Who's running Open Loop with a MAF?
 

I am. After the problems with my narrow-band O2 sensors, I got my speed density tune really good with the wideband. I even leaned out the cruising cells so I'm closer to 15.0:1 A/F ratio so I can pick up a little fuel economy.

Since I've been wanting to run a dry shot again, I went ahead and rescaled my MAF and now I'm running 100% open loop, but with a MAF. Am I one of hundreds doing this or am I alone?

There are a few others out there.

I am for the same reason (dry shot)...

i didnt get to choose, but when i brought it to speed inc to get a basic tune, they put the car on open loop w/ maf. i herd havin ur car on open loop does not make the car ever run the same again. maybe speed inc can chime in on this one. i plan on tuning my car through speed density and leaving the pcm on closed loop

Im running open loop - MAF and loving it. I feel that the MAF has improved drivability. im not worried about it being a restriction as its hogged out pretty darn good.

I have two cars running in this method. narrowband o2's are not pratical in all situations. I nailed down the ve tables then maf. They run great with OL and maf. For awhile it seemed I was the only one doing it too.

I really like the advantage of having kick-ass VE tables to reference and also the ability to run a form of lean cruise. The MAF just gives me a little more flexibility and also enables me to run the sneaky dry shot. I knew I was running these big injectors for a reason, haha.

I've not dealt with MAF for a long time now, but smog time is here again and I'm trying to dial it in, and I'm having major issues--which is funny considering I invented MAF calibration process.

My main reason for staying away from it is that a VE table is just so much more descriptive: you have pressure and engine speed, two major influences. this way you know exactly the conditions that are going on in the engine. With MAF all I got is like 6000Hz--what does that mean? But at the same time, if you hit a 5000rpm/70kPa cell on SD, it's also gonna just calculated to some airflow number, still not yielding any extra information like is it in the process of accelerating or decelerating, and so on.

The good part of SD that it's easy no nail the whole range. MAF is very easy, precise and consistant under more load, but at idle and right off idle, it's very messy and unprecise, making tuning difficult. that's why probably GM decided to give us a hybrid maf/sd mode for the low rpm/light load situations.

Right now I'm Open Loop SD. But I've spent most of my time Open Loop though the MAF.
I haven't been closed loop since the early NoGo-VE tuning days. Since the july 2003 thread -> "Changed VE Table now i have a slight Hesitation!". :D

you can run the dry kit without the maf as well.

How do you trigger the proper ammount of fuel? Are you using the IAT trick to add fuel / pull spark when you spray?

I have done countless cars OL with a MAF. It is easy to dial it in when you use the AFR BEN's just like we do on the VE table.

i was OL with a MAF to dial stuff in and I was running it that way for a while. I liked it. now i'm CL though.

Just curious when did you invent the MAF calibration process?

Ryan

He was the guy who produced the MAF calibration spreadsheet way before HPTuners or anyone else had built in functionality for it. I dont think he meant the original GM calibration process...

if you wanted closed loop and a leaner mixture u could also adjust the o2 switchpoints. i run about 15.5:1 im still working on getting the o2s to move a lil better at idle..........

:lol: The correct way IMO is to use a AFR% error. This was thought of by HumpinSS and tested by myself. I don't uses spreadsheets anymore when all is available in EFILive.

Chad, what do you do for cold and warm starts with the MAF? ive tried it, but ive had issues with it hunting and searching for idle :mad: (not trying to hijack Pat) ;)

I've never tried doing a MAF tune...I've been SD since I started tuning. It ran so well, I figured why change? I did, however, have to switch to open loop when my O2 sensors took a dump, and I haven't looked back. I love how stable it is, and I monitor the A/F ratio with my wideband full time with my XD-16 gauge. It is always right where I want it.

That being said, I now have a full custom intake setup, and the IAT sensor isn't even close to the engine anymore, so I don't have the lean restart issues I used to have. It works great for me, and the car runs strong (for what it is).

Honestly, I don't do anything different. Just make sure you have the proper airflow, timing and AFR. Once those three are correct, they startup everytime.