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Old 02-17-2013, 01:37 AM   #1751
boomhauer
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Before I drove the car (2006, only had it for a week) I thought there'd be no appreciable boxer sound with the equal length headers that came standard beginning that year. Turns out I was wrong. Actually, I've already been looking at Magnaflow mufflers as a modest visual/sound improvement - and not the "bullet" models that would annoy me and the neighbors. Appreciate the advice.
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Old 03-02-2013, 03:54 AM   #1752
adosdrummer
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A 3in hybrid I made for a customer.. and the crazy thing is all the power it made on a tune for a stock intake.. so he still needs a re tune.. the afr's are now in the 11's when it was tuned to lean 12's..
Also saw a lot of knock after the install.. but my timing was pretty aggressive on the stock intake tune. Tuned for 89 shell oct.. so still got some left on the table with upgraded fuel.
this was on a 2006 impreza 2.5i 5spd, only other mods was a weld on muffler.

Will take pics soon "crosses fingers" not my car.
I used a s2k aem intake.. had plenty of pipe left over. So possibly you can find a good deal online for one used and re-create.

Not bad for a first post eh?
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Old 03-02-2013, 02:33 PM   #1753
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Why do you have those two ridiculously rich spikes?
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Old 03-02-2013, 03:42 PM   #1754
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How exactly do I tune, I always wanted to do this. i know i need a tactrix cable and an open source software?
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Old 03-02-2013, 03:46 PM   #1755
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Quote:
Originally Posted by Thesystem3 View Post
How exactly do I tune, I always wanted to do this. i know i need a tactrix cable and an open source software?
Do not ask that question here. There's an entire tuning sub forum that you should go read all the stickies in. If you still have questions, ask them in that forum, rather than crapping up this thread.
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Old 03-03-2013, 02:42 AM   #1756
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That was actually the engine load.. no clue why it displayed that. or why It has those dips.
I have never seen it do that before.
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Old 03-03-2013, 02:49 AM   #1757
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Quote:
Originally Posted by adosdrummer View Post
That was actually the engine load.. no clue why it displayed that. or why It has those dips.
I have never seen it do that before.
Engine load in g/rev or manifold vacuum in PSI?
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Old 03-03-2013, 03:04 AM   #1758
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oops good catch, I didn't see I logged map in psi.
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Old 03-03-2013, 03:16 AM   #1759
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Quote:
Originally Posted by adosdrummer View Post
oops good catch, I didn't see I logged map in psi.
Ah, ok. FYI, the MAP is NOT a good source of data from these cars. If you look at where the MAP sensor is installed in the throttle body, it's effectively on a Venturi tube. As the air velocity through the throttle body increases, the MAP sensor begins to read artifically low as the air flowing past the port pulls the pressure in the tube down.

If you want to pick up engine load, your best bet is to log with something like RomRaider that can poll the ECU directly at a high rate using SSM to read out engine load in g/rev.


I have a feeling, though I've never gotten around to proving it, that the stupid placement of the MAP sensor is responsible for the transient fueling errors during large, rapid throttle plate position changes since those errors don't respond rationally to changes in tip-in.
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Old 03-03-2013, 03:30 AM   #1760
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Hmm, do you know off hand if the map has this same issue on a turbo car? JW

I had it selected for a log on my LGT. No need on a n/a car.

I am using romraider for my logs, I can see if my friend will let me tap into the manifold and move the map.. but I would have to remove the manifold to install and clean out the shavings.

I am fairly new with Subaru's, but I have a tuning back ground in the PFC and FIC.
I wish Romraider had map tracer and tuning on the fly.
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Old 03-03-2013, 04:11 AM   #1761
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Quote:
Originally Posted by adosdrummer View Post
Hmm, do you know off hand if the map has this same issue on a turbo car? JW
I've never looked to see where it is on a turbo, but if it's in the same place, I've wondered before it that was the cause of their rich spikes during shifts when using a front-mount IC.


Quote:
I can see if my friend will let me tap into the manifold and move the map.. but I would have to remove the manifold to install and clean out the shavings.
I would strongly recommend against this. There's a BUNCH of tables that reference MAP. You'd have to recalibrate each and every one of them due to the position change. This would be nearly impossible to do without an engine test chamber with environmental controls and an engine dyno. It's better to just live with it.


RR does have map tracing, or active cell highlight, whichever you want to call it.
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Old 03-03-2013, 05:59 PM   #1762
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Alright guys, so let me get this straight. Which option will yield more power?

1: Stick with my Cosmo SRI and get a tune done
2: Hybrid (+ tune?)

I have the SRI installed and as I understand it, having a tune done will alleviate most of the problems?
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Old 03-03-2013, 06:02 PM   #1763
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Quote:
I have the SRI installed and as I understand it, having a tune done will alleviate most of the problems?
Probably not. As far as I know, no one else has figured out how to fix this issue in the tune. It's NOT just the typical "tune for an intake" adjustment of the MAF scaling. Honestly, I'm shocked someone else hasn't figured it out and posted it for free yet. What that shows, I suppose, is that no one is interested in actually doing good tunes for the NAs.


Quote:
Originally Posted by scoobymatt93 View Post
Alright guys, so let me get this straight. Which option will yield more power?

1: Stick with my Cosmo SRI and get a tune done
2: Hybrid (+ tune?)
They will be so close to each other that most chassis dynos won't be able to show you the difference.
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Old 03-04-2013, 09:12 AM   #1764
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Quote:
Originally Posted by williaty View Post
Probably not. As far as I know, no one else has figured out how to fix this issue in the tune. It's NOT just the typical "tune for an intake" adjustment of the MAF scaling. Honestly, I'm shocked someone else hasn't figured it out and posted it for free yet. What that shows, I suppose, is that no one is interested in actually doing good tunes for the NAs.



They will be so close to each other that most chassis dynos won't be able to show you the difference.
I recall reading a thread from PhatBotti tuning ( I think that was their name, at least) and they said they were able to tune out the problems associated with the SRI. I may be mistaken though
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Old 03-04-2013, 10:09 AM   #1765
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Quote:
Originally Posted by williaty View Post
Probably not. As far as I know, no one else has figured out how to fix this issue in the tune. It's NOT just the typical "tune for an intake" adjustment of the MAF scaling. Honestly, I'm shocked someone else hasn't figured it out and posted it for free yet. What that shows, I suppose, is that no one is interested in actually doing good tunes for the NAs.



They will be so close to each other that most chassis dynos won't be able to show you the difference.
Well for one you could cap the engine load? maf v is determined for calculating load. If its that big of a spike the ecu could be determining a huge engine load more than a n/a car would see in almost any condition. Just a thought.

That could at least put a ceiling on the spike, so it would not make fueling and ignition for say 1.9grev, but instead 1.6

Last edited by adosdrummer; 03-04-2013 at 10:17 AM.
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Old 03-04-2013, 10:30 AM   #1766
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For everyone's reference, Mafv is used in the computers algorithm to determine engine load (g/rev) In the graph above is a good representation on that mafv vs g/rev. Excuse my paint work :P

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Old 03-04-2013, 02:49 PM   #1767
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Quote:
Originally Posted by scoobymatt93 View Post
I recall reading a thread from PhatBotti tuning ( I think that was their name, at least) and they said they were able to tune out the problems associated with the SRI. I may be mistaken though
I'd love for a customer of theirs to test and see if they really fixed the problem or just rescaled the MAF table and think they've fixed in. Until one of their customers tests properly, it's really no different than Injen coming in, oh, maybe 2 years ago or so and claiming they had an intake that didin't have this problem. Customer finally got one, customer tested it, sure enough, it still had a problem.


Quote:
Originally Posted by adosdrummer View Post
Well for one you could cap the engine load? maf v is determined for calculating load. If its that big of a spike the ecu could be determining a huge engine load more than a n/a car would see in almost any condition. Just a thought.

That could at least put a ceiling on the spike, so it would not make fueling and ignition for say 1.9grev, but instead 1.6
Yes, you could limit it in that way. Then you'd only be hitting about 7 or 8:1 AFR rather than 3 or 4:1 AFR. Still isn't really going to be good enough to call the problem fixed.

And you can't just re-scale the MAF either, and that's discussed at length in this thread.
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Old 03-04-2013, 03:03 PM   #1768
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No it wont be fixed, it would be a band aid that only covers half the wound.
If its spiking just below 2.0grev and you limit the load ceiling to 1.5 then in a way you at least cut the problem in half.

In a way I wish my friend chris had the maf spike so I could play with it and see what I would come up with to fix it.. but alas he doesn't with the Hybrid.
I love a good challenge.
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Old 03-04-2013, 03:11 PM   #1769
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Then the question would be does the ECU just cap the load, or is that threshold a limit for error detection and the ECU will conclude the DBW system has failed and set limp mode every time you step on the gas.
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Old 03-04-2013, 03:23 PM   #1770
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good question, only one way to find out.. lol
I am hoping it would read as a flat line at the ceiling.
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Old 03-04-2013, 03:25 PM   #1771
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speakin of dbw system... you could change the throttle position angle's at that rpm and load.. maybe it wont have that spike at 70% throttle as apposed to WOT..
Use the throttle to reverb on the harmonics, like a brass instrument.
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Old 03-04-2013, 03:30 PM   #1772
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That spike let free by the position of the throttle plate not the position of the throttle pedal. The DWB system can't alter the relationship between throttle plate angle and engine output since that is a fundamental physical characteristic.
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Old 03-04-2013, 03:39 PM   #1773
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limit throttle angel to limit engine output at specific rpm the resonance occurs..
at 2-3k, how much power are you really going to lose with 30% less throttle and not have a bogging issue?
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Old 03-04-2013, 03:43 PM   #1774
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Quote:
Originally Posted by adosdrummer View Post
at 2-3k, how much power are you really going to lose with 30% less throttle and not have a bogging issue?
Well, closing the throttle by 30% from full takes away at least 25% of the torque, and if you're asking for full throttle down there, you're probably in a situation where you want 100% of the torque possible. Additionally, the problem isn't present only at full opening. It's present at all throttle openings, but becomes less and less pronounced as you close the throttle. So you'd have to make a personal decision about where your compromise between crippling the engine with bad AFR vs crippling the engine with limited throttle opening is.

Or, you know, just fix the hardware with an intake that doesn't cause problems.
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Old 03-04-2013, 03:47 PM   #1775
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Quote:
Originally Posted by williaty View Post
Well, closing the throttle by 30% from full takes away at least 25% of the torque, and if you're asking for full throttle down there, you're probably in a situation where you want 100% of the torque possible. Additionally, the problem isn't present only at full opening. It's present at all throttle openings, but becomes less and less pronounced as you close the throttle. So you'd have to make a personal decision about where your compromise between crippling the engine with bad AFR vs crippling the engine with limited throttle opening is.

Or, you know, just fix the hardware with an intake that doesn't cause problems.
Exactly would be the best move. Like I said this particular car with the hybrid intake does not have the maf issue, but it has been a pleasure throwing ideas around at ya.

-Jesse
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