Hesitation and high KR Cold weather issues?

[ShoBoat]

"Lambda is lambda regardless of the fuel.  If you're targeting and tuning to a lambda reading, changing fuel to something like MS109 will require more fuel to reach the same lambda. . So you should see an increase in injector duty cycle."  I am guessing this also applies to "winter gas"

A good read here.

http://www.yellowbullet.com/forum/showthread.php?t=244066#/enter


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[AJP turbo]

I see 2100 at WOT all the time. Actually closer to 2200 most the time. Hmmm?

Rich

Then you have room for more boost...that doesn't surprise me as most people with 3 bar tunes are only running 14-16 psi.....that can be easily done with the stock map sensor...and spare me the 14.7 psi limit...the 5v limit of the stock sensor actually may extrapolate closer to 17 psi and the stft would handle boost spikes even tho the sensor couldn't read anything higher....basically I don't know that the 2 bar is actually 2 bar

And rich if u had the tranny locked to avoid a downshift at wot and u could hold 2000rpm ur fuel pressure would plummet when boost rises

[91hybrid]

So do I. But I bet you your car is not programmed like apj's as your car will not allow you to lug a gear below 3000 and build substantial boost. I imagine it down shifts instead, which keeps the hpfp spinning fast enough to supply the pressure needed.

Plus those lme boys don't like adding boost above 15psi so I'm doubt your tune is asking for that much fuel below 3k in anything past 2nd gear.

I may be 100% wrong as I have never even seen your car, so my assumptions could be way off.

[91hybrid]

Ajp beat me to it....

[SHOnUup]

Yup, room for more boost and it does kick down and tear the pavement up. Pretty happy with it right now.

Rich

[ShoBoat]

Here are a few logs from runs at the track last year. The first was a chilly night at 50F (Screen shot) the second was a lot warmer chart of HP side of the fuel system VS speed. As you can see it will hold over 2K PSI during the whole run down the quarter. At least it did. I know that it had similar issues last spring, I wish I still had the logs to compare when I had the issue to see if it was doing the exact same thing. 

Hence my thoughts on the fuel being the culprit here. I am running out of ideas. And am getting very frustrated. I guess the only way to rule out the fuel is to get some summer fuel. Any chance one of you boys down in the south can ship me a few gallons of your stuff? I am still waiting on the race gas store to open for the season.   

[ShoBoat]

Yup, room for more boost and it does kick down and tear the pavement up. Pretty happy with it right now.

Rich

Thanks Rich I feel much better now lol.....

[SHOnUup]

Sorry man...you'll be back there soon I bet.

How's the LOR gauge been reading with the fuel

Rich

[ShoBoat]

Sorry man...you'll be back there soon I bet.

How's the LOR gauge been reading with the fuel

Rich

No worries the LOR gauge works perfectly. It's at -1 when I had the 91 no corn it was reading -0.94 with the 91 tune.


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[SHOnUup]

I actually have had to misfire events in last 12 days.

1st one the wife just filled up at same station we've been using for last 8 months. 2 miles down the road the car starts to stutter and she pulls over and pulled a misfire cylinder 5. Yes, she stopped and used torque app to pull the codes prior to calling me...she crawled home and I checked everything. Tuning device only pulled generic misfire code. Cleared it and no sign of it.

I put in just 93(10%/e) and no added corn next fill up...still fine

Next fill up I add 1 gallon corn...down from 1.25 gallons of corn to the 13 gallons of 93. It happens again a few miles down the road when stopped. Clear codes and it's gone...weird

Car feels great, pulling great #'s across the board....actually better #'s than usual?

Rich

[ShoBoat]

I actually have had to misfire events in last 12 days.

1st one the wife just filled up at same station we've been using for last 8 months. 2 miles down the road the car starts to stutter and she pulls over and pulled a misfire cylinder 5. Yes, she stopped and used torque app to pull the codes prior to calling me...she crawled home and I checked everything. Tuning device only pulled generic misfire code. Cleared it and no sign of it.

I put in just 93(10%/e) and no added corn next fill up...still fine

Next fill up I add 1 gallon corn...down from 1.25 gallons of corn to the 13 gallons of 93. It happens again a few miles down the road when stopped. Clear codes and it's gone...weird

Car feels great, pulling great #'s across the board....actually better #'s than usual?

Rich

Weird, mine on the other hand has yet to throw a code at me.


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[FoMoCoSHO]

I see 2100 at WOT all the time. Actually closer to 2200 most the time. Hmmm?

Rich

Do you have a log?

[SHOnUup]

I see 2100 at WOT all the time. Actually closer to 2200 most the time. Hmmm?

Rich

Do you have a log?

Yes...only torque...I'll try tomorrow...just left for dinner

Rich

[ShoBoat]

Alrighty now, beginning to see a trend. I have posted a few interesting logs below. All the screen caps are from 0 and are at WOT. The first is stock tune, second is from a run last year at the track 93 V8 tune and lasty is today with the 91V7 CW. upon further examination the falling high side fuel pressure stands out. However when I compared the throttle plate position across the three I see the ECU modulating the plate in the first 2 but not the third. Even the track run has this modulation. The one from today it sticks wide open during the pull. The same goes for the WOT roll pulls (only after tuning to something other than stock). Same deal. The throttle plate sticks wide open. Is this a learned behaviour? Does the ECU adapt over time? Any thoughts would be great.     

The one you are looking for is TP1 %

[AJP turbo]

Shoboat I don't think it's so much of a learned thing as much as actual torque vs commanded torque...this is what I'm focusing on in my tuning at the moment...the car will use the throttle plate to control torque output...it's really difficult to match the commanded torque tables with actual torque...hard for me to explain since I don't fully understand it...the tune maybe commanding more torque than what another system in the car wants so the throttle will close....then open and or fluctuate

There are switches in the tune to shut that off but then if u exceed other limits the throttle can still modulate..it's frustrating...there are torque limits for the axles, trans, inputshaft...and they all need to jive.

I think I get my tune where I want it and the throttle will stay open then later on I log again and my throttle is doing weird stuff. I can't feel anything but it should be open...it's the joys of drive by wire....if I lower boost I can keep the throttle open...when it closes its usually because the ecu doesn't like something or is protecting something.....torque tables could need tuning..torque limits could need tuning...and for all I know fuel pressure dips and knock activity could cause throttle activity to control torque