The velocity stack from Vararam, they claim up to 13rwhp! What do you guys think and gals.

 

Only when used with the performance hood seal

 

Yeah. 'Cause you don't want the HP leaking out ... I hate seeing wasted HP laying on the side of the road.

 

Recall Bernoulli's Principal then you'll know.

Hint: http://home.earthlink.net/~mmc1919/venturi.html

This is a cool animated demonstration where you can adjust the shape of the pipe (velocity stack in your case) by moving the yellow 'handles.'

Make the pipe look like the Vararam stack with the purple ***** (fluid/air) moving from left or left to right and notice what happens to the blue velocity curve under the animation. **** There's your answer!

Here's another kind of interesting link that might explain some real world observable phenomena because of the Bernoulli Principal: http://theory.uwinnipeg.ca/mod_tech/node68.html Start reading the text found half way down the page.


I never believe the 'numbers' quoted in ads because they aren't sourced or rarely is a reference point given.

Did they run their test on 800HP engine and get a 13HP increase (1.625% increase)? If so, then a 1.625% increase in a 350HP engine would only equate to 5.7 HP? Hmmmm, big difference huh.

Are they quoting RWHP or crank HP?

Is the figure quoted at 5000 RPMs only or across the whole curve? Observing your experiment in the 1st link above should answer that one for you.

The ads that say 10% HP increase for example, whether true or not, at least give you some reference point. But when they say "a 7 to 10 HP gain" are meaningless unless they describe their testbed.

With all that said, the principal of the tapered carb stack is based on Bernoulli's findings, which haven't been proven wrong in the past few centurys.

So, are you going to buy one? (BTW, its on my wishlist).
..rickko..
Hint 2: Air behaves like a fluid

While we are on the topic of fluid (air) in motion, this is a very cool sight where you can have some fun. http://www.grc.nasa.gov/WWW/K-12/airplane/foil2b.html

 

It's a bit like the forum search function which people also claim works. It both cases you won't know for certain until you try them.

 

Does this really work?

In a word, no. A few guys tried these when they first came out and, if I remember correctly, lost 1-2 rwhp and gained about the same amount of torque.

 

Yes! If you use it in conjunction with the throttle body bypass you will get 43.5 hp to the rear.

 

 

Do they make stickers for this smooth bellow, I mean cause all you have to do is put the sticker on your car and that will give you the 13 hp. WHY DIDNT YOU THINK ABOUT IT. lol HONDA POWER

 

Actually the Honda stickers work somewhat differently. I put one on my car and my gas mileage increased.

 

I know most joke around about certain mods, but seriously think about......you're sticking something into the TB, it's restricting the air flow, you want more air flow not less.

 

 

 

 

Only when used with a Procharger

 

I was curious about this too, but to play devils advocate here...

First, you're smoothing out the airflow path, instead of griding and filling with JB weld like some articles show.

Second, the "stack" is acting like a venturi and should be increasing velocity.

I'd like to see some real world tests on it, i'm pretty neutral right now, even if it was benificial i can't see it making much difference.

-Rich

 

Sorry for my ignorance, but what's "venturi"????

Are you talking about it squeezing the air and shooting it out the otherside into the intake manifold.

Is smoother air that is restricted better then less restictive and rougher air......bottom line is the most air possible right?? so which flows higher??

 

Look in any aftermarket catalog and if you believe all the claims for each gimmick, you would easily gain 100 HP for a few hundred bucks . Lets get real here. Gas, a$$, and grass, no one rides for free or close to it.

 

Right on Ricko!

I bought one, because in theory it should help, and I didn't want to do the more in-depth TB porting job. I run 8.24@87.19mph in the 1/8th with only intake and exhaust mods. No drivetrain or anything else other than tuning. A4 trans.

 

Wait a minute...I'm pretty good at fluid dynamics, but someone has to explain to me how does the venturi / bernoulli effect help?

The flow rate does not change...i.e. the amout of air molecules that go from outside the intake to the engine does not change. The same amount of air goes in one end as comes out the other. Sure the velocity increases, but the flow rate will not. Like putting your thumb over the hose...sure water forces out stronger but it takes just as long to fill a bucket.

How does the physical velocity (m/sec not moles/sec) of the air into the TB affect HP?