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Sarra
08-26-2010, 05:42 PM
Yeah. I put a blockoff plate on my WRX. The Bypass valve was blowing open at 15 PSI, and I want to run 17. When I put it on, my car suddenly stopped knocking, and boost builds a shit ton faster now. Go figure, I have a worn out BPV.

08-26-2010, 05:59 PM
hows saving for a Legacy project car going?

anothernord
08-26-2010, 07:10 PM
Did you try crushing your OEM BPV?

I'd be worried about compressor surge, especially with that level of boost.

Sarra
08-27-2010, 02:30 AM
hows saving for a Legacy project car going?

lol Funny you should ask. It's hard to save for a car when you have no income. :p Though, that will be changing very shortly, as I just got a job.


Did you try crushing your OEM BPV?

I'd be worried about compressor surge, especially with that level of boost.

It's blowing past the seal at all boost levels. It just totally overwhelms the damn thing at 15 PSI. At 10 PSI, my car was knocking, and I couldn't figure that out. With the block off plate, it's not knocking, and my WTDC and turbo burst dynamics is much happier. I should say, when it's 106*F out and after sitting in traffic for 22 minutes, it's not knocking going through second gear with IAT's at 170 to 180 degrees with the blockoff plate. It was knocking and pulling timing and hitting IAM of 1 without the blockoff plate before I started pulling timing from my map myself to combat this, even when it was 70 degrees out and IAT was 80 or 90*F.

That says the damn thing was just letting the turbo blow hot air into itself.

anothernord
08-27-2010, 02:33 AM
That's the strangest thing I've ever heard. :lol:

I guess as long as you aren't knocking, and your AFR's are good, then more power to ya!

jey
08-27-2010, 11:57 AM
Push on the diaphram of the BPV - the spring should have quite a bit of resistance. Mine failed too a while back - I could push on it with my pinky and it would move.

Just replace it with another stock BPV - there are lots of people unloading theirs for cheap.

Sarra
08-27-2010, 02:37 PM
Spring is good... I can barely move it. I used a hand vacuum pump with a vacuum line on it and could open the valve all the way, and a hand pressure pump, and could close the valve all the way, but with the valve closed, I could blow on the pressure side and it wouldn't hold. So, the seal has to be bad. And using shop air with a regulator on it, and a regulator, I put 15.5 PSI of pressure to the valve and it simply opened up (and was hissing a ton before that even with 20 or 25 PSI on the hand pump helping the spring hold the valve closed).

So yeah, valve is bad.

Not sure if I'm going to get another stock valve or if I want to pick up a Forge valve, since I'm hoping to upgrade a TD04 to a 19 trim and push a little more than 22 PSI later on. Clipped impeller blades, ported exhaust housing, ported exhaust, and a new crossover are going to be my mods of choice. Looking for 22 PSI of boost by 2,000 RPM on a 2.1 liter stroker motor. Redline will probably be set at 5,500 RPM. :lol:

anothernord
08-27-2010, 03:47 PM
Get an upgraded aftermarket valve. I'd reccomend a GFB, Turbo XS, or like you said, a Forge valve.

Sarra
08-27-2010, 05:37 PM
Yeah, Forge is probably going to be the way I go.

Reuben
08-27-2010, 07:38 PM
You def want to get a new blow off valve/bypass valve on there at some stage. Compressor surge of the chvchvchvhcv when letting off the gas won't be a big issue.

BUT...

There's another type of surge, and i was having problems with it when i was fucking round with my BOV's after the single conversion... Sometimes, you may be on full boost without realising it. People who don't have boost gauges probably drive like that all the bloody time without knowing. It's called partial throttle full boost. What's happening is, the revs are high enough to get full boost, but you may be only using partial throttle... in this case, the blow off valve will sit there venting it's arse off, cause pre throttle plate is fully boosted pressure, yet in the intake manifold, you might only be half your set boost for example, using only a quater thottle. My mate had an HKS SSQV BOV, in his legacy once, and i manage to drive up a whole hill with it squealing it's ass off, just by getting the power and throttle jusst right to be on partial throttle boosting.

Now this is where the BAD type of surge comes in. If you happen to have no bypass valve, that pre throttle body boost has to go somewhere... and that only somewhere is back out the way it came. And unlike the normal surge everyone is familiar with, this type of surge is with the turbo still boosting, with foot on the gas, intstead of while it's despoooling with foot off the gas... In my case, it was making a god aweful squeeling noise, sort of like in this vid (though not NEARLY as bad, and not on wide open throttle).

http://www.youtube.com/watch?v=nCj6Spwl1CU

Sarra
08-27-2010, 09:46 PM
Ahhh... I'll keep my eye out for that.

I'm gonna probably leave the block off plate in place until I get my stroker motor built. That will be very soon I hope. If it's gonna be more than a month to get the stroker motor done, I'll either pull the wastegate arm off the actuator, or get a Forge valve and stick it on for now.

Reuben
08-28-2010, 07:48 AM
As long as you know about the other kind of surge, you can look out for it. It may not even show itself.

Sarra
08-28-2010, 03:37 PM
On a TD04, I somewhat doubt it. :p

Oh, speaking of ruining turbos, I'm gonna have to do some drastic crap to get the exhaust off the stupid car. One of the nuts that holds the downpipe on the turbo is frozen up, so in order to remove the downpipe, I'm going to have to cut the stud.

I'm just going to get a new turbo instead of mess with it anyway.

Sarra
08-29-2010, 07:25 PM
Blockoff plate FTL.

Started to surge at WOT in 2nd, 3rd, 4th, and 5th gears at 3,000 RPM.

I'll run the leaky bpv for now so I don't pop my motor... I've done the crush mod and applied some ATF to the seal to see if I can get some more life out of it. We'll see...

Reuben
08-29-2010, 09:42 PM
Damn. Oh well, looks like you gotta fork out some cash. I'd stay factory myself, but i do like GFB Hybrids.

As for exhaust bolts, i've never had to cut one, and i've been through a fair few seized ones. Just get the power par/strong arm on, and pull. You'll eventually either crack it, or sheer the stud anyway. Allot tidyer than getting an angle grinder in there.

Sarra
08-29-2010, 10:22 PM
Heh... Forking out some cash... Looks like I have some serious incentive to do some motor building now. I put the stock BPV back on and now my car's running on 3 cylinders.

My guess is that I either lost an injector or fowled some spark plugs (it was running fine then I put my foot down about half throttle and it started blab blab blabbing). CEL flashing and it's obviously got a nasty misfire. I put some cheap ass spark plugs in to see if I could fix the lumpy idle and a light knock at WOT at 4,000 RPM ish... I've got the stock plugs still. Still pulling good vacuum at idle right now, just runs on 3 cylinders with a lumpy idle. No knocking or other horrible sounds...

I think this engine is pretty much done though. I'll check the oil tomorrow, it was nice and full tonight when I pulled a little out to get some off the dipstick for the BPV seal.

Other thought is that the cats have started chunking and are blocking the exhaust (no cat in UP). That may be wishful thinking...

Eh. Stroker motor, here I come?

Sarra
08-29-2010, 10:34 PM
It blows pretty good out the oil fill cap at idle, but still pulls vacuum if you put your hand over if you rev on decel. So I'll keep looking at spark plugs and injectors...

Reuben
08-30-2010, 07:08 AM
Coil pack? Though the modern coils are reliable, and the coil pack on manifold setups run wasted spark, so it's either no cyls, 2 cyls, or all 4. Then again, could be a lead if it's a coil pack on manifold deal.

Sarra
08-30-2010, 02:31 PM
Yeah, we'll see. I get my old spark plugs back today (left them in my box over the weekend a city away).

I also will get my hands on a laptop with a Tactrix cable and ECUExplorer. At least I can run the codes now...

And yeah, WRX has coil on plug. Surprised that it went from running fine to severe misfire so quickly. I'll look into it, it might be something simple like me putting the dielectric grease in the coil pack boots...

Sarra
08-30-2010, 08:31 PM
Was a misfire cylinder 2. I pulled the battery out of the way, and found the coilpack connector loose. I plugged it in, and wiggled to see how secure it was, and it popped right back off.

So, I pulled coil pack 2 and coil pack 1 and inspected them. The coil pack on cylinder 2 was missing hte lock tab, damn. I swapped, and electrical taped the connector into place on the one with the missing tab (now on cylinder 1, easier to access).

Car runs like a champ. The ATF/15w40 I put in the valve seems to have encouraged some life from it, as well as smashing it with a rubber mallet. It vents differently now (still hooked up to the recirc tube).

Reuben
09-01-2010, 05:31 AM
Interesting. This is the first time i've personally heard of post 96 coils fucking about. I might have some off my GTB that i could send up to yah, i think they are the same.

Sarra
09-01-2010, 09:54 AM
Seriously? That would be awesome.

I swapped coil packs on 1 and 2, and for some reason, the car runs better now than it did before. No longer pings/knocks at WOT. Though that might be from the crush mod + ATF and 40 weight on the seals...

I bring my box home today, since we're done in lab, and this was my last term at school. :) Starting in a Subaru dealership next week...

Reuben
09-01-2010, 09:09 PM
Mean! Good luck with that.

Sarra
09-01-2010, 09:42 PM
Muah, thanks. Car runs so much better now...

Now only if my internet was happy... There's apparently a problem with the run, the amplifier, or something else causing my internet to be craptastic. We have TV and Internet, but VOIP is down right now.

anothernord
09-02-2010, 12:01 AM
This is interesting stuff. I'm glad to see that the crush-mod worked!

Sarra
09-02-2010, 12:47 AM
This is interesting stuff. I'm glad to see that the crush-mod worked!

I attribute it partly to the crush mod, and partly to the ATF and motor oil on the seal.

Either way, it still isn't REALLY hitting target boost, but I doubt it's the BPV now. I think it is probably the BCS not capable of handling the pressure.