Well I have reached out to several members for help and cant get anyone to respond so I'm reaching out to the forum for help. Im installing a LT4 supercharger on my l83 sierra. I am confused on a couple of things and I have searched everywhere for answers to no avail. So here it goes.

Where does the PCV port on the bottom of the supercharger hook up to? Does it go to thee pcv nipple under the throttle body on my l83? I have a catch can and it currently goes to to that nipple under the TB.

Which map sensor location is best to use? The rear location or the location near the TB? Ive labeled them on the picture below 1 and 2. I'll block off which ever one is not used. Also which map sensor is recommended to be used on this project?



is the LT4 TB plug and play into the l83 harness? Or do I need to buy a harness?

Lastly what is the purpose of this nipple of the lt4 supercharger and where does it go on a l83?

 

Very interested in this as well

 

I found one more nipple that I missed, that I dont know the purpose of see picture below. I drew a arrow to it.

 

Not sure about your PCV routing. Hard to know exactly how your catch can is configured. You need to watch the video below for possible PCV changes due to clearance. (Maybe you're using the tall adapter plates?)

You need to use #2 for your MAP sensor location. You can use a TMAP sensor which will give you IAT and MAP sensor combined. See the video below.
#1 is for the Throttle Inlet Absolute Pressure (TIAP) sensor. You won't need it.

You can probably use the nipple you have circled for your PCV system. You could also run the brake booster hose to that location and delete your vacuum pump.

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yes I am using the tall adapters, in the video he said he plugged the pcv port on bottom. I was thinking of running a vac line from the lt4 pcv port underneath to the catch can if its meant to be like a drain.

My catch can just goes from nipple under throttle body to nipple on driver side of intake manifold close to the coils.

any downside to deleting vacuum pump? If I were to tie it into my pcv system it would basically need to go to the catch can?
Also which port could I use for boost gauge?

I am having trouble finding the whipple harness for the lt4 map sensor. Cant find it anywhere

Thanks for your help

 

I was able to find the whipple harness and get prices from whipple for the lt4 map sensor plus iat Harness.

 

hey man I got all my questions answered on another forum. If you decide to go this route like i did I'll provide you any info I can.

 

to answer my own questions for anybody else who needs the info.

First question, the pcv port on the bottom of the supercharger can be tied into the pcv system. It will T in right where the pcv port is on the valley cover. You can also not use it and block it off. I think I'm going to use it because I don't want any build up of oil in the supercharger.

Second question. Use the rear port as another member stated above. Block off the front one with ICT billet plug.

Third question. Yes a lt4 tb is plug n play. You will need a extention harness though and you have to clock the TB to clear water pipe which is also sold by ICT billet.

Lastly the big nipple just above the TB. Just plug it.

 

This info is great, I just had a couple of questions. I am doing this same swap and I know you said you block off the front MAP sensor port, but what about the smaller port above that? I’ll include a pic


Also, is there a part number for the Whipple harness?

 

that is where your evap solenoid goes. I ended up going with crawford racing for the map/iat breakout harness. I did get the whipple part number as well though it's #104605