Making a W2A intercooler

[Crampy]

Just wondering if you can weld some plates onto a normal air to air intercooler core encasing it in order to convert it to W2A? Or do they normally have differently designed cores?

Chur.

[Malcolm]

it can and has been done, but I think people tend to use short, thick cores, rather than the traditional tall and (relatively) thin cores used in air to airs.

All factory w/a coolers I've seen do use a quite different core design to an air to air, but I'm not sure what if any performance gains are seen in the differing designs.

I'm not sure if the photos are still around, but IIRC BBBrad's old 3sgte aw11 had a sweet w/a intercooler that he made, integrated into the intake manifold, and it was done using the method you describe. Another option is to flow the water through the original charge-air path, and run the charge-air through the original cooling-air path.

[strx7]

i've seen it done using Series 4 RX7 intercooler cores a few times

[Crampy]

I remember years ago in a magazine (Hot 4s or similar) where they welded up a WRX intercooler and used it as W2A and got very good results from it.

I've been looking at this site:
http://www.frozenboost.com/product_info ... 12bbf53390
It suggests W2A cores need smaller water passages, so traditional air to air cores don't work as well.

WARNING!
Some Water to Air Intercoolers that you can buy online do not contain true water to air cores. A true water to air core has water passages that are much smaller than the air passages. This is part of what allows the water to air intercooler to be so small and have such low pressure drop. Some water to air intercoolers that you buy online use an air to air core design where the air passages for ambient air and intake air are the same size, with an enormous loss of efficiency. Buy from us to make sure that you get a genuine water to air intercooler core!

Now that seems a bit off to me. If the water passages are bigger, it'd mean more water can pass by and collect more heat from the core, yes/no? I can understand the concept is used to make the cores smaller, but a normal size core converted to W2A would still *in my eyes* work quite well and not the "enormous loss in efficiency" they claim.

[tsoob]

One of my guys made an attempt at it once before, it worked but was not really that great, but it was on his diesel super custom.

[XSDRIFT]

I remember years ago in a magazine (Hot 4s or similar) where they welded up a WRX intercooler and used it as W2A and got very good results from it.

I've been looking at this site:
http://www.frozenboost.com/product_info ... 12bbf53390
It suggests W2A cores need smaller water passages, so traditional air to air cores don't work as well.

WARNING!
Some Water to Air Intercoolers that you can buy online do not contain true water to air cores. A true water to air core has water passages that are much smaller than the air passages. This is part of what allows the water to air intercooler to be so small and have such low pressure drop. Some water to air intercoolers that you buy online use an air to air core design where the air passages for ambient air and intake air are the same size, with an enormous loss of efficiency. Buy from us to make sure that you get a genuine water to air intercooler core!

Now that seems a bit off to me. If the water passages are bigger, it'd mean more water can pass by and collect more heat from the core, yes/no? I can understand the concept is used to make the cores smaller, but a normal size core converted to W2A would still *in my eyes* work quite well and not the "enormous loss in efficiency" they claim.

Nah the passages would need to be smaller. The idea is not so much about the amount of water you are putting through but the volume of that water which is touching the metal surface. It is the transfer of heat from the metal to the water which soaks the heat from the intercooler. So hence having more skinny passages means there is more surface area of the water touching the metal to pull the heat from it.

Personally I don't believe a W2A intercooler is as effe4ctive as an A2A and hence why when you upgrade a lot of the intercoolers that were W2A to begine with they go to A2A. In saying that though if money is no issue then there are some decent drag racing W2A options available.
I believe the majority of the time you end up being better off with an A2A as you aren't recirculating warm water as there is a constant supply of air from the front of the car.

My 2 Cents

[4agtepwr]

The one in my mr2 is just a 400 x 300 x75 intercooler with a box 100 wider either side of the intercooler, we pack it full of ice. Im quite lucky in that I have a big boot space behind the engine that allows for this though and its pretty much just for drag racing. The last time we had it on the dyno it was a hot day, 30 deg in the room, inlet air temps were 8 deg and after a run 24 deg still below ambient. And logging at the drags on another hot day it would only go to around 38 so still fairly aceptable.

Out of all the water to air intercoolers I have seen the plazmaman w2a seem to be the pic followed by the pwr. Not cheap though.
I have a modified st205 cooler that was really good up to about 300 hp and then fell over fairly quickly if you would like to buy that?

[Heylin]

My Greddy style 100mm side mount (air to air) on the MR2 runs about 36 deg C on 20 degree ambient. Thats on the dyno after repeat runs at 19psi using only the IC fan.

On a drag strip or track its going to be more like 30 degrees possibly less.

[Crampy]

After taking the Aristo to the drags, I think I'll go for a fan on the stock intercooler for sure. It heat soaks easily.
I think a fan will help to remove that heat generated by the run, but it's still not really ideal, due to the limited front surface area of the cooler. Every little bit will help though.