MauricesExoticP

In an effort to retain my AC and a few other creature comforts I'm looking to put together a w2a intercooler rather than use an a2a front mount.

I'm having a bit of trouble selecting an appropriate pump for my personal preferences.

I'm in the initial planning of this so I've very little hard data to provide other than goals, so with that said;

I'm looking at between 250 and 270 whp from a 1.5L D series equipped with a Garrett 2554R, Ebay W2A 2.5 in/out mounted in the engine bay where the stock air filter assembly usually goes, remote rear mounted heat exchanger for the W2A intercooler mounted behind the rear subframe, I expect mainly street driving on weekends that last roughly 2 hours in hot (110+°F) weather with the odd 450 mile road trip happening maybe once a year. Fuel will be e54 (shitty AZ flexfuel) which should help. Driving is mostly city, occasionally highway, and some weekend canyon carving.

I don't want to be stuck with a pump that can't handle the minimum 2 hour duty cycle and odd 6 hour road trip at highway speed, or a pump that just doesn't move enough water to be effective.

I am not wanting to spend huge sums of money.

There is a 3" in/out W2A intercooler on Ebay with a somewhat larger core that will fit it's rated at well above my goals however I doubt the rating is accurate. With some modification I could easily change the in/out size to something more suitable to what my aims are if the core would be more appropriate. I am apprehensive at adding any more volume to the charge piping as I would like to retain lots of throttle response. I'm well aware there are better W2A intercooler designs out there, for my modest power goals I can't exactly justify well over double the price of these units.

I presume there is a relationship between W2A intercooler core volume and heat exchanger core volume as well as pump flow rates; I want the heat exchanger to have enough time to reduce the water temperature and hopefully have a lower heat soaked temperature on those long highway road trips.

My assumption is that a larger heat exchanger core volume to W2A intercooler core volume will slow water flow through the heat exchanger allowing more time to radiate heat. To this end I'd like to fit the largest heat exchanger I can if my assumption is correct.

As for pumps, I am wondering what kind of factors I need to consider? I think it would be nice to purchase a pump that will not move water so fast that it fails to cool down in the heat exchanger but fast enough to keep cool water running through the W2A intercooler core.

Thanks,
Maurice
*EDIT*
It has just occurred to me that perhaps the AC condenser would be the better heat exchanger to relocate to the rear of the vehicle considering I'm looking for streetable performance first with a few creature comforts second.

Txdragon

Water to air IC for 270hp D15. All to save for space? You kidding? Oh.. You're serious..
Get an air to air front mount. There are soooooo many options small enough (for that power level) that will not hinder your A/C.

MauricesExoticP

A2A is out of the question.
a) I don't want the giant volume of charge pipe that goes along with a front mount IC.
b) I do want the extra intake charge cooling capability of the W2A in both on and off boost situations.
c) It is my project

Balor_Gr

I see you. You want that super small charge pipe volume right?



About the heat exchanger to intercooler sizing well it probably has to do with water flow too.
The rate which the heat attacks the intercooler must be the same or smaller with the rate cold water comes in.If not the water temp would act just as battery and climb when you boost and itll need cruising out of boost to cool down.
This pump moves 23lters per minute with 1amp draw
https://www.demon-tweeks.com/eu/davi...p-kit-dcp9050/
I dont have a clue about water to air cooling but i bet a "Smart for two" radiator (tiny 80hp european car) would be enough.
Like all types of air cooled radiators youll want it to be thin and to have big frontal area for air to hit it.

Chance EG

As you said, it's "your build", but you're really over complicating the hell out of what should be an incredibly simple build with a low HP goal. Especially when you're trying to save money and use eBay parts.

2x0

Do not overthink the velocity of water flow. The more volume, the better. Err on the side of having more than enough flow, and the biggest heat exchanger you can physically fit. Otherwise you risk heating up the water to the point it is no longer effective. I would also put a good fan on the heat exchanger that kicks on when the water reaches a certain temp.

A 500gph pump should support your power goal.

maxwellmercer

I would suggest the Bosch cobra pump (PN-0392022002)

MauricesExoticP

I was thinking more along these lines...

Txdragon

My bad. It's near impossible to convey humorous context in writing. Had you been a bit more specific with your ultimate concerns rather than just keeping ac, I'd have had a more suited answer for ya. I was merely trying to say you can save a LOT of fab time, money, and difficulty in order to conserve those "creature comforts". But you failed to initially mention those specific, technical bits until now.
As you said, it's YOUR project.. Luck to ya..

2x0

Not that the JEGs pump wouldn't work, but you said you were trying to keep the cost down, and that would be overkill for the application. Those are made for cooling entire engines, not just an intake charge.

Balor_Gr

20gpm is like 1.5Liter per second. It probably too fast.Ad there is also the amperage. I wouldnt run anything over maybe 2-3 amp.But thats me.
The 85 euros pump i linked draws like 1.5 ampere. For the same price you can have 2 in a push pull setup to help the super long water hoses.Maybe its not even needed.
Youre gonna mountthe radiator in the rear bumper area right?

khrys771

i found this kit with a quick google search.
Water to Air Intercooler

seems like they have a few kits, sounds easier than piecing it together.

93h2beg

I have built my own a2w setup. I would not do it again. Lots of custom fabrication. Nothing "bolts in".

I run the Bosch pump, this was oe for ford lightning's a2w setup iirc.

I have it powered by a relay and triggered by ignition switch. Same as my fuel pump.

ice box in trunk and heat exchanger behind bumper.

how well does it work? No idea yet, no dyno time. But due to going a2w I spent a ton of time and money on parts I ultimately changed and modified then threw out.

go a2a for ease unless you can fab yourself

MauricesExoticP

Yes it is for cooling a much larger engine than my little 1.5l and I have no doubt the pump will move plenty of water at an adequate pressure.

As for cost, yes it is something I am willing to spend money on; proper AN fittings too, I'm not going to go cheap on stuff that can't run for 6 hours continuously without concern.

My understanding is that more water flow is better in a set up that uses a W2A intercooler.

If I can source a heat exchanger that will fit in front of the core support opening and take up half the height I will go that route.

I believe i could then use a similar sized heat exchanger above it to replace the half sized radiator. This idea takes up the entire space for airflow in the front of the car unless I can somehow find a AC condenser that's nearly equal to the bumper opening in size but I'm not so sure I want to get in the way of airflow at all.

Most likely I am going to move the AC condenser to the rear of the car and deal with airflow issues to it somehow.

I'm looking for a better heat exchanger and pump than those kits provide. That heat exchanger is tiny, I'm looking for something with more frontal area and a dual pass design.

I can do most of the fab work on things that will need to happen except welding, to that end I will do the majority of the cutting and fitting and pass the finish welding off to someone who is able to do more that tack things together.

I'm not going to go A2A, and I don't mind fab work at all. In fact custom fab work is the part I enjoy the most. I know cost of the W2A system is well above an A2A system and complexity is always something that people shy away from but it makes me feel good when an idea works out just like I want it to. If it turns into a mess of leaks it'll be a learning experience.

Chance EG

Well, good luck to you then. Let us know how it all pans out (seriously). I'm interested to see what your results are, failure or success.

Txdragon

93h2beg

I wish you the best of luck. I struggled to find a good sized heat exchanger that fit in front of my radiator and cleared my wastegate, I bought 3 total . It will be a tight fit if you can make it work.

but my power goals are 4-500 so everything I bought had to be able to support that, thus making them larger.

hondalocal

Wood suggest this too. Have it on my S/C setup. 320gph

Picked up heat exchanger from: FrozenBoost

MauricesExoticP

Thanks and I will.

My budget is not unlimited I just need to be frugal with what I'm putting out for this part of the project.

I'm curious if you had a particular method of figure what size heat exchanger to use for your own goals?

I'm hoping that the equipment I get is sufficient to support a bit over what I need for my own goals.

I am going to go ahead and use the engine coolant pump I mentioned above; my thought being if pump flow improves performance of the heat exchanger and W2A intercooler it will have been a good choice to go with in the end.

My very basic understanding is that heat exchange from water through the heat exchanger metal and into the air is going to be mostly limited by water flow in my case. I'm sure there is the whole rule of diminishing returns, if the engine cooling pump is controlled I can easily determine what sort of pump is more adequate for my needs by testing the flow rate against temp drop across the core. More controls like air and water temps at various locations would make for a better science experiment but for me and my needs AIT against ambient checked against water flow is enough.

2x0

Best of luck running that pump. Will be an interesting experiment to say the least, but yes should provide more than enough flow.

I would be concerned with the amperage too, knowing how much of a voltage drop can occur from running a high amp cooling fan. Changes in voltage affects your injectors, ignition, etc. and unless they are dialed in perfectly could affect performance or cause other issues. I know I had to spend some time messing with injector dead times just to get it right from the voltage drop running my fan, which pulls around 15 amps.

The 8 amps for your water pump may not seem like a ton, but it all adds up.

wunfstgsr

I would research the LHT JRSC heat exchanger setup or even just give John a call at LHT performance and just ask them what size pump, heat exchanger they used for there B series Jackson kits. I had one years ago it should work perfect for your setup besides the actual intercooler, that wont be hard as there are many different sizes and shapes available, Even something like the Vortech after cooler for the B series vortech supercharger would work fine.

Alfa Turbo

I will leave the argument "do or not to do" A2W alone. I have a rear mounted tank of about 3 gallons and I use a 800GPH bildge pump with replaceable cartridge. They last about 5 years and run constantly at engine on. They are very inexpensive. This is mounted below the trunk floor and I have access via the screw out deck plate.

khrys771

Alfa, do you have manufacture and part number of your pump? also did you make that tank yourself?

Alfa Turbo

Yes the tank is custom made to fit in the space between the spare tire holder and the exhaust. 3/4" lines front to back. There is also a small radiator up front. Water flows from the tank > radiator > intercooler > tank... repeat.

Here is the pump,

MauricesExoticP

As for amperage demand I want to thank you for pointing that out, I have looked into swapping out the 70 amp alternator for something substantially more capable of handling any increased load and adequate at idle speed too.

In other news I saw a video comparing the generic W2A intercooler I originally mentioned above to another style, in any case it seemed to perform very well in the heat exchange department.

I'm still trying to work out where the actual heat exchanger(s) might go. It would be nice to hear some creative options here.