Continual bad fuel and octane struggles

horsepower_and_hounds · 07-09-2018, 07:00 PM

I am really beginning to think fuel is my enemy. I seen to always get fuel...even at Shell that cannot keep consistent timing at 93 oct. I went to the mtns Sunday and had to fill up right when I got back to the highway .... looked around and found a large Exxon station. No Shell nearby

I did some highway pulls afterwards since my IAT's were down around 103, ambient was I think 79 give or take. The logs were crap..... major timing pull, knock recorded, time sometimes went from 9.5 to 4 on some cylinders. It got boost up to the mid 16's and the load was between 94-99 but timing was all over
the place

Might be time to use the additive again or map down to Stg 1 93 or stg 2 91

http://www.bootmod3.net/log?id=5b425d8cd10b43793494a2fa

http://www.bootmod3.net/log?id=5b426002d10b43793494a2fd

http://www.bootmod3.net/log?id=5b42606bd10b43793494a2fe

http://www.bootmod3.net/log?id=5b426110d10b43793494a2ff

SeanWRT · 07-09-2018, 09:05 PM

It's not necessarily really the bad gas. Especially if you're doing great on cool days.

If you open timing table from stock map, you'd be surprised how little timing retards there is to IAT increase. In reality, cylinder ignition time (and thus ignition timing) is much more sensitive to IAT.

BMW does that to have cars make consistent power under all circumstances. And the premise of that is to not approach timing limit with cool IAT. Therefore, on hot days when DME demands higher boost to offset thinner hot intake air, timing loss would be minimal. So you have the power consistency.

Most of the aftermarket companies tune cars to low or normal temperature. They wouldn't sell tune coming back from 100F track day and telling you sorry there is only so much more power we can reliably make over stock. No one appreciates that.

From my observation, they would make sure your car is holding up great at below 80F with correct octane and doing just fine at 100~110F. Above that, relax a little bit. That's normal and is what happens when you have a map that approaches octane limit to make power on cool days (who doesn't like that) and doesn't retard enough timing to high IAT. BTW, the day before I saw 410whp+ with Dinan turbo on pump gas last year, Dzenan specifically asked me to keep IAT below 80F. So I did.

The dramatic change of timing table would be too many risks and not rewarding at all (sales and customer feedback). People thank tuner only for making big dyno number and driving smoothly on street, not for backing off on power. In addition, absolutely no one with sanity tracks his or her car with the aftermarket tune that makes maximum power on the dyno sheet.

My point is if you want to stay on STG2 93OCT, you either keep IAT under 110F (Pure Inlet will help) or be easy on hot days. Or log STG2 91OCT and report back.

Be easy for a moment, think what happens with piggybacks on hot days LOL

eeyang92 · 07-10-2018, 01:22 AM

Maybe in the summer, increase octane a little bit via octane booster or better gas?

horsepower_and_hounds · 07-10-2018, 03:28 AM

I might try lower oct map till the new IC gets here, I really didn't want to resort back to the orange glow. Am I correct to assume that difference between stg 1 & 2 is mostly boost and between 91 & 93 is timing? If I can get out this morning it should be cooler I will pull a few more on the current STG 2 93 for shits n giggles

Bee Pee · 07-10-2018, 04:42 AM

Quote:

Originally Posted by m2ruder

I might try lower oct map till the new IC gets here, I really didn't want to resort back to the orange glow. Am I correct to assume that difference between stg 1 & 2 is mostly boost and between 91 & 93 is timing? If I can get out this morning it should be cooler I will pull a few more on the current STG 2 93 for shits n giggles

What intercooler are you currently running ?

If FMIC is stock in summer time and stage 2 - your logs sort of endorse PTF recommendation ie stg 2 needs FMIC upgrade

horsepower_and_hounds · 07-10-2018, 06:59 AM

Quote:

Originally Posted by Bee Pee

Quote:

Originally Posted by m2ruder

I might try lower oct map till the new IC gets here, I really didn't want to resort back to the orange glow. Am I correct to assume that difference between stg 1 & 2 is mostly boost and between 91 & 93 is timing? If I can get out this morning it should be cooler I will pull a few more on the current STG 2 93 for shits n giggles

What intercooler are you currently running ?

If FMIC is stock in summer time and stage 2 - your logs sort of endorse PTF recommendation ie stg 2 needs FMIC upgrade

VRSF street stepped HD

Bee Pee · 07-10-2018, 07:55 AM

Quote:

Originally Posted by m2ruder

VRSF street stepped HD

What FMIC are you upgrading to ?

horsepower_and_hounds · 07-10-2018, 09:04 AM

Quote:

Originally Posted by Bee Pee

Quote:

Originally Posted by m2ruder

VRSF street stepped HD

What FMIC are you upgrading to ?

VSRF HD race

Bee Pee · 07-10-2018, 09:07 AM

Quote:

Originally Posted by m2ruder

Quote:

Originally Posted by Bee Pee

Quote:

Originally Posted by m2ruder

VRSF street stepped HD

What FMIC are you upgrading to ?

VSRF HD race

Good to see some brand loyalty !

horsepower_and_hounds · 07-11-2018, 06:55 PM

Well we were to have a cooler morning for a change so decided to go do some pulls on the same gas. Ambient was 72. All IAT's started a good bit below 100 and the max i see at the end of a 3 gear long pull is 122......
I was thinking of trying the stg 2 91 to combat the timing pull but going to play with the E30 and log again

http://www.bootmod3.net/log?id=5b447e1cd10b437911b1c9f8

http://www.bootmod3.net/log?id=5b447e37d10b437911b1c9fa

http://www.bootmod3.net/log?id=5b447e69d10b437911b1c9fb

http://www.bootmod3.net/log?id=5b447ea2d10b437911b1c9fd

07-09-2018, 07:00 PM	#1
horsepower_and_hounds Brigadier General 1836 Rep 4,203 Posts Drives: BMW Join Date: Aug 2012 Location: USA iTrader: (9)	Continual bad fuel and octane struggles I am really beginning to think fuel is my enemy. I seen to always get fuel...even at Shell that cannot keep consistent timing at 93 oct. I went to the mtns Sunday and had to fill up right when I got back to the highway .... looked around and found a large Exxon station. No Shell nearby I did some highway pulls afterwards since my IAT's were down around 103, ambient was I think 79 give or take. The logs were crap..... major timing pull, knock recorded, time sometimes went from 9.5 to 4 on some cylinders. It got boost up to the mid 16's and the load was between 94-99 but timing was all over the place Might be time to use the additive again or map down to Stg 1 93 or stg 2 91 http://www.bootmod3.net/log?id=5b425d8cd10b43793494a2fa http://www.bootmod3.net/log?id=5b426002d10b43793494a2fd http://www.bootmod3.net/log?id=5b42606bd10b43793494a2fe http://www.bootmod3.net/log?id=5b426110d10b43793494a2ff
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07-09-2018, 09:05 PM	#2
SeanWRT Colonel 3179 Rep 2,577 Posts Drives: E90 M3 & F87 M2 Join Date: Sep 2015 Location: Shanghai iTrader: (1)	It's not necessarily really the bad gas. Especially if you're doing great on cool days. If you open timing table from stock map, you'd be surprised how little timing retards there is to IAT increase. In reality, cylinder ignition time (and thus ignition timing) is much more sensitive to IAT. BMW does that to have cars make consistent power under all circumstances. And the premise of that is to not approach timing limit with cool IAT. Therefore, on hot days when DME demands higher boost to offset thinner hot intake air, timing loss would be minimal. So you have the power consistency. Most of the aftermarket companies tune cars to low or normal temperature. They wouldn't sell tune coming back from 100F track day and telling you sorry there is only so much more power we can reliably make over stock. No one appreciates that. From my observation, they would make sure your car is holding up great at below 80F with correct octane and doing just fine at 100~110F. Above that, relax a little bit. That's normal and is what happens when you have a map that approaches octane limit to make power on cool days (who doesn't like that) and doesn't retard enough timing to high IAT. BTW, the day before I saw 410whp+ with Dinan turbo on pump gas last year, Dzenan specifically asked me to keep IAT below 80F. So I did. The dramatic change of timing table would be too many risks and not rewarding at all (sales and customer feedback). People thank tuner only for making big dyno number and driving smoothly on street, not for backing off on power. In addition, absolutely no one with sanity tracks his or her car with the aftermarket tune that makes maximum power on the dyno sheet. My point is if you want to stay on STG2 93OCT, you either keep IAT under 110F (Pure Inlet will help) or be easy on hot days. Or log STG2 91OCT and report back. Be easy for a moment, think what happens with piggybacks on hot days LOL __________________ Lemania 2320 Last edited by SeanWRT; 07-10-2018 at 10:44 AM..
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07-10-2018, 01:22 AM	#3
eeyang92 Captain 319 Rep 660 Posts Drives: LBB M2 LCI 6MT Join Date: Oct 2017 Location: CA iTrader: (0)	Maybe in the summer, increase octane a little bit via octane booster or better gas?
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07-10-2018, 03:28 AM	#4
horsepower_and_hounds Brigadier General 1836 Rep 4,203 Posts Drives: BMW Join Date: Aug 2012 Location: USA iTrader: (9)	I might try lower oct map till the new IC gets here, I really didn't want to resort back to the orange glow. Am I correct to assume that difference between stg 1 & 2 is mostly boost and between 91 & 93 is timing? If I can get out this morning it should be cooler I will pull a few more on the current STG 2 93 for shits n giggles
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07-11-2018, 06:55 PM	#10
horsepower_and_hounds Brigadier General 1836 Rep 4,203 Posts Drives: BMW Join Date: Aug 2012 Location: USA iTrader: (9)	Well we were to have a cooler morning for a change so decided to go do some pulls on the same gas. Ambient was 72. All IAT's started a good bit below 100 and the max i see at the end of a 3 gear long pull is 122...... I was thinking of trying the stg 2 91 to combat the timing pull but going to play with the E30 and log again http://www.bootmod3.net/log?id=5b447e1cd10b437911b1c9f8 http://www.bootmod3.net/log?id=5b447e37d10b437911b1c9fa http://www.bootmod3.net/log?id=5b447e69d10b437911b1c9fb http://www.bootmod3.net/log?id=5b447ea2d10b437911b1c9fd
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