What size intercoolers are being used behind the grille on the nnbs trucks? Any idea on where to get a decent intercooler? I was thinking that bigger is better or is there a point where it can get too big? I was also thinking of one with 3" in and out or should I go smaller like 2.5"? Any ideas?

 

Bigger is better

 

In for the answer, been wondering this myself

 

I went with a House of Boost intercooler think the 31x12x3.5 thick on my previous setup. It was a 3'' in and out. My intake air temps were pretty good for South Texas heat but I also ran water/meth. As for bigger is better I think you want to stay volumetrically efficient, as in stay with the size that will support the cfms your gonna flow. Also air/air intercoolers tend to have a pressure drop so the bigger you go the more pressure drop its gonna have and your gonna have to make up for it with more boost. If you can get away with a smaller intercooler but still retain the cooling efficiency and flow go with that over a bigger one. To fit the intercooler I used you have to unbolt the center grille support and trim off the center tabs so they dont dig into your intercooler. The grille has plenty of support with the other mounts so no worries about it being loose or anything and besides the mods done to the grille everything is reversible back to stock.

Here are some pics on how the intercooler looked...

 

31x12x4

 

ScooterK on here has a NNBS and is using the same intercooler im running at least from his build thread i saw he was, he might have something different by now but its a 4.5'' core and a 12.5''x 22'' core

 

Not exactly...intercoolers in these setups act more like a giant heatsink than a true intercooler. Reason being there just isnt enough time for them to equalize temperature, so with that in mind you want as much material as you can get to better acomodate the heat. Along with that you want as much front area as possible for the air to cool over. As intercooler depth increases there is a diminishing return in terms of cooling because the air going over the last part of the cooler has already been heated by the front part of the intercooler. So an ideal cooler is actually pretty thin and has a huge frontal area...but this is ignoring flow requirments. It needs to be wide enough to not cause a pressure drop. More goes into this than just width, but width is important. A good intercooler will have very little drop (1-2 psi), whereas a crappy one will have a big drop (8-10psi or more).

The only thing you get out of a small intercooler is less volume for the turbo to pressurize, but we are talking fractions of a second here. Well worth the tradeoff in air temps if you ask me. As far as air to air intercoolers go, like I said, bigger is better.

 

Your information is correct don't get me wrong by small I don't mean a Honda size intercooler you still need a decent size intercooler for the application I just don't want him to get some crazy thick big intercooler that isnt going to do any better then ones i posted . Like you said the width only needs to be neccessary for the application and cfm requirement before the cooling effect deminishes. A 31x12x3-4 inch thick intercooler I think would be ideal for his setup given the room he has to work with and cooling requirement.

 

Sweet thanks for the info guys. Good thing is I was already thinking 31x12x4x3. Anybody know where I can get a good one.

 

I went with the CXracing racing kit off fleabay. I'm very happy with the quality of the cooler...the silicone couplers could be a little thicker but I'm knitpicking.I managed to stuff this 4'' core behind the grill of my 99 so I'm sure you could get it on a NNBS.