AVCS - Intake and Exhaust Timing

[Kodename47]

Originally Posted by piaoyi

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

It's not

[thambu19]

Hey guys I was just comparing the OTS intake cam timing map and the changes made to it and saw that at low speeds the intake cam is fully phased (more overlap) but the ignition timing has not been changed much.
Are you guys feeling a better torque at the low speeds 2K and below with the OTS maps compared to stock? Fill me in please.

I have to think Toyota made cams go to lock pin at 800rpm to avoid any chance of pre-ignition by lowering the effective compression ratio.

[shr133]

Well here is my seat of the pants cam table right now.... I'm to the point I need a dyno or acceleration times to fine tune...
Bottom line is what ever makes it faster is the best set up..........
I abandoned most stock settings....
So far seams the best set up is to run the cams with the same map, but I need to fine tune...
I'm NA, with a short ram intake, filter, no pvc and TRD cat back, auto...
I feel most of the exhaust timing was set up for emissions, runs much better now...

Next step is to do some 2nd gear roll ons and data mapping this spring...
But I'm 100 % happy with the low end just need to verify mid and top end..
But runs really good.... Sounded way cooler with more intake timing but I think it runs better like this...

[KoolBRZ]

I've done quite a bit of AVCS tweaking myself. I'll give your tables a try today.

[Wayno]

Originally Posted by thambu19

Hey guys I was just comparing the OTS intake cam timing map and the changes made to it and saw that at low speeds the intake cam is fully phased (more overlap) but the ignition timing has not been changed much.
Are you guys feeling a better torque at the low speeds 2K and below with the OTS maps compared to stock? Fill me in please.

I have to think Toyota made cams go to lock pin at 800rpm to avoid any chance of pre-ignition by lowering the effective compression ratio.

Did you add KCA to base timing? Because comparing Base Timing itself to Stock will lead you down the garden path.

You can get some files with flat KCA from one of my threads so you can compare total timing all you want. You'll find the openflash tunes have MUCH less timing at high rpm / low load.

Or Kodename probably has a spreadsheet for it along with everything else.

[shr133]

I'm happy with it so far has way more low end, I can chug in 6th gear now...
and for daily driving almost no reason to manual shift.... Don't know if that good or bad....
Still have to work out full throttle but it seams really close...

Be interesting to get some feedback to see what other people think, or some ideas to try...

[thambu19]

Originally Posted by Wayno

Did you add KCA to base timing? Because comparing Base Timing itself to Stock will lead you down the garden path.

You can get some files with flat KCA from one of my threads so you can compare total timing all you want. You'll find the openflash tunes have MUCH less timing at high rpm / low load.

Or Kodename probably has a spreadsheet for it along with everything else.

So KCA has been dropped as well at the low speed WOT.
I think moving the cams more advanced definitely improves VE but comes with higher overlap. At super low speeds when intake is opened during the exh stroke its going to increase residuals. So id have expected a different timing. Appears like the higher effective comp ratio with advanced intake prevents a more advanced spark for some reason.

If anyone has a dyno compare of Stock Vs OTS Stg1 93 Oct that might be helpful

[KoolBRZ]

Originally Posted by shr133

Well here is my seat of the pants cam table right now.... I'm to the point I need a dyno or acceleration times to fine tune...
Bottom line is what ever makes it faster is the best set up..........
I abandoned most stock settings....
So far seams the best set up is to run the cams with the same map, but I need to fine tune...
I'm NA, with a short ram intake, filter, no pvc and TRD cat back, auto...
I feel most of the exhaust timing was set up for emissions, runs much better now...

Next step is to do some 2nd gear roll ons and data mapping this spring...
But I'm 100 % happy with the low end just need to verify mid and top end..
But runs really good.... Sounded way cooler with more intake timing but I think it runs better like this...

The mid and top end are a bit flat, so I tweaked them a bit. Now I have a Phantom SC and a long-tube 3" header, so I've got more scavenging going on. Here are my latest take on your AVCS table, and my base Intake table.
As far as dyno tuning @shr133, that's only good for top-end, not for daily driving. If you use an OFT, watch the Engine Load to determine performance. The lower the Load, the better the performance, and mileage too.

[shr133]

Originally Posted by KoolBRZ

The mid and top end are a bit flat, so I tweaked them a bit. Now I have a Phantom SC and a long-tube 3" header, so I've got more scavenging going on. Here are my latest take on your AVCS table, and my base Intake table.

Looks good, I like your tweaks, I'm still tuning, but may be done till spring....
I'm N/A and stock header.
I'm running the the same map on my base and exhaust....

I think I'm going to back down the exhaust map from 30 to 25 in the mid range...
and bump the intake map up in the mid range..
I think we can run more intake than exhaust timing but haven't had the time to verify it yet...

I want to use this map as my base and start getting some solid acceleration times... If I get the time...

This is my do it all map until I up grade to full race rom...

It uses a little more gas than stock but is running too good...
I want to make a MPG map and a more aggressive map...

Sweet, nice to bounce ideas off someone.....

[shr133]

I do remember in tuning It pulled harder with more cam timing but felt more peaky and was smoother over all with a little less...
but I'm not done, are we ever done????

[KoolBRZ]

Originally Posted by shr133

Looks good, I like your tweaks, I'm still tuning, but may be done till spring....
I'm N/A and stock header.
I'm running the the same map on my base and exhaust....

I think I'm going to back down the exhaust map from 30 to 25 in the mid range...
and bump the intake map up in the mid range..
I think we can run more intake than exhaust timing but haven't had the time to verify it yet...

I want to use this map as my base and start getting some solid acceleration times... If I get the time...

This is my do it all map until I up grade to full race rom...

It uses a little more gas than stock but is running too good...
I want to make a MPG map and a more aggressive map...

Sweet, nice to bounce ideas off someone.....

I'm trying out a more aggressive map, but with a less aggressive base map. I used your map up to 1.0 load, with a few tweaks to smooth it.

[KoolBRZ]

I tried out a tune with modified base maps yesterday. It felt like too little, too much. Not much under 2800 RPM, then it really screamed. AFR's were all over the place. I switched back to a known good tune right away. I've found it's always good to keep at least one known-good tune in my OFT, then try out with the other four tunes. Today I'm trying out slightly de-tuned Base tables. I reduced the highest numbers and smoothed out the dips, since I am FI I don't need compensation for the dips. If it works better I will post it. I have determined, however, that the Base tables are active, no matter what temp the engine is at.

[Kodename47]

Originally Posted by KoolBRZ

I have determined, however, that the Base tables are active, no matter what temp the engine is at.

Please do explain then how the base/normal/safe all interact....

[KoolBRZ]

If I knew that...
I'd like to give a shout out to @Td-d to answer that question. There are also several other experts who could answer that, but he is the only one who comes to mind. There should be a sticky, with a definition of how the tables affect the tune, and under what circumstances. I would also like to know in what order to make changes. Which table to alter first, start from the top of each table and work down as each row is tuned for optimum, or should it be each column?