miteymax86 wrote:Yeah, I've got the curriculum from the college I'll be attending in the fall(Grand Valley State University, D2 national champs in football, whoopee) anyway, I'm pretty much destined to fail, but I want a job that pays and doesn't suck, and engineering seems to be the right choice however, the math skills are a little lacking(taking an AP pre-calc&trig class at like 7am is not a good idea) and then physics my senior year was well, my senior year, I got way lazy and didn't crack a book

Hey, my sister went to GVSU!!

Hey man... I failed recess.All these degrees makes me feel like I'm on the weather channel. :D:D

What yr? What'd she major in, etc...?

miteymax86 wrote:What yr? What'd she major in, etc...?

She graduated in 1995, majored in Elementary Ed.

Ok, probably not the chick from Georgia that I worked with at Duba's then

Vimy, In answer to the original question posed, I talked to an engineer today and his answer was that this was done to aid in throttle return do to equal pressure on both sides of the throttle plate when wide open would prevent or severally hinder the return of the throttle and to help create a stable low pressure or vacuum in the manifold behind the throttle plate and manifold.

drjohn wrote:Vimy, In answer to the original question posed, I talked to an engineer today and his answer was that this was done to aid in throttle return do to equal pressure on both sides of the throttle plate when wide open would prevent or severally hinder the return of the throttle and to help create a stable low pressure or vacuum in the manifold behind the throttle plate and manifold.

Thank you very much for getting an explanation, drjohn. This site is cool because we have access to great stores of experience, imagination and knowledge.

The answer has many subtle implications about engine management and engineering. For one thing, the physical forces that would stop those springs returning the throttles to the closed postion must be formidable. I believe you mentioned that possibilty previously.

There must be a huge amount of air flowing through those valves if they could get stalled. Perhaps a runaway engine if they got stuck? However, there have been no mentions of this occuring on the 300zx sites. Only posts about measured horsepower increases and lower 0-60 times etc.

I wonder if alterations to the engine codes in a designer chip might even enhance this effect. It's probably detrimental the engine mechanics, though.

Humm..............................

Thanks again for asking the engineer.

Our Q's open completely. No probs with throttle closing when flat out.

Chally wrote:Our Q's open completely. No probs with throttle closing when flat out.

Hmmm... I wonder if I should try it.

what if the TB plate is just there to creat a vortex that will cause a downdraft into the runners, something like a VG on an airplane (vortex generator) when you make the air tumble you actually have more control of where and how it flows than when you just let it go on it's own (like a rifle bullet). I could imagine that the lower pressure on the top of the butterfly would cause a great deal of turbulence with the higher pressure on the bottom. If they found out a way to tune that then it could be used to help make sure the manifold sends a 'more equal' ammount of air to each cylinder than otherwise possible.

Also there is a slight venturi effect from the TB, (at least once again on the CA) if you look at it the TB tapers down as it goes through the plate, then opens back up on the other side of the manifold.

hope that allmost sounded like I knew what I was talking about...

PaulOrlando, FL

In most, if not all TB's, there is a Venturi of some sort.Turbulence in the manifold isn't a good thing, as it slows down the Air Flow. This is why they are building longer inlet manifolds, to try & get the air to "speed up" at low speeds, & with minimal turbulence.More air, More power.

actually, ideally you want high pressure, low velocity air coming from the plenum into the intake runners.