Losing boost under load/rpm

[Rising]

Okay so I need some help with this one guys.. It could be something stupid but I'm starting to fear something worse.

A few months ago on my way back from buying my daily civic, I hit a chunk of ice that came out from the car in front of me. I heard it hit my car and immediately looked over at my oil pressure gauge and saw it falling and shut the car off, coasted to the side, and waited 3 hours in 7 degree weather for a tow truck in a light hoodie (idiot ) it was still pouring oil out everywhere when I got out of the car.

Got it towed home and ordered a new oil pan. The car sat for about 2 months before I put it in because it was parked in mud and it was freezing outside. Got the new pan on and filled with oil and now it doesn't boost like it used to. Seems a little late coming on, and then it gets to about 10 psi or so and starts to fall off if you keep reving/applying fuel, if you let off a bit it seems to hold the boost there. But if you keep going it falls off to nothing. But then you let off and go at it again and the boost comes right back up. I've had boost hoses pop off but I've never seen it do this. I went over the connections and they all seem good and tight, so I'm not sure I'm losing boost through a hose.

Actually Im wondering if this might be a sign that the turbo got damaged when I lost oil. But I still had over 30 psi of oil pressure when I shut it down and they start moving with 0psi at startup all the time.. So seems weird to me.

Anyway it's a 1.6td block with a vnt 15 , vanes half open, intercooler, n/a pump with gov mod. Before this it was making about 18 psi peak and down to 16 or so and was very fun.

[vanbcguy]

Seems unlikely to be related to the oil loss event given the scenario you describe.

Any chance your vanes are moving?

[burn_your_money]

Vanes moving was my first thought as well.

Next thought is a small boost leak.

[Rising]

Hmm well this was an odd one... Not sure how this happened over a few months sitting...

I checked the vanes and they were still securely tied in place.. So I double checked all the boost piping. All was well couldn't find anything loose or ripped or with holes in it...

So on a whim I pulled the air filter off.. I had a feeling it was too small for this car anyway and it looked pretty gross... And Woah!!! Took the car out and it boosted up to 25 psi!! Now that's way too much for a vnt15 but it's never done that before.. Where I had the vanes set before it never got to even 20! So that filter must be crazy restrictive!

I opened the vanes some more and the car was still boosting to 22 or so with no filter! (and I was confused and why this vnt seemed to be so low boosting) I knocked the filter around and blew it out best I could and the car Returned to done of is weirdness.. but not as bad. Now it was able to make about 15-16 pounds after spiking maybe a bit higher (like it used to run) anyway I guess I've got some serious intake restriction and somehow sitting over the winter the filter got gunned up. Wish I couls get a stock air box again. Anyway the car absolutely rips with no filter so I'm excited to see what it will do when I open the vanes up some more and get a nicer flowing filter on there.. I bet I can add more fuel

Anyway interesting results but in happy I figured it out.

[burn_your_money]

Never, never, never blow an air filter out. You're just putting dirt on the "clean" side of the filter. Very bad for your engine. It only takes something like 2 tbsp of dust to completely destroy an engine. Running around with no filter is not very wise, even just for a short test run.

[libbydiesel]

Running an intake restriction can also lead to runaway as the turbo spools and sucks the oil out of your crank vent.  I'd park the car until the intake and filter is sorted.   

[Rising]

Hey guys, tuning back in, the car has been sitting since that day and I tossed that old filter away. Sourced a fancy 3" cone filter from a buddy and I'm going to throw that on and see if I can dial this car in a little better with a proper filter! Thanks for the heads up!

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