blah
my therory has been confirmed. went out last night to do some fine tuning on the timing side of a stage 2 kit. everything was peachy, 11.2 a/f all the way till 6600. then a.f screamed up to 11.8 at 7k.


tried three sensors, one used, one semi new, one new. all three. same results.

injectors on gm's 07 stage 2 tune {tweeked by me} went static. not good at all. seriously, what the hell is going on here. whose nuts do i need to kick in for this messed idea that people think this is safe.

time for 50's
blah.

 

So if ya get the GM Stg2 and just get bigger injectors, it will be good?

 

you have to get it tuned for the biggers ones
60's are overkill for me.

 

yeah but that would not make sence since all you would be paying for would be for a 3" pulley for 400 bucks. SInce you wont be using the injectors or the tune.

 

lol, ****, This response just talked me out of GM STG2....... I'm up in the air again!

 

think of it like this. gm warranties the stage 2 stuff.

 

So, its kinda like, Buy buying Stg2, your just buying kinda a warentee. U can change the injectors and pully, and if sumin happens swap back in the stock stg2 stuff and go back there with it and say the GM stg2 broke it......

 

to a degree at least
there is always a trail somewhere that shows what you did. depends on how nice the dealership is

 

I c. Damn Now i'm a lil stuck on this. I think I'm gunna wait and see how yours with the 50's comes out.... Cuz I also don't know how to tune, nore do I have any tools to do tuning. (No hpt or anything) So I guess I'll just wait to see how yours with the 50's work out, and then see if I can find some one to tune them?

 

this is y i have put any plans of going with an even smaller pulley than gm stage 2 on hold. Waiting to see what comes out of all the fuel threads.

 

there is a programming error with HPtuners when it reports the duty cycle on the injectors, are you aware of this problem and do you have the fix for it?

 

^^ X2.
tried explaining this before.

 

I didn't know of this. Is it reporting higher then it really is or lower??

 

im fully aware of it. i was not worried about the idc anyways, my worry was the sudden spike in a/f via wideband. nothing on the scan showed it. i even lowered the commanded a.f on the PE table to see if it would do anything. nope. nothing. same result.

 

Did you install the stage 2 or did the dealership install it?

 

a higher af ratio doesnt mean the injectors went static, and even a .6 increase isnt that drastic of an amount. still on the safe side. NO one has ever blown up an engine while running the GM stage 2 with a safe pulley size. I really dont think there is anything to fear.

 

But wouldn't it be a wear and tear issue down the line??

 

Why do you need to run 11.2?

 

what wear and tear? If your not getting detonation or knock you have nothing to worry about. A lean AF ratio doesnt kill an engine, knock and detonation kill an engine. AF ratio is more so used to calculate how close you are to achieving that perfect air fuel ratio in the cylinder that will make the most HP.

You cant tune a car based on one thing, tunning a car needs to be based off of many factors. To many people on this forum think that if you have a nice rich AF ratio, you will be safe or that a leaner af ratio is dangerous. An engine needs to be tunned all around, not just on af ratio but intake temperatures, volumetric efficiency, exhaust temperatures, detonation, timming control, fuel pressure, fuel pump flow rates, and a ton of other perameters.

 

Nice.... I'm still learning! So u can run some what lean b 4 having detonation and knock??

 

I <3 You

 

Is there a round about # where when u get to it, you'll start to get Det + knock ?

 

rich for protection, do i have the ability to blow it up?
yepo.

with it running a nice happy 11.2, then suddenly increasing at an alarming rate to 12.2-12.3. hi, injectors going south quick. id rather be safe, then worry about it later.

11.2 a/f 21 degrees of timing, no knock.


just because someone runs 10.6 a/f and 16 degrees of timing doesn't mean it's safe. some people have no idea what the exhaust temps are either.

"it was safe, no knock or anything, and it blew up"
or so people think.

im not saying they all will do what mine is doing, im just raising awareness of it. nothing more nothing less.


also, could be the higher ethanol content in fuels as well, but i doubt that

 

where is this fix?

it seems as though the day after i loaded a different set of configs my readings were way different while i was scanning. im new to this (extreme newb, gotta start somewhere though) so it could have just been something simple that i didn't see.


edit ~ i just realized the fix was in the custom PID's. 53% IDC at 6800rpm and 17psi in 3rd

 

IMO 11.8 on stage II isn't bad at all. Did you see knock during this change? Just because it went to 7k doesn't mean that the AFR must continue to get more rich, it can be affected by other things as well, such as the computer retarded the timing therefore added a little bit more fuel, no big deal.

You only need to worry if you go over 12 with just the Stage II.