SilverLudeSi

I've got my engine fully built now, but I still have a drag 3 intercooler. I never really see people upgrading their intercoolers - it seems like they keep what they start with. Has anyone ever gone bigger and what were the effects?

sutrusu

drag intercooler is supossed to be good for up to 400 whp

PrecisionH23a

if you have the piping like i have, your pipe runs from your compressor to your stock airbox location, to the front of the car, over the intercooler, and then to the intercooler. a good idea is to notch out a hole so you can shorten this charge pipe. instead of running it to the air box hole, cut out a hole in the radiator support frame and then to your intercooler on the right side of it.

SilverLudeSi

Nah, my piping is already like that. I just have the drag intercooler from a gen 3 kit for integras/civics. So I have custom piping instead of the crappy prelude drag piping.

SilverLudeSi

Right, people always say "good to" 400 whp (I've actually heard up to 500 as well). But what exactly does this mean? Does it mean that upgrading won't yield you any gains until 400+ whp? Or does this just mean it provides acceptable iat's up until this level?

MiraiZ

i think it just means that after a certain level (psi level...or whatever) the efficiency goes down significantly....its not like as if it'll stop working at all though

C-Murdock

i was wondering the same question...I got a spearco 24x6.5x3.5...its supposed to be good up to 500-550whp says spearco...

TurboMinivan

When a qualified manufacturer claims an intercooler is "good to such-and-such horsepower" they are referring to the flow loss through it. The precise level it is "good" to depends on what you, the car owner, deem acceptable. (More on this in a moment.)

The entire purpose for an intercooler is to remove heat from the charge air. To do this effectively, the passages of the intercooler must offer flow resistance to the air passing through it. This resistance provides the time and means necessary for heat transfer to take place, but it is also the evil catch-22 in designing an intercooler. The trick, then, is to use a core whose design offers enough inner passageways to really slow down the charge air; this minimizes the flow resistance while also giving the charge air lots of time to shed as much heat as possible.

Now then, back to acceptability. What, exactly, is acceptable? It's all up to you and your desired efficiency, power output, etc. For a casual street car, a pressure drop of 15-20% of your intake manifold boost (or 2-3 psi, whichever is smaller) can be entirely fine. For a truly serious effort, however, you'll strive for less than 10% and/or less than 1 psi of drop. If you start with a lot of intercooler pressure drop and you upgrade only your intercooler, you will instantly notice more power, better throttle response, less turbo lag, AND cooler charge air temps. It's just plain better everyway you look at it!

As an aside, intercooler pressure drops are not linear. Just because an intercooler is fine for your current boost output does NOT mean it will still be a wise choice after you up the pressure! Example: a friend of mine has a Dodge Daytona Shelby with the stock intercooler. Factory boost was set at 12 psi. With a manual boost controller set to 15 psi, my friend measured an observed pressure drop of 2 psi, which isn't all bad. He continued to up the boost to 25 psi, but then he simply assumed the intercooler was choking his engine so he upgraded to (literally) two stock cores. With no changes to his boost controller, his car now made thirty pounds of boost--JUST from cutting his flow restriction in half!

Spearco and other companies can provide data which tells the measured flow rate for any given core. This is a good way to judge the effectiveness of a particular intercooler for your platform. If ever you're in doubt, get some pressure measuring devices and find out exactly where you stand.

Hope this helps.

SilverLudeSi

Thanks a lot. That's exactly what I was looking for.