1995 LT1 Camaro Tuning tips

[fourcams]

I bought a 95 Camaro to tinker on, im very versed in hptuners with gen 3/4/5 ls and lt engines but first time ive ever messed with one this old.
Car has a 355, GM847 Cam, Jegs XHD Converter, Longtubes and 36lb bosch GTP injectors. It seems to run pretty good will go 12.0@112 on the street havent taken to the track yet only dragy times but i have a few questions on the tuning side on these.

There seems to be a timing adder in there that will pop in another 1-3 degrees at times over commanded. I cant find a afr spark advance table like the newer pcms in it, what could it be coming from?

TCC PWM, i do not lock the converter wot but i can tell it needs the pwm disabled if even possible in a 95 4l60, it kind of slides into lock up

I cant seem to find any good injector data for my bin file with the 36lb injectors, for now i have just changed the flow rate and went from that but would love to have the injector offsets correct.

Car is around 12.5-6 afr wot i plan to lean it up and see if it picks up after i get a cold air intake on

If theres anything anyone sees let me know, this is my first swing at tuning one of these dinosaurs :rolleye:

[dave w]

:welcome:

Link to LT1 Tuning information: https://ecmhack.com/eehack-2/

Gearhead-efi member steveo is the site owner of eehack.

[steveo]

most guys ignore the extra few degrees of spark advance since you need it when in power enrichment due to the extra fuel

on stock heads most people find 13.0-13.3 makes the most power

[fourcams]

Good deal there its not picking up any substantial knock anywhere and none part throttle up to 35-36 degrees. Ill get it leaned up a hair and see if this thing picks up a little more, fueling doesnt seem for off anywhere else open loop may leave the injector data alone

[fourcams]

:welcome:

Link to LT1 Tuning information: https://ecmhack.com/eehack-2/

Gearhead-efi member steveo is the site owner of eehack.

Thats a awesome site, got a lot of my starting info there!

[steveo]

thanks

the downloads are a bit broken but the 1994-1995 lt1 is special to tune because i spent 10000000235893245+ seconds building very special lt1-specific software. flashhack, eehack, and eex (with tunerpro) is the best free tuning combo for any car ever and i challenge anyone to say differently

i would agree to leave your injector data alone if you don't have a solid data sheet. it might trim a bit funny at lower airflows but it wont hurt anything

the LT1 running sufficient fuel can tolerate a crapload of timing due to its reverse flow cooling and optically precise positional reference.

i tuned one of my 'cam-only' lt1s with 91 octane up to 48 degrees at cruise and 35 degrees WOT above the torque peak. i also ran the AFR at 13.0 below torque peak tapering 13.5 above the torque peak (not saying you'll have the same results, but that car really flew)

[fourcams]

Thanks for the tips there! Im fabbing up a 3.5'' cold air over the radiator on it and once i see the gains from that ill see how it does pump e85 55-60% blend and do a ported milled head on it
I dont see a stoich table in these files to go e85 do i just start out adding 30% fuel to the ve tables and go from there like id do holley?

[steveo]

edit: messed the math up
there are stoich target values but what i would do is fudge the injector constant. if you try to scale just the VE in speed density you will run out of room. for that blend you will need 33% more fuel so just take your injector constant and *0.67 so it thinks your injectors are smaller. this fixes every fueling table, constant, and formula in one shot.

[steveo]

edit: i messed the math up
by the way how i figured your 33% fueling modification out is i added a safety margin and called it a 65% blend, then (-0.057*65)+14.7 gives you the stoich for E65 which is 11:1 or so. the difference between 14.7:1 and 18.4:1 is like 33% so there you go. i think if you start there you'll find out you are pretty damn close.