So I just installed the varimax with a second HEX and my results are far from ideal.

I saw a very similar IAT you did on a 0-110 pull, but ambient temps were about 80*. I need to figure out what my current limitation is. I am leaning toward it being the intercooler inlet tubes. They are the largest restriction to fluid flow as best I can tell now. Of course I have no way of knowing if its the intercooler itself... but thats a little harder to change.

 

Being from the HVAC world, I am amazed that under the blower charge coolers do anything at all. Look at it from my point of view: at high rpm, a blower four times as much air as a small residential furnace, maybe double a large furnace. That is a lot of air. Now consider that it is also probably at a much higher velocity. So at peak flow, you are moving enough hot air to heat a large house, through each inter cooler.(There is one inter cooler for each cylinder bank, right?)
So how can it efficiently cool that much air flowing that fast, in only 1-1/2 inches of thickness, or however thick they are?

 

Any air conditioner slows the air down from the blower by sending it to a more open space to give more time to cool it, and then through the evaporator that is as thick or thicker than these inter coolers. And, the A-coil evaporator in a furnace might have five square feet of area that is cooling this much lower volume, slower moving air. The charge cooler concentrates the air flow and cools it in the minimum time.
This is why I find it amazing that intercoolers do anything at all to cool the charge air.

 

It's my opinion that efforts should not be on increasing water flow, but maximum gain would come from decreasing water temperature to gain efficiency from such a small surface area. If I had an air to water system, I would figure out how to refrigerate the water.

 

Using the vehicles air conditioner with specially piped refrigerant and solenoid valves.

 

I know that nobody will do this, I just had to rant about these miniscule intercoolers. Thanks for an ear or two.

 

Check out the killer chiller. Believe it was ls1gto that had a big write up on results.

 

Yeah, I have the KC on my 2000 Silverado. It made a big difference on my IATs here in sunny(hot) AL. Of course I am running an older, less efficient MP122 Magnacharger that makes more heat. I had to buy a crimper and make my own hoses, but in the end it was worth it.

With the KC a cruising IAT is around 10* above ambient. IATs will still climb during a hard run to around 140*-150* but they recover down to around 10-15* above ambient within a minute or so. Before the KC my normal IATs were 30-50* above ambient - talk about no fun... I think the size/thickness of the intercooler are the limiting factor now. If I ever remove the blower I will look at installing a larger/thicker core, if it is even possible.

Of course I have a 2.5 gallon reservoir under the hood and all the hoses are insulated, so it gets kinda crowded under there. But with the 2.8" pulley it makes right at 14 psi. I still have the HEX up front but I have a 3 way valve that I can change the direction of the flow with. It works best, in the summer anyway, to bypass the HEX. My coolant tank water will usually be around 50*-65* unless I am beating on it. And YES, I still have AC in the cab, can't live without it here.

 

Yea people do that.

Speeding up the water flow ensures that you always have cool water in the IC. You dont want it to be in there enough time to heat soak. Along with that you also add fluid volume to the cooling side.

Remember when it gets cool out you have access to cold air that get water temps very low.

 

I have to agree with you man, I expected a better result from adding a second HEX. I really didn't notice much difference except for it recovering a lot quicker when driving.
What we all have to remember is that these "Radix" kits were never designed to run 10+psi. Magnuson designs all their kits to be CARB. certified and that usually means around 6-7 psi. At 6-7psi, the intercooler system works great!
I know the team at Magnuson is working really hard at trying to figure out some upgrades for us guys wanting to run the higher boost numbers.