lt1 tuning help?

[jrgcjnl]

hello guys, i am a newbie to tuning, and i want to learn more about tuning, lt1s in particular
i have already started out by increasing the firmness of the shifts, adding 2 degrees to all across main spark advance and extended spark adv, as well as closed tps advance
i was wondering how i can make more power out of my car?
i also wired up the "transmission perform" button and programmed it to use it as an automated downshifter, for roll races, so that i wouldnt have to drop it to first or etc.
my only mods are intake and cut out, and i use 93 octane fuel
another thing i was wondering, does a higher MAT reading equal less spark advance tolerance?
once again, sorry but i am just trying to get a little bit more juice out of my 96z28 :p
any help is appreciated, thanks guys

[mynumber1hater]

Im here doing the same thing bro, the guys are super cool here. Check out my thread and see if it helps you at all. I have some data logs and my tune posted. GL

[jrgcjnl]

it sure seems like it, thanks a lot man, its hard out here, especially with no tuners for us lt's anywhere close to where i live
ill be sure to check it out, thanks once again

[mynumber1hater]

Same here, dayton tx. I am on a bunch of forums and this is the only place where guys are willing to help..

[EagleMark]

Glad you guys are having fun here. We are just a bunch of obssed EFI guys having fun, teaching others and all learning and working as a team.

With the performance button added you really don't need to firm up shift times, if you look through the mask for your bin you'll see the performace shift times are all 0. Other shift tables have some smooth times in them. I didn't do the button I just zeroed out my tables and have good firm shifts all the time. Tranny temps went down too!

When I forst started playing with my LT1 I found spark tables to be all they could on regular gas and could only get away with a couple more degrees with 93 octane. They are some pretty aggresive tables and others use them for their small block builds. So be careful there and watch your Knock Retard, it's nice that it will only pull .1 degree sometimes but also pull up to 15.0 degrees, so watch knock retard more then knock counts.

Best trick I can give you for a LT1 is need to download and read instructions on WOT BLM locker in EE thread:
http://www.gearhead-efi.com/Fuel-Inj...rmation-EE-EEB

Run your bin through the program and add 20% fuel to the WOT AFR table. That's where I ended up on a stock LT1 to get 12.8 AFR at WOT consistenly. If your don't have the BLM locker it only adds fuel to whatever the BLM is so you never have a consistent WOT AFR.

You can do things like turn up enable temp so air pump does not come on. Turn off traction control and when ypou do a burnout it will not poop out in middle.

[jrgcjnl]

thanks for all the help
actually in the performance mode tables the shift times were 6+ seconds, although i know that isnt true but thats whats on the table, and the only reason i wired up the performance button, is because in case i race a manual car or some guy tries to be sneaky and drop his car in manual mode, all i have to do is press it and it will automatically drop to either first or second (all i did was make the shifts happen at the max speed for each shift, such as make all 1-2 at 36mph, etc.)
now about the blm locker, i just simply run my bin through there and add 20% fuel all across the rpm range? and if so, under what table would i do that?
again, thanks for the help guys

[EagleMark]

The paremeter name in TunerPro is "%Change To Fuel/Air Ratio Vs. RPM at WOT"

After I found the WOT BLM locker and ran it, I played with fuel there while watching the WideBand O2 sensor and ended up with adding 20% to get 12.8 AFR which is supposed to be optimum for this engine.

[jrgcjnl]

alrighty, thanks a lot, im gonna try to borrow a wideband o2 sometime soon, hopefully next week but hopefully ill notice a difference

[EagleMark]

You will, it's a good trick. I couldn't beleive my butt dyno when I tryed it. So I did some logs with times and there was a difference. Look at the picture and you'll see INT and BLM are all 128 and the O2 sensor voltage is not getting cross counts the voltage is .900 + indicating richer then stoich/14.7 to 1

[jrgcjnl]

oh wow thats pretty cool, i cant wait to try it for myself
and woah, your MAT is around 40-50? thats way better compared to the 100-ish degrees my car reads lol

[EagleMark]

That was a warm day on the highway. At idle or after parked mine will be around 100, but it should drop down to real close to putside temps when driving.

Coolant temp was off by 10 degrees as I was learning to make ADX files. Then got it down even more with several flushes of cooling system, it was always serviced by GM dealer with Death Cool, ah.. I mean Dex Cool... no rust or corrosion just clumps and gobs of crap, I've been told it eats intake gaskets too... GM decided to make it's own anti-freeze to save a nickel a gallon over real Prestone around that time... something like the .25 cents a tire savings Ford made that caused all the Ford Explorer tire blow outs horror story... OK enough back to your regular LT1 programming!

[jrgcjnl]

sounds rather fresh
haha yeah, well its been around a couple of weeks and ive been messing around with my air fuel ratio, and i tried leaning it out from a 11.8-12.6 to around a 12.2-13.0 and the car still seems very responsive, although i cant really account for more or less power due to differences in weather lately (darn texas)
anyways hopefully they will be opening the 1/4 here in around a week and a half, so ill be ready to take my car and try about 3 different air fuel ratios, stock, plus 20% fuel and a little bit leaner (dont remember the percentage)
quick question, how do tuners get so much power out with a tune? like i know a good tune can get you around 10-15whp being stock, how do they achieve that? i thought there was only so much you can do with a tune, but it seems like they must really know what theyre doing

[RobertISaar]

because factory calibrations are a compromise of emissions, drivability, fuel economy and power.

emissions are dictated by the EPA
MPG is required to actually sell a car
drivability is important to not make the customer feel like they got ripped off
power is important for reasons i need not explain.

you can usually trade off one or two for an improvement in the others.

[jrgcjnl]

but my question would be what do you change in the calibrations? i mean adding 2 degrees of advance isn't gonna net you 5whp, changing shift points doesnt really give you more power just lowers your 1/4, so is the secret changing your air fuel ratio?
idk im stumped

[RobertISaar]

depending on the application, 2* CAN give 5WHP. in heavily boosted stuff, 2* can be 50WHP.

factory AFRs usually leave quite a margin of safety and can be intelligently tweaked.

but there is a LOT to art of tuning.