Visconti Tuning - Latest BRZ Flash Info

[Sportsguy83]

Originally Posted by Calum

I just got Visconti's latest tune (1.14b5) update. I'll hopefully flash it in today and compare that to William's. Until now the latest tune I had from Visconti was 1.14.

Edit: Um, I'll just let this speak for itself.

Those -4+ are ridiculous! I share your pain.

[Calum]

Originally Posted by CBR600RR

can you help me understand what I an looking at here???

also which is which map?

The top is Visconti's latest tune, the bottom is Delicious's latest. You can see across the top of each log the tune file information is listed.

On each may you can see the Advance Multiplier, Knock Correction, and Knock Correction Learn value.

Once again, I'll let Bruce handle the explaination. @mad_sb

Originally Posted by mad_sb

Short term trims, so long as they are less than 10% most of the time and you see them swing from + to - and vice versa should be ok. It's when you start to see big numbers like high 20's that stick around around that you need to be concerned. SHort term trims go to zero as soon as the ecu transitions into open loop (no longer targeting 14.7:1).

Long term trims, work in conjunction with the short term trims. Your total trim at any time is the combination of the long and short term. Unlike the short term trims, long term trims stay active when you go into open loop. As a result, they directly affect your AFR at WOT. In general, you want the long term trims as near zero as possible. + or - 5% is ok so long as the tuner accounted for that when they dialed in your afr.

There are three knock related values. Knock Correction (CA) is the course correction, if you see an occasional -1 here you are ok. If you see a lot of -1 or any number more negative (like -2) then the tune probably needs work. Knock Correction Learn Value is the long term correction and it works with IAM (Ignition Advance Multiplier). Timing is added to the base timing map by multiplying IAM * Advance map. IAM starts at 0.7 stock. A happy tune will slowly work it's way up from .7 unhappy will work it's way down from .7. Some tuners turn off the system by setting the advance map to zero (in this case you would always see zero for the knock correction learn value). By default, no timing is added till after .6 g/rev load is reached so light throttle cruise and such knock correction learn value will be zero most of the time. You really want to pay attention to the IAM during wot or open loop, if you see it going down timing is being pulled.

AFR will depend on NA or FI and E85 vs pump. Stock sensor only reads down to 12.1:1. NA, anything richer than 12.5 is costing you power anything leaner than 13.2 (WOT) is going to be knock prone. FI, you really want to be in the 12's as soon as you go into boost and ideally drop down into the mid to high 11's (stock sensor can be adjusted to read into the 11's).

Thats should get you started

From what I understand the advance multiplier dropping repeatedly and the negative numbers in the knock correction is the biggest concern. The fact that the AM dropped all the way to .54 after only a short drive, and this was all closed loop, part throttle driving, I was scared to try going WOT. I know modern engines run very near knock at part throttle for emissions and fuel economy, but that's WAY too much knock for me.

If I'm misunderstanding this, I'd love to learn some more.

[mad_sb]

Originally Posted by CBR600RR

can you help me understand what I an looking at here???

also which is which map?

Just to help people understand how the knock control works (this is in relation to feedback correction , not really course or fine learning),.... when the ecu senses a level of activity on the knock sensor that it considers knock (goes through filters etc) it will start to pull timing. it pulls 1 degree then listens if it still thinks i hears knock it pulls another degree and so on. -1's will happen from time to time. I saw it happen yesterday while testing my pump gas map... i hit a seam in the pavement and it immediately flashed a -1. and it imediatly went back to zero. When i looked at the logs latter, the learned value never changed. I believe it was because the crank angle the event occured was outside of the range defined for real knock, but that not the point here.

The point is you will see -1 from time to time, and it is not much to worry about. When you greater than -1 that is when you need to investigate. -3 or -4 indicates the ecu had to keep puling timing to get the event under control and it was almost certainly detonation from what i have seen.

Also, when the IAM works it's way down the ecu is continuing to detect what it believes is detonation and it is NOT a fluke. the subaru knock control strategy has been explained many times so I'm not going to try and recite it all.

[King Tut]

Originally Posted by Calum

I just got Visconti's latest tune (1.14b5) update. I'll hopefully flash it in today and compare that to William's. Until now the latest tune I had from Visconti was 1.14.

Edit: Um, I'll just let this speak for itself.

Looks good. It looks like your DeliciousTuning tune is super conservative with the Knock Learn Value going as high as +8 degrees.

[mad_sb]

Originally Posted by Calum

The top is Visconti's latest tune, the bottom is Delicious's latest. You can see across the top of each log the tune file information is listed.

On each may you can see the Advance Multiplier, Knock Correction, and Knock Correction Learn value.

Once again, I'll let Bruce handle the explaination. @mad_sb



From what I understand the advance multiplier dropping repeatedly and the negative numbers in the knock correction is the biggest concern. The fact that the AM dropped all the way to .54 after only a short drive, and this was all closed loop, part throttle driving, I was scared to try going WOT. I know modern engines run very near knock at part throttle for emissions and fuel economy, but that's WAY too much knock for me.

If I'm misunderstanding this, I'd love to learn some more.

I do want to amend my previous comments on AFR. After more recent testing and talking some other tuners, these motors due like richer mixtures than typical NA motors, thanks to the 12.5:1 compression. Targeting 12.0 - 12.5 on the factory sensor is perfectly fine and will allow you to run a little more timing and get closer to MBT.

[xjohnx]

Originally Posted by Calum

I just got Visconti's latest tune (1.14b5) update. I'll hopefully flash it in today and compare that to William's. Until now the latest tune I had from Visconti was 1.14.

Edit: Um, I'll just let this speak for itself.

William @DeliciousTuning is the man.

[mad_sb]

Originally Posted by xjohnx

William @DeliciousTuning is the man.

looks like he changed the FBKC step value a little bit I did that as well to help pinpoint when the various corrections are in play. :happy0180:

[DeliciousTuning]

Originally Posted by mad_sb

looks like he changed the FBKC step value a little bit I did that as well to help pinpoint when the various corrections are in play. :happy0180:

Nice spot. You have a very keen eye and a very clear understanding of the ECU. I would like to applaud you sir.

This technique has come in quite handy on some serious tunes as one might expect, such as Ken Block's Gymkhana 1. Man did Ken beat the living crap out of that car. Literally donuts for nearly a minute (around the segway) and off the rev limiter too boot.

Cheers,
William Knose

[Calum]

Originally Posted by King Tut

Looks good. It looks like your DeliciousTuning tune is super conservative with the Knock Learn Value going as high as +8 degrees.

It starts off pretty gut less, but a few miles and everything is awesome. I sent the log to William and told him about the differences I'm feeling. But to be honest, I wouldn't mind at all if he doesn't change anything. The safety factor is NOT a bad thing at all. I was meaning to take the car over to a buddies shop to put it on the dyno to compare the tunes, but after seeing that much knock I'm not putting that back into my ECU.

For the reference Visconti hasn't been sent a log to try to clean that up. I wanted to try the B5 (which looks remarkably like BS, just sayin') tune to see if it made any difference, to give him one last chance. Peace out John.

[blubrz]

What octane are you using?
*Best way I can ask without sounding condescending.

[Calum]

Originally Posted by blubrz

What octane are you using?
*Best way I can ask without sounding condescending.

I'm guessing you mean me. The highest we have available, 91 octane. Why would that be condescending? Unless you thought I was using regular or something?

[blubrz]

Originally Posted by Calum

I'm guessing you mean me. The highest we have available, 91 octane. Why would that be condescending? Unless you thought I was using regular or something?

Yes, I mean you.
Yes, I thought it a possibility you were using regular...or something (local gas station lying to you).

While I loath the man and his service, I just don't see my data-logs doing that at all. Although, I do have the FI tune which is an "entirely different tune" as he would remind me. Just seems that if it were over aggressive it would be amplified under pressure... and being mapped for 93 octane as it is.

Perhaps you could save me the trouble of going back though thousands of posts and answer me this: are there many others with logs like this?

[Bleevin]

Originally Posted by Calum

I'm guessing you mean me. The highest we have available, 91 octane. Why would that be condescending? Unless you thought I was using regular or something?

Would you say that there may not be as much knock correction if I was using 94 octane Chevron gas?

[blubrz]

Originally Posted by Bleevin

Would you say that there may not be as much knock correction if I was using 93 octane Chevron gas?

I'd suggest changing gas stations first and leaving the octane the same.