13 WRX long block into 05 LGT? Dual avcs and ticking noise

[shardaerithes]

So several months back I posted about how my engine was failing after multiple turbo replacements. It was making a terrible knock sound. Most everyone thought rod bearing but turns out it was a failed stainless valve retainer. According to the mechanic who tore down the engine, the piston had hit that valve after the retainer let loose? In any case it seemed I needed a new engine.

 

From this same mechanic I purchased a 2013 WRX longblock and VF52 turbo to have installed in place of my failed motor. Seems good, only has 32k miles.

 

Well upon picking up the car, I notice the engine is making a loud/noticeable but much less threatening ticking noise. It didn't strike me as really weird at first, maybe because I was traumatized by the other noise on the failed engine, or perhaps I just figured it was normal cold Subaru noise and was happy to have the car back.

 

Anyway the longer it went on the stranger it got to me, and I asked him about it. It sounded like a valve noise. He said it could be a valve or one of the side-feed injectors. He went on to say it was normal Subaru noise. He said how he would tune his STi to have more valve lash like that because when they get hot, they would expand and it was better if they didn't stick. He said it was fine, and if I wanted he would start up one of the other cars there to show me that it sounded ok. So I asked him to go ahead and start one, he actually had another 2013 WRX there. Well he started it up and it didn't sound the same, there was some ticking but it was much softer, not like what I heard from my engine. That one sounded much smoother.

 

In any case it didn't sound too bad for a used engine, and it was running fine otherwise, so I decided it was OK and I paid him and drove home. He had me take a test drive first, and the car has power for sure, so I figured everything was ok.

 

The ECU map he made was for a MT Outback XT. It seemed to be working OK, but I got weird CEL codes. They went away when he sent me an AT Legacy GT map, but none of them worked quite right and according to learning view I still need a tune and have a wastegate CEL. So now I'm not going WOT at all. Which is annoying but, I figure I can't expect this mechanic to tune it, I can get an etune or get help on the forums. By this time though the ticking noise is kind of driving me nuts every time I put my window down.

 

So I make a post on the ROMraider forum, and someone replies with "Don't the 2013 WRX have dual avcs?"

 

I didn't know the answer to this question, but after a little googling, it seems that they do. It seems like there's some mods that need to be done for it to run only the single AVCS. I don't know if the mechanic did this, he seemed to think the motor would work fine. This ticking is disconcerting though, it does sound like a valvetrain noise. So now I am wondering if the ticking noise I'm hearing could have something to do with the AVCS not being hooked up on the exhaust side? I haven't looked at the motor to see what exactly is hooked up, but I don't really know what I'm looking for. It's a little disconcerting, to say the least.

 

I mean, he had all the parts from my old LGT motor, and he reused my intake/dbw/ecu etc. Is it possible he did this swap properly and this noise has nothing to do with it? Tell me it's fine, please. I'd rather not have an issue. The only CEL I have is for Wastegate perf. range and for EGT high (catless uppipe).

 

Here is a video I took of it ticking:

[seanyb505]

Not sure about noises and all that but...

 

You do not have dual avcs, unless a 2013 sti engine was used.

 

Wrx and sti engines are different. If you look up parts for a 2013 wrx, the exhaust gears are plastic.

 

There are many people who believe later 4th gen legacies and wrxs were dual avcs because they have d25 heads. Every bit of research shows they are not.

 

Also, find a new tuning solution as it sounds like this guy is throwing stuff at it to see what sticks. Accessport, opensource, dyno tuning are all options.

 

Including your location in your profile will give people an idea on how to recommend shops for what's in your area.

 

Best of luck

[shardaerithes]

Oh, that is really good news! I am rather happy to hear that I don't have the dual AVCS! No, I saw the car that the engine came from. It was a 2013 hatchback/wagon WRX.

 

I have the opensource cable. I want to have the car put on a dyno and actually tuned, but the mechanic was saying that I should get a catless downpipe and a fuel pump first. However, I just need something to get my car running properly now! I have seen in learning view one cell which was -2.80 for knock correction. The IAM was still 1. It was 3500 RPM and 1.5+ bar? Or g/sec? It was a load measurement, and it was the highest one. So I have just not been boosting at all at 3500 RPM until this is resolved.

 

I just filled out my profile. Thanks for the help! I do hope that the ticking is no big deal. I guess I would feel better if I had a tuner look at the car and tell me everything is OK!

[StkmltS]

Here's a long-shot. Check all of the bolts in your exhaust manifold. One of mine fell out a few weeks ago and the valve noise was impossible to ignore.

[Max Capacity]

I'd suggest you reach out to http://legacygt.com/forums/showthread.php/tuning-fuel-economy-230552.html

He seems to be pretty good with tuning questions.

[Gex]

You're running a map made for B25 heads and a VF40 turbo. Not D25 heads and a VF52 turbo. Get that thing on a custom E-tune ASAP.

[fahr_side]

You're running a map made for B25 heads and a VF40 turbo. Not D25 heads and a VF52 turbo. Get that thing on a custom E-tune ASAP.

 

 

 

Yep. The B25 heads are larger in volume and need a degree or two more timing than the more compact D25 heads. Note the '08 and '09 LGT models had the same D25 heads, the engine basically being identical to the GH8 and SH9 models with the exception of the turbo.

[shardaerithes]

Oh man, very interesting stuff! Thank you for all the info.

 

I had no idea the heads were that different.

 

I am actually running a map for the B25 heads (05 LGT, AT) that was tuned for a 16G turbo, with the timing and boost reduced a little bit (supposedly, since I have a factory DP and fuel pump).

 

I definitely need to get a tune done asap! Hopefully the map (and my driving style) has been fairly safe for my motor!

[fahr_side]

The VF-52 needs to be tapered off more at high revs vs. the 16G and you also have slightly smaller injectors than the WRX.

Side note. The stock GRB fuel pump is a straight swap on a 4th gen and flows about 20lph more than the LGT one. Useful pump for people with stock injectors and available dirt cheap.

[shardaerithes]

The VF-52 needs to be tapered off more at high revs vs. the 16G and you also have slightly smaller injectors than the WRX.

Side note. The stock GRB fuel pump is a straight swap on a 4th gen and flows about 20lph more than the LGT one. Useful pump for guys with stock injectors and available dirt cheap.

 

If I was going to spend <$100 on a fuel pump, do you have a recommendation for what to purchase? I don't know where to find a GRB fuel pump.

[shardaerithes]

I was considering knocking out my first cat, and getting the fuel pump, before getting tuned. I'm not really sure what all I need for this turbo though.

[fahr_side]

I was considering knocking out my first cat, and getting the fuel pump, before getting tuned. I'm not really sure what all I need for this turbo though.

 

Don't knock the cat out. It's really hard work, it's easy to leave something in there that will trash the turbine when it comes loose, and used stock catless up pipes are dirt cheap.

I did a wiki on what support all these popular turbos need, which is in the 4th gen stickies.

 

If I was going to spend <$100 on a fuel pump, do you have a recommendation for what to purchase? I don't know where to find a GRB fuel pump.

 

 

 

A new DW65c is $130. Used stock GRB pumps in the for sale sections on nabisco, iwsti etc.

[shardaerithes]

I'm sorry, I meant the downpipe cat! The mechanic put in a catless up-pipe, I meant I wanted to knock out the stock downpipe cat. Since my car is an AT the only pipe I can find is the Invidia and I feel like $300 is pretty high for a simple downpipe.

 

Is the DW65c a lot better than say a Walbro 255? Would it make a difference on this turbo?

[fahr_side]

The bends in most downpipes are the same AT or MT, it's the brackets that are different. Easy mod.

 

There are more fake Walbro pumps in the market and using one means modifying both the pump bucket and the pump. Difficult DIY.

[The 2Fiver]

The bends in most downpipes are the same AT or MT, it's the brackets that are different. Easy mod.

 

He has a 5EAT.

 

OP, you'll need an AT Downpipe for your AT Legacy GT if you choose to get one. No two ways about it. The AT DP can be fit to the MT cars but not the other way around. This is old news.

[shardaerithes]

He has a 5EAT.

 

OP, you'll need an AT Downpipe for your AT Legacy GT if you choose to get one. No two ways about it. The AT DP can be fit to the MT cars but not the other way around. This is old news.

 

She* has a 5EAT

 

I read about the fitment and I'm on the lookout for an AT pipe, but $300 for an Invidia just seems SO high. Is it really that much better than if I gut the stock DP?

[The 2Fiver]

She* has a 5EAT

 

 

It would be a shame to gut the stock downpipe and run it with a VF52 and wrx block. You've come this far, what's another $300 for a proper downpipe?!

 

Here's a discussion that went a little sideways but thanks to far_guy taking the reigns, the point was made.

 

 

http://legacygt.com/forums/showthread.php/turbo-back-replacement-do-need-tunei-259995.html

[fahr_side]

I'm sorry, I meant the downpipe cat! The mechanic put in a catless up-pipe, I meant I wanted to knock out the stock downpipe cat.

Oh, well gutted stock DPs are less dangerous than up-pipes, but still have drawbacks. I went this route when I first upgraded the turbo, for stealth reasons. The flat flange design of the stocker leaves a pretty convoluted path for gas leaving the wastegate. Gutting the cat and running a larger turbo (increasing exhaust flow) just makes the flaws in that design more obvious. That convoluted path makes boost control a bit more difficult or inconsistent than you'd like and will also upset your tuner some. I could never get spool either as low as I thought it should come, or smooth, or consistent despite a great many hours spent tweaking the tune. Going to a bellmouth design aftermarket item cleared those problems up immediately. Smoother boost curve, reduced spiking, spool a few hundred rpm lower.

When off-brand catless downpipes, or used name brand ones are so cheap it's hard to justify gutting the cats for any reason other than stealth. Like I said, many brands have one downpipe bend they use on both AT and MT versions, with only different brackets to differentiate them. Invidia is a good example. If you find a good used MT one you will only need a different bracket, or you can usually mod the MT bracket pretty easily.

 

No way are you passing sniffer with gutted cats, so that only works if inspections are visual only and the guy has flu that day (or can be encouraged to pretend). Also, if you have a light colored car I hope you enjoy washing and clay bar sessions because the bumper is going to turn first yellow and then dirty brown every time you get on the gas.

[shardaerithes]

 

It would be a shame to gut the stock downpipe and run it with a VF52 and wrx block. You've come this far, what's another $300 for a proper downpipe?!

 

Here's a discussion that went a little sideways but thanks to far_guy taking the reigns, the point was made.

 

 

http://legacygt.com/forums/showthread.php/turbo-back-replacement-do-need-tunei-259995.html

 

Yes I am a lady doing these crazy things to my 200k mile LGT! I'm afraid the NEXT mod after the tune etc. is going to be a hexmods valve body upgrade... when truthfully I much prefer a stick! According to the previous owner the trans was rebuilt... it shifts well but who knows... I'd rather have a LGT Spec B wagon... but since that's not available... It's a nice grocery getter and road-trip car and I almost have it set up how I like it! The biggest issue is no sunroof. So that's seriously a problem. I might sell it for one with similar mods and the sunroof...

 

Oh, well gutted stock DPs are less dangerous than up-pipes, but still have drawbacks. I went this route when I first upgraded the turbo, for stealth reasons. The flat flange design of the stocker leaves a pretty convoluted path for gas leaving the wastegate. Gutting the cat and running a larger turbo (increasing exhaust flow) just makes the flaws in that design more obvious. That convoluted path makes boost control a bit more difficult or inconsistent than you'd like and will also upset your tuner some. I could never get spool either as low as I thought it should come, or smooth, or consistent despite a great many hours spent tweaking the tune. Going to a bellmouth design aftermarket item cleared those problems up immediately. Smoother boost curve, reduced spiking, spool a few hundred rpm lower.

When off-brand catless downpipes, or used name brand ones are so cheap it's hard to justify gutting the cats for any reason other than stealth. Like I said, many brands have one downpipe bend they use on both AT and MT versions, with only different brackets to differentiate them. Invidia is a good example. If you find a good used MT one you will only need a different bracket, or you can usually mod the MT bracket pretty easily.

 

No way are you passing sniffer with gutted cats, so that only works if inspections are visual only and the guy has flu that day (or can be encouraged to pretend). Also, if you have a light colored car I hope you enjoy washing and clay bar sessions because the bumper is going to turn first yellow and then dirty brown every time you get on the gas.

 

OK the flat flange sounds terrible compared to the bellmouth and just keep my stock DP in case I want to move to some fascist regime in the future.

 

Are you certain the bends are the same? I can get a used invidia here in my town. There's 1000 ebay ones out there for 80 bucks but I'd rather just get a used quality piece.

 

Here in South Carolina there are no inspections. One reason I prefer it here to NY, which is where I'm from

 

I've had a car with no cats before, but honestly I would prefer to still have a high-flow cat or at least one cat. The bumper grime is one reason, the smell is another, and I do care for the environment... but I guess that's not really an option if I get a bellmouth downpipe. Unless I want to spend $500...

 

And no $300 isn't that much gentlemen... but every little bit counts...

[fahr_side]

 

Are you certain the bends are the same? I can get a used invidia here in my town. There's 1000 ebay ones out there for 80 bucks but I'd rather just get a used quality piece.

When they can do one bend and just switch brackets it saves a lot of cost.

 

Yes, the eBay stuff might be fabricated 'okay' but the cats are usually garbage at those price points.

[The 2Fiver]

Like I said, many brands have one downpipe bend they use on both AT and MT versions, with only different brackets to differentiate them. Invidia is a good example. If you find a good used MT one you will only need a different bracket, or you can usually mod the MT bracket pretty easily.

 

I added a helpful link here in case OP decides to buy an MT downpipe for the car, and to compliment the simple bracket swap. After all - anything is possible, anything is awesome?

 

Everything is awesome!!

 

http://www.doityourself.com/stry/how-to-bend-exhaust-tubing

 

I'm afraid the NEXT mod after the tune etc. is going to be a hexmods valve body upgrade..

 

The valve body is useful for quicker shifting under wide open throttle, it would make sense for a specific driving style. Slamming more power down between gears on the auto (vb or not) will wear on the clutch packs faster. If it's just a cruiser and 3rd/4th gear pulls is mostly wear you put the foot down, I don't think the VB would be worth it.

[shardaerithes]

I added a helpful link here in case OP decides to buy an MT downpipe for the car, and to compliment the simple bracket swap. After all - anything is possible, anything is awesome?

 

Everything is awesome!!

 

http://www.doityourself.com/stry/how-to-bend-exhaust-tubing

 

 

 

The valve body is useful for quicker shifting under wide open throttle, it would make sense for a specific driving style. Slamming more power down between gears on the auto (vb or not) will wear on the clutch packs faster. If it's just a cruiser and 3rd/4th gear pulls is mostly wear you put the foot down, I don't think the VB would be worth it.

 

Is that link supposed to be a joke? Are you trying to say that the MT pipe is bent differently? Or that making the bracket is hard? I feel like a good shop could do it but then again that is labor time I'm paying for...

 

I've done a lot of reading about the valve body but I don't know if the VF52 is powerful enough to warrant upgrading to it. I supposedly have a rebuilt transmission and it shifts fine, but the car does have 200k on it. I can try to be easy on it... I do anyway... but...

 

Yes I will want to boost in all gears, and I swear the 5EAT is trying to make me even more of a leadfoot... I'm used to a manual WRX with drive by cable. In the LGT w/ 5eat it seems like the throttle pedal:throttle body is not 1:1 ratio, I give it 50% throttle and it takes off hard with boost and shifts at like 5500... crazy. It's as if the car is in sport or sport sharp mode, but I have no SI drive... I really miss controlling my shifts and no-downshift boosting on the highway without worrying the TCU will override me. Yes I can use sport-manual mode... but still. Feathering the clutch is an art! Control vs. laziness. I like mountain passes. I'm torn on this 5eat thing. With the car not having a sunroof I don't know how far I want to get into it... but I'm too far already

[fahr_side]

We can achieve most of the results a valve body gets you by manipulation of the throttle mapping and some other tables which tell the trans how much torque is coming down the pipe. It's been discussed a bit in the transmission forum.

Yes the stock throttle mapping is not that ideal in the Legacy models and more so in the 5EATs. I think they decided on an, 'it's not a v6 but we'll do whatever it takes to make it feel like one' approach to it. Subaru like the car to take off on a nice swell of power without going WOT to get it. It fools people into thinking to car is quicker than it is, that it has a lot in reserve. The '15~ STi models are even worse, if you can imagine such a thing, the throttle is like a light switch in S mode and is WOT before 50% pedal in most of the rev range. I prefer a much more linear feel but you do get owners who feel the car isn't as fast after tuning because they're not used to having to dip into the second half of the pedal angle.

[shardaerithes]

I hate that throttle mapping, it's terrible. It will change if I get a tune? I read a little bit about requested torque but it seems like the benefits/changes would only exacerbate the problem of the throttle mapping? Hoping the tuners know something I don't

[fahr_side]

I hate that throttle mapping, it's terrible. It will change if I get a tune? I read a little bit about requested torque but it seems like the benefits/changes would only exacerbate the problem of the throttle mapping? Hoping the tuners know something I don't

 

 

 

You would want to have requested torque ramp up more slowly at lower pedal angles but go to higher values at high / max pedal angle. That gets you better resolution in part-throttle and upshifts occurring at higher rpm and with more firmness at WOT. Most tuners can pull this off, though there are only a few of us working with the Calculated Torque tables, which is what really rounds out the shift firmness.