Hmmm, with the stock box and filter I was pretty spot on with LTFT's, 0 or -1 was what I was seeing across the board. Sigh, this makes me hesitant to even purchase charge piping...

 

here in AZ CAI is needed especially when its 120 outside it gets really hott in the engine compartment

 

These cars are way to sensitive about changes to the intake it seems. I have no boost loss or codes or apparent leaks but for some reason my LTFTs are off a few percent. Car runs a ton better now with the stock airbox back on though. Not as much KR as with the intake and no bog between shifts.

 

I'd like to hear what CIA's approach to this problem is with their SRI and CAI kits.

 

I would think they would be colaborating with Vince at Trifecta to make sure the cars LTFT and STFTs are close to stock. Lots of Data logging I Hope.

 

What if you where to put a screen or something like that infront of the MAF to like trick it? My friend has a speed6 and hes says this is talked about on there forums...

 

The screens have been used for a long time... but no one has one for our application... however if we were so inclined we could do something of the sorts.

Put the stock box and K&N back in and it made a world of difference.... Lost MAF flow, but my trims are now off a few % as well.

 

That would help straiten the airflow. I have thought of this too.

Put your stock MAF calibration table back and it should go back to 0 to -1. Car run better now? More responsive?

 

I did put the stock MAF cal back in the car... I sent you the log you can see for yourself. I have the K&N in (which I don't think matters much but it might)... But yes more responsive with less bogging. Weirdest thing ::shrugs::

 

I dont think you really lost flow. Your VE airflow was way less than MAF flow Your STFT were way negative when you were at WOT because of that disparity. Still spinning the tires hard? It seems the CPs may skew the MAF ( less flow restriction I guess) it seems like mine is having that issue. MY LTFTS are -4 or -5 right now. Compared to -9,-10 with the Dejon intake on. When I took my filter out of the stock box the fuel trims chaneged by 3-4% they went to negative -8. Weirdest thing. Who wants to be the first to SD tune this thing. This MAF is pissing me off right now.

 

mine were in the -2 to -4 range... I think it jumped to 7 once but that was an isolated incident

 

CP maybe. Mine are -4 or so with stock airbox and filter.

 

Iunno but I am getting tired of pulling off parts... Someone needs to make some **** that work properly.

Quit just thowing out parts because they fit... GM must have did these things for a reason and we are all finding those out now.

 

I'm sure the CP is directly related to it. I've got several logs pre-intake (stock CP and intake) with LTFT's at 0 or -1. It seems the general rule is 5 or -5 off is "OK" however? I'm just not comfortable with that; isn't your commanded AFR going to be skewed because the ECM is pulling from the last value on the LTFT table to accomplish it?

About to go out and do some logging, made some adjustments to the MAF calibration table.

 

bingo

post #18 has my feelings on the matter, GM seems to agree as they are saying the elbow is where the problem is in the intake(and what they were looking to change)... at this point, if I were a company... i'd be looking to release just the elbow, because as more and more of the word starts to get out, less and less CAIs will be bought... had you rather make $75-$100 off an elbow or $0 off a $300 kit no one buys? basic economics

its kind of like why you rarely ever saw CAIs for 4th gen LS1 f-bodies... everyone got an air lid for the stock box and called it good... and SLP, MTI, etc. were quick to put them out for $100...


and for the record, yes you can get a CAI for the LS1 f-bodies, they just make LESS power than a lid on the stock box... And if you do the math, SLP has made FAR more off their $100 air lid than K&N ever thought about for their $300 kit for the LS1, same principle would apply here

 

Yes your LTFTs will carry over to WOT. STFTs will not carry over to WOT.

 

I might have one this Saturday when I go to the track

 

We need to all get together (once HP tuners gives us the ability) and SD tune these things. Take the damn MAF out of the equation. MAF tunes suck on FI cars they are just too difficult to get calibrated IMHO.

I would really appreciate it man.

 

sorry if this is a noob question, what does SD tuning mean?

 

Speed density. Basically tune off the MAP sensors, load, and rpm no more MAF to worry about maxing out or skewing.

 

ahh the 93 transam i had was speed density...no MAF sensor...

 

Im curious if a test-rig intake that allowed you to easily rotate the MAF element would help sus things out.

I don't have any experience yet with these Bosch units, but the normal round GM MAF elements you can often pick up/lose power depending on how its clocked. Sure wish I owned HPTuners to do my own testing, but not feeling the expenditure right now.

To the SD point, that would be neat... and most likely doable. Hell I converted the 2003 5.3L (came from a Silverado) that I swapped into a little toyota pickup to SD. Was done with EFILive. I did that because there was no room between the radiator and throttle body for a MAF.

 

It might. There seems to be an issue with the time it takes for the intake air to pass through the CPs as well. LTFT seem to change when CP are added into the mix as well. Unsure about ICs at this point. We might need a MAF screen, but I am not sure if that will help or not.

 

Based on all I am reading, are you recommending that we don't do any aftermarket parts on the front end of the air flow (Intake, CP, Intercooler)...at least until we know more about these A/F ratios?

 

Good news! Well thus far, I've had great success calibrating the MAF. My laptop battery died within seconds of saving my log, however after 15-20 minutes of cruising and one or two WOT runs I am now seeing LTFT ranges of 0-3...Still doing some tweaking. KR has also subsided to 1 or 2 counts so I think I'm on the right track!

Not to mention the car drives SO much smoother! No more jerkiness. I'm still messing with it and I'll do some more logging after work.