Vacuum lines for turbo engine

[Velix]

Hey everyone, I’m looking for advice on vacuum line routing for a busa. I have the factory manual, but for a turbo ITB engine not running pair valve setup or iac system, I’m not finding the info I need online.

I’m thinking I would just run from the throttle bodies to blow off valve for one line. From intake to boost control (or maybe this should be taken right off the turbo?)

 

[202mphbusa]

Hey everyone, I’m looking for advice on vacuum line routing for a busa. I have the factory manual, but for a turbo ITB engine not running pair valve setup or iac system, I’m not finding the info I need online.

I’m thinking I would just run from the throttle bodies to blow off valve for one line. From intake to boost control (or maybe this should be taken right off the turbo?)

View attachment 1627103
View attachment 1627104
View attachment 1627105

Tee ALL four throttle bodie hoses into one that goes to the map sensor AND the BOV
Wastegate feed off either the outlet of the compressor if there is a hole and it is threaded, or like mine wastegate is direct off plenum pressure

 

[Boosted Cycle Perf]

Nailed it^^

 

[Velix]

Tee ALL four throttle bodie hoses into one that goes to the map sensor AND the BOV
Wastegate feed off either the outlet of the compressor if there is a hole and it is threaded, or like mine wastegate is direct off plenum pressure

Thanks! Is there a response difference when using the plenum vs the compressor?

 

[202mphbusa]

Thanks! Is there a response difference when using the plenum vs the compressor?

to be honest I have never had mine connected to the compressor

 

[moko]

i have all 4 tb together,with 1 to map.

bov to intake after tb butterfly

wastegate to compressor....but i like idea of it to plenum.

 

[Dustin02]

 

[Dustin02]

This should simplify things...

 

[202mphbusa]

BOV really needs vacum and boost
"bov to intake after tb butterfly"
Not 100% sure what this means

 

[Dustin02]

I think he has it correct. It's tee'd to the lines at the throttle bodies which is post butterfly.

 

[Velix]

This should simplify things...

Thanks! I figured that’s what I needed, but nice to get a visual. I’ll probably be using the plenum though as it makes things a little cleaner in my case.

 

[Dustin02]

That's what we all do. Works just fine.

 

[moko]

yes...I have them post tb's

 

[Velix]

Thanks again for the help everyone!

Could anyone tell me the banjo bolt size for oil line off the block that goes to the tensioner off hand? Need to order a jic adapter for turbo feed line.

 

[Velix]

Just working on the video for this week, but I thought you all might enjoy a sneak peek!

Welding the AN fittings on the throttle bodies wasn’t fun, and still needs a bunch of cleanup.