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

[dhirocz]

When it rains, it pours.

Just finished buying just about everything for the steer axle of my truck. New slacks, drums, shoes, s cam bushing kit, springs, wheel bearings...trying to make it right.

Trying to correct my rigs prior life as a company truck

So my CAC is leaking. It was leaking slightly over the last couple weeks and decided it wanted to start leaking alot...right after fixing all my other boost leaks. I figure the extra strain on the original CAC from fixing all the other leaks probably did it. Go figure.

The engine will make boost, all the way up over 35psi if I let it, but will no longer create pressure at idle, and fails a pressure test. Won't hold 20psi for more than a few seconds, drops fairly quickly, and of course, poor mileage and higher than normal boost #'s regardless of speed.

So my KW dealer is usually pretty decent on parts prices, but the lowest they can go on the CAC out the door is $1500 with the install kit. Is it me or does that seem really high?!? Trying to make sure before I bite the bullet...I don't see anywhere to get a Paccar branded CAC other than the dealer.

Truck info below.

[Brock]

Duralite has a brand is CAC called eliminator which they say is a oem spec cooler at a fraction of the cost. It's in answer to critism over how restrictive thier duralites are.

Also spectra premium parts makes some food priced ones.

I've got the eliminator in my western star and so far so good.

[Rawze]

(10-11-2017 )Brock Wrote:  Duralite has a brand is CAC called eliminator which they say is a oem spec cooler at a fraction of the cost. It's in answer to critism over how restrictive thier duralites are.

Also spectra premium parts makes some food priced ones.

I've got the eliminator in my western star and so far so good.

COUNT THE NUMBER OF PASSAGEWAYS GOING ACROSS IT AND COMPARE TO THE OEM FACTORY -- I WOULD WILL NEVER BUY A DURA$COU%GH!!! -- EVERY ONE I HAVE EVER SEEN WAS SO BADLY RESTRICTIVE THAT THEY ARE HARD TO CUSTOM TUNE.

====

I just finally got a new CAC for mine last week. The old one had 1.19 million miles on it. I paid $1200 for it from the stealers$it. When I went there, they offered me a cheaper after-market one for only $800,... I said HELL NO!. I am not about to play that game.

I kept the old one and want to see if it can be fixed. That means i could have saved $250 if I had turned it in. Maybe I am a fool for that one, but it is all in the name of research I suppose.


i love saving money, but when it comes to saving $400 or $500, and it costing me $3000 in fuel in a year, that is where i draw the line.

[JMBT]

Man, the aftermarket are definitely cheaper, I am running a Detroit radiator power max. It was $300 cheaper then the OEM shipped and has a ten year warranty. HOWEVER....when I visited Rawze a few months back we took a look inside with a mirror, Rawze’s idea, and holy crap, the welds look like they were done by a kindergartener! Many of the passages are blocked because of the haphazard welding inside, and it showed itself a bit during the tuning process. It will be coming off when I can afford to put an OEM back on, hopefully soon.

My $.02, bite the bullet an stuck with OEM on the CAC.

What is in the install kit???

[Brock]

(10-12-2017 )Rawze Wrote:  

(10-11-2017 )Brock Wrote:  Duralite has a brand is CAC called eliminator which they say is a oem spec cooler at a fraction of the cost. It's in answer to critism over how restrictive thier duralites are.

Also spectra premium parts makes some food priced ones.

I've got the eliminator in my western star and so far so good.

COUNT THE NUMBER OF PASSAGEWAYS GOING ACROSS IT AND COMPARE TO THE OEM FACTORY -- I WOULD WILL NEVER BUY A DURA$COU%GH!!! -- EVERY ONE I HAVE EVER SEEN WAS SO BADLY RESTRICTIVE THAT THEY ARE HARD TO CUSTOM TUNE.

====

I just finally got a new CAC for mine last week. The old one had 1.19 million miles on it. I paid $1200 for it from the stealers$it. When I went there, they offered me a cheaper after-market one for only $800,... I said HELL NO!. I am not about to play that game.

I kept the old one and want to see if it can be fixed. That means i could have saved $250 if I had turned it in. Maybe I am a fool for that one, but it is all in the name of research I suppose.


i love saving money, but when it comes to saving $400 or $500, and it costing me $3000 in fuel in a year, that is where i draw the line.

It's not a built the same as the normal duralite CAC. World's apart.

http://www.duralite.net/content/dura-lit...ir-coolers

[Rawze]

(10-12-2017 )Brock Wrote:  It's not a built the same as the normal duralite CAC. World's apart.

The key is to count the number of passageways and their size. That seems to be the downfall of duraquit anyways. On my prostar, the durasmite has 12, but the OEM has 18. - That works out to only about 66% of the flow capacity of the OEM, and i have seen several trucks with intake boots collapsing when you get on the throttle because they are so restrictive.

They all brag about their welds like a bunch of morons, but that is not the problem with CAC units, and never really has been. It is the mounting and torsional loads placed on them by way of worn out mounting bushings, mis-aligned mounting holes, and not enough give to the front structure frame work. That is what makes them fail, and not so much simply bad welds. ALL of that can be corrected when installing a new one if someone just takes the time to make sure all radiator mounting bushings and CAC bushings are in good shape, they all have some give to them and are not binding, and that any screw holes in the framework that don't align well get ground out so that they do.

[Waterloo]

I would put an OEM CAC back on there, everything Rawze said and my own experience. Shop around, call a few dealers and make them fight for your money. I do it all the time with the same dealership chain until we get somewhere reasonable.

[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!

[Brock]

Call pacaar and ask those same questions and see what kind of bafoon answers you get.

The duralite is not junk as Rawze calls it, he has a very bias opinion based solely on his love for the isx engine and he is 100% correct when he says the duralite is not good for the vgt turbos..... the man knows his stuff.

But keep this in mind...... when and what they were built for before you judge.

They came out when the tuning big rig world was kicking up and high HP tuning was the new craze. PukeDits doing 700HP tunes etc. With any kind of tune on the older non vg engine's, they would just add more fuel which added more boost, add a bigger turbo etc etc etc. That's how it was done. The problem was the oem cac could not and still can not handle the stupid boost numbers these trucks were making. In comes duralite with a rock solid cac that can handle the job..... and it did.

I ran duralites on 3 of my trucks for years and loved them but they were 1999 to 2005 engine's.

Fast forward to today where guys like Rawze have changed the tuning game and geometry turbos play a huge part. You can now make 650HP without increasing boost pressure (well you always could..... but they didnt)

Now a restrictive yet bullet proof duralite is actually a bad thing. Doesn't change the fact that at what point they were good, because now they are all but obsolete.

Give credit where credit is due. They as a company have heard the complaints and adapted to survive by coming out with oem options that they claim are built better than oem and flow to specs. I don't crucify a company who learns and adapts, that would be like someone giving Rawze shi#t for a early version of mm that they don't like...... well it's obsolete now so..........

Not saying these new ones are good, I'm curious and gonna go to western star and compare but I just don't like to jump on the bash a company bandwagon.