LS3 Air Intake

[mbisett]

Never Mind - I found the info I was needing.

I am working on a Blueprint LS3 package. I realized that the package did not come with an air intake kit so I ordered one from BP. The kit contained a 90 degree pipe that had a MAF receptacle, vacuum nipple with cap. Id also came with a small vacuum hose and other misc. fittings and clamps. I don't believe I need the MAF because it is already mounted on the engine. I don't know if I need to use the nipple on the 90 or where the vacuum hose should go or if is even needed.

This is my first LS install and now often left wondering if it was the right choice but I do love a challenge.

[PNWTim]

Your MAF should not be mounted on the engine? It is typically mounted on a boss welded to the intake pipe (ideally in a straight section). Can you post a picture?

[lewma]

Your MAP is mounted on the manifold. Your MAF needs to be mounted on the air intake behind the filter. Blueprint should have provided the MAF sensor along with instructions on where to mount it. Make sure you leave enough room between the air filter and your first bend in the pipe. There needs to be a good number of inches of straight pipe. The instructions show this too.

You can take a look in my pic gallery in my signature to see how I mounted mine.

mark

[edwardb]

The LS3 crate in my truck build most definitely required a MAF sensor in the intake. Pictured here. Did your engine come with the Chevrolet Performance electronics package? If so, the sensor was included and the instructions explain it all. The LS3 also has a unique to them steam pipe that goes from the intake to the radiator plumbing. There are several ways to plumb it. How I did mine is visible in this same picture.

https://thefactoryfiveforum.com/attachment.php?attachmentid=154898&d=1635386853

[Chris H.]

I'm not very familiar with Blue Print, what ECU are you using? I know holley doesn't require a MAF sensor, just MAP. I have a filter directly mounted to my throttle body. The nipple is most likely for the PCV/Breather line. I'm running a catch can so I'm not blowing oil into my intake.

[edwardb]

The LS3 crate in my truck build most definitely required a MAF sensor in the intake. Pictured here. Did your engine come with the Chevrolet Performance electronics package? If so, the sensor was included and the instructions explain it all. The LS3 also has a unique to them steam pipe that goes from the intake to the radiator plumbing. There are several ways to plumb it. How I did mine is visible in this same picture.


I'm not very familiar with Blue Print, what ECU are you using? I know holley doesn't require a MAF sensor, just MAP. I have a filter directly mounted to my throttle body. The nipple is most likely for the PCV/Breather line. I'm running a catch can so I'm not blowing oil into my intake.

My response assumed (and we all know what that can mean sometimes...) a GM factory intake, ECU, etc. If that's the case, what I posted is correct. Been there done that. Specifically the Chevrolet Performance 19370416 LS3 430 HP crate motor installed in my truck build was with the Chevrolet Performance 19354328 LS2/LS3 Gen4 Engine Controller Kit. However, after looking at the Blueprint website, I see many of their LS offerings use Holley Terminator components. I'm not familiar with what that means so my answer may not be correct in this case.

[lewma]

BluePrint ship their LS3 engines with a MAF only tune ( at least mine was shipped this way ). I then had to work with a tuner to disable the MAF sensor, tune VVE using the MAP sensor, then enable the MAF again. The GM ECU adjusts fueling using a dynamic air method of combining MAF and MAP readings depending on engine, and power demand conditions. Mine is set to switch over to MAF at 4000rpm ( but the ECU still considers both sensors all the time ). We did this due to the cam that is in the engine. The MAP sensor is more accurate at idle and lower rpms.

I do know that some tunes have the MAF sensor completely disabled and run on VVE/MAP only.

[Its Bruce]

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