Jump to content
Sign in to follow this  
Bowtie70SS

FI VE tuning, MAF scaling

Recommended Posts

I am new to the HP tuners scene. I have version 2.1 and am learning my way around pretty well. I understand the concept of tuning the LTFT's with the MAF disabled to get your VE table in line. However, this is where I kind of lose it...I was told not to disable the MAF since I have a blower (radix). This dosen't make sense to me because I should be running off of the PE table once I hit boost (I changed PE enable to 37% about 3% before I hit boost). I have been logging and changing things in the VE table and my LTFT's are mostly 0 to -3 but this is with the MAF hooked up. Scaling the MAF table affects the fuel trims correct? If my trims are that close do I need to worry about it? I have been looking and just haven't found a good article on scaling the MAF for FI. Thanks.

 

Dave

Share this post


Link to post
Share on other sites

Yes, changing the MAF table will affect the fuel trims.

 

When in PE mode, the PCM will use the MAF for fueling.

 

To accurately dial in your tune (VE, MAF & PE), you should get a wideband O2 sensor. It's the best $300 performance investment you can make.

Edited by SinisterSS

Share this post


Link to post
Share on other sites

A wideband is in the works. I am kind of looking for a procedure. If I hit PE mode and the commanded AFR is not equal to the wideband then the MAF would need to be scaled accordingly? There sure is a lot to learn as far as tuning goes, but I think it will be well worth it in the end. Thanks

 

Dave

Share this post


Link to post
Share on other sites

It was more of a question...What situation would cause the need to rescale the MAF? I have been pouring over a whole lot of tuning info, but there again what/who do I believe present company excluded. I have a new O2 sensor on order right now, my LTFT's are between 2 and 6 numbers off(difference between the 2) and I have been watching B2 sensor 1 (Bosch) and it dosen't seem to switch near like B1, an original GM one with 60k on it. I'm gonna change it as soon as it comes in so I can tune more.

 

Dave

Share this post


Link to post
Share on other sites

Rescaling the MAF is necessary for accuracy's sake, especially with a blower.

 

The wideband is used to dial in the VE in speed density mode. Then renable the MAF and calibrate the MAF. With those things done, what you put for an A:F at WOT will be what is delivered.

Share this post


Link to post
Share on other sites
Why would you scale the maf to fix that?

 

If he's commanding 12.0 in PE mode at, say, 4400rpms, and he's seeing 12.5, logic would dictate that the MAF calibration is out of calibration by around 4%...

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×