question about feeding air to a VTDA...
10-04-2006, 05:47 PM
#1
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question about feeding air to a VTDA...
Steve (or others), your opinions please:
How effective do you think it is to run air feeds to a VTDA, given it's not sealed? Would anyone who's run cold air feeds to the mouth of the VTDA care to comment on whether they felt a difference in hot weather?
And would removing the blanking panel, in the lower side air grill on a 180, be effective, without the flexible tubing--simply freeing up the air path through the fender well?
TIA,
~john
How effective do you think it is to run air feeds to a VTDA, given it's not sealed? Would anyone who's run cold air feeds to the mouth of the VTDA care to comment on whether they felt a difference in hot weather?
And would removing the blanking panel, in the lower side air grill on a 180, be effective, without the flexible tubing--simply freeing up the air path through the fender well?
TIA,
~john
10-04-2006, 06:24 PM
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From a purely fluid mechanical point of view...
At 65 mph (well, 30m/s) with two 6cm feed tubes, you're talking about a volumetric flowrate of (2*30m/s*pi*r^2) = .17m^3/sec, a significant volume of cool air. Assume some moderate headloss and you're looking at .1m^3/sec volumetric flowrate.
Take 1200g/m^3 as the density of air, you're getting 120g/sec of fresh air. From the modshack website, peak mass flow rate of the VTDA is ~190g/sec.
That means that the front air feeds can put ~60% of the total air intake demand to directly in front of the VTDA. Use bigger hoses, and you can bring this number beyond the total intake demand.
Even if this air doesn't go directly into the VTDA it will cool the engine compartment and as a result cool the air that gets taken directly from the engine compartment.
Obviously, at lower speeds these front air feeds will have much less of an effect, but on the highway they should have a significant impact on the intake air temperature.
Now I just have to scrounge up the cash to buy a VTDA for myself.
Take 1200g/m^3 as the density of air, you're getting 120g/sec of fresh air. From the modshack website, peak mass flow rate of the VTDA is ~190g/sec.
That means that the front air feeds can put ~60% of the total air intake demand to directly in front of the VTDA. Use bigger hoses, and you can bring this number beyond the total intake demand.
Even if this air doesn't go directly into the VTDA it will cool the engine compartment and as a result cool the air that gets taken directly from the engine compartment.
Obviously, at lower speeds these front air feeds will have much less of an effect, but on the highway they should have a significant impact on the intake air temperature.
Now I just have to scrounge up the cash to buy a VTDA for myself.
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10-04-2006, 06:34 PM
#8
i'm not sure i would agree with the word DRAMATIC....but i do think that the feeds
help draw the air up there and makes cooler air 'always' available. what i haven't done, is take the rubber hood seal and convert it to the lower vent that the ModShack sells. i would think that would increase the air flow much better throughout the engine bay.
but DRAMATIC? come on...can you really feel a 1HP gain if even that? Hans?
but DRAMATIC? come on...can you really feel a 1HP gain if even that? Hans?
10-04-2006, 06:41 PM
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Here's an install from Steve's fotki...
<ul><li><a href="http://public.fotki.com/ttschwing/new!_vtda_productio/fresh_air_feeds/">http://public.fotki.com/ttschwing/new!_vtda_productio/fresh_air_feeds/</a</li></ul>