A turbocharger builds boost for big performance gains but it comes at the cost of increased heat. Compressing air raises its temperature (typically about 150 degrees more than the outside ambient temps for every seven pounds of boost). The use of an intercooler to bring the intake air temperatures back down to optimum levels is a very good idea, especially if your truck is going to have a bunch of other speed mods. Spearco offers upgrades for a variety of diesel applications, including the Ford 6.4-liter Power Stroke, we’re going to install and test one to see what kind of a difference it makes in a real world environment.
What is an Intercooler?
Think of an intercooler like a radiator for the hot boosted air that comes out of a turbocharger. The boosted air runs through the intercooler’s tubes while outside air runs over the fins. The cooler outside air pulls heat out of the boosted air, thus cooling down the boosted air. The higher your intake temperatures, the more of a difference an intercooler will make. Pretty much every diesel made this century has had an intercooler, but they don’t all perform the same. For more information on how an intercooler works click here. (We did a cool tour of the Spearco/Turbonetics manufacturing facility. Spearco has been manufacturing intercoolers for almost 30 years and they have some innovative technology in their products.)
Lower intake temperatures equal lower combustion temperatures. Exhaust gas temperatures (EGTs) will be reduced, but more importantly, the engine internals will be under less stress. Remember, most factory pistons are aluminum and high EGTs aren’t generally kind to aluminum.
The word “intercooler” came about early in the days of using what is correctly termed a “charge air cooler” (CAC) as they were usually between two turbochargers or between a turbocharger and a supercharger. The term aftercooler is sometimes used as well to describe a charge air cooler. The aftercooler was installed after all of the compressing was done. (So, either after the supercharger or after both turbochargers). Regardless of where the charge air cooler is located, people have just stuck to using the term intercooler.
Spearco by Turbonetics
Spearco has an intercooler for the Ford 6.4 Power Stroke that is a bolt-on kit and can drop the intake temperatures an average of 150 degrees (Spearco says they’ve seen a drop of 250 degrees!) with less than a 1-psi pressure drop. If your truck sees more boost pressure than factory or if you tow frequently, an intercooler should be on your list of upgrades.
What does Bar and Plate mean?
Bar and Plate:
What does that really mean? Well, if you look at the thumbnail above, the very top of the intercooler cutaway there is a bar. Right below that, are sets of fins. If you look very close, you can see that the fins have a high number of louvers in them. These louvers are part of Spearco’s WAVE technology.
Below the Fins is another plate. The next level down, there is a bar on each end with fins in the middle. The bars on each side mated to a plate above and below to create the bar and plate design. The fins that are in between the bars are there to promote heat exchange between the bar and the air.
The extra capacity comes in handy when the truck has been upgraded with a larger turbocharger, or is running more boost pressure. The additional volume can back up the factory intercooler causing a loss of boost pressure (by measuring the boost pressure on each side of the intercooler, you can determine if the intercooler can support the volume of air your system is moving). With a Spearco intercooler, they measure a pressure loss of less than 1 psi, even in high boost/volume applications.
To remove even more heat, some owners will install a misting system to spray water over the intercooler. Water has a much higher convection coefficient than air and is able to remove even more heat than air alone. In some race applications, people will spray CO2 in front of their intercooler to really cool the charge air down.
We grabbed a 2008 Ford F-250 with a 6.4L Power Stroke (they are available ’08 to ’10) and installed one of Spearco’s kits to see just what was involved. We thought this might be a driveway-type install and we were right. It’s super easy to put in the Super Duty.
Spearco’s Reggie Wynn told us, “The intercooler comes with a one-year no fault /no hassle warranty, even if you’re racing.” It doesn’t matter how hard you were pushing your truck, what mods it has or even if you were in a wreck. You’re going to be covered. Maybe that’s why Spearco pressure-checks every intercooler before it’s shipped.
The truck (2008 F-250)
This truck is a perfect candidate for the upgrade as it has a modified set of compounds turbos and is capable of running 55 lbs of boost. The truck has oversized injectors, S&B intake, exhaust and is running a H&S Performance Mini Max tuner.
Installing the intercooler in less than an hour
We headed over to Diesel Dynamics where McClain Young helped us with the install. We didn’t go to a shop because the job is all that tough (Young said, “Uninstalling a 6.4 intercooler is extremely easy. There are 3 bolts, two hose clamps and it is out. You don’t have to remove anything to get to it”) but because we wanted to take photos while someone else did the work. He’s not exaggerating about how easy the job is.
The installation started by disconnecting the charge air cooler (CAC) tubes. With the upper and lower CAC tubes pushed out of the way (Young didn’t remove them), Young unbolted the transmission cooler (one bolt) and unbolted the intercooler (2 bolts).
Yep, half way done already! With the factory intercooler removed, Young removed the grommets from the top and bottom of the intercooler.
Young lubed the lower grommets and reinstalled them back into the factory holes by the radiator. Then he installed the “Z” brackets.
The grommets for the upper mounts were installed on the new Spearco intercooler and Young was basically ready to stuff the new intercooler in place.
With the intercooler roughly in place, Young moved to the underside of the truck. There he bolted the “Z” brackets to the intercooler.
While under the truck, he went ahead and connected the lower CAC tube as well.
With the underside done, Young went ahead and bolted the intercooler in place.
After the intercooler was mounted, the upper CAC tube was installed.
Finally, the transmission oil cooler was slid into place and then bolted to the intercooler.
Before we started this long and intensive 5 minute install, we took the truck out for a baseline run. The temperature outside was 98 degrees and there was little to no cloud cover, no rain and nothing to really cool you down. We took the truck out on the street and did a few hard accelerations. Each time, taking the truck from 30 mph to 55 mph. On average, the stock intake air temperature at about 30 psi of boost was 130 ish. The longer we were able to stay into the boost, the higher the intake temperature was. So, if we could have found a big hill and had a heavy trailer attached, we would have expected the temperature rapidly increase.
After wrapping up the install, we headed back out. It was pretty much the exact same conditions (about 30 to 40 minutes later.) At this time, we started laying into the truck again doing multiple accelerations from 30 mph to 55 mph. This time, we noticed that the Spearco Intercooler was able to cool the air much better, but it also, took longer for it to start climbing. All the extra aluminum and size, really helps to slow down the heat soak. Even though we recorded a few harder accelerations, the temperatures were much lower. On average, the intake temperature was around 110 degrees at 30 psi of boost, a 20 degree difference.
While a quick hit on a dyno may or may not show much difference, the true difference is on the road. Being able to run almost 20 degrees cooler intake temperatures when you are under load, will result in cooler EGTs. This will not only yield useable power, but it will help to reduce the stress the engine internals are under.
Add to the fact that an aftermarket intercooler is all metal and the tank ends won’t crack or blow out and an intercooler upgrade can easily be justified. You’ll be in and out of the garage in 45 minutes- max. Ok, maybe an hour with a beer or two and this is a weekend upgrade you can be proud of.