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Old 07-18-2010, 10:33 PM   #301
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RomRaider lets me put in whatever target I want... you might have hit a limit of the 16-bit ECU. Also, your stock MAP sensor is probably maxed out as well. I switched to an AEM 3.5-bar unit recently as the stock sensors on 32-bit cars are rumored to max out around 23psi or so.
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Old 07-19-2010, 01:43 AM   #302
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thanks for the response!

yes, i'm on a 16 bit ecu. and i'm running the 'half rom' workaround, which effectively, halves the resolution even more, but i don't think that has anything to do with this issue.

so, is that what i need to program the ebcs to a higher setting? in other words, does RomRaider read the range of the sensor, and then offer you the availability to only edit within that corresponding range? thanks for your help!
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Old 07-19-2010, 01:48 AM   #303
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I don't know, but hopefully someone more familiar with 16-bit ECUs can help you out here. Mine is 32-bit so I haven't run into this issue.

It's not due to the "half" workaround, but the root cause is probably similar, in that the way the ECU stores numbers limits the minimum and maximum values that it can work with.
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Old 07-19-2010, 02:47 AM   #304
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right, thanks man. anyone have any 16 bit info?
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Old 07-19-2010, 07:41 AM   #305
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Old 07-19-2010, 10:30 AM   #306
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I'm planning on running 26-28 psi with a 16bit ecu. There is a limit, but I don't remember what it is exactly. It seemed to me that a MAP hack for the 16 bit would be just as easy as a G/S hack. Since the ECU is basing the boost adjustments on the MAP sensor, can't you just skew the MAP readings so that the ECU sees less boost. Basically 20 psi reading = 26 psi actual and a target of 20 would get you 26?
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Old 07-19-2010, 05:17 PM   #307
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That will not work. The limitation is in the physical sensor itself. At damn near 5 volts, the diaphragm is fully extended to one side. It's a mechanical issue. Get a different sensor.

The MAF hack works because the limitation is due to the ECU. Just because you can halve the transfer function doesn't mean you'll be able to read up to 600 g/s with the stock housing. ~350 g/s is the limit for the stock housing/sensor.

You will need an auxiliary boost gauge that is capable of reading boost levels you intend to run. Then use the MBC to set boost ceiling. Set an unattainably high boost target for the stock ECU/sensor and increase your WDC to 100% at WOT.
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Old 07-19-2010, 06:34 PM   #308
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Yes....there is a 24.75 psi limit in the 16 bit ecu. Much like the 300 g/s MAF limit...you simply cant input a higher value into the boost table.

I have gotten around the issue by using an AEM 3.5bar sensor and scaling it 5.25 psi low.

So now if the ecu reads 24.75 psi it would mean im at 30psi.
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Old 07-19-2010, 09:34 PM   #309
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I remember a while back that Merchgod said it was easy enough to make whatever changes were needed to increase the 24.75 limit, but it wasn't important at the time - maybe one of the current devs (Dale or NSFW, etc) would be able to implement this for those who are running a bigger map sensor.

Maybe it can be added so it is only viewable and editable under debug mode (user level 5)?

Leslie
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Old 07-19-2010, 10:32 PM   #310
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Quote:
Originally Posted by Phatron View Post
Yes....there is a 24.75 psi limit in the 16 bit ecu. Much like the 300 g/s MAF limit...you simply cant input a higher value into the boost table.

I have gotten around the issue by using an AEM 3.5bar sensor and scaling it 5.25 psi low.

So now if the ecu reads 24.75 psi it would mean im at 30psi.


so that answers my question... get the AEM sensor, scale it as Phatron said, and then do as MRF582 said.

thanks guys!
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Old 07-19-2010, 11:35 PM   #311
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Interesting. Didn't realize there was a limit on how high one could set the boost target. When I was running 28psi on my 2.0L a few winters ago, I would just set the boost target a bit above what the sensor could read. So the ECU would never think that it reached boost target. My EBC would stay closed and my MBC would be in full control at WOT.

Anyway, thanks for the clarification.
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Old 07-20-2010, 12:57 AM   #312
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You can run boost at whatever you like, just put an MBC or aftermarket EBC on and off you go - it's just that the Subaru ECU can only target 24.75psi max (at least the 16bit ECUs can only target 24.75psi)
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Old 07-20-2010, 09:47 AM   #313
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I was planning on changing the ECU ID code on my car and writing custom definition files so that it would display the true g/s and psi. I tune other cars, so I can't just change the definition for all 16 bit, and I'll forget to switch def files if I have 2 different ones.
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Old 07-21-2010, 03:14 PM   #314
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Default I think I can vouch for this

edit: sorry for busting in on current topic w/ older related topic. wish I had soo much air flow I had to rescale lol.

Quote:
Originally Posted by eminehart View Post
A signal lock occurs that can cause pressure to build between the wastegate solenoid and the boost controller. It won't function properly. You will probably cause the wastegate to open prematurely and it won't behave reliably or consistently.

With a parallel setup this is less likely to be noticed. If you were not running this setup you will be running in circles trying to tune boost.
I think I can vouch for this phenomenon.

I have what is effectively a grimmspeed bcs w/ vent port plugged running by itself in interrupt config. (compressor -> bcs -> wg). My boost is not terribly predictable. I get anything from wg spring pressure to 2-3psi over depending on when I step on the gas and close the solenoid (100% duty) and "lock in" signal. Even w/ 80% duty (way more than I should need w/ interrupt setup), can't get it to build above WG pressure.

Apparently some WG's leak more air then others. This one appears to hold well. I'm trying to source a 1/8th npt hose barb to add 3rd port vent to intake to prove this concept.

I have my hallman on order. I probably won't plug the bleed hole in mine like Ride did his. I'll post back my results.

-- couple learnings:
1) bleed style mbc's don't work well in hybrid setup ( I had turboxs standard for my experience). Expecting great things from the hallman ball and spring. I thought I was buying ball and spring when I picked up the turboxs used.

2) if you have purchased leak down test tool, you can use it as a handy local air pressure regulator for testing wg spring tension, solenoid actuation and sealing, etc.

3) apparently newer td04 wg's have weaker springs or less adjustablity??? On this new (used but new to me) turbo, connector is almost all the way tightened but my spring pressure is ~5.5-6psi. My original turbo wg spring / adjustment was good for well over 7psi. (I had 7psi and had lots of room left to tighten). oh well.

Last edited by batchman; 07-21-2010 at 03:17 PM. Reason: being insensitive.
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Old 07-22-2010, 09:28 AM   #315
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Quote:
Originally Posted by MRF582 View Post
3) apparently newer td04 wg's have weaker springs or less adjustablity??? On this new (used but new to me) turbo, connector is almost all the way tightened but my spring pressure is ~5.5-6psi. My original turbo wg spring / adjustment was good for well over 7psi. (I had 7psi and had lots of room left to tighten). oh well.
Correct. The 2.5 liter WRX TD04 has a weaker spring. Some people add helper springs, but it's better to just buy a wastegate actuator from an older TD04.
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Old 07-22-2010, 11:42 AM   #316
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Quote:
Originally Posted by bluescoobywagon View Post
Correct. The 2.5 liter WRX TD04 has a weaker spring. Some people add helper springs, but it's better to just buy a wastegate actuator from an older TD04.
good to know I'm not crazy. I didn't think about it until you mentioned that but I have my old WG actuator sitting in box in the garage! thanks.

update on the whole signal lock theory:
- I read further in the thread and found at least a couple others who seemed to experience this phenomenon.
- I'm going to drop by a non-chain parts store to see if they have 1/8" npt hose barb. None of the chains have them - plenty of 1/4" though . I guess I could just remove the plug and vta to test the theory as well. I'd like to use the hose barb b/c I have a restrictor pill to use to route back to inlet but what the heck. Should have results after lunch today.
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Old 07-22-2010, 02:14 PM   #317
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Hmmm. I pulled the vent plug in ebcs. Still not building boost like it should. Something else is going on. Definitely NOT the signal lock theory. Plugged or unplugged vent port (NC in diagrams), I get little to no boost over wg spring.

Does the BCS circuit have a fuse? Time to pressure test intake again. Must have missed something.
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Old 08-04-2010, 12:12 PM   #318
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Does anyone have more detailed pics of their setups? Which manual boost controller is recommended? I currently still have the Prodrive 3 port boost solenoid and frankly quite sick of how slow it reacts, etc. Thanks.

Also how was the tuning? Did the tuners have trouble tuning your setups? Any pros and cons?
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Old 08-04-2010, 12:33 PM   #319
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The hallman pro rx mbc is the best one ive ever used.

http://www.importimageracing.com/p/H...ontroller.html

The tuning is easy......above 50% throttle make the initial and max wgdc tables 95%, then below that tune normally. WOT tuning is basically just setting the wgdc tables to 95% and then turning the mbc to your desired boost.
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Old 08-04-2010, 12:50 PM   #320
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Quote:
Originally Posted by Phatron View Post
The hallman pro rx mbc is the best one ive ever used.

http://www.importimageracing.com/p/H...ontroller.html

The tuning is easy......above 50% throttle make the initial and max wgdc tables 95%, then below that tune normally. WOT tuning is basically just setting the wgdc tables to 95% and then turning the mbc to your desired boost.
Do you have pics of your setup? I want to get a visual idea of this.
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Old 08-04-2010, 12:54 PM   #321
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mine is setup exactly like post 1....but my hallman is underneath the brake booster or whatever that thing is on the strut tower so you cant really see it.

is there something specific you are trying to see thats not in this picture?


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Old 08-04-2010, 01:06 PM   #322
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Well I currently have an external wastegate setup with a prodrive 3 port boost solenoid hooked up and tuned. However its quite depressing how slow the solenoid reacts. So I wanted to run something thats faster in response with the features of the 3 port boost solenoid that has failsafes to cut fuel, etc. Then came across this thread.
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Old 08-04-2010, 01:14 PM   #323
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so.....take the line that goes to the int wg in this picture.....and hook it to your ext wg.

i also have an ext wg....and just followed this diagram.

And its probably not the "solenoid reacting slow".....its the turbo dynamics and wgdc tuning thats making it slow. The controller is only doing what its told.
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Old 08-04-2010, 01:20 PM   #324
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Do you believe my tuner would be able to tune this out well? As I'm going to GST Motorsports
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Old 08-04-2010, 01:30 PM   #325
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The whole point of this is that you're using a mbc which doesnt need any tuning besides setting it to your desired peak boost by turning the knob.

if you go there and he doesnt know how to tune it....just tell him this

1 - Hilight Initial and Max wgdc tables from 50-100% throttle....make them 95%

2 - tune mbc as normal. IE turn up to desired boost.


If you're gonna go pay him $400 to do it for you just send me $150 and i'll do it.

Im a vendor on here too

http://forums.nasioc.com/forums/member.php?u=239659

Last edited by Phatron; 08-04-2010 at 01:48 PM.
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