NEW FREE MOD - CRANK CASE VENTILATION MOD.

[Fast03Cobra]

Dont know if anyone has done this. I did mine yesterday. A guy with a SUPERCHARGED VIPER GTS hooked me up and did the install for free!

The CRANKCASE VENTILATION hose goes into the intake. This has 2 problems that ROB POWER:

1. Forces hot crank case air into the intake in front of the throttle body. As we ALL know, mixing more hot air into the intake is BAD!

2. This hot air is OILY! So you are coking or making the TB dirty too.


You have 2 options:

1. Simply remove the hose and put a filter on the crank case ventilation hole. Plug the intake side.

2. Do what I did and run a 2-3' hose from the crank case hole down to the front and connect the filter there. Then put a T in the line and an oil catcher.


VERY NICE and pro looking setup. Will post pics if people need. But this is pretty easy and straight forward. If no power gains, should at least the keep the TB cleaner. SHould use a can of BG44K every 5000 miles or so any way on these cars to get rid of carbon build-up.

Well its ALMOST free. VERY VERY cheap.

Still need to check for oil every now and then. But the guy with the SC Viper did this mod.

BTW his car was absolutey BREATH TAKING! Runs low 10's.

:beer:

 

[mineral03]

Theres one thing i wanted to try on my 03, but not sure how it would affect the 02 sensor reading... basically you install a smog pump check valve into both of your header collectors,and run a hose from the check valves to your crankcase... the negative exhaust pulses in your exhaust will actually draw air out of the crankcase, into the exhaust... seen dyno tests on older cars where theyd gain 3-10 hp... and its fairly cheap. Tried it on a couple old cars, and it seemed to help, but i think it would screw with the 02 sensor readings, and start messin with other stuff though...

 

[Fast03Cobra]

Did not get any feedback on this thread. No one interested? Bogus mod? Any thoughts?

I think it makes sense.

 

[VintagePorscheG]

post pics.... please

 

[dmreitz]

It's an interesting idea... guess I'd have to look into it more before I gave an opinion! (just don't know that much about it!) As VintagePorscheG says... if you got some pics, I'd be interested in seeing them...

 

[Terminator03]

this isnt just on supercharged cars. LS1 guys have been doing this for a while. i believe they call the egr valve or something lke that. IT REALLY DOES HELP. i just havent gotten around to doing it.

 

[KingKobra]

Originally posted by Fast03Cobra
Did not get any feedback on this thread. No one interested? Bogus mod? Any thoughts?

I think it makes sense.

I'm interested, but I just don't get it... I need pics.

I'm mentally challenged this monday morning.

 

[FlashSVT]

Unmetered (outside) air entering the system could result in a lean condition. Has anyone checked fuel trims, O2 readings, AF Ratio, etc to check this?

You can add a oil/air seperation filter to the system without worrying about unmetered air. This will keep your TB clean and oil free.

See http://www.nloc.net/forum/showthread.php?s=&threadid=19681

 

[SoCalBlk03]

Originally posted by Fast03Cobra
Did not get any feedback on this thread. No one interested? Bogus mod? Any thoughts?

Pics, Part #'s and $$ please..........

 

[f4sfed]

YES! Pics please!

 

[Fast03Cobra]

Ok guys I will post pics and explain everything like POSTBAN does. or at least try.

There is NO un-metered air entering the system. That is a false statement.

I will post pics tonight when I get home. Get out the video camera and slice pics. I PROMISE to post better quality than my attempt at the SUPERCHARGED decal thingy...

 

[FlashSVT]

There is NO un-metered air entering the system.

the crank case hole down to the front and connect the filter there

So no outside air can enter this filter? Any air that can enter the system that does not pass through the MAF is un-metered. There have been some cases of Lightning’s throwing lean codes due to crankcase filters. Short term fuel trim can be affected and some tuners even program to accommodate this.

 

[jeffhou]

On the LS1's they have a similar mod as mentioned above. My friend just did it to his 99 TA. He researched and he found that the only reason it puts hot air into the cycle is for extreme cold weather conditions. He lives in texas so there was no need for the extra hot air. So he bypassed the hot air, plugged the two tubes on his throttle body, then connected the tubes that he took off the throttle body. Seemed to make a bit of difference, alot like a 170 thermostat does. Anyway just my input....

 

[noslo50]

The intake where it draws the air is plugged(hense no unmeter air) the filter goes on the hose coming out of the valve cover. as i read it.

 

[T3 Cobra]

need pics, sounds good. Is this mod related to the breather cap for the oil fill hole?

 

[jtfx6552]

The PCV system on the '03's is pretty nice. There apper to be two PCV valves, one goes between the ps cam cover and enters in front of the throttle body, the other from the other cam cover and appears to enter on the pressure side of the blower.

PCV valves, when they are not gummed up are a check valve in one direction, and a metering valve in the other. The check valve function dates back to carburators and back fires. The reason was to prevent a backfire from igniting crankcase vapors. In the old days, cars had an "open" pcv system. In an open system, there was a breather connected to the crankase somewhere, usually on one valve cover, and a PCV 'metering" valve on the other. Under conditions of engine vacuum, a metered amount of air would be pulled through engine through the PCV valve. I. e, there is a vacuum under the carburator, which would pull air out of one valve cover (an amount metered by the pcv valve) causing a vacuum, which would pull air in through the breather. Under WOT, there is not a lot of vacuum and high "blow by" so smoke will come out the breather. The emissions people don't like this, so that was the birth of the "closed" pcv system.

in a closed pcv system, the pcv valve pulls a vacuum against the crankcase, but there is no breather anywhere. Usually the other valve cover now has an oil fill plug with an o-ring on it. In this system, crankcase vapor will be sucked in, or pushed in to the engine inlet depending on manifold vacuum.

Blowers complicate this whole deal, now the manifold can and will have a lot higher pressure than the crankcase. You don't want the blower pushing all your boost into the crankcase, or weird things will happen. Dip stick blown out of the block anyone? The check valve function of the PCV should prevent this, but depending on where you connect things, there will be nowhere in the engine for the crankcase vapor to get 'pulled' to under boost. Then you end up with smoking dripping breathers.

If you search some forums frequented with cars with aftermarket blowers, you will see that some guys add a check valve in series with the PCV, I am not sure why they need to do this, maybe the PCV "check" valve function is not reliable. Anyway if you have the PCV feeding into the pressure side of the blower, you would blow boost pressure into the crankcase if the PCV didn't seal in the reverse direction.

With the '03, if you put a breather in one pcv location, and leave the other one connected, you will allow unmetered air into the engine. If the connected PCV is the one connected to the pressure side of the blower, you will not add unmetered air when under boost, since air does not flow from a low pressure area to a high pressure area. The check valve function will prevent boost from going into the crankcase. You will have blow by out the breather. Depending on how well the breather location is baffled, and how good the ring seal is (should be good on our nice new cars) this could lead to the mosquito sprayer look, or dripping oil on your engine.

I wouldn't want either of these things if it is worth 1-2 or even 10 HP, so I won't be playing with the PCV system.

If you remove both PCV valves, you eliminate the unmetered air problem , but now you are venting the crankcase to atmosphere all the time, which usually leads to more smoking dripping breathers.

JT

 

[cobrablue]

i did this mod on my corvette. on the ls1 this is done for oil control. what we found on the ls1 was that because of the very shallow valve covers the pcv system sucks up oil. it will pick it up in a mist or in abundance if your driving hard and cornering hard. they believe this to be one of the main causes for carbon buildup and detonation on the ls1. basically what you are doing is putting a plastic filter between the pcv and intake inlet. when oil is sucked through the pcv system and down the hose it is trapped by the filter. this will not allow the oil into the throttle body, intake or cylinders. it is a good mod for the ls1 but only because of the poor oil control within the pcv system. my mustang doesnt consume oil and the pcv works perfectly. so as the old addage goes if it isnt broke dont f--k with it. no powergains at all. just an oil control device. hope this helps. :beer:

 

[Jerryk]

Originally posted by jtfx6552
The PCV system on the '03's is pretty nice. There apper to be two PCV valves, one goes between the ps cam cover and enters in front of the throttle body, the other from the other cam cover and appears to enter on the pressure side of the blower.

PCV valves, when they are not gummed up are a check valve in one direction, and a metering valve in the other. The check valve function dates back to carburators and back fires. The reason was to prevent a backfire from igniting crankcase vapors. In the old days, cars had an "open" pcv system. In an open system, there was a breather connected to the crankase somewhere, usually on one valve cover, and a PCV 'metering" valve on the other. Under conditions of engine vacuum, a metered amount of air would be pulled through engine through the PCV valve. I. e, there is a vacuum under the carburator, which would pull air out of one valve cover (an amount metered by the pcv valve) causing a vacuum, which would pull air in through the breather. Under WOT, there is not a lot of vacuum and high "blow by" so smoke will come out the breather. The emissions people don't like this, so that was the birth of the "closed" pcv system.

In a closed pcv system, the pcv valve pulls a vacuum against the crankcase, but there is no breather anywhere. Usually the other valve cover now has an oil fill plug with an o-ring on it. In this system, crankcase vapor will be sucked in, or pushed in to the engine inlet depending on manifold vacuum.

Blowers complicate this whole deal, now the manifold can and will have a lot higher pressure than the crankcase. You don't want the blower pushing all your boost into the crankcase, or weird things will happen. Dip stick blown out of the block anyone? The check valve function of the PCV should prevent this, but depending on where you connect things, there will be nowhere in the engine for the crankcase vapor to get 'pulled' to under boost. Then you end up with smoking dripping breathers.

If you search some forums frequented with cars with aftermarket blowers, you will see that some guys add a check valve in series with the PCV, I am not sure why they need to do this, maybe the PCV "check" valve function is not reliable. Anyway if you have the PCV feeding into the pressure side of the blower, you would blow boost pressure into the crankcase if the PCV didn't seal in the reverse direction.

With the '03, if you put a breather in one pcv location, and leave the other one connected, you will allow unmetered air into the engine. If the connected PCV is the one connected to the pressure side of the blower, you will not add unmetered air when under boost, since air does not flow from a low pressure area to a high pressure area. The check valve function will prevent boost from going into the crankcase. You will have blow by out the breather. Depending on how well the breather location is baffled, and how good the ring seal is (should be good on our nice new cars) this could lead to the mosquito sprayer look, or dripping oil on your engine.

I wouldn't want either of these things if it is worth 1-2 or even 10 HP, so I won't be playing with the PCV system.

If you remove both PCV valves, you eliminate the unmetered air problem , but now you are venting the crankcase to atmosphere all the time, which usually leads to more smoking dripping breathers.

JT

JT, you almost got it. Very nice write-up. 2 points of clarification:
- we have 1 PCV valve. Not 2. I could be corrected but I haven't checked the passenger side yet so I'm going off the most likely scenario. The side before the TB is air going IN to the engine. It goes into the valve cover, down to the crank, back up the other valve cover. From there it goes through a PCV valve and into the back of the blower. In this way METERED air (after the MAM but before the throttle body) is used to scavenge blowby gases from teh crankcase and sent back into the engine to be burned. The second thing this solves for us is a vacuum in the crankcase allows the piston rings to seal better against the cylinder, thereby increasing power. Why do most top race engines have vacuum pumps? Not for emissions but rather ring seal.

The DOWNSIDE of this is that oil vapor is present in this system. Oil vapor contaminates teh intake charge (oil reduces effective octane of gas thereby increasing the chance of detonation).. it also cruds up the intake ports/valves and in our case it mucks up your intercooler and turns your exhaust pipes nice and black.

Why do engines have so much oil in the PCV system?? They all do. I swear my next engine will have Total Seal piston rings just for this reason. Don't know if they work but I'd love to find out. What can you do? Vent to atmosphere. Upside: no oil contamination. Downside, no vacuum in the crankcase AND your clothes stink. Those fumes go somewhere! Usually the trailing edge of the hood, right into your cowl induction for your HVAC and stink up your clothes.

What can we do about it? Put an oil seperator inline on the return side of the PCV loop. If you go to the thread that FlashSVT provided on the L forums you'll see what I mean. That is a great thread by the way. My solution is more expensive and differs from what they prescribe. I wrote about it on that thread if you look at page 6. I did install it on my Cobra a few weeks ago and its picking up plenty of oil! Want proof: I installed my new Dynomax catback (<- Drone zone.. sucks) and the inside of my tips going back about 12" are still alumimum color.. CLEAN! Granted it probably only has 500 miles since the exhaust but you get the picture..


This is gonna be a LONG thread.. I was gonna do a write-up and post the oil-seperator solution but have been too busy.


Jerry

 

[jtfx6552]

Originally posted by Jerryk


JT, you almost got it. Very nice write-up. 2 points of clarification:
- we have 1 PCV valve. Not 2. I could be corrected but I haven't checked the passenger side yet so I'm going off the most likely scenario. The side before the TB is air going IN to the engine. It goes into the valve cover, down to the crank, back up the other valve cover. From there it goes through a PCV valve and into the back of the blower. In this way METERED air (after the MAM but before the throttle body) is used to scavenge blowby gases from teh crankcase and sent back into the engine to be burned. The second thing this solves for us is a vacuum in the crankcase allows the piston rings to seal better against the cylinder, thereby increasing power. Why do most top race engines have vacuum pumps? Not for emissions but rather ring seal.

Jerry

You are correct, sir! 1 PCV valve, I just checked. I had noticed what looked like two before and didn't check before posting. When I first thought I saw two, I thought, wow, tht's weird, why two? Anyway the passenger side deal is just a 90 degree plastic elbow that looks like PCV valve.

JT

 

[FlashSVT]

jtfx6552 / Jerryk :thumbsup: