MAF and MAP on 2007 LBZ

Terminal Angler

New member
Jan 21, 2022
2
1
3
hey Guys,
I'm new to the forum but have been building a custom 2007 Duramax 2500 4x4 with a 1951 Chevy COE over it for a few years now. A lot of details but in a nutshell:
~ i cut the crew cab frame from 153" to 98" and changed the rear suspension from leafs to a 4 link with coils overs & airbags
~ tilted the bed and cab hydraulically
~ took the turbo OUT of the valley and put it down along side of the Allson on the passenger side. It uses a water to air intercooler with custom SS piping & rad
~ 53 gallon fuel tank is behind the rear end
~ im working on the steering system and have decided to try a hydraulic motor set up like a marine application
~ FASS 165 lift pump directly to the CP3
~ Front facing thermostat housing from a van set up
~ working on the intake and fuel system and have some questions about what is best

I have an aluminum intake horn from (i think) an LML engine that needs to be piped to a cold area (remember the turbo is down along side the Allison).
Do i need to weld in a bung for the MAF and MAP sensors somewhere in the intake piping? Is there a best place & or order to do this? Are the MAF & MAP absolutely necessary? Im pretty sure they are but if not are they the best thing to do to get info to the ECM and have a proper running 6.6 LBZ?
Hope that's not too confusing and that this is explained in some semi understandable way.
Thanks,
Dave
 

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Lazariko

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Dec 24, 2025
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Australia
Yes, you want both sensors. On an LBZ, the MAP is absolutely required and should stay in the intake manifold (or very close to it) so the ECM sees true boost/air density.
 

Terminal Angler

New member
Jan 21, 2022
2
1
3
Yes, you want both sensors. On an LBZ, the MAP is absolutely required and should stay in the intake manifold (or very close to it) so the ECM sees true boost/air density.
My turbo sits below the engine now. Should I just weld in a bung for the MAP to the stainless pipe going to the Y bridge?
See foto
 

Bdsankey

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Feb 1, 2018
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Larsen, Wisconsin
You will want both MAF and MAP, use only OEM GM sensors.

MAF will go pre-turbocharger in the supply tube to the turbocharger in the middle of the straightest section of that pipe.
MAP will go post-intercooler so anywhere on that pipe/intake horn is just fine.
 

Jakezed22

Active member
Dec 2, 2016
329
178
43
hey Guys,
I'm new to the forum but have been building a custom 2007 Duramax 2500 4x4 with a 1951 Chevy COE over it for a few years now. A lot of details but in a nutshell:
~ i cut the crew cab frame from 153" to 98" and changed the rear suspension from leafs to a 4 link with coils overs & airbags
~ tilted the bed and cab hydraulically
~ took the turbo OUT of the valley and put it down along side of the Allson on the passenger side. It uses a water to air intercooler with custom SS piping & rad
~ 53 gallon fuel tank is behind the rear end
~ im working on the steering system and have decided to try a hydraulic motor set up like a marine application
~ FASS 165 lift pump directly to the CP3
~ Front facing thermostat housing from a van set up
~ working on the intake and fuel system and have some questions about what is best

I have an aluminum intake horn from (i think) an LML engine that needs to be piped to a cold area (remember the turbo is down along side the Allison).
Do i need to weld in a bung for the MAF and MAP sensors somewhere in the intake piping? Is there a best place & or order to do this? Are the MAF & MAP absolutely necessary? Im pretty sure they are but if not are they the best thing to do to get info to the ECM and have a proper running 6.6 LBZ?
Hope that's not too confusing and that this is explained in some semi understandable way.
Thanks,
Dave
That is some really unique turbo mounting and plumbing, looks great!

This is something im also questioning for my swap. I know MAF is critical, although i have played around with tuning it out for research purposes, with it removed your essentially running fuel map at a 1-1 with throttle input and therefore it actually becomes easy to "flood" or stall the turbo. Was fun for a weekend lol.

As far as MAP, someone please chime in here, Is it still necessary when ditching the variable vane turbo? I thought i read somewhere that its main purpose is for vane position.