Boost leak test... results

[NateS]

Okay so I finally got around to making a boost leak tester as found on ( http://www.vfaq.com/mods/ICtester.html ). I got it all together and started putting pressure it in and it would only hold 5psi for a very short amount of time (wierd considering I'm running 16psi). Right away I noticed a HUGE leak coming from the TB area. I also found a small leak coming from my BOV gasket so, I used some liquid gasket and fixed it first. The leak coming from the TB area seemed to be coming from the TB gasket to the IC elbow. I used the liquid gasket and sealed it back up. However, the leak was still loud as hell and I could not tell where it was coming from other than the TB area. I was feeling around and I found that the vacume line on the backside of the TB was not there and the air was rushing out of it. I found the missing vacume line hanging in the engine bay and put it on. I then re-tested first at 10psi, then 15psi, then I stopped after 22psi. My tester couldn't hold more than 22psi because, I did not seal the valve stem in completely, which I am doing now. This is pretty good considering it is the FMIC from ssautochrome and that I am using a few worm clamps untill I get unlazyfied and order t-bolt clamps.

Only question I have is, what is the vacume line that was disconnected from the TB? It was the vacume line directly behind the TB. The part where the line connects is very long probably like an inch or so.

[scottsee]

I have the same problem with my ssautochrome fmic on the UICP/TB. I bought 2 of the tb/tb elbow & tb/intake gaskets. I'm going to try and double up on the gaskets see if I can get away with doing that for a little while before getting my UICP flange milled flat.

[NateS]

Sorry I think you miss understood me or I typed it wrong but, the TB elbow - TB gasket was not the problem. I thought it was but, it was actually the vacume line on the back side of the TB that was making the noise. So, basically I sealed the gasket for nothing haha. The entire setup sounded leak proof as far as I could tell but, it was kind of hard to hear over the leaking boost leak tester. I will re test probably tommarow and update this post.

[scottsee]

Yeah, looks like I did.

[NateS]

Yes. Does anyone know what that vacume line is for? It was apparently unplugged for a long time and I didn't notice any performance loss or gain when I put it back on. BTW I plan to test around 25psi tommarow so, I'll be sure to leave a post on how it goes. Maybe I'll go to 30psi if I feel lucky. haha.

[1stGenRocks]

you should have noticed a difference in idle speed/smoothness. just to be safe i usually zip tie all my vac hoses.

[NateS]

So that vacume controled part of my idle? BTW I also noticed that the screw( I think it controls idle) that is on the front part of the TB was leaking a little bit when I did my boost test. I used soapy water on my TB and various other spots to help pin point leaks. The screw I'm talking about deffinatly blew bubbles. Is this normal?

[defiancy]

Depends, On the TB most of the nippes are for EGR. On my gsx I have them all blocked off. I think if memory servers correct there is only one or maybe not one at all on the TB that you need period. If I had my car I could tell you.

[kjewer1]

Definitely some emissions crap. I had similar issues with certain lines, for the charcoal/evap canister in my case. There are a lot of solenoids and valves back there, it is very possible to have a leak under boost, but not under vacuum, so idle won't be affected. It wasn't in my case mentioned above. At any rate, good fix. Always a good thing

To explain your comment about the 5 psi thing, when you could run 16 psi, the turbo is a MUUCH better air pump than a compressor going through a tiny schreader valve, it just makes up for the lost air. The result is the correct boost, but running too rich (metered air escaping the closed system), costing you power. My above mentioned leak was worth a consistent and repeatable 5 tenths and 5 mph. Roughly the same gain I get from switching to race gas and cranking the boost up Always worthwhile to fix those little leaks.

[gstclips]

I found that using a hose and holding it one end next to my ear and moving the other end around the engine comartment works quite well when testing for boost leaks...works very well for pin pointing small leaks...

[Eclipse4ever]

Wow I gotta meke one of those too. I dont think I have a boost leak but then again I cant get over 7-9psi so .

[NateS]

Yeah the boost leak tester is deffinatly a nifty little tool to have around. Even if you don't think you have a boost leak it is still a good idea to test it.