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1Cor10:23 · 04-02-2014, 09:46 PM

Final Update / tl;dr

Running some OTS stage 1 tunes in 91 OCT (v-power, in my case) will drop IAM below 1 in many situations (I had .57 at my lowest). Some debate between top tuners on the forum whether it is better to scale back and hit 1 IAM for best performance OR just let IAM drop to compensate for fuel, since the ECU is quite smart, resulting some up / down adjustments, eventually resulting in best IAM for current fuel while maintaining upside potential if you get better fuel later. Both sides have merits, I personally don't know enough to make a judgement call. I got my IAM back up to 1 running 94 Octane Ultra from Petrocan and will continue to do so.

a very special thanks to the following individuals who have greatly contributed to my quest for understanding (some posted, others PM'd). We need more people like you in this community - @jamesm, @Thorpedo, @Kodename47, @TemeCal, @steve99

[ame="https://www.youtube.com/watch?v=vMa_CDXROYI"]Abnormal noise - YouTube[/ame]

Update 1: Haven't tried with revving not in gear (as shown in this video - not my car) but I do notice that I will get that noise when puttering around town at 2k rpm and I quickly put down some rapid throttle, makes that noise (originally thought to be mechanical) once I jab the accelerator. Most prevalent in 3rd/4th under high rapid load.

Update 2: did some logging tonight

http://www.datazap.me/u/1cor1023/dat...om=11808-12055

Freaked me out when I say IAM at 0.57 - this is VPOWER 91 in Canada. I only had about 1.5 gallons left so I filled up immediately with petrocan 94. As you can see throughout the ride in the log, IAM steadily is rising.

However, after listening carefully to see if I can spot the noise in the above video and the video below by @Thorpedo, I noticed that I can hear the noise even when I downshift rev match as I jab my accelerator.

I'd be pretty bummed if my seals were fried already - just over 6K miles, this car has seen redline perhaps 5 times and has never been tracked. Currently running OFT V1.5x

Update 3:

Found original owner of video clip with same issue (sorry didn't see this before!) Some discussion here but no resolution.

Update 4: After another afternoon of driving and cycling the 94 E10 throughout the system, IAM has come back to 1. Idle revving the car by giving it some jabs no longer makes the clicky noise, more of an intense induction/intake/suction noise - I assume this is normal.

So, what I've learned is that 91 octane being the lower edge for most OTS stage 1 tunes, it's best not to risk getting a bad batch and just go for the 93/94 with ethanol. I welcome crickets over knock any day. No more V-Power for me in Canada.

Thoughts?
Thanks!

04-02-2014, 09:46 PM	#1
1Cor10:23 Senior Member Join Date: Jul 2013 Drives: '13 Whiteout FR-S (M/T) Location: GTA Posts: 1,205 Thanks: 492 Thanked 392 Times in 238 Posts Mentioned: 14 Post(s)	Does this sound like 'tip-in knock'? Final Update / tl;dr Running some OTS stage 1 tunes in 91 OCT (v-power, in my case) will drop IAM below 1 in many situations (I had .57 at my lowest). Some debate between top tuners on the forum whether it is better to scale back and hit 1 IAM for best performance OR just let IAM drop to compensate for fuel, since the ECU is quite smart, resulting some up / down adjustments, eventually resulting in best IAM for current fuel while maintaining upside potential if you get better fuel later. Both sides have merits, I personally don't know enough to make a judgement call. I got my IAM back up to 1 running 94 Octane Ultra from Petrocan and will continue to do so. a very special thanks to the following individuals who have greatly contributed to my quest for understanding (some posted, others PM'd). We need more people like you in this community - @jamesm, @Thorpedo, @Kodename47, @TemeCal, @steve99 [ame="https://www.youtube.com/watch?v=vMa_CDXROYI"]Abnormal noise - YouTube[/ame] Update 1: Haven't tried with revving not in gear (as shown in this video - not my car) but I do notice that I will get that noise when puttering around town at 2k rpm and I quickly put down some rapid throttle, makes that noise (originally thought to be mechanical) once I jab the accelerator. Most prevalent in 3rd/4th under high rapid load. Update 2: did some logging tonight http://www.datazap.me/u/1cor1023/dat...om=11808-12055 Freaked me out when I say IAM at 0.57 - this is VPOWER 91 in Canada. I only had about 1.5 gallons left so I filled up immediately with petrocan 94. As you can see throughout the ride in the log, IAM steadily is rising. However, after listening carefully to see if I can spot the noise in the above video and the video below by @Thorpedo, I noticed that I can hear the noise even when I downshift rev match as I jab my accelerator. I'd be pretty bummed if my seals were fried already - just over 6K miles, this car has seen redline perhaps 5 times and has never been tracked. Currently running OFT V1.5x Update 3: Found original owner of video clip with same issue (sorry didn't see this before!) Some discussion here but no resolution. Update 4: After another afternoon of driving and cycling the 94 E10 throughout the system, IAM has come back to 1. Idle revving the car by giving it some jabs no longer makes the clicky noise, more of an intense induction/intake/suction noise - I assume this is normal. So, what I've learned is that 91 octane being the lower edge for most OTS stage 1 tunes, it's best not to risk getting a bad batch and just go for the 93/94 with ethanol. I welcome crickets over knock any day. No more V-Power for me in Canada. Thoughts? Thanks! __________________ \|1Cor10:23 \| Whiteout FR-S \| Form Follows Function Build\| Last edited by 1Cor10:23; 04-07-2014 at 10:13 AM.