Wait...my CAC is how much?!?

[dhirocz]

So, I'm just sharing at this point...I ordered a new CAC from my dealer today and I'm waiting for it to show up.

I was curious, so I called duralite. I wanted some answers, because I like to know the 'why' in things. I spoke to this salesman, who instantly went to work on the whole...it's Tig welded...silicone grommets...blah blah blah. So I asked him:
How many tubes compared to OEM?
Thermal efficiency compared to OEM?
Pressure drop across the core vs OEM?
How were these tests conducted and to what standard were they compared?

...an hour later, I had an engineer, or at least someone who told me they were an engineer, call me back with answers since it's obvious 90% of their sales tactic is based on the durability of it only.

We had a long conversation. I was told the duralite has fewer, but larger, tubes across the core, because the tubes have a larger cross sectional area than stock. I was told that it's superior because of how it's welded and sealed... I was also told alot of the claims are based on calculation, and not real world tests...but was assured that the cooler fell within the 2 psi pressure drop criteria that Cummins uses on a CAC.

Based on what I heard and what I know of mechanics and physics, of their 7 year warranty and all that, I had to ask a question...if there are less tubes, and the remaining tubes are larger, even though there may or may not be an acceptable level of pressure drop, that is less surface area within the core for the compressed air from the turbo to interact with, meaning it's harder to cool in it's short trip across the core. Since this thing has such a long warranty on it, I had to ask...

'What gage aluminum is the core made of?' He had no idea.

Now think about it. In something such as a charge air cooler, where it's main job is to cool heated and compressed gas, alot of factors come into play...the number of tubes...fins per inch...the alloy it's made out of...dwell time in the tubes...and yes, the thickness, among other things. The thinner it is, the more efficient it will be at heat transfer at the expense of durability.

The man had no answer. An engineer at that. I can't fathom how you wouldn't know that with a part such as that whose main selling point is durability. I'm speculating here, but I'm guessing it's a thicker gage than stock...meaning combined with less rows, more than likely less thermal efficient...making for a less dense air charge in to the engine, and potentially less power and a more inefficient burn as a result...and that doesn't even consider if there is more pressure drop across the core than the engine would like to see.

Also heard 'nobody calls and asks these kind of questions' more than once. They weren't prepared to answer them apparently. Most people just ask about their durability, so I guess if you want to sacrifice efficiency for durability it would be a good option. For this approach to work, I would expect a cooler like this to be larger or have more fins per inch to increase thermal transfer...I would also expect it to be more expensive.

So yeah, it's paccar time. Now I know!

If I'm wrong, someone come ring the bell. I'm the kind who likes to consider everything, but after deciding what facts are actually factual and valid, and making my own decisions on things. I'm here to learn, so I love asking why.

I'd love to put a temp probe and a pressure gauge into each side of a good OEM cooler and one of these just to tickle my pickle. Hell, throw them up on a flowbench while I'm at it!