Winter fuel not as good.....

[Speedy!]

I dialed my tune in during the middle of summer when it was 95 deg F and 80% humidity. I always use Shell 93 fuel for the street tune. I had the IAT modifier setup properly and it would remove a tick or two of timing as IATs climbed and things looked great in the data logs at WOT with zero STKR ever.

I went to confirm the tune now that it's cooling off. Put in a little over half a tank of Shell 93 from my usual place. Made a couple WOT pulls and log showed a degree or so of STKR in a couple spots. Hmmm. Lambda/AFR, boost, fuel pressure, everything else was the same as summer logs. Not a big deal but not what I expected as I figured in cool 60 degree air I'd be less prone to STKR than in 95 degree air. I thought maybe something up with the gas so I drove it out and a week or so later put in more Shell 93 from my usual spot. Re-tested, same tick of STKR in a couple spots.

So I read up on winter blend fuel and it seems it's mixed a bit differently to account for really cold areas in order to aid in cold starting. The fuel is a bit more volatile as a result and more prone to knock. So I removed .5 deg from my tune in a couple spots and good to go. I could have left it but I don't like to see more than .5 deg of STKR in a spot or two in a log and I was seeing 1 deg at around 5800 and again at 6300. My knock sensors thresholds are all stock except for 4,000, 4300, and 4700 RPM and 1.4 air charge where they're increased a tick from race fuel testing to get them dialed in and avoid false knock from supercharger noise.

May be common knowledge for some here but thought I'd mention it just the same.

 

[Hpindy]

I agree . Up here they even advertise on television about "winter grade gasoline " being better for harsh winter performance.

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[Blkout]

I've never seen a gas station here in GA that states winter blend. Or do they change the blend and not tell the customer?

 

[Catless]

I've never seen a gas station here in GA that states winter blend. Or do they change the blend and not tell the customer?

Correct. They don't tell the customer anything.

 

[FlyByU]

Were you making more boost?

 

[hellno]

GOOD STUFF SPEEDY .IM CURIOUS HOW THAT GOMANGO RUNS NOW

 

[Blkout]

Correct. They don't tell the customer anything.

No issues for me since I'm on E85 but the knock sensors in these cars are perfectly capable of adjusting for a winter blend of gas unless you're running a pulley setup generating more than 15psi or a very aggressive tune which Speedy might be.

 

[Hpindy]

I put my car away for the winter so it has no impact on someone like myself .

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[hellno]

the research ive done so far seems on flex fuel even at e50 its a higher octane rating the pump gas ,I believ im going to be very happy with the flex fuel set up

 

[Speedy!]

Correct. They don't tell the customer anything.

Correct, they are not required to disclose the change over.

Were you making more boost?

No. Boost, and more importantly aircharge, were the same.

GOOD STUFF SPEEDY .IM CURIOUS HOW THAT GOMANGO RUNS NOW

It's running great. 1/2 a degree if timing isn't going to make any real difference either way. I coulda just left it but I'm a bit OCD lol.

No issues for me since I'm on E85 but the knock sensors in these cars are perfectly capable of adjusting for a winter blend of gas unless you're running a pulley setup generating more than 15psi or a very aggressive tune which Speedy might be.

That's my point. The knock sensors did exactly what they're designed to do. I'm running a pretty conservative tune on pump gas and once the winter blend fuel switchover occurred the knock sensors started telling the ECM to remove a degree in a couple spots. I coulda left it be, but see above LOL. Did some logs tonight after work and it's dead nuts now even on the winter fuel so I'm g2g with good and less than good fuel from the pump. I'm not trying to set the world on fire on pump gas, just wanna maximize the setup and still leave some safety net overhead.

the research ive done so far seems on flex fuel even at e50 its a higher octane rating the pump gas ,I believ im going to be very happy with the flex fuel set up

You're right. Those flex fuel setups are pretty slick. I might eventually start playing with that. From what I've read E60 is like 100 octane equivalent, and it goes up a bit to E85, but kind of diminished returns.

 

[hellno]

when are you gonna track it again speedy??

 

[Blkout]

That's my point. The knock sensors did exactly what they're designed to do. I'm running a pretty conservative tune on pump gas and once the winter blend fuel switchover occurred the knock sensors started telling the ECM to remove a degree in a couple spots. I coulda left it be, but see above LOL. Did some logs tonight after work and it's dead nuts now even on the winter fuel so I'm g2g with good and less than good fuel from the pump. I'm not trying to set the world on fire on pump gas, just wanna maximize the setup and still leave some safety net overhead.

You're right. Those flex fuel setups are pretty slick. I might eventually start playing with that. From what I've read E60 is like 100 octane equivalent, and it goes up a bit to E85, but kind of diminished returns.

Yea, even E60 is a HUGE upgrade over 93. I say go for it.

 

[Speedy!]

when are you gonna track it again speedy??

I was planning to go Saturday, but the track is rented for a private event

So looks like 11/9. The last three weekends in Nov are open TNT at my local track so we're gonna capitalize....pray for good weather

 

[hellno]

you gonna be in the 9s easily

 

[hellno]

blackout I noticed that you showed a pic of the oil filter have you ever cut the lid off the top and looked whats at the bottom of the filter I have a cutter that cuts it perfectly off with no residue

 

[Blkout]

blackout I noticed that you showed a pic of the oil filter have you ever cut the lid off the top and looked whats at the bottom of the filter I have a cutter that cuts it perfectly off with no residue

Haven't tried that. Got a cutter you recommend?

 

[hellno]

Haven't tried that. Got a cutter you recommend?

I have a large tubing cutter but if you have a nice set of cutters it may cut the top off easily when I had all the fuel issues I changed mine out early and had what looked like carbon in the bottom .,im going e 85 right now so im curious about what it will look like

 

[Slows2k]

I experienced this a long time ago with a Vortech on a S2000. If you can get 100% ethanol free you’ll probably notice a different ignition timing need.

 

[FFBOS]

Winter blend is "real" with both pump gas and ethanol by me in Chicago....just have to adapt.

 

[hellno]

I was planning to go Saturday, but the track is rented for a private event

So looks like 11/9. The last three weekends in Nov are open TNT at my local track so we're gonna capitalize....pray for good weather

what track is that speedy??