Boost Defuel after Overdrive Shift

[kzimmer]

Hey guys,

So I've been using a boost Defuel setting of 50psi. Works great. No matter what tune I run, boost ramps up quickly and sits about a needle width below 50 on my gauge, and 48psi on the quad. Beautiful.

 

Now that's where it stays until the 47re shifts from 3rd to OD. Canbus fuel must be clamped to a certain # in 3rd, and when OD takes over, rpms are much much lower (.69:1 instead of 1:1 gear ratio), so I've lost that much fuel. Boost drops significantly at this point. I haven't datalogged but I believe I'm losing more than 10 psi in overdrive.

 

The only option I have is to let off the go fast pedal and get back on it.

 

Any ideas?

[Me78569]

can you datalog it for me?  

[kzimmer]

Sure, next time I get the truck on the highway I'll hook my phone up and try to get a log.

[Me78569]

Thanks.  It is hard to say what it is, but hte defuel is coded to be a little lazy so it isn't jerking the truck around to try and keep a perfect psi.  

[kzimmer]

As far as I've noticed it works pretty much perfect if there's no upshift. It's only the 3rd to OD where boost drops.

[Me78569]

Yea I will be curious to see what the defuel sensor is doing while this happens.