EFI

[jackdidley]

New guy here. I convereted to E85 last December, really like the octane and have hopes of getting a little h.p. out of it. It seems everyone here is carbed. My car has EFI. Anyone else tuning there own car for EFI ? Its been interesting but a slow process. I drive the car daily but it will be April before I can get to the dragstrip and fine tune it. Just looking for any input or general info on this.

[adamsvega]

hey i know jackdidley about fuel injection....lmao
your fuel and timming map will need less curve to keep it happy
.start off by raising initial time by 3 deg. move your curve down about 500 rpm and keep total the same to start . is your system feed back ? then just plot a 33% addition across the board as long as your max pulsewidth is less than 85% with your new injectors at W.O.T.see how and were it preforms if you go off map just adjust those blocks as needed . at cruise you can lean on it preaty hard with efi .the rest of the time in all but WOT shoot for best lean torque . on w/o go for max rich power and then back down ,
if you can envision this in your minds eye on gas you whole map looked like the Rockies now with the right injector /fuel psi it will look more like the Poconos

[jackdidley]

Feb 16, 2010 6:45:46 GMT -5 adamsvega said:

hey i know jackdidley about fuel injection....lmao
your fuel and timming map will need less curve to keep it happy
.start off by raising initial time by 3 deg. move your curve down about 500 rpm and keep total the same to start . is your system feed back ? then just plot a 33% addition across the board as long as your max pulsewidth is less than 85% with your new injectors at W.O.T.see how and were it preforms if you go off map just adjust those blocks as needed . at cruise you can lean on it preaty hard with efi .the rest of the time in all but WOT shoot for best lean torque . on w/o go for max rich power and then back down ,
if you can envision this in your minds eye on gas you whole map looked like the Rockies now with the right injector /fuel psi it will look more like the Poconos

Thanks for the input. Timing curve is the big mystery for me. I currently have 20* at idle and a total of 28* at 4000 RPM. I have had these questions in my head for quite a while. You are saying take that to 23* and bring it all in 500 RPM sooner and thats sort of what I had in mind. Past experience tells me it will need 34* total, I just have not gotten there, yet. I'll see if I can post my timing map later. I just need the snow to leave so I can burn some chips and try. For the record, this is a mild 350 SBC with a 700R4, daily driver/drag car.
For injectors, I was able to keep the 24# injectors by tweaking the tune and cranking the FP up to 70#. Yes the pump is deadheaded and nothing is bypassed back to the tank. Wide band O2 numbers look good but I do have it a bit rich at WOT for safety. I'm pretty sure I came close to melting it down the first time I went WOT on straight E85. I was datalogging and all the numbers were looking great. Stood on the gas entering the interstate and at about 4500RPM it started cutting out. BAD. I didnt react fast enough. Got home and pulled some plugs and there were traces of aluminum on them. After that I figured out a way to fatten it up. Its been over 1000 miles ago, so I guess its not hurt bad.

[adamsvega]

aHHHGGGHHHH! i hope that was carbon not alum. ya saw.
does your pump have a bypass in the tank? dead heading a pump will drop psi as the rail gets depleted from increasing pulse width .how in the world did ya get a fuel curve right with psi dropping?

[jackdidley]

Feb 16, 2010 18:47:00 GMT -5 adamsvega said:

aHHHGGGHHHH! i hope that was carbon not alum. ya saw.
does your pump have a bypass in the tank? dead heading a pump will drop psi as the rail gets depleted from increasing pulse width .how in the world did ya get a fuel curve right with psi dropping?

No, pretty sure it was aluminum. I'd say there are some divots in the pistons. Hopefully small ones.
Yes, it does drop fuel pressure but not enough to hurt. I have a 255 Walbro pump. Volume is there. Only varies about 4#. BLMs are not perfect but acceptable. The car has a MAF sensor and the ECM compensates better than I expected. I do have plans for bigger injectors but thats not in the budget right now.
I'd really like to get the advance curve nailed down. Burned a new chip today but theres too much snow/ice on the streets to get a good datalog. I put up a pic of the curve on Imageshack but could not post it here for some reason. Maybe because I'm new ??

[jackdidley]

Curve here. Copy to browser. IMG tags would not work. Advance is limited to 42* max so you can disregard anything over that on the graph.


img706.imageshack.us/i/curvey.jpg/

[adamsvega]

being as this is a public board i must warn you as walbro 255 ,255hp and the 190's dont like being dead headed .the cavitation at idle beats the crap out of them they dont even like to be pulsewidth controlled when dead ended ... this is hopefully only a short duration test .if you went lean one time allready and melted some crowns a pump out put that falls off when you need it most will self destruct and the o2 wont be able to catch it . put a cheap hobbs switch for a low limit to kill ignition to be safe .jmfo

[jackdidley]

Thats the kind of information I'm looking for here. I will have to do something about the pump situation. Really need injectors.
Ran a nice datalog today and plan on adding a degree of advance and trying again tomorrow. Car is now dirty, slushy, salty, filthy, so, nothing to lose.

[adamsvega]

images1f.snapfish.com/232323232%7Ffp9%3A9%3Enu%3D335%3A%3E8%3A2%3E979%3EWSNRCG%3D33387255%3B%3A335nu0mrj THERE IS A TRAILER AND CAR OUT THERE SOME WHERE. I 'M GOING TO DIG EM OUT AFTER 2 WEEKS AND 45" AND TAKE EM TO WORK AND CHANGE MANIFOLDS , if ya put the hobbs on the ASD circuit youll have to overide it on start or add a separate start momentary (theft deterrent) if your rail wont hold psi over night a thief or you will crank untill the snow melts and it wont flood or start .

[jackdidley]

WOW, you really got hammered with the snow. We just got 7' last week and 1/2 of that is gone. More coming this weekend though.
I think I will be replacing the injectors soon. I prefer that over the safety switch. I may have a new job next week. Will know tomorrow.
Whats the deal on posting pics here ? Bandwidth ?

[adamsvega]

yeah we are beating alberta canada by 43"
dont know some stuff works and other stuff like snapfish i cant figure i have to transfer stuff from cell phone to snapfish then to may computer then to photobucket to get stuff on .

[jackdidley]

I gave it some advance and ran a datalog. Got spark knocks in first gear. I think the total is OK but the curve needs work. Tweak, tweak, tweak. May be a couple days before I get back to it. In this case, thats a good thing. ;D

[adamsvega]

WHAT WAS THE AFR JUST BEFORE THE KNOCK? WHAT LOAD %?

[jackdidley]

Narrow band in the low 900s. Load range 200.

[wicked94z]

get a wideband on that car, best thing I did for my car when tuning on gas and now on e85. I have an AEM UEGO, easy to switch to lambda and see right where you're at. BTW, I started with 30% fuel added, and ended up at 25% to get my tune roughly where it was on gasoline. I'm speed density, and open loop... so I have 0 input coming from the computer on fueling or spark. I'm running a 255 here with roughly 600 fwhp, but then again I have a return in the system.