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Old 04-19-2017, 10:31 AM   #776
arghx7
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looks like the tuner took out the high overlap for fuel economy up to 3200rpm.
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Old 04-19-2017, 01:24 PM   #777
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Chances are they took the aggressive spark advance out of the cruise portion of the map, as well. These two changes are why many people get ~10 mpg after a tune.
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Old 05-01-2017, 05:52 PM   #778
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Mine was telling me the TGV Deletes was the reason for my bad fuel economy. But he pulled a lot of AVCS advance out in the cruising area. Down to like 15. I should look at the ignition advance in the cruising area as well. Stuff like this is why I started teaching myself.

No where and I mean No where did I find anyone ever saying TGV Deletes on an EJ will hurt fuel economy. I searched high and low. I mean how do the JDM Subaru (Yes I know the 207 is a different motor) get along just fine.
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Old 05-01-2017, 06:12 PM   #779
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Quote:
Originally Posted by Delphi View Post
No where and I mean No where did I find anyone ever saying TGV Deletes on an EJ will hurt fuel economy. I searched high and low. I mean how do the JDM Subaru (Yes I know the 207 is a different motor) get along just fine.
TGV's only help on cold start to control emissions (hence their use in the US). They are pretty much useless otherwise. There is no reason anyone should loose MPG from them alone.
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Old 05-02-2017, 11:24 PM   #780
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Default Dual AVCS Cosworth S2

thanks for all informations !

what do you recommend using for Cosworth AVCS cams S2? (in my sti 08 Dual AVCS for GTX3582 GEN2)

the specs are

Int 278 Degree, 10.74mm Lift
Exh 274 Degree, 10.0mm Lift


I couldn't find much data on, how much i can do for better and for max ?
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Old 05-03-2017, 06:23 PM   #781
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Quote:
Originally Posted by dplancy View Post
thanks for all informations !
what do you recommend using for Cosworth AVCS cams S2? (in my sti 08 Dual AVCS for GTX3582 GEN2)
the specs are
Int 278 Degree, 10.74mm Lift
Exh 274 Degree, 10.0mm Lift
I couldn't find much data on, how much i can do for better and for max ?
Tuning them basically follows the same lines as any other AVCS tuning. I have the same 04 STI heads (no exhaust) in my built motor. All depends on when your car is making boost by.

I hope you have enough fuel! With mine running a 52lbs/min turbo, I ran our of injector at 18PSI. Then again, I have smaller injectors (850cc).

If you need help, feel free to PM
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Old 05-04-2017, 01:04 PM   #782
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thanks for your answer.

For me I have small injectors too (1000cc), I think to buy next month 2000cc ID

For the tune, I thought I had a good starting point or angle errors to avoid not to hit the piston.

Thank you very much, I will try some adjustments and I contact you soon
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Old 03-01-2018, 10:31 AM   #783
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Default AVCS tuning Mileage & Power.

Cam timing is a degree of cam = 2 degrees on the Crankshaft.

Taking notice on the two stock valve timing maps on AVCS Cruise and non Cruise.

Max out in area's on Both at 40* advanced but much less on the Non Cruise settings.
Hence you looking at where the power settings are on the non cruise.

You can see were the Cruise map is choking you engine out with EGR blowing into the engine.

If we know what the physical advertised or actual duration of the cam is then we could come up with some very interesting programing to get the full benefits of the (AVCS) programing of your engine.

I have made one map with only adjusting the Cruise settings lowered the advance settings a bunch and gained highway mpg to 27.4 on a 14 mile run reset mpg counter and put cruise on 70 mph. ( max advance was 14 degree)

Noted on this map at 80 mph it seemed to get hunger pains on the gas tank but still better than stock settings.



Were talking on a 2008 Outback XT Limited Automatic.

My Wife's 2011 Outback 2.5 L non turbo gets 30 mph @ 80 mph all day long.

Noted though gearing with her six speed trans gets a reduction in 500 RPM over my XT.
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Old 03-01-2018, 06:18 PM   #784
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speaking of avcs

don't know if anybody noticed, but tomei posted recommended values for dual avcs engines



its on their website under cams
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Old 03-02-2018, 07:06 PM   #785
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Before anyone blindly plugs those numbers into the AVCS table - those are a recommended WOT base map for the Tomei cams, not OEM. It's literally a single stripe of the entire table.

OEM cams run a considerably different range.
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Old 03-02-2018, 07:28 PM   #786
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Quote:
Originally Posted by mrsaturn7085 View Post
Before anyone blindly plugs those numbers into the AVCS table - those are a recommended WOT base map for the Tomei cams, not OEM. It's literally a single stripe of the entire table.

OEM cams run a considerably different range.
+1, and those are also for the EJ207
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Old 03-03-2018, 01:44 PM   #787
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Quote:
Originally Posted by ShinjiML View Post
+1, and those are also for the EJ207
That is true and noted in the image - this thread covers all AVCS tuning though the vast majority here will be on some generation of EJ255/257!
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Old 03-03-2018, 02:03 PM   #788
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I can't believe we have to start adding disclaimers and warnings to our posts now
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Old 03-04-2018, 12:10 AM   #789
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It just seemed like an odd thing to post given the extremely limited application of the info.
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Old 03-04-2018, 04:30 AM   #790
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really? I've seen so many posts in the past with "I've got these kelford/tomei/any other cams, what should I use as AVCS values" I figured it'd be useful
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Old 03-05-2018, 02:46 PM   #791
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It is appreciated and useful! By odd thing to post, I meant without the disclaimer - that's all!

Sadly, you've gotta work around the lowest common denominator here.
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Old 03-31-2018, 09:01 PM   #792
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Default avcs edit map by expanding map size in ecuflash

I have been tuning my obxt 2008 auto.

I have sum success in expanding some of the maps to sizes used in stock
2009 WRX STI map. But on other parts of the mapping when trying enlarge the mapped area It seems to screw up the map when you ad data to it.

Any solutions advice ?

I now I can copy past parts of mapping into obxt map. but I was wanting to duplicate the maps information then give it a go.
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Old 05-11-2018, 04:21 PM   #793
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Need help sourcing a part number

I noticed some W25 heads have separate AVCS line on the passenger's head, not connected to the back of the head and turbo (the ever-breaking trio)

My D25 heads also have that opening, so I want to get it

here is what I mean

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Old 09-22-2018, 02:56 PM   #794
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i have been playing with some AVCS on my JDM ej205. some things i have discovered are that you can in fact control AVCS at idle. im running carberry and set up map switch with one table 0 and the other 45 just to test the system. when i fliped the switch the cams will go all the way to 45 and the engine will want to stall at idle. (not useful but i thought people would like to know that the cams can have full control at low rpm). i also noticed that the engine is extremely sensitive to AVCS and ignition timing while cruising at around 2800-3200 rpm 10-20 PSIa. on the highway. im having issues getting smooth acceleration in this range. i switched to SD and it helped so im not sure if there is some sort of odd airflow going on or if its AF corrections doing something weird and causing a bucking.

im also confused that people in this thread say at high load you should not have overlap but most maps i see ramp the advance up as load increases (or in the case of carberry MAP ^ =more cam advance), and ramp down with rpm. basically the advance is highest when the load is highest with most maps.
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Old 09-22-2018, 04:39 PM   #795
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you can do it on any aftermarket ECU, question is why
you have low oil pressure at idle, and I am not sure what is the minimum that AVCS is happy with
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Old 09-23-2018, 03:02 PM   #796
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Accurate control is key. Yes, you can get high advance at idle, but it is not predictable (extreme variations with oil temp.) and on OEM maps, you don't have a 4D fueling table to loop the AVCS position back into a feedback loop. The closed loop control will try it's best once the O2 sensors are warm, but if you're wildly changing the VE of the motor at idle... well, have fun with that one.
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Old 10-03-2018, 03:13 AM   #797
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Quote:
Originally Posted by BrucesOutbackXT View Post
Cam timing is a degree of cam = 2 degrees on the Crankshaft.

[...]

If we know what the physical advertised or actual duration of the cam is then we could come up with some very interesting programing to get the full benefits of the (AVCS) programing of your engine.
I strongly suspect that the AVCS tables are in degrees of crank, not degrees of cam. But if someone has evidence to the contrary I'd love to see it.

Any, I think the durations and events are as follows:

EJ25 single AVCS cams at 0.006 - Durations are 240/240

Valve events:

Intake retarded: open at 5 ATDC, close at 65 ABDC
Intake advanced 40 degrees: open at 35 BTDC, close at 25 ABDC
Exhaust: open at 55 BBDC, close at 5 ATDC

Overlap:

Maximum 40 degrees (intake advanced 40 degrees)
Minimum 0 degrees (intake retarded)

Centerlines:

Intake centerline, retarded: 125
Intake centerline, advanced 40 degrees: 85
Exhaust centerline: 115

AKA "120 -5" with the intake retarded, "105 +10" with the intake advanced.

EJ25 single AVCS cams at 0.050 - Durations are 204/208

Valve Events:

Intake retarded: open at -23, close at 47
Intake advanced 40 degrees: open at 17, close at 7
Exhaust: open at 39, close at -11

Overlap:

Maximum +6 (intake advanced 40)
Minimum -34 (intake retarded)

But, again, if anyone has reason to believe otherwise, I'd love to see it.
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Old 10-03-2018, 04:44 PM   #798
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ECU AVCS tables can be in cam or crank degrees, depending on manufacture of the ECU (aftermarket vs. OEM).

The maximum advance of the cam itself is easily measured by looking inside the AVCS housing and measuring the empty space in the recess (with the moving part installed) with a protractor. Maximum advance is usually less than this due to instability given the oil pressures when you actually WANT the maximum advance.
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Old 10-05-2018, 12:56 AM   #799
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Quote:
Originally Posted by mrsaturn7085 View Post
ECU AVCS tables can be in cam or crank degrees, depending on manufacture of the ECU (aftermarket vs. OEM).

The maximum advance of the cam itself is easily measured by looking inside the AVCS housing and measuring the empty space in the recess (with the moving part installed) with a protractor. Maximum advance is usually less than this due to instability given the oil pressures when you actually WANT the maximum advance.
What do you think the factory ECU uses?

Has anyone actually measured the mechanism with a protractor? What did you / they find?

I have a partially disassembled exhaust AVCS mechanism, but no protractor.

If I understand how the AVCS solenoid and mechanism work, oil pressure fluctuations wouldn't matter much unless it drops WAY down. If oil pressure goes up or down (and the solenoid doesn't vary the split) the oil pressure goes up or down the same amount on both sides of the lobes, so there shouldn't be much movement. Unless the oil pressure drops so low that it can't overcome the return spring on the exhaust side or the... opposition (for lack of a better word) from the valvetrain on the intake side.

My LGT runs 30 degrees of intake advance in cruise, with BC 272 cams, and it's very stable. Unless you really want max advance/retard below 1500 RPM I'd be surprised if you had trouble getting it. And if you do want max at such low RPM, I gotta ask, why?
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Old 10-05-2018, 07:51 AM   #800
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when the cam table has values of 0 and above this is cam degrees, and when it uses cam centerline point and below this is crank degrees

I believe the JDM phasors were measured to be able to provide up to 50 degrees physically
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