I just installed a 100mm MAF from Ligenfelter. I changed the maf readings to the amounts provided by Ligenfelter.

Should I be worried about running this w/o a retune? I previously had an 85mm maf from slp.

thanks

 

I probably wouldn't trust their canned values at WOT without some sort of way to verify the air/fuel ratio...I would certainly want that checked before I went out and beat the snot out of it.

 

Was the 85mm MAF table re-scaled when you installed it? A re-tune is probably best, in order to check the MAF table settings, unless you have a wideband 02 sensor & can confirm A/F ratios @ WOT. Although, you are probably OK. It's best not to chance it.

 

Don't chance it, have it tuned again.

 

You MUST retune for a new MAF, no questions, its a FACT!!! The Lingenfelter tables are a base just to get you close and running so you can tune immediatly. The LPE MAF is a little harder to tune for idle, they will tell you that themselves.

I prefer the new LS3/LS7 card style MAF myself (I have both). Haltech makes a nice housing for it and everything. It works great at idle, since its an OEM piece, the only problem is the IAT is scaled a little differently, so you have to either reuse your old IAT or HPTuners has now built in a place for you to fix the IAT error.

Edit: IIRC the LPE MAF has the same IAT difference as well!

 

It definitely does.

 

Why doesn't Lingenfelter let their customer know this? The scaling of the MAF is related to the MAF itself. Are you suggesting that Lingenfelter doesn't understand the scaling of their own MAF? Main reason to have to re-scale the MAF after having loaded the Lingenfelter tables would be to correct flaws in the tune that existed in the car before installing the new MAF. If the IAT needs to be re-scaled, then the new scale needs to be provided for by Lingenfelter. Something is f'ck up here. Why would Lingenfelter provide a scaling table for the MAF frequencies that are not correct for the MAF?

 

Because every car is different and runs different Air Mass/LTFT/STFT/error %s per give freqency based on quite a few different reasons. They give you the scale to begin with so you can work from there. Its a head start in the right direction.

Its def not that Lingenfelter does not understand the scaling of their own MAF, its that they will not know how much air your car wants. You cannot expect them to.

 

Would think the fuel trims would self correct. That's why they are there, no? In regards to air mass, MAP, MAF, IAT & ECT should provide enough information to know what it is. The PCM uses IAC, IAT, MAF, MAP, ECT, spark, 02 sensors & has the ability to correct by using LTFT & STFT for idle & normal driving. Further, the PCM uses MAF, MAP, ECT, spark for WOT, of which has PE as a back up. Maybe the reason I don't see issues like you're describing is 'cuz I run OL/MAF.

Only reason I can see for needing a new tune is if the previous MAF had been a restriction which isn't the case during idle or normal driving. Could be the case @ WOT, but, depends. Even if it were a restriction @ WOT, wouldn't be enough to cause a dangerously lean condition.

 

Sure would be an issue at WOT if it isn't scaled properly, stock restriction or not.

Even clocking the MAF (rotating it) can affect the readings, which thereby would technically necessitate a tune!

 

Also, at some point the customer has to have some grain of knowledge especially when it come to changing sensors that are absolutely critical. This is where you ask questions first, then decide if this is a swap you should tackle on your own or not.

MAFs are almost stupid simple to tune once you done it a time or two, or watched someone else.

 

Where did anyone say the MAF didn't need to be re-scaled? There's a difference between re-scaling & re-tuning.

Good heavens..hate to think what would happen should the car hit a bump, LOL. Guess we should drive around w/ our tuning software hooked up, just in case.

 

Rescale, retune, same difference. Every engine is different and requires a different scale/tune. Everyone agrees, the data they give is just to get you started.

 

As mentioned, what do you think part of the tune process is? Scaling the MAF.... And you can't do that with preset value provided to you. A proper MAF scaling is specific to every car/combination.

If your MAF is jostling around while you are driving, you have much bigger problems than the tune.... If you are serious with your second comment then I have lost hope for the power of the human mind.

 

Thanks for the info. I did rescale the 85mm from information provided by an LS1tech member. I tried running it yesterday. Throttle response seemed to be much better. At the top end it felt a little funny so I took it off (didn't want to ruin my motor). When I did I noticed the Maf had come out of the lid which may have been the reason it felt funny. The opening of the lid kind of sucks. I guess that I need to complete a wide band install before I try it again.

 

You can use your narrow bands to get your idle and cruise areas close. I perfer a wideband myself.

WOT has to be done with a wideband since the car goes into open loop.

 

Have you ever seen a stock car try to tune itself on a datalogger? It is pretty pathetic. The PCM has little ability at all to correct for any change really. I can put it like this. The computer will try to compensate for X part by going to a -15% LTFT. Just in case some people do not know what that means, it means over a normal setting, it is pulling 15% of the fuel relegated by the adaptation of the long term fuel trim because it believes that the engine is running too rich via the narrow band oxygen sensors. If you think it is perfectly fine for that, just try to drive one that is doing that. After 2 mins in the car, you will smell like fuel. EVERYTHING in the car and around it will smell like fuel.

The PCM is just not that smart.

 

OK, I was wrong. Didn't realize that most consider a re-scale a tune. Yes, I've seen a stock PCM try & tune itself. My statements were made considering that the Lingenfelter scaling was close enough for the PCM to be able to handle. In this threas, the people who have experienced the major differences between their scaling & what the PCM can handle have stated that the PAM cannot, including you. It's just surprising to me. I know how much a head, cam, intake, TB mod changes everything about the tune & requires a full tune. I'm still pretty much shocked, 'cuz @ WOT we're talking 375 g/s & 4000 RPM & above would most likely have a very conservative frequency setting in the MAF scaling from the manufacturer. Understood... we have to rescale even w/ the manufacturers table.

 

If the MAF error % is any amount really, the computer does not learn that. You have to program it. It will only try to compensate with LTFTs and STFTs. But that is a horrible bandaid.

The MAF works differently so it has to be changed. As was said. Both in the HZ of the MAF itself and the IAT settings. Both of those are huge as to how a car runs.

 

OK, thanks for clearing that up.