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Old 08-30-2006, 02:37 PM   #26
Element Tuning
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The stock STI mapping has the intake cam advanced in the high rpm and this is where power gains are realized by reducing it. We've been mapping this way on the Hydra since day one and realized the gains some time ago. Many had asked why are the Hydra cars making 30-40 whp more on the top end and that's part of the reason. I remember when I was data logging the OEM mapping and thinking to myself, what were they thinking

Thanks,
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Old 08-30-2006, 02:48 PM   #27
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Here are the cam advance tables for various USDM cars:
http://freon.shackspace.com/car/ecu%...ing/camadvance

I don't think any of the different year cars have had their AVCS map retuned unless the powertrain has had a major change (i.e. 06 WRX).

Cam advance goes to zero above 4400rpm or so, besides the 06 WRX for all the USDM cars. JDM is drastically different.

Last edited by Freon; 08-30-2006 at 03:06 PM.
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Old 08-30-2006, 03:00 PM   #28
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Quote:
Originally Posted by Element Tuning View Post
The stock STI mapping has the intake cam advanced in the high rpm and this is where power gains are realized by reducing it. We've been mapping this way on the Hydra since day one and realized the gains some time ago. Many had asked why are the Hydra cars making 30-40 whp more on the top end and that's part of the reason. I remember when I was data logging the OEM mapping and thinking to myself, what were they thinking

Thanks,
Phil
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I dont agree... I do not run the cams at 0. I think you need to get back on the dyno phil

Clark
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Old 08-30-2006, 03:28 PM   #29
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Quote:
Originally Posted by Freon View Post
Here are the cam advance tables for various USDM cars:
http://freon.shackspace.com/car/ecu%...ing/camadvance

I don't think any of the different year cars have had their AVCS map retuned unless the powertrain has had a major change (i.e. 06 WRX).

Cam advance goes to zero above 4400rpm or so, besides the 06 WRX for all the USDM cars. JDM is drastically different.
im having trouble finding a rhyme or reason with the stock maps...
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Old 08-30-2006, 03:28 PM   #30
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I dont agree... I do not run the cams at 0. I think you need to get back on the dyno phil

Clark
do you also run bigger-than-stock turbo cars with 0+ towards redline?
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Old 08-30-2006, 03:30 PM   #31
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Well, comparing the EU and USDM to the JDM maps, I have to wonder if there are emissions concerns. Obviously the JDM cars get away with plenty of advance in upper RPM ranges. The USDM and EU cars just drop to zero above 4400rpm, again besides the very slight advance that's left on the 06 WRX.

I added a bunch of maps.
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Old 08-30-2006, 03:36 PM   #32
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Originally Posted by Freon View Post
Well, comparing the EU and USDM to the JDM maps, I have to wonder if there are emissions concerns. Obviously the JDM cars get away with plenty of advance in upper RPM ranges. The USDM and EU cars just drop to zero above 4400rpm, again besides the very slight advance that's left on the 06 WRX.

I added a bunch of maps.
i agree that the lack of advance above the 4400 range in the jdm/edm ecus is probably for emissions...

...but with avcs really helping the turbo spool, why are the lower (load and rpm) range cells also drastically different? (ie, the LGT goes from 0-5-10-0-0-10-10-0 in the .25 load site...why up down up down?)
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Old 08-30-2006, 03:49 PM   #33
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Originally Posted by AZScoobie View Post
I dont agree... I do not run the cams at 0. I think you need to get back on the dyno phil

Clark
Prove me wrong I’m just not seeing anyone netting higher HP numbers than cars with Element Hydra base AVCS mapping. I’m not saying they cannot be duplicated with another EMS but I’m not seeing the top end gains of running the intake cam advanced at high boost and RPM. Advancing the intake cam under high boost just blows it out the exhaust so I’m not sure I understand how that would help in a boosted application unless you could retard the exhaust cam. But hey I don’t claim know or have tested everything

Quote:
Originally Posted by Freon View Post
Here are the cam advance tables for various USDM cars:
http://freon.shackspace.com/car/ecu%...ing/camadvance

I don't think any of the different year cars have had their AVCS map retuned unless the powertrain has had a major change (i.e. 06 WRX).

Cam advance goes to zero above 4400rpm or so, besides the 06 WRX for all the USDM cars. JDM is drastically different.
The target is one thing but what it’s actually doing with duty cycle and the resulting cam advance is another. From some of the logging I did a couple years ago the OEM ECU was holding the AVCS on too long reducing peak power. Also keep in mind the systems are run in closed loop and often stray from the actual target.

Thanks,
Phil
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Old 08-30-2006, 03:52 PM   #34
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Quote:
Originally Posted by happasaiyan View Post
...but with avcs really helping the turbo spool,
Looking at USDM/EU vs. JDM, there are two possibilities. #1, this statement is a misnomer, and it can help power up top as well, not just spool. OR, the EU/USDM cars have different cam duration/lift/advance at rest, which leads to different mapping. Perhaps the USDM car cams start out with more advance, thus not needing any in upper rpm range. Maybe it isn't even emissions.

I had always assumed you'd want to retard the cams at high load due to exhaust backpressure, but looking at the JDM maps makes me question this. I actually hadn't looked at the JDM maps until today when I ripped them and posted them.
Quote:
why are the lower (load and rpm) range cells also drastically different?
Different turbos, cams, gearing? Though I agree they're still all over the place, and don't seem to make much sense at a glance.

Look the 06WRX and 04STI. Airpump? Turbo? Very odd maps to compare.
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Old 08-30-2006, 04:55 PM   #35
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Dont compare STI 2.5 engines to Legacy or Forester or even new WRX 2.5s.. The cam map is changed ALOT and for good reason. The little Td04 turbo. I spent 2-3 hours mapping the legacy. I had to start from scratch because nothing worked as it should.

I took a good look at the cam map one day and something occured to me.. I began to remap it from scratch. What I found was very interesting. I think Subaru actualy put that Cam map in the car to reduce power output of the 2.5 STI engine. Once they obtained the 300hp they where after they used the AVCS System as a detuning feature. My only regret is that I did not map AVCS out sooner. The changes are pretty dramatic Talk to people that have my new STI map. They will tell you power does NOT let up at ALL until 7200 rpm

I am have yet to map out my Type RA heads on the 2.5 block with 35R. I will when it goes on the dyno next. Now that I am running the SPeed density system on the Utec my car finaly runs right. The Cams will just be Gravy for an already killer setup.

Clark
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Old 08-30-2006, 04:57 PM   #36
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In theory you are correct Phil. But only In theory. I honestly think you need to remap this system for fun to see what you can produce.

C

Quote:
Originally Posted by Element Tuning View Post
Prove me wrong I’m just not seeing anyone netting higher HP numbers than cars with Element Hydra base AVCS mapping. I’m not saying they cannot be duplicated with another EMS but I’m not seeing the top end gains of running the intake cam advanced at high boost and RPM. Advancing the intake cam under high boost just blows it out the exhaust so I’m not sure I understand how that would help in a boosted application unless you could retard the exhaust cam. But hey I don’t claim know or have tested everything



The target is one thing but what it’s actually doing with duty cycle and the resulting cam advance is another. From some of the logging I did a couple years ago the OEM ECU was holding the AVCS on too long reducing peak power. Also keep in mind the systems are run in closed loop and often stray from the actual target.

Thanks,
Phil
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Old 08-30-2006, 07:53 PM   #37
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Geez go away for few hours and everybody chimes in...

I don't think Subaru had power in mind at all when adding AVCS, their likely target was emissions and maybe economy. The JDM STI may have exploited it for a different reason.

Certianly overlap at high RPM can help power up top, so I can see how clark found some power up there. On the other hand if you are at the edge of "reversion" keeping the exhaust backwash at bay would be good too. I think a lot will depend of the turbine, boost level,.....

More fun on the dyno to come.
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Old 08-30-2006, 08:42 PM   #38
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Originally Posted by bboy View Post
Geez go away for few hours and everybody chimes in...

Certianly overlap at high RPM can help power up top, so I can see how clark found some power up there. On the other hand if you are at the edge of "reversion" keeping the exhaust backwash at bay would be good too. I think a lot will depend of the turbine, boost level,.....

More fun on the dyno to come.
Always worth testing something new but.....advancing the intake cam timing typically reduces the length of time for the fuel and air to burn. By retarding the exhaust cam you lengthen the amount of burn time. This is a good thing as it allows for more complete combustion. This is already a big problem with our motors and results in having to run lots of ignition timing. Earlier intake cam opening and later exhaust cam timing lengthens the burn window. Once you put boost into the mix then you have to be careful not to blow your intake charge out the exhaust valve and this can be tricky. This is typically why you can advance a lot at low boost but not so much at high boost or high rpm.

Thanks,
Phil
http://www.elementtuning.com

Last edited by Element Tuning; 08-31-2006 at 10:55 AM.
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Old 08-31-2006, 02:44 AM   #39
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I'm sorry to try a mini-hijack on this thread, but...

What about N/A AVCS applications, what benifits would there be to AVCS tuning for those motors? (EZ30-R, the JDM AVCS DOHC N/A motors, and maybe the 06+ 2.5i i-active system)
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Old 08-31-2006, 01:54 PM   #40
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That's another arguement for widening the LSA so that that intake cam is more advanced and the exhaust cam is retarded, you can always bring them closer together with AVCS or a even more sophisticated system that works on both cams. Doing so would elevate the importance to AVCS tuning overall. Maybe some of us should try retarding the exhaust cams with a sprocket.

NA motors can also benefit from tuning of the AVCS following the more classic arguement that cam overlap will increase induction velocity at high RPM. The map for an NA car is just a portion of the one for a force induction car. The big difference to me will be that you can be slightly more aggressive with cam overlap under vacuum because you don't have this big blockage in the exhaust called a turbo. In an NA motor, I'd think that you could keep AVCS active all the way to redline and still have gains, where as under boost there's the blow thru potential that Phil is talking about.

Trent
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Old 08-31-2006, 03:14 PM   #41
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Quote:
Originally Posted by bboy View Post
NA motors can also benefit from tuning of the AVCS following the more classic arguement that cam overlap will increase induction velocity at high RPM. The map for an NA car is just a portion of the one for a force induction car. The big difference to me will be that you can be slightly more aggressive with cam overlap under vacuum because you don't have this big blockage in the exhaust called a turbo. In an NA motor, I'd think that you could keep AVCS active all the way to redline and still have gains, where as under boost there's the blow thru potential that Phil is talking about.

Trent
Thats good info. I was thinking the difference would actually be a bit more useful with an NA application, but wasnt sure. I really hope there is more work with this in the future.
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Old 09-03-2006, 01:24 PM   #42
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Ok. I have ask a STI owner for his time to start AVCs in High RPM range testing.

Unfortunately, we only have EcuTek Road Dyno. He also have a Gtech Pro, but you know many variables in this equation.

We plan to run avcs=0 from 5600rpm + and see what happens.

This STI is doing 300/300 hp/lbft on ecu tuning. Not much mods, except down pipe and max hp not even on the 7500 range


Here is the link for the car in Trinidad http://www.hostingphpbb.com/forum/vi...20&mforum=tsoc

http://www.hostingphpbb.com/forum/vi...orum=tsoc#2925

Last edited by west_minist; 09-03-2006 at 02:08 PM.
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Old 09-03-2006, 05:13 PM   #43
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good thread!

clark, any chance on seeing a dyno plot of some of the gains you've managed?

ken
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Old 09-03-2006, 07:15 PM   #44
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great info guys
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Old 09-03-2006, 10:48 PM   #45
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Quote:
Originally Posted by AZScoobie View Post
The changes are pretty dramatic Talk to people that have my new STI map. They will tell you power does NOT let up at ALL until 7200 rpm
My PDX OTS stage2, they specifically told me that they make changes to AVCS timing. Comparing to cobb stg 2 is night/day, despite having nearly the same boost levels in the upper rpm range, the pdx map does NOT feel like its fallen on its face after 6200 rpm, it just keeps going and going.
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Old 09-03-2006, 11:37 PM   #46
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Guys, slightly off topic.

In a NA application, a colder plug will cause what effects?

Can it cause pinging?

I noticed that I shift from Denso IK22 to the NGK replacement BKR7IX and the normal fuel mixture for +ve Knock correction is now still in -ve. The only thing that I can think of is the is the new NGK in there.

Thanks for your response
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Old 09-04-2006, 08:39 PM   #47
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anyone experiment with trying to get a aem to run avcs
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Old 09-05-2006, 12:34 PM   #48
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AEM will not control AVCS in Closed loop. The Link G3 plugin will.

The problem with just changing advance around in the map is that doing so changes the amount of air going into the engine and the dynamic compression. Fuel and timing must then be adjusted to find the correct settings for that angle of advance.

C
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Old 09-05-2006, 06:16 PM   #49
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Quote:
Originally Posted by AZScoobie View Post
AEM will not control AVCS in Closed loop. The Link G3 plugin will.

The problem with just changing advance around in the map is that doing so changes the amount of air going into the engine and the dynamic compression. Fuel and timing must then be adjusted to find the correct settings for that angle of advance.

C
judging by clark's comments, it seems the key to really unlocking avcs would be to:

1) run conservative timing and afrs
2) set boost map
3) adjust avcs map to maximize maf across the board
4) revisit boost map as needed
5) revisit fuel map
6) revisit timing map

the key is your metric to judge avcs efficacy would be engine load.
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Old 09-06-2006, 12:44 AM   #50
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Quote:
Originally Posted by ride5000 View Post
judging by clark's comments, it seems the key to really unlocking avcs would be to:

1) run conservative timing and afrs
2) set boost map
3) adjust avcs map to maximize maf across the board
4) revisit boost map as needed
5) revisit fuel map
6) revisit timing map

the key is your metric to judge avcs efficacy would be engine load.
Ken-

I've found that you can make great power on STi's with very little timing advance. On a stock turbo, after remapping AVCS, with only 10-11 degrees of advance at peak torque I was able to make nice power.

Compare that to a 2.0L where I was running 15 degrees of advance on my stock turbo.
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