[Hodgdon Extreme]

My target idle ignition timing is 15°, but ECU dithers +/- 10° to control idle speed.

Under light/moderate load, I'm about 25-30°.

Under full load, timing sinks down to 15-16° by 4500rpm, then increases to 16-18° by 6500rpm.

I can share a pic of the map. It was transposed from the map on the old Haltech that ran my car for years and years.

There's a youtube channel called "twojay" - dude has a beautifully prepared IS300. He's posted several in-car videos with a picture-in-picture overlay of his AEM - which shows his real-time data throughout a bunch of WOT pulls. His timing sags to 8-9° at high boost (30psi or more).

 

[Hodgdon Extreme]

You should start collecting knock data during wot pulls; and get your knock strategy up and running.

For VVTi mapping - check out last post in this thread:

https://www.my.is/threads/what-rpm-is-the-vvti-switch-point.150255/#post-8382003

If you'd like, tomorrow I can dig up the VVTi map my Link shipped with.

 

[Hodgdon Extreme]

Stock Toyota knock sensors are narrow-range and pretty lousy. You'd be well advised to swap to a Bosch wide-range "donut" knock sensor.

VVTi mapping is not as simple as going for best/highest VE, because it can be leveraged for better mpg, too.

Thus, pegging it to TPS makes sense because high TPS implies desire for high torque (VE) and low TPS implies desire for mpg.

 

[Hodgdon Extreme]

Ignition:

Notes: I've properly synched ECU via a timing light to my ATI balancer, and set my ignition delay. However, I've not verified the timing marks on the balancer to truly be piston TDC. I've not been beyond ~135 kPa MGP. My engine idles @ 750rpm and about -65 kPa. Engine has GE-VVTi head with GTE rods/pistons. I THINK it has a GTE head gasket but I've not verified. I believe I have my knock sensitivity and thresholds set appropriately, and do not believe I'm experiencing any knock with this table on either 93 pump gas, straight E85 or any blend between - but this is for reference only. Use at your own risk; no warranties expressed or implied.

VVTi:

Notes: I've really not spent much time with this table so I make no claims of goodness. In fact, I'd defer to the reverse-engineered table Dodo came up with from a stock ECU. Toyota engineers probably did a better job of it than either you or I could. Again, use at your own risk; no warranties expressed or implied.

 

[Hodgdon Extreme]

Interesting, the VVTI doesnt continue into the higher rev range? I always understood it was advanced with increase in revs as well as throttle, but then my knowledge is pretty limited... and im getting old and forgetting things these days lol

Well, I can't speak to the JZ specifically - but usually advancing the cam improves VE (torque) at lower engine speeds, and hurts it at higher engine speed. Reason for this comes down to closing the intake valve sooner, when air velocity and inertia is less, and can't overcome being pushed back out the intake valve as the piston rises. As engine speed increases, so does air velocity and therefore inertia...making it so the incoming air can resist being pushed back out the intake valve - thus having the intake valve closing event occurring later provides more time/duration for air to continue piling into the cylinder.

But of course, advancing the cam means you'll be opening the valve sooner too - oftentimes earlier than is ideal for getting air to start going into the cylinder... That's why these are just general trends and not settled fact. Everything effects everything.

However, if you look at the reverse-engineered VVTi map Dodo posted (I linked to it above in post #5), you'll see the same basic mapping - Toyota starts advancing the cam a bit north of idle speed, ramps it in aggressively through the midrange, then ramps it back out for the top end. Overall their map is similar but quite a bit more aggressive than mine.

I've not spent much time with it so I've no idea how much "goodness" I've left on the table.

 

[Hodgdon Extreme]

Man, compared to that timing table, I think I need to be pulling out timing.

Your posted table looked pretty aggressive to me. However, mine is pretty conservative. The ignition table in my Haltech always had a minimum of 15* timing in it. It ran like that for years at who knows what boost... When I got the car, the boost controller was set to 25psi. I quickly discovered the fuel system wasn't sufficient for that so I dumbed it down to 17psi. Anyway, it didn't break during all those years...

I mentioned the youtuber "twojay", who's posted some in-car rips where he overlays his AEM infinity data. His timing was quite a bit more conservative than mine - and he makes a crapload of power - and I was starting fresh with a new ECU - and I wanted to get my knock sensitivity and thresholds all set...

...which is to say; I pulled timing by a good handful of degrees all throughout the boosted zone of the table. It's my intent, soonish, to start doing some timed pulls and see if/how much timing I can add back in... especially with the much cooler weather we're seeing now.

I am a stock GE so what is that 10:1 compression?

10.5:1 as claimed by Toyota and 10.44 per my calculations

MGP is manifold gauge pressure

Indeed. I think it's really only Link that likes to use MGP instead of MAP; though you can configure it to MAP if you prefer. There are some inherent advantages to using MGP instead - it sorta automatically corrects for changing BARO.