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Well its been over a year now since the 5.3 took a dump on me but the 408 is in and ready for tune. Went all forged, Afr heads, with this cam
INTAKE EXHAUST
DURATION @ .050" 23* 24*
ADVERTISED DURATION 28* 29*
LOBE LIFT 0.38* 0.35*
GROSS VALVE LIFT 0.649 0.609
LOBE SEPARATION 111
ADVANCE GROUND IN 1
OPEN CLOSE
VALVE TIMING @ .050"
INTAKE 8 BTDC 51 ABDC
EXHAUST 52 BBDC 10 ATDC
hopen good #s ill keep posted on this for ya
well its at 464 but its not geting enough air up top. so im guessing the cold air i got for the 5.3 isnt big enough along with the stock mass air... Its also throwing a code at 6200 and i cant fig out why any help on this. i cant remeber code off topof my head ill get it tomarrow
are you running the stock 5.3 MAF? that might be the problem. need to go bigger! :)
so a MS4 in a 408?
im betting torque is around 415-422
your numbers are about right for that combo,enjoy your combo
I would think a bigger cam would be in order for those cubes.
Yes you are correct. The tq was 424, but still can't understand why its throwing a code one time at 6200 then the next time its not. And yes its still the 5.3 maf who makes a bigger one? Im not getting enough air threw it for the top endQuote:
Originally Posted by Quik
all the mafs are the same for the gmt800 trucks. if maf size is restriction time to go SDQuote:
Originally Posted by maze2525
So no one makes a bigger one for these trucks..... and y sd thought they went away from that for a reason.... just askn questions cause this kind of build is all new to me. Is it cause its n.a? I plan on turbo and cam for turbo later on. Is the sd what everyone doing for trunk also?
you can get a 100mm maf but what is the point? youre not going to gain performance from it, if you want to spend another few hundred dollars on a part that isnt going to gain you anything then go right ahead.Quote:
Originally Posted by maze2525
i was about to say the same on cam, being an ms4...like quik mentioned.....lol
good # enjoy your new found power
I agree with quik, throw the maf away and get a speed density tune. If you plan on the turbo, why waste the money finding a bigger maf? Turbos require an SD tune. SD tunes on non turbo/sc vehicles is an option that some prefer due to possible restrictions by the maf.
IIRC, Flaco does tons of MAF tunes on turbo trucks using a card type sensor. Mine is done SD but thats just how my tuner prefers to handle the tune.
dont forget that no matter what maf you have on a GMT800 truck the PCM is hard data at a set value. nothing is gained past that point then you use a half breed tune of maf/sd
on the GMT900 trucks its totally different
Can you explain the differences and how it works? I understand that the OS on the GMT900 is 3bar capable from what I've read. I also hear the MAF is good to much higher levels than the GMT800 one. In your opinion, what would be the best way to tune a NNBS turbo truck? I know Greg is full on SD, but I've read about a lot of the Vette and Camaro guys using the MAF.Quote:
Originally Posted by Quik
Can you elaborate further on this method, never heard about it?Quote:
Originally Posted by RedHeartbeat
Maybe Flaco will see this thread and reply. He has all the details on what and how he does it. He has some of the fastest trucks in the south so I can definitely trust his opinion. I believe he puts a C6 Corvette card type MAF sensor in a 4" tube and tunes it.
Greg, I emailed Flaco about it and this was his reply
"I use the cobalt map sensor. And the stock maff. We made 1001rwhp on one of my customers 370 with a stock intake and maff."
I seem to remember this build being posted on this site at some point.
Really? Maybe he has changed his method. I too emailed him a while back and his response was to use the card type MAF sensor. I guess we all evolve as we learn life's lessons. When did you email him, mine was after I installed the STS kit and needed help with getting the tune right.
I emailed him after I spoke with you via email. I asked if he was using the LS7 style MAF like others had and he said stock, so ....
Cool, I'd like to know what OS he's got a 2.5 bar tune for. I'd really like to be able to tune for 20+ PSI. :thumb:
According to the guys on HPT, the stock OS is good to 3bar with proper scaling.
What exactly do you mean by n-bar, n being an integer?
Quote:
Originally Posted by cjriojas
The ability for the OS to see N bars of psi and interperate it.
1 bar = 14.5037738 psi
2bar = 29 psi
1bar is good to around 10-12 psi of boost. It's good to leave a little left on the table. Most people go in increments of 10 in the boost world.
By bar, we are referring to the MAP sensor really. There are MAP sensors that read up to 3bars available for the GM OS.
Just not to confuse the guy asking the question.
2 bar is 14psi
3 bar is 29 (28)psi when speaking turbochargers/gauges/tire pressure, etc., zero referenced to atmosphere.
You're speaking of absolute pressure.
Don't forget, we live in a world that has an atmosphere, or at least some of us do :)
Sorry, I forgot. I'm used to the calculations I've done in Chem and Physics lately where it is asumed we are at 1 atm.Quote:
Originally Posted by farmtruc
was always under impressiong that 1 bar = 14.6, 2 bar was 29.2 which is 14.6 psi of boost, 3 bar is 43.5 [which is what most injectors are rated at] which is also 29 psi of boost
1 bar is atmospheric pressure at sea level. A column of air from sea level to the top of the atmosphere with a 1"x1" face weighs 14.6 pounds (this doesn't account for garbage in the air obviously). God damn I remembered something from school. So a 2 bar sensor reads 14.6 psi above atmospheric.
i didnt realize bar was referring to pressure, i thought it was something completely different :lol:
You're trying to identify 1bar, which you did correctly, however, when speaking in terms of boost/tire pressure/fuel pressure, it's assumed you're referencing atmosphere at zero, not absolute pressure, which is atmosphere added into the equation.Quote:
Originally Posted by Quik
1bar is what your stock engine is running at now, no pressure reading, 105kpa
2bar is 14psi - 210kpa VE table in hptuners, map sensor reads 14psi of boost (atmosphere + 1bar)
3bar is 29psi - 315kpa VE table in hptuners, map sensor reads 28psi of boost (atmosphere + 2bar)
etc...
I know, you know, what you're talking about when speaking boost/pressure/map sensor/bar, etc, just keeping it clear for those who are asking, because 2bar in relation to auto talk and fuel pressure isn't 29 (28) psi, it's 14psi.
I guess it just depends on how you're used to seeing it and calculating pressure, but almost everyone starts at zero, but when talking boost, assumes absolute pressure.
What a confusing thread.
I hope I didn't make any mistakes in this long post, hahaha.
No its understandable. I was just confusing my regular daily calculations (including fuel and tire pressure). I wasn't aware that boost was referenced differently.Quote:
Originally Posted by farmtruc
youre all stupid!!!!
is there a 4bar map sensor thatlll work on our trucks? :D
i believe MSD has one. now for you and your tuner im sure he knows. once you max out your giving map sensor you can still boost higher then that last row. you just have to edit that last row with higher tables for fueling. this is same way that Jared tunes hsi truck with 1 bar map sensor and going 9.6Quote:
Originally Posted by sprayedenali
Quote:
Originally Posted by pl4yboy
George, any opinion here?
i havent done a boosted GMT900 truck yet however seems as ppl are keeping the maf in the camaro and vettes. Id say if the maf is allowing you the room to go XX amount of psi without being maxed by a hard data value then i would do it that way. Now not sure if EFI has a better setup then HP as were still using Beta. Ive heard that the new 2.3 is going to have a actual VE table so that will help for sure. If i was going to boost my crew cab which may happen for now ill run the maf.
Now i know flaco does a good bit of newer trucks but not sure if he is using GMT800 pcms or notQuote:
Originally Posted by pl4yboy
Give me a second, I have the hard values for the new MAF's somewhere.Quote:
Originally Posted by Quik
4000 g/sec & a 15000 Hz limit. Also the IFR table allows up to a 127 lb hr injector.
Also found this little gem. May try using it sometime...
http://www.hptuners.com/forum/showth...t=bluecat+tool
on the truck we did 1001 whp was a 2008 model, and used a cobalt 2.5 bar map sensor with the stock maff, due to using the 100mm lingenfelter having some surging issues, we did 80# injectors with a return style fuel system and i cut the tables in half commanding 46.5 injector size all the way accross due to boost pressure regulator, and cut the maff table in half aswell as the adders, crancking fuel, etc...this helped a ton when boosting high, we are at 23 psi and still have not maxxed the maff, we still have a couple of #,s left before i start to look into the adders to command more fuel...
but over all it drives perfect and the only issue we have had is blowing the maff to peices a couple of times " being blowthrough " where the sensor goes has come out sometimes under boost, so we got a new one and took it appart and J/B weld it together and so far it has held together
i have used the card type sensor but lateley this is what i have been doing on the higher HP trucks
works very well
Flaco
The stock MAF on a 2008 is different than ours (George and I). We have the 2bolt Ford type. If I was to boost my truck, it would see 10 psi tops as a daily. Did you use the stock OS?Quote:
Originally Posted by flaco
something to think about. depending on the combo 10psi might be over 700 hp :)Quote:
Originally Posted by pl4yboy
it has the same frequenzy as the 08, 15000 hertz, but basicly can be done the same thing.....ive done a few times aswell, i have even rewired a 07 and 08 to accept a 2 bolt 09 style maff, on some trucks...Quote:
Originally Posted by pl4yboy
yes i used the stock OS, and running these on just the maf, extending it like that also give u more room before u enter REP mode on high boost,
it appears that on all trucks even OBS there is a limit on the PCM on grams per sec that can register before it does REP mode, which is 2.35, no more than that.....if u hit it it will shut the throttle no matter what.....we were bumping it at the 18 psi level before, by reducing the tables in half, the same 18 psi we were at 1.18-1.20..........soooo, thayt gave me way more room to go up on boost safeley, i also saw my maf table not get maxed out like before, so could go ahead and add fueling accordingly with the maff instead of adders