Hey man thank you so much, I PM you,
Can i still tune the car and still be able to use my mass air flow sensor,
I just picked up a stock one , to try.

or do i have to now tune the car SD?
my tuner tuned the car WOT and played with the idel a bit , but i dont know what he did as far as driving at a cruise (1500-3000RPM)???
he told me to try the stock mass air sensor and then he will look at the way the car is running?
talk to you soon
check your PM

 

I just tryed a stock LS1 mass air sensor,
Its better now, but still not right , my LTFT are still very high 20+

 

I jumpped to conclusions earlier thinking there was a mechanical issue since someone had tuned your car. But after reading everything......if your tuner gave you the car back in it's current condition (with 20+ LTFTs), I'd start looking for someone else. It sounds like he didn't really invest the time required for getting your car to run right at all driving conditions. If you are your own tuner, you might want to check into the stickies above to read up on what you may be missing.

 

Ding, ding ,ding!!!!

histograms, gotta love em
2 bar makes life alot easier

 

DITTO. The part throttle driveability stuff should be sorted out first. On the big cam cars I spend a considerable amount of time on the VE tables before I make any "pulls". I'm working on a SD TPI with a good size cam, dont know the specs. Less than 10 in of manifold vacuum at idle. The VE tables look NOTHING like the OE tables. And we're just working the idle to 3000 range, so far.

 

your right he did not spend much time if any to get the car running right in all driving conditions.
I talked to him today

my tuner said to through a new set of O2's in, and bring it down next week , he is
going to go over the whole thing.

I ran a few gals of 110-114 octang , 20-80% mix over the past 3 months while playing with the car , and it looks like my O2's are switching a little slow,

But i have a Razor methanol injection system , i now want the car tuned for pump gas (only) , at about 11.8 - 12.0 AF and add methanol to get the AF down to around 11.0-11.2

this should be a safe tune and keep the knock away.

I made 540WRHP as it sits now with 9-10 PSI of D1-sc boost , i am happy with the power , since its only a stock LS1 with FLP long tube headers and a accufab 75mm throttle body ,
but the off idel and under 2,500rpm acelatration sucks and my gas milage is about half now , i might be only getting 10 miles to the gal,

I know at a cruise anywhere from 2000-3,000 RPM at 40-70 MPH the car is using to much fuel and with LTFT's at 20-25%
something is telling the ECM to dump fuel.
This sucks but i will figure it out ,
And thank all of you for helping me out

 

how should i have the car tuned,
With a Stock mass air flow sensor?, or a real 85mm LS6-ZO6 MAFS?,

or with a 2 bar map sensor?

EFI live, HP tunners, LS1 edit?

Please let me know

 

OK. To begin with, the MAP and MAF are totally different and one isn't used over the other. While the MAF measures airflow into the engine, the MAP is measuring the atmospheric pressure of that air. For a FI car it'll be over atmospheric pressure, thus the need for a 2-bar MAP sensor. (The car comes from the factory with a 1-bar as it was NA from the factory.) You need the Cobalt SS one (PN 12580698)

Doesn't matter what tuning program you use, as long as it'll tune for 2-bar. HP TUners and EFILive both will for sure.

To tune the VE table, you do this in SD mode. Period. Then afterwords you can reenable the MAF and tune that into the equation. The MAF is like the VE in that it has to be tuned for your mods. Doesn't matter if it's stock size or 85mm....still needs to be tuned if using the MAF. And again, you can't tune the VE table with the MAF enabled. It'll be all F'd up if you do.

So:

Use the 85mm MAF or SD...doesn't matter. If MAF, then tune the MAF.
Get the 2-br MAP sensor.
Personal advice - seek out a different tuning shop. From your Q's you are asking your current tuner does not seem to be giving your car the attention and changes it needs. He's also not explaining to you what has been done.

 

OK schantin, thank you very much

One thing i dont fully understand?

("Use the 85mm MAF or SD...doesn't matter. If MAF, then tune the MAF.
Get the 2-br MAP sensor.")

OK if i am to tune the car Speed density , does that mean i dont need to run the MAF sensor at all???
And then all i need is a 2 or 3 bar map sensor?


And if i do use the MAF sensor , what one should i use?
The 85mm SLP MAF sensor has a resister that SLP solders on to two of the bars inside it , you can eazly see it , BoB from EPP said to never tune with the SLP mAF sensor.
We had to remove the Resistor otherwise the car stumbled real bad whacking the throttle,,
so i have a stock one on the car now, but how about a real ZO6-LS6 85mm MAF sensor? can i use one of these?
the SLP one is a truck MAF sensor with the resistor solder onto it .

 

The lead coulda killed the 02s. I've seen it happen. Once that happens, all bets are off!! That should be the first thing you do, replace the 02s.

 

Hi Schantin
The Cobalt SS map sensor (PN 12580698)
will this install where my stock one bar sensor is now? ,

Just un plug it pull it out and push the New Cobalt one in?
Please let me know
and how much does one cost and where can i get one.

 

by the way i picked up a new set of Orginal GM O2 sensors today , should i replace my old ones after we figure out the tune , or now,
I dont want to F up these new ones ,
will running rich hurt them?

 

OK i installed a new set of GM O2 sensors, and a stock MAF sensor, one at a time with the MAF being first ,
The Stock mass air defently helped the car run , idel and off the clutch at a stop drive better .

After the New O2 sensors , the LTFT are still maxed out at a cruse 60mph,
The LTFT seem ok at a idel,

 

What values are in your IFR table and are you using a boost -referenced regulator?

 

No , no boost - referenced regulator

I have a Duel double Racetronix In tank fuel pump that is wired to a hobbs switch , only one pump runs all the time and the other kicks on at 5 PSI of boost , fuel pump system works great,
I am running motron #60 pound injectors, everything else is stock (lines, rails etc,

I am supposedly good for 700 RWHP, i am only at 500.
But i would like to install a fuel regulator to adjust satic fuel pressure at the (T) at the back underneith the car , or maye one day just do a boost -referenced regulator
with a return Line , but like i said i dont think i need it .


I have no idea what a IFR Table is, and i dont know the values,
Please let me know what they are
thank you

 

Injector Flow Rate tables...