I am sure this has been on here multiple times although does anyone have a step by step process on how to perform this? I read multiple posts although really not a step by step. I understand whats needed(parts) But dont want to tackle this if Im going to perform it wrong. Your feedback is grealty appreciated. Thank you in advance.

 

Here's Markski's writeup.

https://www.6speedonline.com/forums/...cs-inside.html

 

Do yourself a favor and purchase the boost test kit from Markski
The kit makes it easy and worked great for me. Also the customer service you get from Markski is un paralleled.

 

i am assuming the best way to perform this test is at the turbos? My car sits so low to the ground i can not jack her up...have to bring her to the shop i guess ...unless there is another way?

 

You can drive up onto a piece of 2x4 or 2x6 to give you the clearance necessary to get the jack underneath it, or just buy a low profile jack.

 

As an owner of a 996TT, checking for boost leaks is a task every DIY'er really should learn to do. Setting up and pressurizing the boost system is the easy part. It can be done from the topside or underneath. Topside is a bit easier. Really, once you have done it once, you can repeat the topside setup in 10 minutes. If you find/hear leaks, at least you will have diagnosed or ruled out a problem.

The hard part can be finding and fixing the leaks. Some are easy to access and fix and you will be happy you took the time to fix those, while others are hard to find and are not easy to access. This is where you really get to know your car, which is a great benefit of being a DIY'er

 

@joe731 thanks for the information- how is the test done from the topside? What part of New York are you in?

 

To do the test from the topside, you have to remove your airbox (1 bolt between airbox and rear body, and loosen the clamp that secures the airbox to the 4" intake hose. Then rotate the airbox counterclockwise around 180-220 degrees and it will come out with little effort.

Then you need a "tool" to clamp into that 4" intake hose. I believe Marksee from 911 tuning sells one and it's probably very well made, but I (and others) fabricated one for less than $10 by going to Lowes/Home Depot and getting a 4" outside diameter PVC cap (check inside diameter size of intake hose before buying as I am doing this from memory), drilled a hole in it, screwed an air compressor quick release nozzle on it (use a pipe fitting nut to secure). Basically you are making a plug for that 4" intake and putting an air compressor fitting on it so you can pressurize your system to 15-20 lbs to see if it is leaking.

I could post a picture of it next weekend if you are interested in fabricating. Let me know if that would be helpful

 

Oh, and in answer to your question, I am in Gardiner, NY (near New Paltz).

 

Hopewell Junction NY here

 

Here is a picture of the simple plug I made to do boost leak testing from the topside. It is six pieces in total as follows:

1.) Charlotte Pipe 3" Cleanout Adapter Fitting (PVC schedule 40) Lowes # 23303 (FYI, this has an inside diameter of 3")
2.) Charlotte Pipe 3" Cleanout Plug Fitting (PVC schedule 40) Lowes #23307
3.) 1/4" Steel male threaded stud air fitting Lowes# 11303
4.) A rubber washer to fit on threaded side of fitting
5.) A washer to fit on threaded side of fitting
6.) A nut to fit on threaded side of fitting. The threads are pipe fittings, but I found that lamp nuts have same thread. I found the right nut in a local hardware store.

So putting this together is pretty self explanitory, but here are the basics
1.) Drill a 1/2" hole throug the center of part 2 just big enough to screw part 3 through part 2
2.) Screw part 3 through part 2 and secure with part 4 then 5 then 6
3.) coat part 2's threads with PVC cement and part 1's threads with PVC primer, then screw them together (let dry) (cement and primer are Lowes # 150887)
4.) Take some sand paper to the side of part 1 that goes into the intake to rough it up a little so the screw clamp will hold it better under pressure.

That's it. 10 minutes tops once you get the parts together.

This part goes into the air intake instead of the airbox.

 

Doing from the top airbox area will not allow you to boost it to 20 or 25 psi... pre turbo piping is not pressure sealed.... its doable but not as good as taking it at the turbos or the hoses to ICs after the turbo..... that's instant and immediate results....

 

Marksee, you are the master and I learned a lot about boost leak testing from your threads, so I cannot disagree with you that the bottom side, i.e., turbo outlets is better for discovering small/high pressure leaks.

That said, I have tested to 20 PSI from the topside and found it works as my pre-turbo intake piping seems to hold 20 PSI.

Since I am doing a little DIY, here are the parts and pictures for making the bottom side tools

1.) Two 2" Lasco 2" PVC Plugs (lowes # 51457)
2.) Two 2" Flexible Couplings (lowes # 23473)
Parts 3-6 from earlier topside post (fitting washers and nut)

Assembly is super easy
1.) Install a fitting in one of the plugs as described in my topside post
2.) sandpaper couplers to rough up a bit then put the plugs in the rubber couplers and tighten clamps

To use, attach these to the output sides of your turbos (disconnect hoses from the intercooler to turbo and attach one of these to each turbo). Going via the bottom side is a little bit more of a PITA because if you don't have a lift it's easiest to jack the rear of the car and remove the wheels for easier access.

 

I've done it the way Joe has..tested it from the top..at the airbox. I also tested at 25psi with no problems...lucky I guess. I made the same "tool" for about $15 from Home Cheapo. I think I gave it to another forum member after I sold my car...

 

this is what i think is confusing me. by plugging the output of one turbo and blowing compressed air into the outlet of the other turbo are you blowing the air thru the turbo into the exhaust and engine and then into all the vacuum lines and tubing?