AVCS - Intake and Exhaust Timing

[steve99]

Originally Posted by KoolBRZ

About 3 psi. The Phantom only makes from 3 to 5 psi.

@KoolBRZ kodename47 and vgi have added a vvt optimisation tool to the maf scaling tool if you download the new version you will get new tool works using map
maf sensors and woirks out volumetric efficiency @thambul9 may also be interestedhttp://www.romraider.com/forum/viewt...p?f=32&t=10481

[KoolBRZ]

Originally Posted by steve99

@KoolBRZ kodename47 and vgi have added a vvt optimisation tool to the maf scaling tool if you download the new version you will get new tool works using map
maf sensors and woirks out volumetric efficiency @thambul9 may also be interestedhttp://www.romraider.com/forum/viewt...p?f=32&t=10481

I also left a shortcut to the wiki page on my desktop, since I'll be learning it from scratch.

[thambu19]

Originally Posted by steve99

@KoolBRZ kodename47 and vgi have added a vvt optimisation tool to the maf scaling tool if you download the new version you will get new tool works using map
maf sensors and woirks out volumetric efficiency @thambul9 may also be interestedhttp://www.romraider.com/forum/viewt...p?f=32&t=10481

I haven't looked at it yet. Will do when I get back home and login from laptop. Do you know how cams are optimized? Does it compare the volumetric efficiency with different cam settings and find which one have the best airflow?

Originally Posted by KoolBRZ

I also left a shortcut to the wiki page on my desktop, since I'll be learning it from scratch.

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[thambu19]

Originally Posted by thambu19

I haven't looked at it yet. Will do when I get back home and login from laptop. Do you know how cams are optimized? Does it compare the volumetric efficiency with different cam settings and find which one have the best airflow?



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If that is the case we must be cautious when using it on boosted applications. We can get into a situation where engine is scavenging a lot but not improving trapping efficiency.

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[steve99]

Originally Posted by thambu19

If that is the case we must be cautious when using it on boosted applications. We can get into a situation whebre engine is scavenging a lot but not improving trapping efficiency.

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When i did some testing with kodename47 he got me to log my current timing then log with intake +10 then intake -10 (some ignition timing pulled for safety) then load all three logs into tool and it compares, then repeat for exhaust cam

[thambu19]

Originally Posted by steve99

When i did some testing with kodename47 he got me to log my current timing then log with intake +10 then intake -10 (some ignition timing pulled for safety) then load all three logs into tool and it compares, then repeat for exhaust cam

Thanks @steve99
So I believe the tool looks to see which of the settings gives max Airflow. Which is okay except when running any kind of boost combined with lots of valve overlap.

I would recommend going in steps of 3deg since it is easy to miss a tuning peak with +-10deg.

Those running boost should start with OTS/OFT intake cams and retard the cams depending on how much boost one is running. In the case of Phantom SC like @KoolBRZ is running the boost is strongest at lowest engine speeds and dies off at higher engine speeds. So in that case the lower engine speeds would have more intake cam retard and as we approach peak power speeds the cams can be similar to OTS/OFT maps. For those running a SC that scales with engine speed this tapering off of Intake will not apply.

As a general thumb rule with higher boost levels the trapping efficiency is not lost by closing the intake at a later angle because the blower can out power the piston to some extent.

[thambu19]

Originally Posted by KoolBRZ

Here are the latest AVCS tuning maps I have developed. Although they are works of art, I am sure they are wrong in any number of places. I'm opening up my work here for criticism, not my personal life, so keep it respectful. Although I developed these maps while NA, I'm still using them with a Phantom ESC. If you have any suggested changes, describe them, post pics, and I'll make the changes and try them out. If you want a tune with these changes already in them, or an xml definitions file to enable extra tables, just ask and I'll post it if I have it or if I can make it. The pics are in order; Exhaust Safe-Exhaust Normal, and Intake Safe-Intake Normal

Do you think you are running too much overlap? Can you try
1. OTS/OFT Exhaust table - 4
2. OTS/OFT Intake table - 4

Basically take the table that @Shiv@Openflash came up with for NA engines and subtract 4 deg on intake and exhaust surfs. This will open the exhaust valve 4degrees earlier and close the intake valve 4degrees later.

[jvincent]

Not sure if you guys saw, but there are new OFT maps coming out.

Supposed to be better optimized for the OFH. Curious what the changes are.

[thambu19]

Yep just did

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[KoolBRZ]

Originally Posted by thambu19

Do you think you are running too much overlap? Can you try
1. OTS/OFT Exhaust table - 4
2. OTS/OFT Intake table - 4

Basically take the table that @Shiv@Openflash came up with for NA engines and subtract 4 deg on intake and exhaust surfs. This will open the exhaust valve 4degrees earlier and close the intake valve 4degrees later.

The OFT tables for AVCS are different between NA and SC. Do you mean take 4 degrees off the entire table, or just off the peaks, or just when the SC is active?

[steve99]

Originally Posted by thambu19

Thanks @steve99
So I believe the tool looks to see which of the settings gives max Airflow. Which is okay except when running any kind of boost combined with lots of valve overlap.

I would recommend going in steps of 3deg since it is easy to miss a tuning peak with +-10deg.

Those running boost should start with OTS/OFT intake cams and retard the cams depending on how much boost one is running. In the case of Phantom SC like @KoolBRZ is running the boost is strongest at lowest engine speeds and dies off at higher engine speeds. So in that case the lower engine speeds would have more intake cam retard and as we approach peak power speeds the cams can be similar to OTS/OFT maps. For those running a SC that scales with engine speed this tapering off of Intake will not apply.

As a general thumb rule with higher boost levels the trapping efficiency is not lost by closing the intake at a later angle because the blower can out power the piston to some extent.

Yes agree, kodename47 has a sprintex SC so that why he got me to do some tests since im still NA :-)

[thambu19]

Originally Posted by KoolBRZ

The OFT tables for AVCS are different between NA and SC. Do you mean take 4 degrees off the entire table, or just off the peaks, or just when the SC is active?

Do they have a separate table for phantom sc? I meant just the WOT region

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[KoolBRZ]

Originally Posted by thambu19

Do they have a separate table for phantom sc? I meant just the WOT region

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Here are pics of the OFT NA intake and exhaust maps, as well as the OFT ESC maps for comparison. When I first got my Phantom ESC, this is what I ran. It very little low-end torque and it was like waiting for turbo lag. I was on the throttle switch and learned never to stab the throttle below 3000 rpms. It just made a wooshy noise with no appreciable gain in power. I have the Procede controller now and I'll also include a pic of the map I'm running.

[thambu19]

@KoolBRZ Are you running headers in yours?