Why so much lag?!?

2005 LGT
5spd manual
107k miles
Protuned


Supporting mods:
3 inch Invidia TBE
Invidia Up pipe
HBC manual boost controller
K&N Air Filter (panel)
Stock top mount IC, re-enforced endtanks.

I was tuned almost exactly 1 year ago.
Had the up pipe put in a few months back and the tuner made a slight map adjustment after install.

No mods since the tune.

Haven't had a problem until recently.
First I thought my exhaust sounded a little different.
More like the static/farty sound of an older WRX.

My car was hitting around 15psi, when it should be around 17psi.

I hope it's just some kind of leak.
All my hoses and vacuum lines seem good and tight.
I did not do a good inspection yet to the upipe/turbo/downpipe gaskets.

It's slow to build boost in gear on the highway, and feels like it falls flat on its face when I upshift under throttle. If i try to launch, it will just crap itself and then start to go.


What do you guys think?

when was the last time you did a tune up? you can try sea foaming your pvc line to clean your valves and also putting some in your gas tank to clean your injectors. hows your idle? when you let off the gas does your car idle seem normal?

.... Why do you have a MBC? The car comes with an electronic boost controller!

i missed the manual boost controller... my buddy blew up his sti because of one of them. thats probably whats causing it.

Originally Posted by Diavolo

First I thought my exhaust sounded a little different.
More like the static/farty sound of an older WRX.

probably a leak somewhere

Sounds like a leak... maybe that pesky T connecter under the IC. Definitely check the MBC as well.

What does it sound like when you let off the gas on boost? Do you get the Psssssh from the BPV, or does the turbo flutter?

+1 for sticking with EBCS esp at mild Stg 2!

+1 for needing to sea foam...fixes most boost problems.

1) Check the T under the TMIC.
2) YTF are you using a MBC...

Sudden raspy exhaust note plus slow spool? Sounds like a stuck injector. :facepalm:

3) Post logs.

My tuner suggested the MBC. Heres a post he made about why:
http://www.iwsti.com/forums/ecu-tuni...-i-need-7.html

Originally Posted by mumblinaviator

What does it sound like when you let off the gas on boost? Do you get the Psssssh from the BPV, or does the turbo flutter?

I still get a PSSSSHHH!

Originally Posted by seabass07

Sudden raspy exhaust note plus slow spool? Sounds like a stuck injector. :facepalm:

hmmm,... sometimes my car has start up problems.
I thought it was just the starter drying, but could this be causing that too?

how does an injector get stuck?

if your tuner is EQ Tuning he seems to be arguing with EFI logics which is a highly respected tuner for the Subaru community. There are very few people who think MBC > EBCS.

Or are you saying that you adjusted your MBC after the tune???

A starter failing would be simple. If its turning over at a good pace that's not your starting problem. I would say to much fuel during cranking from a stuck injector like said before

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Originally Posted by dr_sharp

if your tuner is EQ Tuning he seems to be arguing with EFI logics which is a highly respected tuner for the Subaru community. There are very few people who think MBC > EBCS.

Or are you saying that you adjusted your MBC after the tune???

no, i know better than to mess with it.
I was just posting that link since so many people asked why I have one.
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