gdutch

The argument is as follows: Stick saw an 8hp improvement with his velocity stack over stock. Nobody is arguing the validity of that claim. But you can't conclude that it is better than the deckplate unless you compare it to the deckplate. There's no way to determine how much of the improvement is attributable to the new 4" hole in the airbox and how much to the velocity stack (if any).

rockota

Can you please post all three pre and post-stack pulls? I'd like to see the high/low between each of them.

The concern I have is not the concept, but the testing methodologies. You took three pre/post pulls and (if I'm reading correctly) randomly selected the "middle" pulls. If there was a large variance beween high and low for each, it tells me that there are other variables at work that need to be deciphered and accounted for in the overall summary. Typically, it's not the median pull, but an average of the three pulls that would determine the overall "average" power...



Thanks.

okie81

I've always been a believer of the elbow mod in terms of airbox performance gains. That being said, two supplemental dyno experiments I'd like to see

1) Elbow mod alone compared to aforementioned results
2) A smaller velocity stack on the elbow intake hole, although it may be physically restrained (or maybe even at the end of the elbow)
Like DailyDrive mentioned, the intake elbow is a good example of a straw that the engine is trying to suck air through (#4 &#7 below). You're ultimately doing the same thing, just with a smaller hole and no speaker screen.



This is a great thread! Good, constructive debate

aviator

Lots of good discussion here. Remember folks Stick offered to do a test with a basic deckplate mod airbox if someone (from the san D area) would loan him one to use.

Something else to remember in all this fluid dynamics/gas dynamics discussion is that air acts like a fluid (berni's theorem) not a gas.

eddieleephd

it is possible to use a deck plate over the bass tube if you really wanted the option of the tube. the Deck plate should be designed to stand over the Bass tube or you can place it on the inside of the air box and then the deck plate on the out side and solve that!!!

I do have the Deck plate mod and like the screen idea you could put the screen then the tube with the deck plate and have it all i mean $3 for a bass tube...

the real benefit to the deck plate instead of the bass tube is not the water level but rather the rain factor!! rain getting in the air box is a horrible idea!!

sharrack

Funny.........i did all those deckplate and air box removal mods and it killed my gas mileage.
I reversed them all and now enjoy good mileage again.
Too bad it's got to be that way but at 2.75 a gallon...and a 18 gallon tank...
I'm at the pump way too much!

dave_mcmillan

Thanks for improving the whole mod...it can't hurt.

glenyoshida

Gotta say that your credibility isn't shining so bright here. How about sharing some real data instead of the loosely related theories that you seem to be throwing out there in hopes something will stick?

A vehement statement just doesn't cut it. Real data that can be verified, repeated, and fairly criticized as Stick has provided.




Stick, thanks for taking the time and for sharing. I'm not so sure that the shape of the duct or the length of it had much to do with the additional HP gain but I love that you've shown 8HP gain with very little cost. Regardless, it's really cool of you to share your findings.

FWIW for the few that don't already know this. The stock air intake tube is undersized. Duh.

Factoid: A 3.4 liter 5,500 max RPM motor airflows at approx 250CFM (cubic ft/min). For our third gens we really should not be running a duct smaller than 3" in diameter or the loss starts to become significant. A 2" tube will have roughly 6 times more friction than a 3" and 26 times more friction than a 4" tube. Size matters and an inch can make a big difference.

Ha! Turns out my girlfriend was correct. Size matters.

Stick, Since you have actual verifiable data (even with the small sample) you smash arguments lacking real data. I'm certainly not convinced by some haphazard theories with no data, no control, not even a junk experiment for crying out loud.

DailyDrive

Use the search. It's already been beat to death.

Of course! All it takes is a 5th grade education and some parts from Home Depot to improve an engine that Toyota spent millions to design! If anything, your logic is rock solid!

Factoid: Friction does not make sense in this context. But even if we disregard that you use wrong words to describe concepts in a subject matter that you want us to believe you are proficient in, air "friction" in a straight tube is primarily a factor of diameter, length and velocity. You kind of forgot one of the factors there, so your numbers are most definitely meaningless.

Here are so real pressure drop numbers for a hypothetical straight pipe intake, air @ 75F, 250CFM:

4" diameter 24" length = 0.0013 psi
3" diameter 24" length = 0.005 psi
2" diameter 24" length = 0.032 psi
1" diameter 24" length = 1.100 psi

If anyone thinks they can measure with a dyno, and especially feel a difference, when their intake's pressure drop improves to a few 1/1000s of a PSI, I will laugh at them long and hard. This is pretty much what this thread is about. Trying to make changes on the borderline of ridiculous.

The deckplate mod is not even a tube of 24" length, it's a 1/4" length at most, which puts at 0.00015 PSI pressure drop @ 250CFM.

I don't know what is more ridiculous here though, trying to improve on that 0.00015 PSI pressure drop, and coming back with 8HP more, or trying to discredit someone by the simple fact that they didn't try it. Come to think of it, both things are ridiculous.

DailyDrive

I feel sick after arguing with a guy that mentions penises with his scientific data. That's it. I'm out of this thread! If anyone wishes to believe the world is 6000 years old, they are more than welcome to.

glenyoshida

Me too. I think it's great that people try new things out and share what they come up with. There's been some great stuff that came about because of it.


Yer right, poor choice of words on my part. I thought it was obvious when we compared rigs but I can understand why there is still skepticism. It might be one of those things that is in debate forever. I'll post up when we get around to testing out the deckplate again here in Colorado. And yep, I'll post up if we measure no difference in performance as well.




Stick, how about finding a nice straight section of road, another 3rd gen buddy, and testing out the mod. If you are both side by side and step on it at the same time you can see the difference in acceleration between both rigs. You'll be able to do several runs with and without your velocity setup to verify that the change isn't a fluke. I think I might do similar with some of the other 3rd gens that have the deck plate mod here in Colorado.

KU_MechE

This will increase the gains to 20hp!!

http://www.tornadoair.com/buy1/

xxxtreme22r

See an earlier comment of mine in this thread, explaining why this is a wrong statement.

aviator

I see our debate here is as civil as ever... lets continue to play nice everybody...

aa1911

iTrader: (1)

jeez guys, the time I've waisted reading this thread with all the back and forth, everyone could have polished up their TB's and cleaned their airfilters by now... maybe that will get you your extra 1HP hahaha

go spend some more time under the hood wierdos...

speaking of which, I got halfway thru installing a new intake/cone filter on my deckplate modded taco today plus cleaning up some crappy wiring; then it started raining and since I melt in the rain, I cleaned my garage instead of finishing... no dyno results until I finally purchase my own wideband scanner though... will need a retune after this mod...

abd9810

K&N Sells a velocity stack that goes inside or under the airfilter of a 4 barrel carb. Everybody with a Holly, Quad, Carter, FoMoCo,...etc use them at the dragstrip, unless they want to go slower. Velocity stacks work! Go to the racetrack and look at what's under the hood. So even before the filter it still can work, maybe just not as well.

Opening up the airflow to the airbox has always been worth more hp, regardless of the of the engine or car it came in. OEM's even make higher flow systems for their faster cars and parts/racing divisions. If my deck plate makes 7hp it's because I read it somewhere, and I also get 100mpg 'cause i read that too! And I'm not Lying...my Mom said so!
I have always found that Bench Racing without proof is nothing but CutRateAutoParts...
So He makes 8 hp on the Dyno, How much does your Deck Plate Make??? Huh, don't know do ya? You only know what youv'e been told...Check your Dipstick, I think it's low.

Taro

I have a deckplate modded airbox for my '00 4runner I'm willing to share for the comparo. I'm in L.A. but will pay to ship it to you to settle this. That is as long as I get it back.

rockota

Apples/oranges. Compariing velocity stacks on top of a carb and one over 2' away from the intake is not a solid comparison.

I'm still waiting for the dyno info for the other runs...

Welchs80

iTrader: (1)

Isn't the theory behind how a snorkel can increase hp is from air forced down the tube more readily than in the fender? You will be sitting still on the dyno so that ram effect will have no effect.