LGT AVCS Tuning Discussion

Seems to be a bit of mystery behind AVCS tuning and how to go about it best. Without a dyno it is pretty difficult to dial this in comparison to boost and ignition timing. From reading thread after thread the general consensus seems to be to go aggressive with the timing then start tapering down as you get into boost, then for the most part completely zeroing it out in the upper rpm's. So let's see em' post your's up!

 

Below is a screenshot of my current AVCS timing with the following mods:

 

Xo2 Racing FMIC

Xo2 Racing CBE

Megan racing Downpipe

Gutted OEM Uppipe

Ported & Polished manifolds

Grimspeed V2 Crossover pipe ported, coated and wrapped

LGT TGV Deletes

APS hard pipe turbo inlet

K & N Typhoon intake

Prodive 3 port EBCS

Greddy Type S BOV(recirculated)

NGK LFR7AIX sparkplugs (1 step colder)

I haven't begun to tinker with this, so all I have is questions.

 

For starters, why the stripe of 15s at 2000 rpm and low load, when everything above and below is 10?

 

 

Thanks!

^^ you should contact Clark Turner

I haven't begun to tinker with this, so all I have is questions.

 

For starters, why the stripe of 15s at 2000 rpm and low load, when everything above and below is 10?

 

 

Thanks!

Good question! Simple answer is that it is also in the stock rom I figured why change it in low load levels where I haven't made changes in most of the other tables as well.

^^ you should contact Clark Turner

Clark for the mostpart keeps all his "AVCS tuning magic" to himself, which I can definately understand why.

Good thread.

 

Here is mine.

 

FWIW bigger turbo = more AVCS. (over-simplification)

 

 

AVO380

AEM CAI

Perrin TMIC

Aquamist HFS-5 alky (50/50) 550 cc/min

3" TBE w/ HFC

iON UEL headers/UP (coated)

 

and other stuff that doesn't matter.

 

http://i248.photobucket.com/albums/gg194/littlebluegt/AVCSalky500.jpg

Clark for the mostpart keeps all his "AVCS tuning magic" to himself, which I can definately understand why.

 

I saw a ROM that Clark tuned. Looks very similar to a JDM 2.0 liter.

 

FWIW that car blew up.

Clark for the mostpart keeps all his "AVCS tuning magic" to himself, which I can definately understand why.

not if you get him drunk .

I saw a ROM that Clark tuned. Looks very similar to a JDM 2.0 liter.

 

FWIW that car blew up.

are you talking about the car that Jon from TDC really blew up?

are you talking about the car that Jon from TDC really blew up?

That whole situation was just classic, sucks for Ron but we live and we learn...

Good thread.

 

Here is mine.

 

FWIW bigger turbo = more AVCS. (over-simplification)

 

 

AVO380

AEM CAI

Perrin TMIC

Aquamist HFS-5 alky (50/50) 550 cc/min

3" TBE w/ HFC

iON UEL headers/UP (coated)

 

and other stuff that doesn't matter.

 

http://i248.photobucket.com/albums/gg194/littlebluegt/AVCSalky500.jpg

 

Any explanation for the choice in mapping? I just picked up a vf39 that I will be installing in the next couple of days.

not if you get him drunk .

 

So, what did he tell you about AVCS?

are you talking about the car that Jon from TDC really blew up?

 

No, not that one.

Any explanation for the choice in mapping? I just picked up a vf39 that I will be installing in the next couple of days.

 

I kept the timing the same (conservative)

I loaded the rt map in the car with 20 30 and 40 degrees advance.

 

The with 40 produced the most whp in the lower rpm range.

 

I then have been smoothing it and changing a bit here and there.

 

I taper it a bit in the really high load, as I can hit 4.2 load (I know this is more then accurate, as my upper end MAF scaling on my AEM has lower g/s then every other one I have seen) and I want it to taper a bit in that situation, only happens in the winter.

 

I have found that having above 30 in the 1.5 load area actually hurts performance. In fact the numbers I have right now may in fact be hurting partial throttle performance a bit. I find that I have to build a map especially for testing partial throttle, and it is a PITA. ie: make 25% throttle the max you can go, then do "wot" runs and log whp

 

I have only done 4 tests in the upper rpm range with the small amount of AVCS that I had, and I can't say anything conclusive.

 

I have heard that headers can make the optimal AVCS map quite a bit different. But I can't say that I have a full grasp of the science behind it.

I kept the timing the same (conservative)

I loaded the rt map in the car with 20 30 and 40 degrees advance.

 

The with 40 produced the most whp in the lower rpm range.

 

I then have been smoothing it and changing a bit here and there.

 

I taper it a bit in the really high load, as I can hit 4.2 load (I know this is more then accurate, as my upper end MAF scaling on my AEM has lower g/s then every other one I have seen) and I want it to taper a bit in that situation, only happens in the winter.

 

I have found that having above 30 in the 1.5 load area actually hurts performance. In fact the numbers I have right now may in fact be hurting partial throttle performance a bit. I find that I have to build a map especially for testing partial throttle, and it is a PITA. ie: make 25% throttle the max you can go, then do "wot" runs and log whp

 

I have only done 4 tests in the upper rpm range with the small amount of AVCS that I had, and I can't say anything conclusive.

 

I have heard that headers can make the optimal AVCS map quite a bit different. But I can't say that I have a full grasp of the science behind it.

Do you have a EGT tap? After I installed mine was when I figure things needed to be dialed down a bit (Boost & AVCS possibly). Temps were in the mid 1600's on pump gas with a 10.8-11.1 AFR target.

Do you have a EGT tap? After I installed mine was when I figure things needed to be dialed down a bit (Boost & AVCS possibly). Temps were in the mid 1600's on pump gas with a 10.8-11.1 AFR target.

 

Just the OEM one, til it failed. (my header has a bung in the UP just like OEM)

 

Wouldn't the EGTs from my alky injection be lower? I run my alky injection with that AVCS map. My pump gas is much more stage2ish.

So, what did he tell you about AVCS?

i can't remember. i'm not a tuning wiz. but the alcohol works for sure

Just the OEM one, til it failed. (my header has a bung in the UP just like OEM)

 

Wouldn't the EGTs from my alky injection be lower? I run my alky injection with that AVCS map. My pump gas is much more stage2ish.

Damn you and your alky , that would definately lower cylinder temps. I will be adding meth sometime later on this year.....

LOL, I know more than just LBGT and I are tweaking AVCS.....

I haven't touched mine. I don't know enough about it. I'm glad you guys posted your whole tables up. Some day when my tune is done maybe I'll load each of your tables and do a run with each of them and what I am running now. Or maybe somebody else would volunteer.

LBGT has a AVO380 which has a substantially larger hotside than the VF40. You can't use his AVCS table.

As soon as I finish the suspension and moving to Chicago I'll start tuning the AVCS and add to this thread. Thanks for sharing your info / experience!

LBGT has a AVO380 which has a substantially larger hotside than the VF40. You can't use his AVCS table.

 

Playing with AVCS is pretty low on my list of things to do. Lack of knowledge is my biggest problem so I really ought to steer clear of this... I had about arrived at this conclusion in my prior post, hence the comment "Or maybe somebody else would volunteer."

 

Ok guys, resume discussion.

Playing with AVCS is pretty low on my list of things to do. Lack of knowledge is my biggest problem so I really ought to steer clear of this... I had about arrived at this conclusion in my prior post, hence the comment "Or maybe somebody else would volunteer."

 

Ok guys, resume discussion.

 

I doubt your knowledge is much less then anybody else's.

 

I have yet to hear anybody sound like they really know what is going on, except generalities:

 

bigger turbo, more advance

headers, more advance

 

Just do some minor changes, do back to back whp tests, the winner is the better map.

 

If you can test EGT, good.

 

Run your timing conservative (might not be applicable to an E85 tune) and test for best power. Once you have that, then get your timing back as best as you can, but you may not be able to run as much timing as before, better VE means less timing is needed.

I doubt your knowledge is much less then anybody else's.

Some "Pro" tuners included....

I freshened up my table a bit in the lower load region to match an 06 Sti since the vf39 is in now. I should be able to get some good runs in this weekend, if the AVCS is vastly different I will post my my table up again.