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I have kind of a weird problem. I have a 2004 GTO LS1 with a P1SC Procharger. When I first purchased the car it had a lot of low end power and I was able to break the wheels loose in second with no problem. The only issue that I had with it was that the guy before me put a cheap Ebay RS BOV and it had a blown diaphragm.
Now, I noticed that I had a power steering pump leak so I had to remove the blower to gain access and rebuild it. I also thought that while I have the blower off I might as well get rid of the crappy BOV and install the TIAL (I made sure it had the green supercharger spring). I had no room to install it where the original BOV was to I welded that part closed and installed it right before the intercooler (which I have read was a good place for it).
With everything double checked and perfectly tight I started the car and man does it sound good! It sounds like a Wicked Whip when revving and letting off the gas .. My only problem like I mentioned in the first paragraph is that it now seems to lack power? I have a boost gauge and for some reason I only was producing 3 PSI as well? It did hold steady but I double checked everything and there is no boost leak.
Did I miss something when reinstalling everything? What do you think is going on? Any feedback would be appreciated. The air filter had one electrical clip going into the center of it that I did not put back on. I don't think that could be causing it?
Man, sounds like a boost leak, but if you checked for that, not sure what it could be. How much boost was it making before the change? Any idea how much power?
Thanks for the reply. Yes, you are right it does sound like a boost leak. The only thing that I checked was that the piping was tight. I know that a boost leak could be coming from anywhere but how do you diagnose it at home? Where are the usual places that boost leaks come from? By the way, this is my first time with an LS1 and a blower. Thanks
I thought about that to but TIAL only has 2 springs for their BOV's. I have the green one. Can you test it with the car off or on? How would I know if the valve is open when the car is on and not being revved? How can I diag this? Thanks
I have another idea. I have the vacuum line is running from the supplied Procharger metal attachment (not a T) that has the boost gauge running to it as well. Maybe there is not enough vacuum being generated to fully close the valve? The TIAL website stated that a 1/4" vacuum line must be run directly to the intake? If so, where should I hook it? www.tialsport.com/documents/w3_tial_qqr_sp.pdf This link should work?
The bov gets held closed with spring pressure and boost pressure when your on the gas.
It also gets helped opening when you close the throttle blade from the spring/vacuum/and boost pressure.
Soon as the tb blade closes and the motor goes back into vacuum in the intake manifold it begins to draw a vacuum on the diaphragm in the bov, at the same time the excess boost pressure in the charge piping helps force the valve open.
So yeah a good line running the intake manifold is needed. I originally had it hooked up to the barb for the evap line right behind tb. I later hooked up a vacuum block I got off ebay and used the same spot behind the tb for a reference line to the vac block.
I have the belt tensioned pretty well and I don't think its slipping but I am not sure how I would tell? I have the boost gauge hooked up and it stays steady at 3psi when I am on it. Although I did notice that the BOV does close to slow because it seems to act like a turbo lately with the boost slow at kicking in.
I guess I am going to try and find a better place for the vacuum line and take it from there.
Well, I checked the vacuum line and hooked it behind the throttle body. Now, my car is acting like it has a turbo? When I gun it in second it takes almost 2 seconds for the rear wheels to break loose. Is my BOV not closing all the way right away? Is my belt slipping and catching 2 seconds later every time? This is getting very frustrating! I feel like I am going in circles lol. Any other ideas?
EDIT: Although I do see it says : The supercharger spring is specifically for supercharged cars only. If you have a quick spooling turbo it can actually push the valve open briefly before the charge gets to the maniforld; dumping boost.
Sounds like what you've been experiencing with the lag.
you can disc. the vac line to the valve, it will stay closed, then test drive it
that will tell you if its the valve
if its ok then, that would belt slip or hose leak
if not using T bolt clamps, I have seen hoses slip off under boost, then slip back on off boost, driving people crazy
I tighten the spring loaded tens. until they give a good snap back on the belt
I took one apart once, so I would know how they work, why the need a lot of tension
Ok, I did find that the belt was slipping so I re-tentioned it and it is fine now. The lag is still happening though which is probably causing the rest of the problem.
I also think the vacuum line that I am using is to long and might be slightly to small in inner diameter (its a standard vacuum line and does not quite measure the 1/4" inner diameter that is recommended). I also really need somebody to show me another location idea for a vacuum line tap off the intake that is simple to do, (I think I tapped into the wrong line). Thanks again everybody for your help!
I run the one that is supplied with the Procharger but I also run my boost gauge from it as well. Tial recommends a dedicated vacuum line because it might cause a delay. I am getting a major delay when punching it of almost 2 seconds which almost feels like turbo lag.
I have read everywhere that people are tapping behind the throttle body but cant seem to find anything? Are there any easier locations beside the brake booster?
I run the one that is supplied with the Procharger but I also run my boost gauge from it as well. Tial recommends a dedicated vacuum line because it might cause a delay. I am getting a major delay when punching it of almost 2 seconds which almost feels like turbo lag.
I have read everywhere that people are tapping behind the throttle body but cant seem to find anything? Are there any easier locations beside the brake booster?
I just cut the brake booster hose in half, and then ran a "T" and ran a line straight to the dist. block. Took all of 5 mins. I looks clean, and has like 6 ports to run other stuff off.
This is what I have hooked up right now. It is the supplied splitter from Procharger that runs between the brake booster. It is an old picture so I now have the BOV line on the left and the boost gauge on the right. Should this be suitable to activate the BOV and the boost gauge? The line is pretty long but it needs to be to get it to reach the front of the car. What do you think?
09-05-2014, 07:51 PM
Procharger Loss Of Power With TIAL Q BOV? 
.. My only problem like I mentioned in the first paragraph is that it now seems to lack power? I have a boost gauge and for some reason I only was producing 3 PSI as well? It did hold steady but I double checked everything and there is no boost leak.
lol. Any other ideas? 
