Safe values?
 

I just installed a rom from my tuner.. and although this isn't the final one since I'll be sending him logs, I'm curious if it's safe to drive the car with this tune. This is after a 20 minute run on freeway and windy roads.

.24 doesn't sound too good, but I guess it won't hurt? I use 93 Oct (91 + 100) 76. I'm also asking my tuner but it's the weekend so not sure when he'll reply.

Mike

Well the AFR reading is useless. It's at the cruising/idling AFR under "current" and the "Max" is from deceleration fuel cut.

It looks like the knock control system is consistently retarding spark, because your Advance multiplier should have increased up to 1.00 instead of dropping down to .24 and coming back up to .28 .

Is it safe to drive the car? If this were a WRX or STi, there's a lot bigger risk of damaging something simply because they are turbo. In the interest of being kind to your engine though, lay off heavy acceleration until you get the updated tune from your vendor.

It's useful to log knock correction, fuel trim long and short trim, IAM, and, well, quite a few other parameters.

But in general, seeing a knock event of that size along with an IAM around .24 means you are seeing a fair amount of detonation. On crap 91 octane at 8psi of boost, if my IAM comes down to the .7 range I'm generally concerned and take my foot out of it, unless there is no knock events and it's just pulling the timing due to load.

What were the max and minimum knock correction learn values? It is much more useful to post up a screen shot of say RPM, AFR, Knock Correction, Knock Correction Learn Value, and Ignition Timing.

With our tunes we prefer to keep the Advance Multiplier as close to 1.00 as possible in all scenarios. Of course with these cars they do adjust, as these ECU's do seem a lot more sensitive to knock then STI's and WRX engines.

Though the compression is quite a bit higher, nearly 8:1 on an STI and 12:1 on a BRZ/FR-S, is quite a jump. So we do expect to see changes within the range of 0.70-1.00 over weeks/months of driving. But do note this is our method of tuning and not every tuners preference.

Though 0.24 may be low by some tuners standards it still has the ability to adjust, as it has not pegged it's lower limit of 0.00. So it really depends on each tuner and how they prefer to tune each vehicle. More information can be helpful in determining what is more likely happening within the tune.

Cheers,
William Knose

Thanks for the info, I'm learning something new each day. This is just the base tune, used to send logs to my tuner - I wasn't sure what to expect, hopefully it will look much better on the next ones. I was just curious if it was safe to drive if it goes that low.. I guess it's safer than high and knocking. It's hard to get a got street pull anywhere immediately around here with all the traffic but I think I know a better place for next time.

Now that I'm kind of babying it this week, I miss driving it hard. But soon.. :)

Definitely speak to you tuner about it, as that will really be the only way to tell how the vehicle is running from the information that has been provided on the forums.

Glad we could have been some help. If you have any more questions, please ask.

Cheers,
William Knose

It's hard to know what an engine is going to like on the first shot, especially without the engine in front of you. Your tuner will figure it out with time. While e-tuning is not something I personally do (I only tune local cars), I respect the amount of experience and judgment that a successful e-tuner acquires.

Along the same lines, why did my IAM drop from 1 to 0.39 over the span of 2 weeks of daily driving (myslef in economy mode - no heavy foot)? During daily driving I get almost no knock correction (-0.7 being the max I saw once in a blue moon). Does the IAM decrease for other reasons than knock? Is there a "bad spot" in the tune in the low rpm zone that is triggering the IAM to decrease?

After realizing it was so low today, I did some aggressive driving (lots of high load/high gear/uphill/boost) on the way to work and saw it slowly crawl up to 0.50 by the time I got to work. Will see if I can get it to crawl up to 1.0 later today after work.

Does anyone know why this happens?
@DeliciousTuning @jamesm @mad_sb

You're not logging every drive though--maybe you missed some knock retard events? It could be picking up false knock.

i'm not sure if anything else can besides knock can cause the iam to drop (maybe it has other offsets for atmospheric conditions and what not?) but it could be that you're experiencing the tip-in knock myself and several others have run into. i'd reset the ecu to establish 0.7, log knock feedback and knock learn values along with iam and see what you find. pay attention to areas at around 2.5-3.5krpm when your getting on the throttle to accelerate (not flooring it, just normal 'brisk' acceleration like passing someone).

We will need to see the logs. I am going to guess that it is in the very low RPM range, as this seems to be the most common area for the ECU to pull the IAM when driving. Now with a smaller pulley the loads are higher and the vehicle/ECU was never designed around such high loads at low RPM's. So I would say it just needs to be dialed in a little more.

Cheers,
William Knose

Take a look at my post. I have logged the same thing too and not over a long period, this was over minutes. Like you, if I go and do some aggressive driving it works its way up.

http://www.ft86club.com/forums/showp...2&postcount=56