AVCS - Intake and Exhaust Timing

[freerunner]

Originally Posted by steve99

I will try to plug my tactrix into someones car with stock header on petrol and see what the temps are

http://datazap.me/u/freerunner
Cat temp has been logged in the more recent entries. Stock header, stock front pipe.

[solidONE]

Originally Posted by freerunner

http://dataset.me/u/freerunner
Cat temp has been logged in the more recent entries. Stock header, stock front pipe.

the link is no good...

[freerunner]

Originally Posted by solidONE

the link is no good...

Typed it on my phone. Damn auto-correction.

s:set/zap/g

[thambu19]

Originally Posted by solidONE

You know, I'm really not sure why in the log the intake cam stays that much advanced 37.5~40* to 6000rpm. On the intake advance table it's set to 40* from 2400~4600rpm, and from 4800~6000rpm it's set to 35* advance. Very strange... I'll need to log the cam timing some more just to double check.



The exhaust cam retard table is actually not hugely different than the stage 1 OTS tables designed for use with factory headers. Although the OTS stage 2 tables actually run even more exhaust retard than the stage 1. I'll have to see if I can find the stock rom see what they look like.

Difference compared to OTS STG1:


Difference to OTS STG2 EL:


Thanks again for all the pointers, BTW.

Edit: Yup the intake cam is staying advanced further than designated by the cam tables.

4th gear pull just now:
http://datazap.me/u/solidone/af-lear...zoom=2699-3008

3rd gear pull in the same log where it drops down to 37.5* at 4800 rpm. Still not at 35* when it was set to on the table:
http://datazap.me/u/solidone/af-lear...zoom=1595-1732

There's got to be something else effecting the cam timing that we don't yet know about.

Cams usually have a lockpin or end stop and if the commanded positions are close they snap into those positions. I don't know what the end lock pin numbers are for FA20. I would assume they will be retarded intake and advanced exh though to be safe

[solidONE]

Originally Posted by thambu19

Cams usually have a lockpin or end stop and if the commanded positions are close they snap into those positions. I don't know what the end lock pin numbers are for FA20. I would assume they will be retarded intake and advanced exh though to be safe

I suppose I can change the table to 35* degrees advance max and see if it will stick, or if it shifts up or down. From the logs, though, it seems to change at 2.5* increments. The exhaust cam seems to change smoothly through the range instead of increments of 2.5* from the looks of it.

[solidONE]

Originally Posted by freerunner

Typed it on my phone. Damn auto-correction.

s:set/zap/g

eh... lol

[arghx7]

cross posting from the other thread:

The AVCS intake side has the negative values @thambu19 and others were talking about because it is a mid lockpin AVCS. That means the intake side can retard, not just advance. The retard is a fuel economy thing. It's the same type of AVCS that's on the FA20DIT. In fact, it's the BorgWarner phaser technology that Ford uses on the 5.0 Mustangs. On those FA20DIT engines when you delete the tumble generator valves you need to advance the AVCS or it runs like crap without all that tumble motion in the combustion chamber.



more details (mostly relevant to FA20DIT) here http://forums.nasioc.com/forums/show....php?t=2687550

[solidONE]

@arghx7 Y U so Awesome!? lol

So I went ahead and changed my cam tables to be at 35* advance max.



4th gear pull:
http://datazap.me/u/solidone/af-lear...zoom=7716-8003

3rd gear pull:
http://datazap.me/u/solidone/af-lear...zoom=5197-5341

It seems even with the intake cam advance targeted at 35* from 2200~6000rpm it will fluctuate between 35~37.5 degrees. Is this due to the "tumble generator" effect you are talking about? It seems to be advancing by 2.5 and not retarding here. And in the previous logs where I have the intake advance targeted at 40* 2200~4600rpm then 35* 4800~6000rpm it would be as much as 5* more advanced than the targeted 35* from 4800rpm.



4th gear pull:
http://datazap.me/u/solidone/af-lear...zoom=2699-3008

[KoolBRZ]

Are you changing both Safe, and Normal tables. They both have to be the same or you'll get inconsistent results.

[Kodename47]

Originally Posted by solidONE

@arghx7 Y U so Awesome!? lol

So I went ahead and changed my cam tables to be at 35* advance max.

4th gear pull:
http://datazap.me/u/solidone/af-lear...zoom=7716-8003

3rd gear pull:
http://datazap.me/u/solidone/af-lear...zoom=5197-5341

It seems even with the intake cam advance targeted at 35* from 2200~6000rpm it will fluctuate between 35~37.5 degrees. Is this due to the "tumble generator" effect you are talking about? It seems to be advancing by 2.5 and not retarding here. And in the previous logs where I have the intake advance targeted at 40* 2200~4600rpm then 35* 4800~6000rpm it would be as much as 5* more advanced than the targeted 35* from 4800rpm.

4th gear pull:
http://datazap.me/u/solidone/af-lear...zoom=2699-3008

We don't have the TGVs, they're also in the intake manifold and nothing to do with the cams.

I guess what you log will vary what you see, the cams will never be perfect and follow the map due to the way they operate. There will also be variances between the banks too due to this. On ECUtek I have 2 sets of logging parameters, one shows "From Rest" values which are close enough to the values in the table, the others are cam angle which are a little different.

[solidONE]

Originally Posted by KoolBRZ

Are you changing both Safe, and Normal tables. They both have to be the same or you'll get inconsistent results.

Yes, I know this.

Originally Posted by Kodename47

We don't have the TGVs, they're also in the intake manifold and nothing to do with the cams.

I guess what you log will vary what you see, the cams will never be perfect and follow the map due to the way they operate. There will also be variances between the banks too due to this. On ECUtek I have 2 sets of logging parameters, one shows "From Rest" values which are close enough to the values in the table, the others are cam angle which are a little different.

It seems to error on the + advance side and not the other way around. I guess I can set it 2.5~5* under the amount I want to target depending on what I'm trying to do.

[Kodename47]

Originally Posted by solidONE

It seems to error on the + advance side and not the other way around. I guess I can set it 2.5~5* under the amount I want to target depending on what I'm trying to do.

Just had a look at your log now I'm on a laptop, it seems that the logging parameter for the Intake AVCS is just to the nearest 2.5 degrees. That does not mean that it's actually operating like that.

As for the exhaust, it may well be a parameter that doesn't directly relate to the values in the table, and it could be that only one bank is suffering if that is an issue. I would't go changing tabular values to get the logs to read what you want as it may well be that the OFT is logging a different cam angle value.

Just so you can see some of the full AVCS parameters:

[Kodename47]

Resurrected this old spreadsheet of mine:
AVCS Viewing/Comparison Tool

Paste in your own AVCS tables, it will show you overlap (based on suggested 0 positions of cams) and allows you to compare 2 different AVCS maps. It also has a tab to allow you to adjust axis scales if you desire and also one to convert normal/safe tables to a base table.

The charts are taken from the max load column as these all usually set the same for WOT load areas.

[piaoyi]

Does anyone know if this is an interference type engine and can make contact with the valves?