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Old 11-15-2012, 01:38 PM   #1676
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Originally Posted by gdoggmoney View Post
You are right there, the accordion pipe and torque box are not that elegant.
Torque box and accordion pipe aren't the issue at hand. The hybrid does away with them. The issue is whether going from a hybrid to a CAI results in more massflow. My testing showed that it doesn't because the parts from the throttle body on out to the tail pipe are the real restriction so the airbox and snorkus are never a problem.

Unless you're going to fix the metal parts called "the engine" fixing the plastic parts in front of the MAF isn't going to get you anything.
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Old 11-15-2012, 03:14 PM   #1677
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Originally Posted by williaty View Post
Torque box and accordion pipe aren't the issue at hand. The hybrid does away with them. The issue is whether going from a hybrid to a CAI results in more massflow. My testing showed that it doesn't because the parts from the throttle body on out to the tail pipe are the real restriction so the airbox and snorkus are never a problem.

Unless you're going to fix the metal parts called "the engine" fixing the plastic parts in front of the MAF isn't going to get you anything.

Well. So far:

EGR bar? Gone completely. EGR completely removed. Exhaust manifold? No cat, 3" mandrel off the 4-1 merge that goes down to 2.5. 2.5" exhaust to the tailpipe with straight through mufflers.



Soon: Ported heads (there is a nice corner in the intake ports.) Probably Delta 2000 cams. Slightly larger injectors if required. The car needs headgaskets, so "while it is apart...".

It is not quite "stock", but I just started tearing down a 3076R powered 1.8T jetta with headwork and cams I drove daily for 2+ years. So to me it's very stock.
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Old 11-15-2012, 04:24 PM   #1678
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You're heading in the direction where the stuff before the MAF might become relevant. The reason I still remain skeptical is that the same setup is good 300 at the wheels on the turbo applications and you're not getting anywhere close to that.

Also, you're wasting a LOT of money unless you're using the Techworks Engineering headers. How are you planning on running 2000 Grind cams on a 2007? I hadn't heard Delta had come out with more than one cam for the AVLS system yet. Are you a guinea pig?
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Old 11-16-2012, 09:44 AM   #1679
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Originally Posted by williaty View Post
You're heading in the direction where the stuff before the MAF might become relevant. The reason I still remain skeptical is that the same setup is good 300 at the wheels on the turbo applications and you're not getting anywhere close to that.

Also, you're wasting a LOT of money unless you're using the Techworks Engineering headers. How are you planning on running 2000 Grind cams on a 2007? I hadn't heard Delta had come out with more than one cam for the AVLS system yet. Are you a guinea pig?
I ran across a video of a guy with an AVLS car saying he had delta 2000's. I have not looked much further than basically toying with the tune on the car, and and seeing where the powerband is. The car pulls pretty hard until about mid/upper 6k where it runs out of cam. I saw SOHC avls head flow numbers and intake manifold flow numbers that looked VERY good, almost Honda like. Which shocked me...... I know the flow bench does not equal reality all the time, but it is often a good predictor. I also read the AVLS heads were changed from earlier heads to be more "honda like" (I do not recall exactly what, perhaps valve angle[hemi/pent]) One thing I did not like was the corner basically at the bowl area of the intake ports. It reminded me of a 80's volvo SOHC cylinder head. They gain dramatically in the ways of flow with simple intake porting. The dog leg exhaust ports on this head may hurt some, but that's the way the thing was cast/done.

I would be a willing guinea pig, in fact I would consider "locking" the avls as folks do with the v-tecs. Unplug solenoids, and keep the valve in high lift all the time. By consider I mean i've been thinking about doing this a good bit.

The modifications to my header cost me about 50$ and made a dramatic difference. When you look at what they neck the cat down to, it is obvious. I have pictures of the entire thing dissected but someone else probably put them up around here. In fact the modified stocker is coming off tonight and I am putting new flex joints in said header. I had an exhaust popple I could never find, once I had the car on a lift, it was a slit in the accordion flex for cyl 2 or 4. I picked up 2 treadstoned 1.5" flexes that are lined. My buddy is going to tig them into place this weekend.

Techworks looks VERY nice, but 1050$, it should be. Then again, proper fabrication costs a lot in materials now, gas to backpurge isn't cheap neither is the time of a solid fabricator. The runner look super long on the techworks. I am no expert on runner length and pulse timing, but iirc the shorter the runners the better up high. I could be wrong and may be, since I have been in simple log manifold ball bearing turbo world, where it's like "oh just turn the boost up, another 30-40whp, bam"

This AVLS motor seems to love being rev'd out and make power up high more so than early 2.5RS cars I have driven with similar mods.

While the setup may be "good" to 300whp on a turbo car, N/A cars do behave differently and teeny tiny gains seem to be much more linear across the entire power band. The mods so far to this car, it has become dramatically quicker compared to what it was, and i drive it with a torque box and accordion pipe.

Unfortunately it came with no snorkus I'd like one for temporary use to get rid of the stumbles.
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Old 11-16-2012, 11:36 AM   #1680
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I ran across a video of a guy with an AVLS car saying he had delta 2000's.
You'll want to talk to Delta. Like I said, the last big word from them was that there was only one moderate gind available.

Quote:
I saw SOHC avls head flow numbers and intake manifold flow numbers that looked VERY good, almost Honda like. Which shocked me...... I know the flow bench does not equal reality all the time, but it is often a good predictor. I also read the AVLS heads were changed from earlier heads to be more "honda like"
The SOHC heads have never been bad heads. They've always been the best-flowing ones Subaru made, NA or turbo. The rest of the system has always let them down. As far as has been published, the design of the heads didn't change much when the AVLS was added. They just sort of grafted the AVLS on top.

Quote:
I would be a willing guinea pig, in fact I would consider "locking" the avls as folks do with the v-tecs. Unplug solenoids, and keep the valve in high lift all the time. By consider I mean i've been thinking about doing this a good bit.
Look at the research Teslamaster and I did on this. It's on here under his username. Basically, the AVLS system is locked almost 100% of the time if the car isn't at idle. There's no point to locking it permanently or putting in a manual switch. Another tester has reported that it refused to idle well when locked onto the high lobes. Probably not an area to waste your time.

Quote:
The modifications to my header cost me about 50$ and made a dramatic difference. When you look at what they neck the cat down to, it is obvious. I have pictures of the entire thing dissected but someone else probably put them up around here. In fact the modified stocker is coming off tonight and I am putting new flex joints in said header. I had an exhaust popple I could never find, once I had the car on a lift, it was a slit in the accordion flex for cyl 2 or 4. I picked up 2 treadstoned 1.5" flexes that are lined. My buddy is going to tig them into place this weekend.
TBH, just stop wasting your time and money and buy the Techworks Engineering Equal-length 4-2-1 High Output header. It's an expensive part, but dollar per horsepower, it's the best value in the NA Subaru world. The rest of the mods for the engine are really going to depend on the header being perfect and that one is. Nothing else on the market even comes close and, yes, I've personally tested them all. To address your concerns, it not only added torque all the way up to peak torque, it held it for another 800 RPM on the top end, which pushed peak power up in both senses of the word.
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Old 11-16-2012, 02:20 PM   #1681
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Originally Posted by williaty View Post
You'll want to talk to Delta. Like I said, the last big word from them was that there was only one moderate gind available.


The SOHC heads have never been bad heads. They've always been the best-flowing ones Subaru made, NA or turbo. The rest of the system has always let them down. As far as has been published, the design of the heads didn't change much when the AVLS was added. They just sort of grafted the AVLS on top.


Look at the research Teslamaster and I did on this. It's on here under his username. Basically, the AVLS system is locked almost 100% of the time if the car isn't at idle. There's no point to locking it permanently or putting in a manual switch. Another tester has reported that it refused to idle well when locked onto the high lobes. Probably not an area to waste your time.


TBH, just stop wasting your time and money and buy the Techworks Engineering Equal-length 4-2-1 High Output header. It's an expensive part, but dollar per horsepower, it's the best value in the NA Subaru world. The rest of the mods for the engine are really going to depend on the header being perfect and that one is. Nothing else on the market even comes close and, yes, I've personally tested them all. To address your concerns, it not only added torque all the way up to peak torque, it held it for another 800 RPM on the top end, which pushed peak power up in both senses of the word.


Interesting. I wonder if with locked AVLS I could run a bigger grind.. but then the idle issues.

That header is way out of reach for now. I need to finish my 98 A4 1.8Tq 5857 Precision powered car, and my 914. Perhaps sometime get to my 89 syncro Golf.

The subaru is more of a modified daily, one thing for sure is the exhaust leaks are no good and I have a child with leukemia who can't ride in the car until it is fixed. So I have to replace the flex joints for now. Eventually when it gets up there in mileage, i'll do something like put the 3076 I have sitting around on it, or just leave it as is. It's nice having something all motor and reliable/boring.
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Old 11-17-2012, 09:33 PM   #1682
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so i finally figured out how to post pics....figured i would show you what i mean so that everyone can get my point. \\ again my only concern is if this will cause any issues...i know there will be some benefits.....but im not going crazy with my car performance wise....mainly for looks....and its my daily...so it has to stay reliable.



soon i will replace the airbox and accordion pipe as well as the box at the intake manifold with a straight pipe. and get a better filter and try to connect it closer to the fender...


sooooo......
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Old 11-17-2012, 09:35 PM   #1683
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btw please ignore the writing on the airbox...and i needed to use the zipties to hold the filter a little from rattling as it shakes a bit against the abs lines
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Old 11-17-2012, 11:55 PM   #1684
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1) What you have just done shouldn't cause any problems with the MAF resonance. It will do nothing other than suck in hot air, however, which is a very bad thing.

2) Removing the airbox gains you nothing

3) Removing the accordion pipe and the "torque box" is the whole point of a hybrid.
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Old 11-18-2012, 07:41 AM   #1685
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Well realistically I'm not looking for any gains other than what will be provided by the hybrid intake.

And I remember reading about the difference in cai and short ram where short ram sucks in hot air from the engine bay which helps with mpg vs the cai which sucks in cold air giving a little hp since there's more oxygen. Isn't this true? How is the hot air very bad? Before the pipe was coming from the snorkel in the engine bay as well....
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Old 11-18-2012, 02:40 PM   #1686
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And I remember reading about the difference in cai and short ram where short ram sucks in hot air from the engine bay which helps with mpg vs the cai which sucks in cold air giving a little hp since there's more oxygen.
Whoever told you that is a god damned idiot.

Hot air is less dense than cold air. Less dense means less oxygen per cylinder. Less oxygen means less power. Hotter air is also more likely to cause knock, which means less power AND less fuel efficiency.
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Old 11-18-2012, 03:14 PM   #1687
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Thanks for explaining...good to know where I can get the proper knowledge....really appreciate it.. I will make the necessary changes.
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Old 11-18-2012, 05:49 PM   #1688
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If I get a wrx hood with the scoop....will there be sufficient cold air coming in the engine bay for the intake...will that make any difference? Or it's not worth it
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Old 11-18-2012, 05:53 PM   #1689
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I don't think it'll be sufficient. Using the intake trumpet thing from a turbo to feed the snorkus actually is a BIG help. But that requires not doing what you want to do.
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Old 11-18-2012, 05:58 PM   #1690
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If I get a wrx hood with the scoop....will there be sufficient cold air coming in the engine bay for the intake...will that make any difference? Or it's not worth it
Personally, I would think that the slightly colder air you'd get, would be counter-acted by the now MUCH higher drag that the hood would produce. Not to mention cooling your engine block/exhaust too much and reduce your exhaust effectiveness (I'm not an exhaust expert by any means, but from what I know, the hotter the exhaust the better it tends to flow).

That's why WRX/STI's have a rubber gasket around the TMIC that forces ALL of the cold air through the TMIC.

I would think that on an RS its a lot more of waste then a benefit.

Now... I had one interesting idea awhile back, but only useful if your heavily tracking your car. You could run brake cooling pipes up to the hood scoop and get MUCH colder/cleaner air that you could duct down behind the block, besides the trans. into some brake cooling ducts. I have no idea if that would actually fit/work but it would be an interesting idea if you don't want to run them through the fog light location.
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Old 11-18-2012, 06:03 PM   #1691
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The hood scoop definitely helps even on an RS. Underhood temps are lower overall and recover to a lower temperature after being beat on MUCH faster. It's also quite helpful in stop and go traffic as there will be convective cooling.

That being said, I hate the scoop on an RS. I'd much rather have a mesh grille up there so I don't look so damned dumb as having a scooped RS.
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Old 11-19-2012, 07:44 PM   #1692
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ok ive read throught the entire thread and got a question could you not take the one picture from Jb2.5rstst from this page and just get rid of the filter box and keep the snorkus and just run a pipe from the hybrid pipe setup to the snorkus and then put a filter like the picture shows? then possibly put a shield or something to make it cold air? (like what k&n cai come with) this would keep the snorkus in the fender right? its an honest idea and saw no one else with it.
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Old 11-19-2012, 07:52 PM   #1693
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ok ive read throught the entire thread and got a question could you not take the one picture from Jb2.5rstst from this page and just get rid of the filter box and keep the snorkus and just run a pipe from the hybrid pipe setup to the snorkus and then put a filter like the picture shows? then possibly put a shield or something to make it cold air? (like what k&n cai come with) this would keep the snorkus in the fender right? its an honest idea and saw no one else with it.
Because, as Williaty has said... there is absolutely no benefit in doing it, unless your replacing your headers with very high flowing headers.

secondly, those cone filters let in A LOT more crap into your engine then the standard filter.

Someone else said this: If the standard airbox filter is good for a WRX/STI, we don't come close to pulling that much air, so there is no benefit to be had there, besides having to manuf. something completely. Which... is cool if you can do it yourself, but in my opinion, the the filterbox and filter is most likely lighter then the entire box being replaced with piping (or are VERY close to the same weight).

- spyrule.
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Old 11-19-2012, 07:55 PM   #1694
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u should just not bother at all. These cars are perfect the way they are. i ran a SRI and a hybrid in my 07 impreza, after running the SRI for 4 months and the hybrid for 2 weeks i ended up with a clogged intake manifold due to my intake mods letting more dirt into my engine. After that the same thing started happening to all the other cars running these in my area. Honestly i think one of the worst things you can do on a subi is mod the intake. i sure as hell learned my lesson.
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Old 11-19-2012, 07:57 PM   #1695
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ok i was just wondering thank you
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Old 11-19-2012, 07:59 PM   #1696
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has anyone else besides rallyb have issues after installing the hybrid system?
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Old 11-19-2012, 08:53 PM   #1697
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has anyone else besides rallyb have issues after installing the hybrid system?
What rallyb describes isn't physically possible. He either has no idea what he's talking about or he's just trolling. Probably the latter.

Quote:
Originally Posted by RallyB View Post
u should just not bother at all. These cars are perfect the way they are. i ran a SRI and a hybrid in my 07 impreza, after running the SRI for 4 months and the hybrid for 2 weeks i ended up with a clogged intake manifold due to my intake mods letting more dirt into my engine. After that the same thing started happening to all the other cars running these in my area. Honestly i think one of the worst things you can do on a subi is mod the intake. i sure as hell learned my lesson.
So you clogged your intake manifold, huh? You're saying you actually got a piece of dirt over 2" across to come through a filter and then block some portion of the intake manifold. Call me a critic, but somehow I don't think you're telling the truth.

For those that are worried, the hybrid maintains your stock airbox and your stock filter. That means that the filtration is as good as stock, so long as you don't make it worse by using something like a K&N filter. Most of the CAI/SRI kits out there do come with crap filters on them that let more dirt through than the stock filter. However, even those crap filters aren't letting chunks that could clog anything through. The level of stuff they let through is very, very fine dirt. It's basically silt, if you're familiar with that stuff. The dirt that's so small and light it stays in the air as much as it settles out. That stuff can, over time, destroy an engine. What it can't do is clog an intake manifold.
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Old 11-19-2012, 09:55 PM   #1698
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My mistake, i meant to say throttle body! the SRI had a k&n cone filter, after 4 months of hard driving and a few track days.....and some rallying, the amount of particles that had built up in my throttle body essentially "clogged" it, causing my throttle shaft to not completely operate the way it should have. I also have the previous owner of my car to thank for a lot of the particles too. I then swapped to a hybrid before realizing all of that above^^, after the 2 weeks with the hybrid the throttle body was so screwed up i couldn't make it out of my driveway without stalling. I'm sure the hybrid was doing me more good than the cone filter. But the particles had other plans. My apologizes for getting "intake manifold" and "throttle body" confused. give me a f***ing break. On top of all of that i know for a fact both the SRI and hybrid were causing me to run rich (little gadget we call a air/fuel ratio gauge). just something to think about.
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Old 11-19-2012, 09:58 PM   #1699
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So if u really want to mod the intake, do a hybrid. but stay away from SRI's and CAI's
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Old 11-19-2012, 10:07 PM   #1700
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My mistake, i meant to say throttle body! the SRI had a k&n cone filter, after 4 months of hard driving and a few track days.....and some rallying, the amount of particles that had built up in my throttle body essentially "clogged" it, causing my throttle shaft to not completely operate the way it should have.
Black stuff, fairly gritty, pretty hard to remove without using some aggressive solvent?

That's a known issue on these. It's caused by the PCV puking oil up into the intake tract combining with the EGR dumping hot gasses into the intake manifold plenum. There's enough turbulence at some throttle opening angles to cause the oil mist to hit the hot gasses in the region of the throttle body and the oily soot that results sticks to the throttle plate. The only real long-term fix to it is to disable the EGR and to put an oil separator into the PCV system. I can see that getting made worse by dumping other contaminants into it, as it is a bit sticky.

Quote:
I also have the previous owner of my car to thank for a lot of the particles too. I then swapped to a hybrid before realizing all of that above^^, after the 2 weeks with the hybrid the throttle body was so screwed up i couldn't make it out of my driveway without stalling.
While I think K&N filters are horrible things and do allow too much dirt through, the severity of your problem suggests an assembly problem with both intakes. If you have even a small leak post-filter, you'll get all kinds of crap in there. I'm sure you believe you didn't have any mistakes like that, but I do make a living fixing things like that for people who are sure they did everything right.

Quote:
On top of all of that i know for a fact both the SRI and hybrid were causing me to run rich (little gadget we call a air/fuel ratio gauge). just something to think about.
I'm suspicious of this as well. Other than the specific issue addressed in the first post in this thread, I've never seen either a CAI/SRI or a hybrid substantially alter the AFR. That's over hundreds of cars I've worked with on intakes. Generally, the AFR will change less than 1.0 from stock, so it's worth fixing with tuning but not to the OH GOD I'M RUNNING RICH! stage of things. Stock itself is often VERY rich. Did you do a before and after to see what your specific car as measured by your specific gauge did in a totally stock configuration? I've seen completely stock cars hit as rich as 9:1 all on their own.

I know it sounds like I'm being a hardass about this but too many discussions of technical matters on these forums get too sloppy and lazy and that's how some stupid things come to pass.

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So if u really want to mod the intake, do a hybrid. but stay away from SRI's and CAI's
Amen, brother.
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