oldskool

Has anyone in the LNF cobalt world tried this beta yet? I'm waiting until i finish my IC install on my GXP and grabbing a boost gauge before trying it.

Tofu

I've downloaded the beta and played with the new tables, but unfortunately my Cobalt is under the knife until next week.

I'm anxiously waiting for some results from someone with an LNF though. I need to purchase myself a mechanical boost gauge as well...

umrdyldo

iTrader: (1)

What does overboost control do?

Is it the new fuel tables or what?

Tofu

In layman's terms it gets rid of the overboost and underboost scenarios that throw our cars into limp mode if certain boost pressure is exceeded or if it's too low.

No additional fueling tables at this time

oldskool

progressive meth injection can passively serve as supplemental fuel

supermantxz24

i have been playing with it today and i cant seem to boost over 21psi im playing with my desired airload and im in the 400's right now so im just gonna take them higher and see what happends.

1badBlueberrySC

Guys... it won't help us stock turbo stock wastegate guys.

It's only for those with bigger turbo's with non ECM controlled wastegates. I tried it, and a couple others I know did as well with us being stuck at 22 psi

Tofu

Yeah, I had a feeling this was going to be more of a band-aid in terms of hitting limp mode or over/under boost codes rather than allowing us to push past the 255kpa limit on the stock MAP sensor.

supermantxz24

has anyone tried the wastegate mod with the new beta?

Terminator2

Nope. How do you do the wastegate mod on this car?

boostking

I dont understand whats going on with these cars.... I could run 25+psi on my stock turbo if I wanted and then one day the most I could do was 20-22psi. and its been that way ever since. I can only flow 33 lbs/min in my maf airflow and I only show 28-29 lbs/min in my VE airflow........ whats going on?...

supermantxz24

i dont know lol but i heard people where doing it and hitting 25 psi but they would go into limpmode. but i think it might work now since we can eliminate the over boost. before i blew my first map i would spike 25psi and hold at 21 but now since i replaced it i just spike 21 and it drops off to like 18. im thinking its my intercooler but idk

mkriebs

The wastegate mod is basically messing with the WG rod adjustment. Which, I believe is bad on the turbo. You might be able to tweak it, but I am not sure. I might play with mine... but I am not sure as of yet.

I have played with the tables as well, and have gotten no results. I can't even hit the 255 kpa MAP limit, and I had my DALs to 370+ for a little bit. I have since turned them back down, and will be tweaking them a bit better now. I didn't even push much more MAF lb's.

1badBlueberrySC

29# V/E airflow is about the max I get as well... I have a feeling it's due to the wastegate only being active on 80% duty cycle.... Hence why we need those W/G tables so we can play with it more.

Plus having access to using a 3bar map would be a nice thing too!

boostking

I have done this mod. I set the nut closest to the wastegate to the last thread and then ran the other nut at the end of the rod all the way up. this shortened the rod as much as it would go. this is what allowed my turbo to spike 30psi if I wanted. but then one day after a month or so it stopped doing it. now it rides the 20-22psi mark.

1badBlueberrySC

When I had the SRI on my car it would spike to about 25-26 and then drop back to 22. Now with the stock box and K&N in it, it jumps to 22 and just stays there for the duration!

boostking

I wish Hptuners would just stick with our ecm untill its done..... this little at a time sh*t is getting old......

1badBlueberrySC

Very much so...

Term and I have pretty much maxxed out the stock turbo's... I guess it's time for more boltons...

OR bigger turbo's or something

Terminator2

That is normal. Mine flows 29-30 lbs/min VE airflow and 34lbs/min MAF. Anything over 34lb/min is MAF skew causing a false high MAF reading. The stock turbo maxes out at 34lbs/mn or so even at higher pressure. More boost will mean more torque but less powerband on the stock turbo. I believe the reason for the disparity between MAF and VE airflow (there is a 10% disparity even with the stock airbox on) is the pumping and other frictional losses associated with the combustion cycle.

Yep. I remember those logs 37.4 lbs/min MAF but only 28.6 lbs/mn VE airflow that was why your STFTs were -12 at those moments.

boostking

what do you mean maf skew?
I might try setting my wastegate back to stock and seeing what happens. I would like to look at one of your logs with you maf at 34lbs/min if you dont mind. also how is that aem doing in regards to stft/ltft

Terminator2

The intakes skew the reading that the MAF sees. Any log I have never seen that showed more than 34lb/min MAF flow had negative fuel trims to go along with it either LTFT or STFT or both sometimes. You need to make a custom PID of LTFT+STFT and insert it into a histogram. The AEM is 10% larger diameter than the stock intake so the fuel trims are +10 to +14.

Baldturbofreak

*providing your fuel trims are spot on, The discrepency in the two readings is the result of a changed system. The backup method of calculation airflow using pressuredrop across the TB becomes less accurate when the pressure drop is almost nil.
You see it with a gt35r. It's like 10 lbs/min off.