No Oil cap more horsepower - Page 3

***fullerton*** · 05-15-2008, 01:56 PM

noob question:

what are the negatives to relieving the vacuum in this manner?

SubySteve · 05-15-2008, 01:59 PM

I would have to assume this would have a hugh affect on oil pressure. Doesnt the crankcase pressure work with the oil pump for proper oil delivery.

JMSSTI · 05-15-2008, 06:33 PM

Hmmm. I'm curious.

mllrsti · 05-15-2008, 06:38 PM

Quote:

Originally Posted by flatthump

How the hell do you spell seperator?

sepArator!!!!!!

nautique196 · 05-15-2008, 07:01 PM

all this is doing is relieving positive crankcase pressure. When air gets past your rings it will actually "pressurize" the crankcase. The PCV system is supposed to rid of all the pressure. If it isnt doing a good enough job. which it probably isnt. then leaving the oil cap off gets rid off all that pressure alot better. I wouldnt recommend just leaving it off. i would probably a big -AN line from the valve covers or somewhere to a catch can. if you use small tubing the air velocity is increased and oil has a better chance to leave with that air. to take this one step farther, a vacuum pump could be installed. If you actually pull a vacuum from the crankcase, probably like 15-20 in, you would it helps seal the rings and make more power. OP, alot of LS1 guys are doing this now as well. In NASCAR they used to run huge drysump oil pumps to pull alot of vacuum. NASCAR made a rule sayin it can only be so big now, but they still pull vacuum, just not as much.

***Szumita*** · 05-15-2008, 07:10 PM

Quote:

Originally Posted by nautique196

all this is doing is relieving positive crankcase pressure. When air gets past your rings it will actually "pressurize" the crankcase. The PCV system is supposed to rid of all the pressure. If it isnt doing a good enough job. which it probably isnt. then leaving the oil cap off gets rid off all that pressure alot better. I wouldnt recommend just leaving it off. i would probably a big -AN line from the valve covers or somewhere to a catch can. if you use small tubing the air velocity is increased and oil has a better chance to leave with that air. to take this one step farther, a vacuum pump could be installed. If you actually pull a vacuum from the crankcase, probably like 15-20 in, you would it helps seal the rings and make more power. OP, alot of LS1 guys are doing this now as well. In NASCAR they used to run huge drysump oil pumps to pull alot of vacuum. NASCAR made a rule sayin it can only be so big now, but they still pull vacuum, just not as much.

good post

Howie STi · 05-15-2008, 07:34 PM

I hope you all are aware of the fact that this is already in the engine bay...

Now I don't meen to piss in you bowl of wheaties...

Go look just to the right of the throttle body look for the small "vacuum" hose that is 1/16th of an inch in diameter and about 4-5 inches long. Now I know that there is no cach can attached and it is not the same sive as the oil fill line. But it is what you guys are talking about with creating a vacuum with in the crankcase.

I'll wait untill you return...

Ok, you back from the garage. Lets think about how you can get a vacuum in a engine. And how any car with "Forced induction" will not have a vacuum as the turbo/supercharger starts to boost.

I hope we all know the four differant strokes that happen in our engines. and that one of those strokes are called intake/induction stroke or vacuum.
Because the first stroke is sucking in the fuel air mixture.

Now to the OP. Unless you can prove what you clame with a Dino, 1/4 mile or even 1/8 mile times I say put the oil cap back on.

I appoligize if this comes off a little harsh.

flatthump · 05-15-2008, 08:43 PM

Quote:

Originally Posted by Howie STi

I hope you all are aware of the fact that this is already in the engine bay...

Now I don't meen to piss in you bowl of wheaties...

Go look just to the right of the throttle body look for the small "vacuum" hose that is 1/16th of an inch in diameter and about 4-5 inches long. Now I know that there is no cach can attached and it is not the same sive as the oil fill line. But it is what you guys are talking about with creating a vacuum with in the crankcase.

I'll wait untill you return...

Ok, you back from the garage. Lets think about how you can get a vacuum in a engine. And how any car with "Forced induction" will not have a vacuum as the turbo/supercharger starts to boost.

I hope we all know the four differant strokes that happen in our engines. and that one of those strokes are called intake/induction stroke or vacuum.
Because the first stroke is sucking in the fuel air mixture.

Now to the OP. Unless you can prove what you clame with a Dino, 1/4 mile or even 1/8 mile times I say put the oil cap back on.

I appoligize if this comes off a little harsh.

Those are coolant lines buddy...

Dude, cmon, were not trying to achieve a vacuum in the damned crankcase. We, or rather me, want to hook it up to a vacuum SOURCE as to help scavenge positive crank pressure more rapidly.

it doesn't come off harsh at all. Just a little dumb.

B.B. Rodriguez · 05-15-2008, 11:02 PM

I've seen a few race cars that had breathers going from the valve covers to the collectors on the headers. They use the exhaust to pull all that crank case pressure out. Made them look like the were burning oil. But it's the same theory. especially when you factor in piston speed. Thats allot of air working against you. imho.

prerunrigg · 05-16-2008, 02:43 AM

when i was building the motor on my chevy (v8) i had a pcv in one valve cover and a breather in the other, and the motor would run lean under throttle because of the vented opposite valve cover. as far as i know, if a system is supposed to be contained... i.e. nothing venting to atmosphere, it should remain contained. if a system is to be vented to atmosphere it, that's fine but without use of any pcv. most race motors i've seen dont run pcv's they run 2 breathers per valve cover along with pan breathers. as soon as i closed off the opposite valve cover and ran an enclosed breather back into the intake tract it stopped leaning out under power. granted, this was not a forced induction motor, but i would still be leary to just uncork it when it seems like it's made to be fully contained

Rootus · 05-16-2008, 06:27 AM

Quote:

Originally Posted by B.B. Rodriguez

Thats allot of air working against you. imho.

Is it, though?

Regardless of the ambient pressure inside the crankcase, as one piston is moving down another one is moving up. Moving air around a little, not further pressurizing it.

Further, let's assume for a moment that the piston was working against the air. How many horsepower are you going to give up before you've blown the PCV valve out?

I hate to let physics intrude on the discussion, but it's a necessary point. When you talk about a car feeling noticeably faster, you're looking at a 5-10% power difference. That means 15-30 horsepower (11K to 22K watts) is being corked up by the PCV system, which is a tremendous amount of energy. The alternative being that the PCV introduces enough crap into the intake to reduce the combustion efficiency by a similar amount, which I also think is very unlikely.

Rootus · 05-16-2008, 06:30 AM

Quote:

Originally Posted by prerunrigg

when i was building the motor on my chevy (v8) i had a pcv in one valve cover and a breather in the other, and the motor would run lean under throttle because of the vented opposite valve cover. as far as i know, if a system is supposed to be contained... i.e. nothing venting to atmosphere, it should remain contained. if a system is to be vented to atmosphere it, that's fine but without use of any pcv.

That is a very good point. It probably wouldn't cause a turbo motor to run lean because the intake pressure will be positive when it matters. Shouldn't have any effect except when the engine is in vacuum.

jungo75 · 05-16-2008, 08:22 AM

Where are the tests and the results of them. Not verified? Keep it on. Easy enough.

KiTsuNe · 05-16-2008, 10:19 AM

Quote:

Originally Posted by flatthump

You got plenty of info in the Nasioc thread.

Why don't you tap into the oil cap and include it as a breather? That's definitely what I'm doing this weekend.

still need me to make that cap?

STI-LOS · 05-16-2008, 10:53 AM

I will be getting Ebay anodized Oil caps and drilling holes in them and then advertising a 8-10HP Gain... I will be Rich Biotch.........

no one take my idea or I will sue..

I get the whole idea of the pressure release but it seems like a waste of time, we only got interested in this cause the guy stated his car felt faster.. I just cant see that happening at all. I am not hating I am always up for new cheap mods. But you guys know what I mean

05-15-2008, 01:56 PM	#31
*fullerton* abracious Car: AW GDF-D Fav Mod: Track time Location: Near a 100oct pump Posts: 16,074 Join Date: Oct 2005 Trader Rating: (10)	Re: No Oil cap more horsepower noob question: what are the negatives to relieving the vacuum in this manner? This ad is not endorsed by this member. Please register or login to hide this ad.

05-15-2008, 01:59 PM	#32
SubySteve STI Driver Car: 04 Subaru WRX STi Fav Mod: Coming Soon Location: HOLLYWOOD,FL Posts: 256 Join Date: Jul 2005 Trader Rating: (0)	Re: No Oil cap more horsepower I would have to assume this would have a hugh affect on oil pressure. Doesnt the crankcase pressure work with the oil pump for proper oil delivery.

05-15-2008, 06:33 PM	#33
JMSSTI Amateur STI Driver Car: 05 Sti black/silver Fav Mod: APS cai Location: Los Angeles Posts: 49 Join Date: Mar 2008 Trader Rating: (0)	Re: No Oil cap more horsepower Hmmm. I'm curious.

05-15-2008, 07:01 PM	#35
nautique196 Amateur STI Driver Car: 99 Civic POS Fav Mod: Coming Soon Location: T-hizzle, NC Posts: 20 Join Date: Nov 2007 Trader Rating: (0)	Re: No Oil cap more horsepower all this is doing is relieving positive crankcase pressure. When air gets past your rings it will actually "pressurize" the crankcase. The PCV system is supposed to rid of all the pressure. If it isnt doing a good enough job. which it probably isnt. then leaving the oil cap off gets rid off all that pressure alot better. I wouldnt recommend just leaving it off. i would probably a big -AN line from the valve covers or somewhere to a catch can. if you use small tubing the air velocity is increased and oil has a better chance to leave with that air. to take this one step farther, a vacuum pump could be installed. If you actually pull a vacuum from the crankcase, probably like 15-20 in, you would it helps seal the rings and make more power. OP, alot of LS1 guys are doing this now as well. In NASCAR they used to run huge drysump oil pumps to pull alot of vacuum. NASCAR made a rule sayin it can only be so big now, but they still pull vacuum, just not as much.

05-15-2008, 07:34 PM	#37
Howie STi Junior STI Driver Car: OBP 05 STi Fav Mod: Oh $hti Handle Location: Tulsa OK Posts: 62 Join Date: Aug 2007 Trader Rating: (0)	Re: No Oil cap more horsepower I hope you all are aware of the fact that this is already in the engine bay... Now I don't meen to piss in you bowl of wheaties... Go look just to the right of the throttle body look for the small "vacuum" hose that is 1/16th of an inch in diameter and about 4-5 inches long. Now I know that there is no cach can attached and it is not the same sive as the oil fill line. But it is what you guys are talking about with creating a vacuum with in the crankcase. I'll wait untill you return... Ok, you back from the garage. Lets think about how you can get a vacuum in a engine. And how any car with "Forced induction" will not have a vacuum as the turbo/supercharger starts to boost. I hope we all know the four differant strokes that happen in our engines. and that one of those strokes are called intake/induction stroke or vacuum. Because the first stroke is sucking in the fuel air mixture. Now to the OP. Unless you can prove what you clame with a Dino, 1/4 mile or even 1/8 mile times I say put the oil cap back on. I appoligize if this comes off a little harsh.

05-15-2008, 11:02 PM	#39
B.B. Rodriguez Amateur STI Driver Fav Mod: Coming Soon Posts: 9 Join Date: May 2008 Trader Rating: (0)	Re: No Oil cap more horsepower I've seen a few race cars that had breathers going from the valve covers to the collectors on the headers. They use the exhaust to pull all that crank case pressure out. Made them look like the were burning oil. But it's the same theory. especially when you factor in piston speed. Thats allot of air working against you. imho.

05-16-2008, 02:43 AM	#40
prerunrigg Senior STI Driver Car: 04 subaru WRX STi Fav Mod: KEY!S steering wheel Location: so cal Posts: 376 Join Date: Dec 2005 Trader Rating: (8)	Re: No Oil cap more horsepower when i was building the motor on my chevy (v8) i had a pcv in one valve cover and a breather in the other, and the motor would run lean under throttle because of the vented opposite valve cover. as far as i know, if a system is supposed to be contained... i.e. nothing venting to atmosphere, it should remain contained. if a system is to be vented to atmosphere it, that's fine but without use of any pcv. most race motors i've seen dont run pcv's they run 2 breathers per valve cover along with pan breathers. as soon as i closed off the opposite valve cover and ran an enclosed breather back into the intake tract it stopped leaning out under power. granted, this was not a forced induction motor, but i would still be leary to just uncork it when it seems like it's made to be fully contained

05-16-2008, 08:22 AM	#43
jungo75 Senior STI Driver Car: 06 Subaru WRX STi Fav Mod: The Hooptie Location: Maryland Posts: 380 Join Date: Jun 2006 Trader Rating: (2)	Re: No Oil cap more horsepower Where are the tests and the results of them. Not verified? Keep it on. Easy enough.

05-16-2008, 10:53 AM	#45
STI-LOS Silver Member Car: 06 STI / STG 4 Fav Mod: DOM 3.0R + METH!!!! Location: Vernon, NJ Posts: 1,181 Join Date: Jan 2008 Trader Rating: (4)	Re: No Oil cap more horsepower I will be getting Ebay anodized Oil caps and drilling holes in them and then advertising a 8-10HP Gain... I will be Rich Biotch......... no one take my idea or I will sue.. I get the whole idea of the pressure release but it seems like a waste of time, we only got interested in this cause the guy stated his car felt faster.. I just cant see that happening at all. I am not hating I am always up for new cheap mods. But you guys know what I mean This ad is not endorsed by this member. Please register or login to hide this ad.