Area47

still think the 42.5lb/hr injectors are still small?

one might think so, but gm doesn't.




this log is a straight gm tune, aside from torque management removal. nothing done to the PE file, nothing on spark advance. so unless someone on here got the config file wrong on the duty cycle.
so my thinking is this. yes the stage 2 runs rich {about 10.7a/f} call me crazy!


that run was a second gear pull, nothing special.

third gear pull


again, stock gm issue stage 2 tune. nothing done.

FSRbikr98

wow if my eyes dont decieve me thats 122% duty. holy **** batman

Gonzo2007

That is insane......now if gm warrantys that....is the 2.8 and a good tune safe? hmm...

Area47

whats messed up is, the 2.8 runs lower duty cycle due to it leaning out.

you can lean out with the 3.0 pulley, IE stage 2, and get the IDC down, but i doubt it will go below 100. dunno. going to do some more testing.

this is the config file that denny posted on hptuners forum. sooooooooooo there we go

t5munoz

I thought that the injector duty cycle should not be that high, is that safe

Area47

my thinking is that the PID file is not right in the hptuners stuff. as in it's not reading it right. i have to check with some people first before i go off the deep end and make a weird claim like that.

time to do some diggin to see what i can come up with

t5munoz

Run a 2.85 pulley and let me know what you come up with

Area47

i was on a 2.8 for a couple days, idc is only a couple percentage lower, but would knock more.

t5munoz

Hey what are your mods

HighPSI_LowCC_Speed

Are you sure that your inj duty cyle % is being calculated correctly, i.e. with the 42 lb/hr injector in mind and not stock (which to me would appear to be the default in any tuner application). Just wondering...cause that would make sense given those numbers.

Kaisoboy

2.85 and 42' tune

I tried two diferent config files, one had a IDC of about 92 % on the first one. I then tuned the car tried a diferent PID and got a IDC of just under 50 %. What is up with that. I am confused. I tried re-aplying the IDC scan to the PID but got the same results of less than 50 %. hmmm


P.S. How do you post pics. Itried but can't get it to work. If I can post a pic I will put my log file up.

Doc

the first config file is one I posted to the hptuners site....its correct. I have another bit of info if you want to check out the math, here it is http://www.stealth316.com/2-calc-idc.htm

try uploading the pics to the gallery then it'll be easier to get them on here.

an0malous

i remember someone talking about HP tuners not giving the correct duty cycle without changing some variable....


Im just diggin at an old memory here....but im sure someone will know what im talkin about.

Area47

there is no way in hell that gm would put out a car, with 122% duty cycle.

im not even sure how close to be accurate that is on the PID file.
with duty cycle comming closer to 100% the engine will lean out because it can not keep up. how ever, the highest i say with the 2.8 was 117 at 7100 rpms. yes the 2.8 leans it out, hence lower duty cycle due to more air being thrown in, and no fuel compensating for it.

SSdan

I'm a firm believer that 42lbs will support a 2.8 on the safe side.

Area47

you're not the only one.

that fact is, it does NOT go lean up top like a maxed injector would on a 2.8. if anything i make it go richer, although idc spikes, but it doesn't go lean.

SSdan

I need to get HPT and slowly learn how to tune.

What are your mods that you got 262whp? on a dynojet or mustang?

I did 244whp/220tq on a mustang dyno with catback,cai,stage2 tune + 2.8.

Area47

2.8, 42's, straight stage 2 tune, minus torque management, k&n intake

dynojet

nothing fancy

SSdan

damn dynojet. I'd probably have roughly the same on one of those.

Area47

ya should!

i was lookin over the log i did on that run, it was not happy. was only seeing max of 12.5 degrees total timing.
ouch.

fixed that problem, it's a happy car now.

in short, the stage 2 tune sucks *****. it's ment too. to be safe for 100k miles.
if it's ment to be safe, why does it knock its ass off?
hmmmmmmmmm

makes one wonder

an0malous

what octane are you running.

91 octane = stage 2 knock
94 octane = no knock.

Area47

91. the highest i can get here in kc is 92, and it is actually worse then the 91 octane. i knock more on 92, then i do 91.
we don't have much of a choice in kc. i however, have the powa!

an0malous

thats why you get knock

put some 92 in and go get a bottle of NOS Racing formula Octane boost.

the knock will dissapear.

GM wasnt kidding when they say you MUST use premium.
they should have specified that 91 premium isnt good enough.

MacG321

it actually does seem safe to run a 2.8 inch pulley on a stage 2 tune? please enlighten me if i'm wrong.

Area47

read what i typed again.



cliff notes. I GET MORE KNOCK on 92 then i do 91.

id rather spend the 12 bucks on a couple gallons of 104 unleaded then drop 12 bucks for half a point of octane boost.

im not going to give anyone false hope on anything. i don't beat the **** out of my car, so mine will survive. i am also taking precautions to make sure it does as well.


if you want to try it, be my guest, but don't blame me for something i said.

yes the duty cycle is lower {because the 2.8 leans it out}
yes there is a greater risk of blowing it due to heat and various other things.