iTrader: (1)

:shrug: I don't know what the operating range is for the throttlebodies on the VHR; I've never tore into one or taken readings.

Yes, I do know how they work.

Ivoidwarranties

iTrader: (7)

Well ok, I just told you the operating ranges. To be even more exact, on one G37 on here it is 0.40v closed and 4.3v full open. Not every car is the same. The throttle bodies do in fact throttle.

I could always take a drill bit, boroscope, and a video camera and make a video of the throttle bodies in action for you. I'm not willing to do that to Her car (because I like to get laid), but I'm willing to do it to a rental or someone else's car.

The Nissan training video of the VVEL (animation) was just an introduction to the VVEL. That video said the TB's would just go full open. That was incorrect. It might work that way in theory, but it's not the way the VHR does it right now.

JessterCPA

Has anyone ever done a LS1/LS2/LS3 into a G?

Ivoidwarranties

iTrader: (7)

G35's, yes. There are even shops out there selling swap kits to assist you. G37's, I haven't heard of any yet.

gsm026

Regarding VVEL and throttle bodies, I read somewhere (maybe on the 370Z forum) that varying the valve lift alone did not give enough "turn down" at lower throttle openings - meaning that they use the butterflys to meter below a certain throttle level. The idea is to reduce pumping losses and improve throttle response. In reality we have lag time in the (CANbus?) hardware connecting the different processors in the car.

Jarrett barbaro

That's so not true. Z1 motorsports sells a 400hp kit that puts you at 400hp crank and around 340wheel assuming 15-20% drivetrain loss. If you can manage to drop 60-80lbs unsprung weight. Do an entire intake system such as a cai, 70mm aftermarket throttle boddies, modded intake plenum, modded air intake manifold, modded headers, hfc(high flow cats)/test pipes(cat delete)(cat= catalytic converter). And and modded cattback exhaust with a tune will put you over 400whp. Possibly upgraded injectors. But it's doable. It'll cost you just as much to turbo it. Gets kinda close to a small turbo set up but it's also more reliable. But there's also other ways such as replacing the exhaust cams but we're talking 3k in parts and labor. It'll add about 26hp and 33wtq though. But it's more of a complementary thing needs to have the intake and exhaust systems to fully make it's hp.

gomogloVQ

I made 340whp without headers so I beg to differ