Hey all,

I'm wrapping up my FAST 92/90 install on my 2002 Z06. Last piece of the puzzle is re-routing my PCV set-up as the LS2 TB doesn't have a port for the PCV. I also have a catch can installed.

I was going to route my set-up just like Mark (Toque), but I'd like to try and avoid any potential vacuum leaks. Here's his set-up:



My concern is the hose/end assembly going into the air coupler. He doesn't seem to be having any issues but it concerns me since that hole is nearly an inch wide and getting a good seal there is very important.

So I did some research and found this neat little fitting:

http://www.atpturbo.com/mm5/merchant...egory_Code=BCS

My concern with that fitting though is that it might be too small to allow the PCV system to breathe and allow good airflow. It says to punch a 5/16" (8mm) hole into the air coupler if that helps...

Can anyone help with input on that matter?

Another option I've seen is some people have simply installed a breather filter on the passenger side valve cover. Something like this:

http://www.autozone.com/autozone/acc...er=480746_0_0_



I'm not sure if that exact one would work, or what pros/cons to this set-up vs. into the air coupler there are - any insight would be greatly appreciated. If anyone has a specific part # for a breather filter that would work, I'm all ears...

I have a tune scheduled on June 10th and this is the last piece of the install I absolutely need to wrap up.

Thanks for all the help!

 

 

Since you have an 02 you could upgrade the 04 valley cover to eliminate the external PCV valve. I think if you sealed the grommet with some kind of glue/silicone/etc. it'd seal just fine. Every car I've seen with a breather on the valley cover emits oil mist all over the motor.

 

Or he could install the fixed orifice PCV "valve". It looks like the original spring loaded PCV valve, but it just has a 2.5 mm orifice in it like the 04 valley cover tube has.

http://forums.corvetteforum.com/c5-t...pcv-valve.html

 

Right now I'm not as concerned about my valley PCV setup because I have that running to my catch can and to the FAST intake manifold.

What I'm trying to figure out is the best method for the passenger side valley cover since the LS2 TB doesn't have the port that the LS6 TB does.

I'm considering either using a method similar to Toque where I obtain vacuum from the coupler to the TB or possibly Y'ing into my catch can and using the intake manifold as my single source of vacuum.

Another issue I thought of though - and this would apply to just about everyone and not just me. When you install a catch can, you remove the hose that has the inline PCV valve in it - but all the installs I've seen don't re-use the PCV valve.

See below - that's the OEM set-up with the inline PCV valve.



Here's Mark's, and just about everyone else's install:



Why don't we re-use the PCV valve? That doesn't seem right. I have to be missing something though as literally everyone else runs their catch can set-up this way.

Any help would be great here, otherwise I'll talk to my tuner and see if he can offer any advice...

 

Mark doesn't have a PCV valve on his catch can setup because his z06 is a 2004 so his valley cover has a built in PCV valve. 2004 was the only year to have this PCV setup on a Gen 3 motor. If you don't want to drill a hole in your bellow you could try your "y" setup going to your catch can to see if that works. You could also try to "y" it where the catch can goes to the intake manifold at that "tit". I have the setup as Mark except I'm running a FAST 78 so I kept my stock throttle body.

 

Mine is very similar to your first photo. The piece you found looks pretty good and I might of used it had I known at the time I did mine. The air inlet side is only to provide filtered air to the motor internals and the size in your first photo doesn't differ much from the stock size from the throttle body.

The valley cover I have installed is the later self metering and I run that through the catch can into the intake manifold. Fresh air is provided similar to your picture from Toque. I have never had an issue with it.

I don't like the breather idea because the air coming in is not metered by the MAF.

 

Just did a little more research and found that you do need to keep the PCV valve in the original location when installing a catch can. After seeing a lot of installs done, I hadn't seen any that kept the PCV valve in place so maybe all I found were 2004 LS6 installs haha. OK, that issue's out of the way so glad to hear that.

Found this little diagram which I'll re-route for my catch can:



So, that's one issue out of the way...

As for the rest of the PCV system, I may try to Y it, or I may try the ATP fitting when it arrives. I forwarded this all to my tuner to get his thoughts on the best way to run it as well. I'll be sure to report back.

I'm not huge on the breather idea either, but I did see others running it so figured I'd include it here. If most of you are running it the way Mark is and not having issues then I feel more comfortable going that route.

Appreciate the help everyone. Always open to more insight but I think I have a better grasp on all this now...

 

I use the PCV valve between the catch-can and the intake manifold. You just need to re-use the PCV valve "holder" and come up with the right hose setup. As discussed earlier, I replaced the spring loaded PCV valve with the fixed orifice style, which fits in the same holder.

 

Yep, that's because 2004+ don't have a PCV valve, but instead the fixed orifice built INTO the nipple on the RH front corner of the valley cover.

I see you found the setup I was saying to use to retain the PCV valve between the catch-can and the intake manifold.

 

I don't know about the PCV but that is one sano engine compartment.

 

The valve cover connection is for fresh air to the engine internals. It supposed to go to the air intake on the inlet side of the valve body so it doesn't see manifold vacuum. In other words, it just draws from the air filter to give a filtered air supply. Do not T it into the PCV valve or catch can hoses.

Another option is to find a small 90* fitting that matches the hose from the valve cover and a grommet the 90* fitting fits snugly into. Put the right size hole for the grommet into the air bridge and then plug the 90* fitting into the grommet. Basically, duplicate that fitting in the Vararam that feeds the AIR pump.

 

Yeah that was a great help so thank you. I re-installed the OEM PCV valve and routed it going into the intake manifold. So that part's done. Do I need a check valve going into the valley cover though?

Ok, so that option's out now, as well as the breather filter option. I'll see if the ATP QuickTap fitting will work first as long as a 5/16" opening is large enough to allow the system to breathe. That was my concern with that option. If that doesn't work then I'll go the route Mark did.

Thanks for the help everyone! I'm almost there

 

Make sure you pull air post MAF. It might not be much but it is an inlet source of air to the engine so it should be metered. Anything before the MAF will push the AFR more lean than commanded as more air is in the engine than the computer knows about. Is it enough to be concerned? I dunno, but when it comes to a vehicle that will see a fair amount of WOT I would never knowingly lie to the computer in a way that will lean out the mixture.

 

Yeah, that's what the plan is. I have a Vararam power duct but moved the MAF back to the OEM location for now. I ordered a new air bridge that will fit better and keep the MAF at the OEM location. After that gets here I'll try the ATP QuickTap fitting on the air coupler and if the system doesn't breathe enough with that, then I'll go the route Mark did.

I installed the pcv valve into my catch can last night...



Anything look out of place here? Besides what I stated above...

Don't mind the 'seal' I made with the RTV on the power duct either...all temporary haha.

 

Unfortunately, the ATP QuickTap fitting won't work. It's way too small for the vacuum line and even if I got it to fit there I think it'll be too small to allow the PCV system to breathe. So, my only option now is to do it the way Mark did in the first picture posted. I'm still waiting on the new air bridge to show up before I can really do anything, but the car runs for now so just need to get that piece and button everything up for the June 10th tune day.

 

Welp, it's done! I routed it just like Mark did and honestly have no concerns. The grommet in the air coupler is secured with epoxy so it should be leak-free.

A HUGE thanks to Mark for his write-up! I would've been lost without it at some parts of this install.



I still have to shave the FRCs to clear the new mani too.

Got a tune scheduled on Monday so things are coming along!

Oh, and I need to pick up my sway bars from the powdercoating shop too...

 

I had my builder/tuner make me a custom catch can with 2 breathers, here's how it is routed. The Fast 92 port is capped off. A hose runs from the valley to the catch can, and 2 other hoses from the catch can to the valve covers. PCV valve was removed. 2003 Z06.

 

Glad it worked out for you ! Looks great ! If you find anything more permanent for the connection to the air coupler let me know. I have a second section of air coupler in my garage just in case....

Toque

 

Will do! For now though, this will work just fine so again thanks for the great write-up!