AVCS - Intake and Exhaust Timing

[Kodename47]

Originally Posted by D-VO

NP. Do the pulls have to be in the same gear?

I would try and get a few in say 2/3/4 and see if it really is a gearing overshoot etc. Then maybe you can start looking at the OCV duty tables and have a play. Obviously make sure the AVCS is in use (car warm etc) and that all 3 tables are set the same for intake and exhaust.

[D-VO]

@Kodename47 Here's one of my logs. VE reads very strangely.

[Kodename47]

Originally Posted by D-VO

@Kodename47 Here's one of my logs. VE reads very strangely.

Tool works with MAP but you're logging MRP

@vgi.....

[vgi]

@KOdename yep, we've been pm'ing

[D-VO]

Here was the difference in VVT. Blue is 4th gear and red is 3rd gear.



By the way: the yellow VE line is after changing MRP to MAP. Still strange. VE should definitely be rising.

Here's what my overlap looks like with the VVT maps I'm using:



One last thing here. Check out what happened in 6th gear at 4400RPM. Looks like the Exhaust VVT turned off.

Thanks again.

[Kodename47]

The VE probably looks flat due to the high values of runs 1 and 2 and therefore inflated y axis. If you get rid of those it should probably return to normal.

If you use the Log View tab, how do the left and right banks differ when this is happening? Without OCV logging we're just guessing, but they could be operating incorrectly. What oil are you using too?

[D-VO]

Both left side gears are higher until 5400 RPM, but they are both lower from 5500RPM - 7400RPM where they meet again. Intake varies by about 2 degrees and exhaust varies by 1. Not sure if that's normal. Also I'm using the factory oil 0w-20. Did you see what happened to the exhaust VVT at the end of my 6th gear log?

I'll PM you about the OVC duty.

[Nah]

whats up guys... I am trying to understand vvt angles but honestly it would be easier if you guys just explained to me what would happen if I advanced or retarded at certain rpm points under different types of load.

Im currently using shiv's vvt angles for the JDL UEL header and oh goodness the car drives so much better. I am looking to go even further to dial this in.

He basically kept the intake the same from his base map and the exhaust he retarded from 2400-7400... why would that change make such a huge difference while driving?

Thanks guys really appreciate it and im sure others will too.

[Kodename47]

Originally Posted by D-VO

Both left side gears are higher until 5400 RPM, but they are both lower from 5500RPM - 7400RPM where they meet again. Intake varies by about 2 degrees and exhaust varies by 1. Not sure if that's normal. Also I'm using the factory oil 0w-20. Did you see what happened to the exhaust VVT at the end of my 6th gear log?

You'll get variance between sides, but if there is a big difference then this would be a hint there is something failing. It would be unusual if both sides were failing, so this would remove the need for OCV logging.

In both of your logs it seems you have 2 sets of Exhaust AVCS - Left Bank, I assume one is the right bank.

If you look at the whole 6th gear pull, the ignition timing falls just before the AVCS decides to drop to zero. Looks like it's due to the Ignition Advance Table, is this intended? Maybe drop the intake cam advance by 10 degrees and see what happens?

A side note, I see you have SD parameters logged. Are you running one of @ztan's SD maps? Is it worth trying a standard map just in case it's having some strange side effect on the AVCS output.

[Nah]

Anything guys?

[D-VO]

Originally Posted by Kodename47

You'll get variance between sides, but if there is a big difference then this would be a hint there is something failing. It would be unusual if both sides were failing, so this would remove the need for OCV logging.

In both of your logs it seems you have 2 sets of Exhaust AVCS - Left Bank, I assume one is the right bank.

If you look at the whole 6th gear pull, the ignition timing falls just before the AVCS decides to drop to zero. Looks like it's due to the Ignition Advance Table, is this intended? Maybe drop the intake cam advance by 10 degrees and see what happens?

A side note, I see you have SD parameters logged. Are you running one of @ztan's SD maps? Is it worth trying a standard map just in case it's having some strange side effect on the AVCS output.

Ok Thanks for that. You assume correctly; I keep forgetting to change the left exhaust column to 'right bank'.

6th gear had a crap ton of knock in that area which was why the ignition advance dropped and the engine is a bit rich there, but why would the Ex. VVT shut off like that?

Believe it or not I was thinking to reduce the intake advance as well. The intake sounds like a rice burner in that area and I don't remember it being that loud in previous revisions so, I'll give it a shot.

[Kodename47]

Originally Posted by Nah

Anything guys?

Oops, I missed you previous post as I was posting at the same time.

Try and find info on the web about VVT as to explain what's going on, there's quite a bit in the early part of this thread too, including some links.

As for dialing it in, it's quite hard without a dyno. You can try using virtual dyno alongside the VVT tab of vgi's tool. It'll be harder to determine the differences though. Try +/-5 under high load for the exhaust 1st, and then the same for the intake. If you can't make out any difference then return it as it was.

[D-VO]

Its strange how changing the exhaust VVT from 40 to 20 does nothing for fuel economy. I'm only finding Intake doing much of the difference.

[steve99]

Originally Posted by D-VO

Its strange how changing the exhaust VVT from 40 to 20 does nothing for fuel economy. I'm only finding Intake doing much of the difference.

A couple of pro tuners have suggested advancing the intake cam about 10 15 degrees in the load rpm area where your highway cruising ie about 2500 rpm load 0.3 ,0.4 or what ever it is on your car. if you advance it too far it will bog and you will notiice it in low speed city driving.