Re: "Maybe a new thread for cold side"

got any pics of the hat youre using Chimp?

 

Re: "Maybe a new thread for cold side"

I think i have a few pics, let me dig through my pics or find the youtube of my friends dyno runs i think it shows it. I have three different ones i made, my friend claimed ownership of the larger one that made 1237hp on his 417 mopar after seeing the results LOL!

I am currently running a real short one on my stang as hood clearance is tight but the setup is all new and i haven't put it under more than 1psi yet. I feel it will work but i haven't track tested or dynoed this hat yet, but i feel confident it will work pretty well.

 

Re: "Maybe a new thread for cold side"

I didn't mean for that to insult, just trying to pry out some more info for the thread.
I looked thru the build and see the spacer on with charger also. Did you ever run it without the spacer?

 

Re: "Maybe a new thread for cold side"

I didnt take it as an insult .

I had the 2" spacer on the Procharger set-up originally because I used a Procharger hat , and we all know they have a hard time straightening the air .

I bought Brents EV hat and it all ready had the 1" spacer welded to it . I used the 2"also because you can never have too much spacing . If it fits , use it .

 

Re: "Maybe a new thread for cold side"

That looks like a SDCE hat.

 

Re: "Maybe a new thread for cold side"

I thought the same thing . Just using a stack for a defuser .

 

Re: "Maybe a new thread for cold side"

In regards to bov placement should there be any consideration to the intercooler acting as an accumulator? If you have 20 psi pushing air into a storage reservoir ie intercooler once the throttle has closed the compressed air is going to continue expanding on top of the flow continuing from the turbo, if the bov is on the turbo side of the intercooler would these 2 separate sources cause problems? I ask because you often hear a fluttering noise from the cooler when the bov is on the turbo side.

 

Re: "Maybe a new thread for cold side"

I am willing to agree with the theory that this is the case, however I will counter with the thought that any thing that was significant would likely be considered detrimental to the response of the system when it's coming up on boost. That means that in general people would try to make this effect minimal.

 

Re: "Maybe a new thread for cold side"

I tend to look at it this way:

1) You have Mass Flow coming from the Boosting Device thru the inter-cooler and then to the Throttle body and on to the engine.

2) Now you slam the throttle shut. Vacuum builds under the throttle plate(s) and that signal opens the Bypass valve(s). The Mass Flow coming from the Boosting Device thru the inter-cooler and then to the Throttle body is now DIVERTED to a different location but the Mass Flow continues. As soon as the Throttle Blade opens again some of the Mass Flow will immediately be available to the engine.

3) If you have the By-pass valve at the Boosting Device location, several things happen:

a) A Pressure Spike builds from the closed throttle blade(s), expands to the Inter-cooler, and then eventually is bled off at the By-pass location.

b) The air previously going into the engine after the by-pass valve (near the boosting device) basically stops. It may be at a higher pressure but the flow has stopped.

c) When the Throttle Valve is opened again, the vacuum signal must drop as it travels from the previous vacuum source below the blade(s) to the By-pass valve. During this time the air between the by-pass valve and the throttle body must be "restarted" and regain its velocity and the By-pass valve is still bleeding off mass flow until the By-pass valve completely closes from no vacuum being applied to the valve.

So my point is, the engine can only make power when it sees Mass Flow. How quickly it regains power depends on how long it takes for the previous Mass Flow to be fully restored. Take your Pick.

Tom Vaught

 

Re: "Maybe a new thread for cold side"

Might have misinterpreted my post, I am for having the bov at the throttle body, i was more wondering if it has an effect or not? Many fluid and pnuematic systems have an accumulator after the pump to help reduce effects downstream harming the pump such as spikes also helps in resuming fluid flow in the moments after a valve has been actuated in this case the throttle, to me it is another advantage of placing the bov after the intercooler. Why not use it no matter how small an advantage.
Cheers Ben

 

Re: "Maybe a new thread for cold side"

Well if I did then I apologize for that deal.

Not claiming to be a Accumulator "Expert" but have been around a lot of transmission builds at Ford's Livonia Transmission Plant. From what I have seen most of the accumulators have a heavy spring that the high pressure spike has to overcome but that spring and movable piston keeps the parts from failing due to the shock loads.

With an inter-cooler as long as the system is flowing a given boost pressure and the inter-cooler is designed for that pressure under stead-state conditions to be durable, then you are fine. If you get pressure spikes, then things fail over time: panels blow out, welds crack, etc.

I would agree that if you could design a transmission style accumulator device into the inter-cooler plumbing it would "act" like a transmission accumulator and soften the pressure spikes. Most instead try and dump the pressure vs contain it. You can dump air. You dump Trans Fluid from the system and shortly there after you have no fluid, LOL!

Tom Vaught

 

Re: "Maybe a new thread for cold side"

An accumulator would be an interesting thought in some ways, my question is more of how much volume would you need. I am of the thinking it could be staggering at best! I mean you're talking about likely10 cubic feet per second if not more! Don't get me wrong it would be a killer setup though in some ways especially if you added some electronics to it.

 

Re: "Maybe a new thread for cold side"

I would say that a typical By-pass Valve (say 30mm) can dump air a bunch of air in a short time. If your air induction system were 9 liters in volume, not very much really, most 30mm By-pass valves should dump that volume in less than 100 milliseconds (1/10th of a second). The deal is average gas speed is 300 ft per second in a decent air system.

So now let us say we have a 4" diameter pipe that is 10 feet long and we are trying to figure out the volume, how much we can dump, and how quickly we can dump it.

A bit of math:

Say we have a 4" tube with a .060" wall thickness. Tube is sold by the outside diameter dimension but the area of the tube is based on the inside diameter dimension.

A 4.0" tube with a .060' wall thickness would be: 4.00" minus .060" plus .060" or 3.880"

We now divide the tube diameter 3.880" by 2 to get the radius which is 1.940".

Then we multiple the radius number by itself: 1.940" times 1.940" and get 3.7636

Now we have to multiply times PI to get the area for 1 square inch of pipe.

3.7636 times 3.14159 and we get 11.8237 Cubic Inches of Volume.

This we multiply times 12 to get volume per foot of pipe or 11.8237 times 12= 141.8844
Cubic Inches of Volume. And, Finally we multiply that number by the 10 foot length of pipe in the question and we get 1418.84 Cubic Inches of Volume.

A Liter is 61.0237 cubic inches of volume so we divide 1418.84 by 61.0237 and we get 23.2506 liters of volume. Above we said that we know we can dump 9 liters of volume in less than 100 milliseconds (1/10th of a second) so if we divide 23.2506 liters of volume by 9 we get 2.5834. We multiple that times 100 milliseconds and we get 258.34 milliseconds to dump the volume. Over 1/4 of a second. Drag racers know that a 1/4th of a second is a LONG time.

So then you think: If I use two valves then I can dump the air in 129.17 milliseconds seconds but that is still over a tenth of a second. (.129 Seconds)

With a 300 ft per second Volume Flow (typical average head flow speed) (if my simple math is correct) we will move 90 liters of air through that pipe in one second.

So even with two 30mm By-pass valves we miss out target of dumping the volume in less than 100 milliseconds by about 25%.

So basically we get a pressure spike because we can't dump the volume fast enough.

One 30mm valve has about 1.1 square inches of area so two 30mm valves would have 2.2 square inches of area. A 57mm by-pass valve has 3.96 square inches of area.

This is why a big valve can dump the volume and even two smaller valves cannot.

The only issue is that the 57mm valve might be a bunch slower in opening to dump the air so the pressure spike might still be there.

Only testing can verify this as everyone has different system volumes, the air speed might be different from 300 ft/sec average velocity, and the By-pass valve is only one part of the plumbing in most non race systems.

Just my thoughts.

Tom Vaught

 

Re: "Maybe a new thread for cold side"

G'day Tom,

Would you not also need to take into account the fact the air is under pressure? So if you had that pipe with 10psi it would be closer to 40Litres of air, and nearly 55L of air at 20psi.
While I would guess that most systems would not hold that much when static, probably closer to 10-15L it is still something that needs to be considered.

For me personally I would think maintaining air flow in the correct direction when the BOV is operating rather than all that air reverting back towards the compressor and then fighting with the air still being pumped from the turbo would have to be a good thing.

I was probably wrong in calling the intercooler an accumulator maybe reciever or resivoir would be a better term, I could not see trying to make an accumulator setup worth the complexity time and trouble?

 

Re: "Maybe a new thread for cold side"

Say that you had a Drum that could hold 100 cubic feet of liquid, in this example I will use water and air.

If the Drum is full of water, the Drum holds 100 cubic feet of water.

If the Drum is full of Air, the Drum holds 100 cubic feet of Air.

Water is basically "Incompressible". (One part in 5×10,0000000 decrease in volume for each atmosphere increase in pressure'”that it is incredibly rigid if constrained within a solid skin.) Yep, it can be compressed in a pure sense but not in a practical sense.

So if we tried to compress water to twice the pressure we would shrink the density of the water by 1/500,000,000 of its previous size. (one 500 millionths smaller).

Air, on the other hand, can be compressed. If we pressurize the Drum to 15 psi we would still have EXACTLY the same Volume of Air in the Drum (100 cubic feet of Air) but we will have in simple terms twice the air molecules in that same 100 cubic foot Drum. So you do not have 40 Liters of air or 55Liters of air in volume terms. You will have twice the density of Air Molecules or (more in the 20 PSI case).

Engines make power based on the number of air molecules that we can mix with the proper ratio of fuel molecules.

Hope this helps out.

Tom Vaught

 

Re: "Maybe a new thread for cold side"

Still Tom, to capture the air that would normally be expelled through a BOV into a canister (accumulator), I would imagine would have to be a very large container, keeping the original boost level. Some would still have to be expelled in the end, not being able to capture all of the air into a reasonably sized container. But, if just some of the air could be captured under pressure, it could be reintroduced when the throttle was again opened.

 

Re: "Maybe a new thread for cold side"

At the risk of making myself look like a complete tool.... I think you maybe wrong on some of what you have written Tom. ( I may regret this statement!)

If the Drum is full of water, the Drum holds 100 cubic feet of water.

True, and as you have stated it can not be compressed, so if placed under pressure it will still be only able to hold 100cubic feet of water.

But it needs a medium of sorts to compress it, Either an mechanical force such as a piston pressing upon it or in the case of a pump, the pump will try and push more fluid into the drum, but as it can not be compressed and the fluid in the drum is static, pressure will rise.

Air, on the other hand, can be compressed. If we pressurize the Drum to 15 psi we would still have EXACTLY the same Volume of Air in the Drum (100 cubic feet of Air)

True, sort of... If you used a mechanical medium to compress the air you would have the same volume of air in the drum, but it would not take up the same physical volume of 100 ft3 in the drum you would find you have squashed the piston half way down the drum to reach 15psi.

If you use a pump to compress the air it is totally different to fluid, air compressed as you have said so if you use a turbo screw compressor or such to be the medium in which the air is being compressed it will pump more air into the drum, and then more and more, as the air compresses to the point it cant compress anymore the pressure will rise, and you will find that you have twice the amount of air in the drum as before (made the amount up because Im not smart enough to work it out) but the physical size of the drum has not changed. It still has an internal volume of 100ft3.

but we will have in simple terms twice the air molecules in that same 100 cubic foot Drum.

This is where your extra molecules come from, they cant multiply simply because they are under pressure, they have to come from somewhere? you have stuffed twice the amount of air into the same physical space.

It gets more tricky when you pump air as it heats up, as every body knows it expands, so you will fit less air into the same space at 15psi if it is hot rather than when it is cold, how you would work out the actual volume in a system when there is 15psi of hot air on one side of the intercooler and 15psi of colder air on the other, hurts my brain, in reality it is probably irrelevent for us at this level because our systems are not static.

Here are my thoughts on using an accumulator in the system.

Type of accumulator?
Spring/gas and piston, big heavy and prone to failure, any system with compressed air creates moisture, lots of it. I could not see it lasting long without corrosion

Bladder type? maybe but they are heavy, and what ever your system pressure is they have to have the nitrogen bladder charged to, so that they can equal that pressure.

Then you have to charge the accumulator, when does this happen? it would have to be when under boost, the last thing you want is half of your air flow going to an accumulator and not your engine.

What about when the BOV operates(which is now effectively a divertor valve)? well then you have your relieved air not venting into a low pressure area, ie the atmosphere, you have it venting into a container, that has a rising rate of pressure and a reduction in flow the more you pump into it.

Actualy the more I think about it I was completely wrong in saying that you could call the aftercooler a accumulator. I have never seen a air system with one in it, they dont need one, nor do I think that one would work properly with air as the medium being used?

Well hopefully my ramblings make sense, and I maybe completely of track! Have I got it tragically wrong?

 

Re: "Maybe a new thread for cold side"

Nothing wrong with your ramblings. How people sort out stuff, including me.

My point earlier was that it might be easier to divert the flow and then switch it back to the engine quickly (at the Throttle Body) vs dumping air at the boost device and thinking that the Inter-cooler would store the extra air.

"True, sort of... If you used a mechanical medium to compress the air you would have the same volume of air in the drum, but it would not take up the same physical volume of 100 ft3 in the drum you would find you have squashed the piston half way down the drum to reach 15psi."

In a hydraulic sense that would be correct because you used a piston to compress the volume. The piston has to move to compress the volume to twice the pressure. With a boosting device (from example a supercharger that has a displacement of 3.3 Liters per revolution) if you spin it twice as fast you will basically be trying to compress twice the air molecules into the same fixed volume (the engine) so you have twice the "boost).

I am saying the "Fixed Volume" (the engine does not change). If it displaces a given volume per crankshaft revolution it will always displace that volume. It will displace more total volume as the rpm increases but the fixed volume per revolution stays the same.
(The fixed volume in my previous example was the 100 cfm drum). It could have been a 3.3 Liters per revolution engine.

Hope this makes sense.

This is why a smaller engine might have a high boost number to make say 1000 hp (or 100 lbs of air mass per minute of flow.

A large engine might have 1/2 the boost number and still consume the same 100 lbs/min of air mass and still make the same 1000 horsepower.

Tom Vaught

 

Re: "Maybe a new thread for cold side"

Is there a reasoning on this? 57mm having a greater surface area will be easier for the BP to "push" open as soon as enough pressure is lost on top of the valve actuator.

Also the 57mm valve should lift higher compared to the dual 30mm BPVs considering the amount of force delivered to each valve.

But springs are more of the deciding factor at any rate.

As always all up for discussion.

 

Re: "Maybe a new thread for cold side"

Guess im one of the few that has done many different setups on a certain engine and havnt noticed any/enough difference between bov placement, pipe diameter(to a point obviously) and many other variables being discussed in this thread to warrant doing it this way/that way. Gets to the point of splitting hairs and not worth the time/customers money.
just my. 02. Debates are always fun however