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Turbo Car runs 9's or 11's, depending on where I set my boost controller.
Tuned via HPTuners, P01 with Flex Fuel sensor.
Recently swapped the SEP1000cc injectors for some SEP1500cc ones.
Only changed the injector data, as was provided (by Greg Banish), and also lowered base fuel pressure down to 43psi (from 60). I run dual 450lph Walbros with 1:1 Aeromotive regulator.
Car starts, idles, runs and drives great. IDC has dropped from 80-85%, down to 50-55% at 15# of boost.
I run closed loop, speed density, 2 bar OS. I only had to touch up the VE slightly to get it starting and running well.
Issue that I cant seem to get under control, is datalogs showing it trying to take anywhere from 15-25% fuel away in the 30-35kpa down to 0 areas, on DECEL only.
I dont have DFCO enabled, and never have on this car, and never had this issue with the old stock injectors, a set of 60# injectors, or the 1000cc ones.
What I have done is zeroed out the VE table from 400-4000 RPM, from 0 or 20kpa, then interpolated it from 20kpa to 40jpa, so at 30-35kpa, VE is only on the teens.
This has helped a good bit, but mainly wondering if doing it this way is "OK", or if I should just turn on, and tune, DFCO? I cant recall why I once enabled, then immediately disabled the DFCO function in the past, but only remember it not being "happy" in regular old cruising around.
I'm also going to either go back to a Hobbs switch for the 2nd pump, or research if I can use Turbosmart boost controller to turn the relay on at a set boost and/or RPM
Even if the pulsewidth is small, say 0.5mS, there is high vacuum in the intake sucking extra fuel from the injectors. So it goes rich.
DCFO of course turns the injectors off.
I messed with fixing this a bit, then decided extra fuel in the chamber on decel after a hard pass might not be such a bad thing.
The absolute lowest pulse width I saw on any log is 2.0ms...will NOT go any lower.
It doesn't have to be after a harder hit, to do this. It will do it when just cruising along, locked in 3rd gear, I'll let off and it goes rich...
As rich as .74 Lambda, as per the wideband, and .800-.900mV on the factory O2's
I'm even getting RICH backfiring, out of the cutout, a good bit.
I attached the last log from Saturday, as well as the tune that's in it currently, in the Original Post above.
I will attach the latest tune, "CHANGE 3" to this post, where I lowered VE even more.
(I have NOT flashed or tested this tune yet)
Cruising, and WOT seem to be fine. Idle gets a little weird, "sometimes", as far as richer than commanded.
I'd rather not re-enable DFCO, but if that's the only option, I guess I'll have to.
I'm not seeing or understanding why the pulse width won't go lower than 2.0ms.
I am running CLOSED LOOP with only STFT "corrections".
LTFT's are DISABLED
The logs having me chasing my tail around in circles, because my STFT ERROR's "usually" are logging the complete OPPOSITE of the WIDEBAND EQ ERROR....
I’m assuming by your Injector flow rate you have a return style fuel system?
If so, your volts/vac table should have column 1 copied across the table. I doubt it will make much difference.
You might try cutting Min and Default Injector pulsewidth tables in half. See if that drops the pulse width in decel.
Are you on E or Pump.
I see it’s a flex fuel tune.
I’m assuming by your Injector flow rate you have a return style fuel system?
If so, your volts/vac table should have column 1 copied across the table. I doubt it will make much difference.
You might try cutting Min and Default Injector pulsewidth tables in half. See if that drops the pulse width in decel.
Are you on E or Pump.
I see it’s a flex fuel tune.
Hey Ron,
Thanks for stopping back by.
I'll answer in order of how you asked.
~ I honestly do not remember when, or why, I changed the Min Fuel mg to .002
I wanna say it has been like that for over 2 years...originally with Siemens Deka 60#ers, then the SEP 1000's, and now the 1500's. Highest it's ever been, on tunes I have saved from the past, is .008mg. (This setting, in 2019, with 60# injectors [pre flex fuel], was .0028 mg)
~ Yes, I do have return style fuel system.
Dual 450lph intank Walbro's ... both on full time
base pressure 43psi,
-8 ptfe from billet hat, to -8 "Y" to dual fed Holley rails
SnakeEater 1500cc EV1 injectors
-6 ptfe to Aeromotive A1000 1:1 return regulator, -6 back to tank
- I wasn't aware of the volt/vac settings having to be the same. I just changed that...
~ I looked back into the 1000cc injector data, just to compare, and it also called for the .790ms Min and Default Inj. P/W I just reset both to 50% of that, .395ms <--- This number is actually close to the setting I had back in 2019, with 60# injectors, pre-flex fuel (.349ms)
~ I normally try to run 75% or better, ethanol content, if racing, and 50-60%, just cruising around, and/or playing.
Doesn't seem to matter, as far as performance (anywhere above 50% or so), but gives me false security if it's higher, lol.
What's in the tank, right now, is 66% ethanol, according to last log.
I honestly only have a flex fuel sensor, in case I am out and need fuel, and there's only unleaded available.
Generally speaking, I add 4-6* total timing, depending on ethanol content.
I run rather conservative, IMO, at total timing of 12-14* on gasoline, and 16-20* on ethanol.
I think it is supposed to be raining for the next 2-3 days.
Hopefully not, so I am able to test these new settings out and report back
Finally got to take a little drive today after work. Looks like lowering both of the pulse width settings by 50%, definitely helped.
I left the modified VE, at 35kpa and lower, settings alone. They were drastically lowered, trying to figure out the 20%+ rich wideband readings on decel. With just the pulsewidths lowered by half, the wideband showed a 20% error the other way, now lean instead of rich.
I was going to simply "Paste Special Multiply by %", just the 35kpa and lower parts of the VE, and retry again tomorrow, but instead just re-entered my 35kpa and lower VE numbers from last week. In theory, it "should" be close enough to call good, or at least close enough to do one more log and a "Paste Special Multiply by 1/2%".
Cruise and WOT was still good. Cruise being 1.0 lambda most of the time, and .78 lambda at 14+ psi of boost, yet never more than 2-5% richer than commanded A little leaner at my "low boost" setting of 4 psi...mostly .78 - .80 lambda.
Bonus*
The new Hoosier 28x9 Drag Bracket Radials seem to work VERY well, and are ready for Test and Tune this Saturday.
I attached graphs of last week's IPW% readings, and also yesterday's to show the differences just from lowering the 2 PW settings by 50%
Snake Eater Performance Injector Data (according to them), is supplied by Greg Banish, FWIW.
I am running the SEP 1500cc EV1 Deka injectors at 43psi base fuel pressure with an Aeromotive A-1000 1:1 boost sensitive regulator
Still have to tweak the low kpa VE numbers, for street driving, but no biggie there.
My goal for the T&T was mainly to dial in my new dual wastegates to try and run 11.50. That's what I need to run next Saturday.
First pass, went 11.506@120, at 3# of boost and less than a psi on launch, so knowing I could easily work with that next week, and track was packed, turned it up to about 14#
2nd pass, went 9.91@140, with a horrible transbraked 1.59 sixty foot, only leaving on 1.8# of boost, and only maybe 2600RPM.
3rd pass, turned up the 2 step to 3300 RPM, which made about 10#, and let go of the TB button, car started to pull the front up, then immediately blew the tires off.
Went a 10.20@140 and tossed the serpentine belt, I'm guessing because of the launch shaking the tires so hard.
That was all I could have gotten in anyway, but now I really need a solution for this POS On3 alternator mount setup. This was the 5th time its tossed a belt. Have tried leaving it a little loose, so tight it had zero deflection, and everywhere in between.
Sounds like a successful outing except for the belt flying off!
I was a spaz first pass short shifted both gears went 9.07@150.
So instead of trying to just get the shifts right added 5% to the boost controller, hit both shifts at 7k and ran 8.87@153.
Added another 4% and although it didn’t blow the tires off, it spun and shook pretty bad. 8.94@154
Sounds like a successful outing except for the belt flying off!
I was a spaz first pass short shifted both gears went 9.07@150.
So instead of trying to just get the shifts right added 5% to the boost controller, hit both shifts at 7k and ran 8.87@153.
Added another 4% and although it didn’t blow the tires off, it spun and shook pretty bad. 8.94@154
I need to add some tire pressure.
Drove it home! I was pleased.
Nice! Sounds like your day went well also.
I actually saw your thread later yesterday. Car looks great!
Thanks for the replies and help!
03-13-2021, 02:09 PM
20% rich on decel only, HPTuners 
