AVCS - Intake and Exhaust Timing

[banane63]

Saw the same problem.
Watch the low det or high det map : that was accurate to the high det as my AM was 1 !
Seems that it doesn't care of AM much...

[Kodename47]

Originally Posted by banane63

Saw the same problem.
Watch the low det or high det map : that was accurate to the high det as my AM was 1 !
Seems that it doesn't care of AM much...

I know on my S/C map that the high/low det maps are the same, but that's not as bad as the pic above. What's even stranger is that I found some older logs and they still followed the exact same pattern. I'll have to check my old N/A map and see.

I've noticed there is logging available for intake and exhaust VVT #1 & 2 and commanded values for them as well. I wonder if #1 and 2 are the different banks? I guess a log of everything might help.

[mad_sb]

Originally Posted by Kodename47

This is a really great idea, the issue is we need this info. Even a firm operating range of the cams would be a good start.


My basis is that full intake retard is 24 deg ATDC, so 0 on the map is 14 deg ATDC and therefore full advance opens at 26 deg BTDC.

Range of adjustment on the intake cam in the rom is from -10 to 40, -10 is max retard, 40 is max advance. On the exhaust cam 0 is max advance 50 is max retard.

[Kodename47]

Originally Posted by banane63

Saw the same problem.
Watch the low det or high det map : that was accurate to the high det as my AM was 1 !
Seems that it doesn't care of AM much...

Give this man 10 points!!! Could it be a feature of the G series ROMs and ECUtek? Loaded in the high det maps from my NA map, which are stock BTW, and the graphs lined up perfectly. My IAM was at 1 throughout. @EcuTek this may be worth looking into.

@mad_sb the map range is correct, but what angle does the cam sit physically when the map is at 0?

[Kodename47]

Right, I thought I'd collate some better info. I'm comparing the OFT v1.55 maps and stock. This is based on base cam timing (map value of 0):
Exhaust opens 81 deg. BBDC and closes 9 deg BTDC
Intake opens 14 deg ATDC and closes 89 deg ABDC


Note - these base timing may be incorrect. I'll update if I get any confirmed information. This means that the overlap is an indicator in what the map is doing. Negative figures in the overlap table show the range between closing of the exhaust valve and opening of the intake valve. I did this to show if there is any relationship even if the individual cam timings are being changed. The graphs are WOT timing.


It's worth noting that this is for N/A applications. F/I requires a different approach, even turbo and S/C are different due to the timing affecting turbo spool up.

[arghx7]

Thanks for putting those charts together. I'm having some trouble understanding the exhaust opening timing in degrees BBDC. Looking at the stock timing: So with the 800rpm row, the phasing is set to 0. Shouldn't the opening timing be 81 in your map instead of 31? and then at 2400 full load, the phasing is 50. So shouldn't it be 31 degrees BBDC opening?

The exhaust opening timing is retarded (fewer degrees before bottom dead center) for greater expansion ratio. The exhaust closing timing would at the same time be retarded for more overlap or for more evacuation of exhaust gases.

[Kodename47]

Originally Posted by arghx7

Thanks for putting those charts together. I'm having some trouble understanding the exhaust opening timing in degrees BBDC. Looking at the stock timing: So with the 800rpm row, the phasing is set to 0. Shouldn't the opening timing be 81 in your map instead of 31? and then at 2400 full load, the phasing is 50. So shouldn't it be 31 degrees BBDC opening?

You're correct, I'll update that when I get home. I explained it correctly above but did the formulas the wrong way round.... oops.


Edit - Pics updated

[Kodename47]

Just stumbled upon another good discussion thread started by @Td-d:
http://igotasti.com/vBforum/archive/...hp/t-4616.html

[banane63]

Originally Posted by Kodename47

Just stumbled upon another good discussion thread started by @Td-d:
http://igotasti.com/vBforum/archive/...hp/t-4616.html

I found that also !

They prefer Virtual Dyno to monitor the changes on torque, power and load.
I also find it more readable, instead of a VRE, too linked to MAF crappy signal...

[diodelphi]

good

[Toyota John]

The Virtual dyno sounds interesting. Anyone try that?

[diodelphi]

Originally Posted by Toyota John

The Virtual dyno sounds interesting. Anyone try that?

the only helpful software for street tuning is Virtual dyno

[D-VO]

VDR is good if you have a baseline pull on the same stretch of road you plan on doing your tuning on. Of course atmospheric pressure and IAT temps will very the reading a bit, but its great!

[Toyota John]

I down loaded it I will check it out. At least I will have a better idea if my changes made more or less power.