[389SixPack]

Who here has played with an Air to Water CAC on top of the engine? Eliminating the 6 feet of tubes and CAC must greatly reduce lag increasing spool. Has anyone played with them?

 

[TerminatorEngineering]

bbunting!

 

[DarkShadowDiesel]

i think BWD has done a couple - like joey said one is definitely on brian's truck

 

[69W900A]

Not on a powerstroke, use them on a lot of other stuff.

They work well. In fact, some manufacturers will be using them shortly. I think International will have quite a few models out next year, among others.

 

[389SixPack]

Yep, knew BB has one on puller. Just wondering about others.
Looking/thinking of aw-cac, replace stock cac with radiator, plumb in TE coolers and pump, and maybe a cooler storage tank. I could conceivable dramatically shorten the air flow passage, and with the coolers, drop my charge temp to -20 to -40*C. Quicker spool, more reactive throttle and higher density charge air. Looks like might it may be a plan. Still investigating.

 

[TerminatorEngineering]

Nigel, just add a second turbo, instead.oke:

 

[389SixPack]

Nigel, just add a second turbo, instead.oke:

That is in discussion also, but I still need to cool it efficiently and the WA-CAC would do that well.

 

[69W900A]

Depending on ambient conditions an air-to-air will have lower high road speed charge air temps. But a AW cooler will create a more stable temperature in at all speeds. One of the reasons why truck manufactures are using them again is with the VGT compound turbos they are making a lot of boost (read heat) at low road speeds where an air-to-air isn't particularly effective.

Obviously in a race environment ice water can be used to get really low temps for a short time.

 

[389SixPack]

Depending on ambient conditions an air-to-air will have lower high road speed charge air temps. But a AW cooler will create a more stable temperature in at all speeds. One of the reasons why truck manufactures are using them again is with the VGT compound turbos they are making a lot of boost (read heat) at low road speeds where an air-to-air isn't particularly effective.

Obviously in a race environment ice water can be used to get really low temps for a short time.

Yep, an ice/water mix can drop coolant temps to 28*F as circulated. Using a radiator to cool the initial heat rejection and then adding TE coolers would allow for much cooler temps for race or normal street use. Ice water in the cooler has been used for years as a cold source. Looking for a full time system.

 

[69W900A]

Well, get a big bottle of liquid nitrogen and blow it across your cooler, that'll get you in the -200*F range depending on ambient and loss from tank to nozzles, etc.

With a properly sized cooler for an on-road application will keep the charge air close to engine coolant temperatures. Or, in the case of a separate cooling system, whatever the charge air temp to AW coolant stabilizes at. A separate coolant supply is really going to add a lot of weight and plumbing if sized for normal use.

 

[Arisley]

A/C coils. ??? Maybe some kind of valve to divert cab a/c to CAC a/c when needed (racing).

Not even sure if it is possible. Just throwing something against the wall and seeing if it sticks.

 

[cowboy_dan]

An air to water CAC for continous use needs a radiator to cool the water also. Using engine coolant won't gain much other than a fairly stable inlet temp, probably higher than it should be at idle due to engine coolant heating the air. You would need the air to be significantly hotter than the engine coolant to make it effective.
But, using a seperate system with its own fluid, radiator, and CAC heat exchanger might work.

 

[racehauler]

Who here has played with an Air to Water CAC on top of the engine? Eliminating the 6 feet of tubes and CAC must greatly reduce lag increasing spool. Has anyone played with them?

In my own expierence going from non-intercooled OBS to adding and intercooler was a barely noticable difference in spool up. I was really worried about slowing down spool up because I had just gotten where I wanted to be by changing exhaust housings.

I do think there would be a gain in engine performance at very low or zero boost situations just from cooling the intake air to temps lower than ambient. That could result in a feeling of a better spooling turbocharger.

I have also wondered about using the A/C to cool a water to air IC.

 

[Charles]

Turbo lag shouldn't be a priority to determind going A:W for cooling IMO. Because I doubt you can even measure a difference in most cases, much less a substantial difference.

However, super cold charge air, is like having another turbo stage

The more you can cool the intake air post turbo, the more air the system takes in through the compressor inlet. Yes, actually more airflow.

You can actually cool the air sooo much that your turbo is now undersized for the flow reaquirements. Or conversely, if you take a turbo that is properly sized for an engine with good charge air cooling, and you remove the cooling, you will very often have a turbo too large for the engine now. Resulting in surging and compressor efficiency losses, as well as overboosting.

Intercooling moves more air through the engine. W:A can do that with amazing levels of efficiency for short term duration where a reservoir can be used for the cooling medium. But for durated runs, you simply revert back to the same basic efficiency as an A:A with the water simply serving as the medium between charge air and ambient air at the front mounted exchanger.

Dropping charge air temp is just as powerful as adding boost as far as CFM flowing into the charger. It's just much harder to actually get the charge air temps to come way down, whereas it's very easy to run the boost up.

I have often thought of making my own intake manifold with an integral W:A core inside. More plenum volume as well. But, things are a taaaad tight in there on a powerstroke, lol.

 

[mad_matt]

Why not go the overclockers route and add an evaproator onto the surface of the Intake tube on the cold side of the CAC and use that to permanatly super chill the air. It will last longer than a cold source like ice water. Me I'm sticking with the A2A for now. Oh ya I also have a second stage being added. :ford:

 

[bbunting]

Well, couple points here. Where Spearco units are concerned, there is less than .5 to 1.5 psi pressure drop across the core-we have measured 5.5 psi restriction across the stock 7.3 core at 30 PSI.

Water can dissipate more heat than air given like conditions-meaning 100 degree water can scrub more IAT then 100 degree air at the same pressure-by about 4x

The cost of the A/W used to price them too far out of reach, but for a street set up, TN has some that are less than the air to air units. You'd have to run a large enough front mount exchanger, and reservoir to keep the water at or near ambient air temps. I used an aluminum racing radiator mounted where the old A/A used to be, and a 16 gallon fuel cell in the bed for the water tank. Spearco has a OE quality water pump that is made by Bosch. Total price estimate is 2g for a street app.

I run two A/W coolers on my truck, one for each stage-(not ***, but me) and we also did the same for a customer truck that was at Houston (again, not ***). That is the ultimate power adder for a competition set up, as I can control IATs down to 35 degrees or so, each stage.

 

[imelmo]

Pics?

 

[389SixPack]

Well, couple points here. Where Spearco units are concerned, there is less than .5 to 1.5 psi pressure drop across the core-we have measured 5.5 psi restriction across the stock 7.3 core at 30 PSI.

Water can dissipate more heat than air given like conditions-meaning 100 degree water can scrub more IAT then 100 degree air at the same pressure-by about 4x

The cost of the A/W used to price them too far out of reach, but for a street set up, TN has some that are less than the air to air units. You'd have to run a large enough front mount exchanger, and reservoir to keep the water at or near ambient air temps. I used an aluminum racing radiator mounted where the old A/A used to be, and a 16 gallon fuel cell in the bed for the water tank. Spearco has a OE quality water pump that is made by Bosch. Total price estimate is 2g for a street app.

I run two A/W coolers on my truck, one for each stage-(not ***, but me) and we also did the same for a customer truck that was at Houston (again, not ***). That is the ultimate power adder for a competition set up, as I can control IATs down to 35 degrees or so, each stage.

Yep, that is the direction I was think. Aluminum radiator in front. W-A CAC like a 2-230 with the side tanks pointing the same way. Insulated storage tank below frame and one or more TE coolers to drop the temps using a controller. Even in the worst conditions on road or off, it will maintain ambient or below. In a race/pull situation the controllers an be turned full bore at get coolant well down below ambient prior to the event.

Did you notice any difference in response going from A-A to A-W? I would think shorter length, less restriction, more responsive.

 

[bbunting]

As for the responsiveness, it will spool faster once you lose the restriction of the stock IC. I never measured the speed, but I also went from stock to A/W.

One thing to remember is the speed (GPM) of the pump needs to be 6-8 GPM. Faster than that, and the water can't absorb the heat, and too slow, and you get heat soak. The 2-230 has .18< PSI drop at 30 PSI @ 700 CFM. The inlet/outlet location and size are completely custom-I have 4" v bands on one, 3" v bands on the other.

I am considering using some Evans waterless coolant for heat shedding properties other than water. It also won't freeze, where adding antifreeze to water slightly diminishes its cooling properties.

I don't have pictures of the twin A/W, but here is one of the single on my truck from 2005. LINK

And here is one of the coolers I use LINK

 

[Haul_n_horses2]

I am considering using some Evans waterless coolant for heat shedding properties other than water. It also won't freeze, where adding antifreeze to water slightly diminishes its cooling properties.

AutoJim told me that the viscosity of the Evans is higher than water based coolants (probably even more so when cold) and with the same pump, Evans had decreased heat shedding properties compared to gylcol/water. Something to consider.