Ok so looking to turbo my ls1 t/a soon and i need to figure out how to prep my ls1 for boost. heres acouple of things that came to mind. please add or lmk some feedback.

1. Brake booster. do I need to add a 1 way check valve? from my understanding booster works on vacuum and may be damage under boost?

2. plug the egr port on 98 ls1 intake.

3. add catch can and add a 1 way check valve on "dirty side" feed the "clean" to turbo filter.

4. how to secure the connection where the brake booster connect to intake manifold? mine you can turn less than 1/4 or a circle and feels loose. how do i boost prof this?

any others that i need to worry about / convert?

 

few other questions come to mind here, mainly how much pressure are you planning to run and what kind of emissions concerns do you have?

 

1.) Yes, you need a check valve on the brake booster. Every brake booster needs a check valve in order to "store" vacuum in the accumulator. Otherwise when the motor went out of vacuum you wouldn’t have any brake assist.
2.) Yes plug the EGR.
3.) Catch can is a good idea. Some use it as a crank case vent. In that case you don’t need a check valve. If your plumbing it back onto your intake to pull a vac at idle/cruise then you need a check valve.
4.) Are you talking about the barb insert on the back on the intake? I used structural silicon sealant around this. Then used push lock hose with a snug zip-tie to secure it. You don’t want to damage this piece. It is not sold separately by GM. You’d need to buy a new manifold to replace it. I pressure tested my whole system to 25psi with shop air and soapy water. I had no leaks in those areas.

 

your brake booster has a check valve mounted to it from the factory. nothing else needed.

you don't need to plug egr hole unless you are removing egr.

you need a check valve or checking pcv valve between intake manifold and crankcase, so that you don't put boost into the crankcase. Also you will need to relocate the fresh air inlet from the top of throttle body (plug or cap this), to in front of the compressor.

a catch can is not required for forced induction, but always a good idea, especially as hp increases so does blow-by that you will need to manage.

 

thanks for the reply guys. is there anything else i should do?

oh ok cool. i must have missed that when i drop the engine.

ok thanks.

and yes im planning on a "closed" system.im not understanding how this system would still be able to build pressure at below 20 psi.

the clean side will become the "dirty side" and pull air using the turbo under boost. so essentially the crankcase will always have a "vent" when in boost and when in vacuum.


thanks im not a fan of vented pcv so i diffinitely want to run it in a "closed" unit. is the pcv for this car inside the hose from the driver side valve cover? I dont think i see it mounted on the valve cover like im used to seeing it.

yes the back piece. im talking about where the red arrow is pointing. i think thats what your discribing. how did you removed it?

id like to clean it up before sealing it all up.



what kind of questions?

i want to be able to pressure test for atleast 20psi ideally 25psi.

but in reality i will be running only around 12-15psi.

i wont be worried about emissions. my custom install turbo wont be legal so im ditching anything i dont need.

 

the system will build pressure anytime more is coming in than is going out. just a few psi is too much.

sometimes a single line going to a restrictive catch can, and or coming from a restrictive fitting /too small fitting on the engine, is not enough flow. you will know it the first time you blow out the dipstick (or rear main seal)

 

Removing the “plug” is very difficult. You have to run a long dowel of some sort in through the TB inlet and push/pry the tabs holding it in place. It’s not easy and you risk breaking it. I’d just run some JB weld all around the seam and call it sealed. I saw very little leakage out of it with no sealant. Mine felt loose as you describe as well.