Intercooler HP Loss on Naturally Aspirated Car
 

Just figured I'd post some random findings while in the process of boosting my NA. Been prepping the car for the turbo, recently hooked up the intercooler and the piping. When out and test drove the car and man it is SLOW! I virtually dyno'd the car and it was making 76whp (as to the opposed 103whp before). Crazy stuff. Didn't think the intercooler (27.25"x7"x2.75") would sap that much power from the engine. I gotta get the snail on soon...
https://cimg0.ibsrv.net/gimg/www.mia...6b91e08031.png
Pre-Intercooler Piping
https://cimg4.ibsrv.net/gimg/www.mia...080295d667.png
Post Piping
(Yes i know my AFR is wack, its fixed now)

It's a restriction.

While I was waiting for my 6258 to come in, I installed the stock header back on the car and put a cone filter on the intercooler piping. Basically a intercooler NA car. The car drove fine, but did seem slow.

This is also evident on the VE table. Load is at 60-80 depending on intercooler.

Spei; Mind sharing which brand intercooler it is? Curious if it's a particularly restrictive one, or if this is a fairly common power loss with most of the available ones.

Looking at the virtual dyno graph, is it seriously showing ~80kpa at redline? That seems incredibly restrictive to me and certainly explains the power loss.

Maybe I'm way off base, but a 5whp loss would have disappointed me. Losing nearly 30whp on a n/a 100whp car due to installing an intercooler does not seem reasonable in any way to me. Any details on the intercooler? Is it new? Beat up? Tiny? Something living in there?

:bigtu: eBay https://www.ebay.com/itm/202691407474 it's also running 2" hot side and 2.5" cold side

It's an eBay intercooler so that might be why. Has a couple dings on it from installation but nothing big. 2" hot side to 2.5" cold. I hope nothing is in there.

Will happen with even the best intercooler available.

Your intercooler is adding extra volume between the air intake and intake manifold AND is restricting air flow between them as it directs the air through small channels connected to the intercooler fins that dissipate heat when air flows over them (ie. when you're moving).

With a turbo, this isn't a problem because the high pressure on the hotside is forcing already-compressed air through the intercooler (the intercooler fills quickly and there's plenty of air for the intake manifold).
With no turbo, pressure needs to be built up on the hotside before enough air flows through the intercooler into the intake manifold.