Why does my Advance Multiplier keep dropping?

[jeebus]

What sucks is I can't exactly go to a dealer and get them to do anything about my IAM dropping.

"Is the CE Light on?" - No
"Is the car running?" - Yes
"Does it make any weird noises?" - No

I have to wait until something bad happens to it....seems unwise.

[DeliciousTuning]

Try using different brands. The fuels we have seen that work decently are 76 and Sunoco. I actually have found the worse offenders to be Chevron and Mobil. I know that might sound a little odd, but more marketing/advertising does not mean it is always better.

Cheers,
William Knose

[Ethan]

If Bill's suggestion doesn't work, try using 8 ounces of Torco Accelerator in 10 gallons of gas. I had knock issues and that cleared it up. You can order directly from Torco or get it from one of their distributors.

[fstlane]

Originally Posted by Circuit Motorsports

Yes CA gas is bad. The dropping Advance Multiplier indicates the tune is too aggressive for the fuel you are running.

I have a customer who mixes 100 octane fuel with the CA 91 to bring it up to 93 to prevent having to de-tune the car. E85 is certainly an option if you can get it.

The AM dropping to .45 should be addressed.

-- Bob

I've also been adding a few gallons of 100 octane to every tank of CrAp 91 octane fuel we get here in Las Vegas. Here's a blending chart if anyone needs it.

[jeebus]

Originally Posted by DeliciousTuning

Try using different brands. The fuels we have seen that work decently are 76 and Sunoco. I actually have found the worse offenders to be Chevron and Mobil. I know that might sound a little odd, but more marketing/advertising does not mean it is always better.

Cheers,
William Knose

I had the best luck with 76 in my modded Forester XT...so it doesn't sound odd at all. However, I had the best luck quieting the crickets with Chevron which is why I stuck with it. That, and every convenient stop on my commute is Chevron....however, I'll give 76 a whirl if I don't just run e85 all the time.

[PMok]

would someone mind taking a look at my first log? sorry I did not run all the way to redline, but hopefully someone can tell me if things look normal or anything is out of whack. I am totally new to this and don't really have much understanding of what all the values mean, but this discussion of low adv multiplier has me worried, as I was down at the .5x range and now it seems to be climbing to .6-.7x range. I am running Vishnu OTS Stage 1, and on CA 91 gas.

http://www.datazap.me/u/pmok/stage-1...&data=1-8-9-12

[jeebus]

Originally Posted by PMok

would someone mind taking a look at my first log? sorry I did not run all the way to redline, but hopefully someone can tell me if things look normal or anything is out of whack. I am totally new to this and don't really have much understanding of what all the values mean, but this discussion of low adv multiplier has me worried, as I was down at the .5x range and now it seems to be climbing to .6-.7x range. I am running Vishnu OTS Stage 1, and on CA 91 gas.

http://www.datazap.me/u/pmok/stage-1...&data=1-8-9-12

Is your car stock other than the tune? Your AFR looks pretty rich...low 11s.

[PMok]

Originally Posted by jeebus

Is your car stock other than the tune? Your AFR looks pretty rich...low 11s.

very close to stock... drop-in performance filter and a catless front pipe are the only mods. everything else is stock. stock headers with cat, stock exhaust.

[garfull]

afr at wot should be around 12.1 and 14.7 under normal load. adv mult should be at 1. the way i understand it is a smaller adv mult number means the tune is too aggressive and the ecu is lowering the numbers in the maps and visa versa for a number larger than 1. give it some more miles and itll get to 1.

long term fuel trims should stay within +/-10. If they go beyond 25 it'll throw a code. short term should be within that range too but once the ecu starts to learn it'll usually be +/-5 and 0 at wot.

Originally Posted by PMok

very close to stock... drop-in performance filter and a catless front pipe are the only mods. everything else is stock. stock headers with cat, stock exhaust.

[solidONE]

I'd suggest taking some logs and try to pin point where and when it is knocking. I had the same problem with the stage 1 tune. took some logs and looked at the ignition map. Turned out that there was a peak where it was knocking, so I dialed back the ignition advance a little bit where it peaks. (at around the neighborhood of 0.70~.80 g/rev at 2000~2500 IIRC) IAM pinned at 1 after that on 91 octane.

[StormTrooper]

There is also an issue on the cruise timing...up into 50deg adv on the stock tune.

I found if you tried to accelerate in 6th gear pretty much at legal speeds can cause knock.


I noticed this stock and stg1. I'm at 4k feet elevation with 91oct gas. (Others noticed similar issues with race gas)

[solidONE]

Originally Posted by StormTrooper

There is also an issue on the cruise timing...up into 50deg adv on the stock tune.

I found if you tried to accelerate in 6th gear pretty much at legal speeds can cause knock.


I noticed this stock and stg1. I'm at 4k feet elevation with 91oct gas. (Others noticed similar issues with race gas)

Do you have logs showing this to share with the class? Let me find mine.

http://www.ft86club.com/forums/showp...&postcount=937

And above 2000rpm:
http://www.datazap.me/u/solidone/1-1...2&zoom=265-694

[PMok]

I was reading one of the other threads and noticed that mad_sb had mentioned that you might get more knock readings if you are low on fuel... I was running nearly on empty when I did my log. So I have tanked up and will try to do some more logging tomorrow to see what happens...

[StormTrooper]

I have some logs showing the timing but it didnt happen to knock that time. I'll try and do some more when i have time off work.

Only have 2 logs.
It happened to me when watching real time...lowest i saw was .76. It was cold i live at 4500ft and my 91 oct isn't cali piss( correct me if i'm wrong)