a1320addict

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I'm debating designing a "cold-air" intake for my turbo for the upcoming season. I've done a lot of searching around on here, and most of the dyno comparisons etc are big-red-x's so, and weren't that specific, so I turn here.

Would a velocity stack with maybe a foot and a half of piping directly to the compressor inlet make any difference whatsoever? This would be solely used at the track, and my main reason for it is to avoid heat-soak, I'd like to have semi-consistent IAT's, which should assist in more consistent runs.

I'd just like to see if anyone has any past expereience with this, as in no way shape or form is it anything new, just looking for some help/advice.

Drew Peacock

It would definitely help hard to say how much depends how hot the intake temps were before. Still going to run a filter?

a1320addict

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I haven't sketched anything out yet, everything is just in my head. I would realy like to incorporate a filter, most likely a hks-mushroom to fit the velocity stack, as I can't think of any other way besides a mesh screen, which I am not a huge fan of, or a chamber of some sort where I can fit a oem-style flat filter

Drew Peacock

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by yehiknowrite &raquo;</TD></TR><TR><TD CLASS="quote">I haven't sketched anything out yet, everything is just in my head. I would realy like to incorporate a filter, most likely a hks-mushroom to fit the velocity stack, as I can't think of any other way besides a mesh screen, which I am not a huge fan of, or a chamber of some sort where I can fit a oem-style flat filter</TD></TR></TABLE> A CAI will make a differnece but it has been proven that bellmouths do not. Not sure if the velocity will help a turbo car really. But the pro dragsters use them ....

a1320addict

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thanks for the input

anyone else?

a1320addict

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up

yellowturbo

im also going to run a kind of cold air intake with my new turbo. It will take the fresh air from the front bumper on the driver side. I was running a KN directly clamped on the turbo that was sucking the hot air on the engine bay.

I doesnt see why it could not improve the performance... its like a regular intake that suck the air from the engine bay vs a AEM cold air intake.

Im not going to run a velocity stack but just a pipe with a KN at the end.

a1320addict

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From my understanding, there will be little-to-no actual power gains, I was reading on an old thread about how an intake for a compressor reduces turbulence to the compressor, and allows for a laminar effect of the incoming air. I've been looking at bell-mouths and velocity stacks...don't know if either will assist in. I'm also running a K&N right off the turbo, but am looking for something new.

Turbo-charged

on the dyno.....instead of having the filter mounted to the turbo behind the radiator....ive made temporary intake tubes that put the filter outside of the fender...and seen as much as a 30 horsepower gain on a higher HP car. before and after runs done 10 min with in each other, no other changes.

tony1

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbozxi &raquo;</TD></TR><TR><TD CLASS="quote"> A CAI will make a differnece but it has been proven that bellmouths do not. Not sure if the velocity will help a turbo car really. But the pro dragsters use them .... </TD></TR></TABLE>

Where has that been proven? I've seen gains from a velocity stack on more than one occasion with a turbo car.

The Weather Man

Hm....i remember someone like earl or someone making a thread about this. had a lot of different information.

Drew Peacock

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">

Where has that been proven? I've seen gains from a velocity stack on more than one occasion with a turbo car.</TD></TR></TABLE>I am talking bellmouths not a true velocity stack.

I'm off to work right now I'll find the source when I get back. They did back to back dyno runs with a bellmouth intake versus just the regular intake from the turbo..

So will a velocity stack help the OP out?

tony1

What are you considering the difference between the two?

99_GS-T

A bell mouth inlet is worth like 5% lower pressure drop then a straight tube end.

The higher pressure at the turbo inlet the better off you are.

lower pre-trubo inlet temps can really help when you are pushing the limits of the turbocharger. On my own car, I observed a ~2 pound/min increase in airflow when I went to a cold air intake. That would be roughly 15-20 WHP, on a 300 WHP car. A 5% gain is pretty good considering it cost me a 2' sheet of aluminum and $10 in aluminum drier ducting.

I also noticed my engine made more consistent power. Before the intake, the car would always pull noticably hard right after it got up to temperature vs. after it had had a chance to warm up the under hood temperatures. After the intake, I no longer noticed this change in power.

Drew Peacock

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">What are you considering the difference between the two?</TD></TR></TABLE>Well I'd think a well thought out VS would have the cold air being forced into it as the cars velocity increases..

Bellmouth is just sitting there on the intake of the turbo. I guess if you had ducting from the front of the car going down the throat of the bellmouth there would be gains to be had?? But over a CAI I'm not to sure. Right I'm late.


Modified by turbozxi at 5:16 PM 2/10/2006

tony1

I think for the most part a velocity stack and a "bellmouth" are the same thing. Ducting cold air into it is a whole different deal.

Drew Peacock

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">I think for the most part a velocity stack and a "bellmouth" are the same thing. Ducting cold air into it is a whole different deal.</TD></TR></TABLE>So what I consider a velocity stack is more like a Ram air intake? So you think a bellmouth on the intake of a turbo will add HP by itself? Not from I have seen. Try ad find the source.

Red_Greddy_Si

color me confused.....but isnt a CAI kind of counterproductive when no matter what the air is going to go through the IC anyway??? I would think an intercooler sprayer whether it was water or co2 or no2 would produce much better results.
or am I just crazy? I just dont see how introducing cold air at the turbo inlet is going to make a difference when the IC is going to bring it close to ambient temp

Drew Peacock

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Red_Greddy_Si &raquo;</TD></TR><TR><TD CLASS="quote">color me confused.....but isnt a CAI kind of counterproductive when no matter what the air is going to go through the IC anyway??? I would think an intercooler sprayer whether it was water or co2 or no2 would produce much better results.
or am I just crazy? I just dont see how introducing cold air at the turbo inlet is going to make a difference when the IC is going to bring it close to ambient temp </TD></TR></TABLE>It all helps of course. Think about it.

Bailhatch

wantboost

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nice blank reply... adam

a1320addict

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colder the air going in...the more the ic can cool it down..no? so...i'd see more dense air then...

thanks everyone for the replies

Bailhatch

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by yehiknowrite &raquo;</TD></TR><TR><TD CLASS="quote">

thanks everyone for the replies </TD></TR></TABLE>

no prob

a1320addict

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lmao!

im going to give it a shot, ive got some spare piping laying around, ill datalog a bit..if anyones interested in the outcome..lmk

Drew Peacock

[QUOTE=boosted hybrid]I have read a great deal concerning this topic since I posted this awhile ago. Basically a velocity stack forces the air to go from turbulent to laminar as quick as possible. The laminar air entering the turbo inlet would be less likely to heat up as turbulent air. This would net some gain, but nothing really significant. The gains that are seen on N/A engines are due to the vacuum conditions the engines operate at. The velocity stacks increase the airflow from turbulent to laminar flow, and therefore speed up the airflow allowing for more overall flow to be generated. On a compressor inlet of a turbocharger air is already quite laminar so the gain is minimal. If you would add internal velocity stacks inside of an intake manifold, greater flow would be achieved and more power would be made. There arent any aftermarket intake manifolds to my knowledge that have internal velocity stacks for Honda's. Flow would improve around 10-12%.[/QUOTE

Meh the info I read was in a magazine, so that should do.