No Oil cap more horsepower? - Page 10

WRX4ME LE 482 · 06-06-2008, 07:22 AM

^Great info. That's just what we need here.

I had initially thought of it possibly acting like a BOV and screwing up the MAF metered air, but dismissed it. Not saying it's not true, just that I started exploring other theories.

My MAF readings come from load, measured off the ECU. As most of us know, load (at least on our cars) is calculated from MAF and RPM. With everything else constant, MAF would have to be the only thing that is lower from one experiment to the next. Im honestly not sure where the PCV system connects to the intake, but I *think* it's past the MAF and (obviously) before the turbo.

So, maybe there actually is equal or greater load with the cap off? I wish I had a wideband. I would love to see what my AFRs have been doing. I still dont think anything (AFR, timing, etc) is off enough to make this much more power. If more testing and information proves that this is a safe, good mod to do, and the increases in power keep leaning toward the numbers I believe they will, then this is definitely one of the first mods people should make. It's easy and cheap, and from my experience from doing *my* style of power tests, it makes a noticeable, worthwhile difference.

Also, there was a guy, I think earlier in this thread that mentioned how the PCV system had piping or a valve or something that seemed far to small for our application. Maybe this is another area where Subaru could've increased the flow, and increased the power of the car. God knows, it wouldn't be the first time.

A friend of mine mentioned how on some cars, particularly N/A cars with filter systems like what I'm running, experienced excess moisture in their oil, which over time led to issues brought about by poor lubrication. I think I've got 1000 or 1500 miles left on this oil. If I'm not given a reason to take the filter off, Ill leave it, and see how my oil test comes up this time. Moisture was very low in my last oil test, so I'll know if there's a problem.

WRX4ME LE 482 · 06-08-2008, 11:25 PM

Ok, as much as I hate to say it, I think I may have proven now that our cars are not appreciably faster without the oil cap on.

I ran numbers tonight, several times while I scaled my MAF. I worked it until I got almost the exact same load values for a rom I ran with the oil cap off, as another that I used for with the cap on. All other things in these roms were exactly the same. I do now believe the loss in load is directly related to a loss in metered air, similar to what would happen with a BOV, but across the entire range. This was causing me to run more timing, and leaner fueling, therefore netting me slightly better times. There is a slight possibility that I gained a very small amount of power from this, but it's truly nothing to waste any time over.

With all that said, I can't help but wonder what actual benefits might come from this. If most of the crankcase vapors are going through this filter now, that's keeping hot air, as well as oil vapors from being sucked back into my intake, which we all know can cause multiple problems.

However, there are still the AVCS maps to mess with. This whole thing may have thrown them off, so there may be some gains to be found there...

For the time being, I'm going to keep the filter on and monitor things. Also, I still want to get my oil tested with this having been run for a while, and see what effects it may have had.

***bue car*** · 06-09-2008, 07:44 AM

i like your style on this

WRX4ME LE 482 · 06-09-2008, 12:32 PM

Thanks. Well, as much as I'd like to believe that this is a cheap, simple mod that makes a significant difference, I'm ultimately after the truth. The last thing we need is another mod that gives more "power" without giving any more power.

I still think it's possible there may be some (especially long term) benefit to filtering crankcase gases this way. Hell, the only reason we do it the other way is because it's government mandated, like catalytic converters, CARB approval, and unleaded gas.

I'm also worried it could cause excessive power loss in older engines though. But I guess that depends on how much more blowby older engines actually get than fairly new ones.

I guess time will tell.

***bue car*** · 06-09-2008, 01:09 PM

Like I said before about the release of gases, will this affect our cabin air? No body need carbon monoxide in their car

***bue car*** · 06-09-2008, 01:17 PM

My cap

PIC-0042.jpg - Image - Photobucket - Video and Image Hosting

WRX4ME LE 482 · 06-09-2008, 05:34 PM

I have heard that these kinds of systems can feed into the cabin. I don't think it'll cause any kind of deadly inhalation hazard though. In fact, I haven't smelled anything at all, and I'm pretty sure I'd be able to smell it if it was an issue.

Iguana · 06-10-2008, 02:07 PM

this was an interesting read.

esqdgg · 06-10-2008, 02:27 PM

very interesting read thus far.

any concerns from my fellow statesmen re: our friendly local pd or chp seeing that "thing" in the engine bay and immediately asking "where's the carb certified label?" or worse yet, just straight-up issuing you a fix-it ticket for it? i can pretty easily imagine that happening to me with my luck.

WRX4ME LE 482 · 06-11-2008, 07:25 AM

I'm certain if the cops around here were anything like Cally cops, they wouldn't like it at all...

Glad they're not.

I would like to get out and do some more testing and tuning, but my brokeness and gas prices and g/f in labor are making it difficult...

***bue car*** · 06-11-2008, 07:44 AM

Congrats on the little one man!

Also i carry my normal cap in my glove box for just that reason. If I was pulled over, I would say i was running tests (Hence the aggressive driving) and simply put the OEM back on

Unlimited · 06-11-2008, 11:39 AM

Quote:

Originally Posted by viperguy

If you want to experiment, by all means drill the oil filler and fit a line to the airbox dirty side or induction pipe from the airbox to the turbo. .

Doesn't Prova already make this

RAPTR · 06-11-2008, 11:43 AM

^link to where someone sells that?

flatthump · 06-11-2008, 02:13 PM

Quote:

Originally Posted by Unlimited

Doesn't Prova already make this

Umm wow

bluedemon_II · 06-11-2008, 08:20 PM

That actually looks nice

06-06-2008, 07:22 AM	#136
WRX4ME LE 482 Spec C Club Car: '07 STi Limited #482 Fav Mod: Disabled seatbelt dinger Location: Mississippi Posts: 1,158 Join Date: Mar 2007 Trader Rating: (0)	Re: No Oil cap more horsepower ^Great info. That's just what we need here. I had initially thought of it possibly acting like a BOV and screwing up the MAF metered air, but dismissed it. Not saying it's not true, just that I started exploring other theories. My MAF readings come from load, measured off the ECU. As most of us know, load (at least on our cars) is calculated from MAF and RPM. With everything else constant, MAF would have to be the only thing that is lower from one experiment to the next. Im honestly not sure where the PCV system connects to the intake, but I think it's past the MAF and (obviously) before the turbo. So, maybe there actually is equal or greater load with the cap off? I wish I had a wideband. I would love to see what my AFRs have been doing. I still dont think anything (AFR, timing, etc) is off enough to make this much more power. If more testing and information proves that this is a safe, good mod to do, and the increases in power keep leaning toward the numbers I believe they will, then this is definitely one of the first mods people should make. It's easy and cheap, and from my experience from doing my style of power tests, it makes a noticeable, worthwhile difference. Also, there was a guy, I think earlier in this thread that mentioned how the PCV system had piping or a valve or something that seemed far to small for our application. Maybe this is another area where Subaru could've increased the flow, and increased the power of the car. God knows, it wouldn't be the first time. A friend of mine mentioned how on some cars, particularly N/A cars with filter systems like what I'm running, experienced excess moisture in their oil, which over time led to issues brought about by poor lubrication. I think I've got 1000 or 1500 miles left on this oil. If I'm not given a reason to take the filter off, Ill leave it, and see how my oil test comes up this time. Moisture was very low in my last oil test, so I'll know if there's a problem. This ad is not endorsed by this member. Please register or login to hide this ad.

06-08-2008, 11:25 PM	#137
WRX4ME LE 482 Spec C Club Car: '07 STi Limited #482 Fav Mod: Disabled seatbelt dinger Location: Mississippi Posts: 1,158 Join Date: Mar 2007 Trader Rating: (0)	Re: No Oil cap more horsepower Ok, as much as I hate to say it, I think I may have proven now that our cars are not appreciably faster without the oil cap on. I ran numbers tonight, several times while I scaled my MAF. I worked it until I got almost the exact same load values for a rom I ran with the oil cap off, as another that I used for with the cap on. All other things in these roms were exactly the same. I do now believe the loss in load is directly related to a loss in metered air, similar to what would happen with a BOV, but across the entire range. This was causing me to run more timing, and leaner fueling, therefore netting me slightly better times. There is a slight possibility that I gained a very small amount of power from this, but it's truly nothing to waste any time over. With all that said, I can't help but wonder what actual benefits might come from this. If most of the crankcase vapors are going through this filter now, that's keeping hot air, as well as oil vapors from being sucked back into my intake, which we all know can cause multiple problems. However, there are still the AVCS maps to mess with. This whole thing may have thrown them off, so there may be some gains to be found there... For the time being, I'm going to keep the filter on and monitor things. Also, I still want to get my oil tested with this having been run for a while, and see what effects it may have had. Last edited by WRX4ME LE 482 : 06-08-2008 at 11:31 PM.

06-09-2008, 07:44 AM	#138
*bue car* Platinum Member Car: 07 STi Blue Fav Mod: stock :] Location: Torrance, California Posts: 489 Join Date: Sep 2007 Trader Rating: (1)	Re: No Oil cap more horsepower i like your style on this

06-09-2008, 12:32 PM	#139
WRX4ME LE 482 Spec C Club Car: '07 STi Limited #482 Fav Mod: Disabled seatbelt dinger Location: Mississippi Posts: 1,158 Join Date: Mar 2007 Trader Rating: (0)	Re: No Oil cap more horsepower Thanks. Well, as much as I'd like to believe that this is a cheap, simple mod that makes a significant difference, I'm ultimately after the truth. The last thing we need is another mod that gives more "power" without giving any more power. I still think it's possible there may be some (especially long term) benefit to filtering crankcase gases this way. Hell, the only reason we do it the other way is because it's government mandated, like catalytic converters, CARB approval, and unleaded gas. I'm also worried it could cause excessive power loss in older engines though. But I guess that depends on how much more blowby older engines actually get than fairly new ones. I guess time will tell.

06-09-2008, 01:09 PM	#140
*bue car* Platinum Member Car: 07 STi Blue Fav Mod: stock :] Location: Torrance, California Posts: 489 Join Date: Sep 2007 Trader Rating: (1)	Re: No Oil cap more horsepower Like I said before about the release of gases, will this affect our cabin air? No body need carbon monoxide in their car

06-09-2008, 01:17 PM	#141
*bue car* Platinum Member Car: 07 STi Blue Fav Mod: stock :] Location: Torrance, California Posts: 489 Join Date: Sep 2007 Trader Rating: (1)	Re: No Oil cap more horsepower My cap PIC-0042.jpg - Image - Photobucket - Video and Image Hosting

06-09-2008, 05:34 PM	#142
WRX4ME LE 482 Spec C Club Car: '07 STi Limited #482 Fav Mod: Disabled seatbelt dinger Location: Mississippi Posts: 1,158 Join Date: Mar 2007 Trader Rating: (0)	Re: No Oil cap more horsepower I have heard that these kinds of systems can feed into the cabin. I don't think it'll cause any kind of deadly inhalation hazard though. In fact, I haven't smelled anything at all, and I'm pretty sure I'd be able to smell it if it was an issue.

06-10-2008, 02:07 PM	#143
Iguana Spec C Club Car: 06 Aspen White STI Fav Mod: Defi's Location: Northern California Posts: 1,427 Join Date: Apr 2006 Trader Rating: (0)	Re: No Oil cap more horsepower this was an interesting read.

06-10-2008, 02:27 PM	#144
esqdgg Professional STI Racer Car: 05 STi Location: SF, CA Posts: 670 Join Date: Sep 2006 Trader Rating: (0)	Re: No Oil cap more horsepower very interesting read thus far. any concerns from my fellow statesmen re: our friendly local pd or chp seeing that "thing" in the engine bay and immediately asking "where's the carb certified label?" or worse yet, just straight-up issuing you a fix-it ticket for it? i can pretty easily imagine that happening to me with my luck.

06-11-2008, 07:25 AM	#145
WRX4ME LE 482 Spec C Club Car: '07 STi Limited #482 Fav Mod: Disabled seatbelt dinger Location: Mississippi Posts: 1,158 Join Date: Mar 2007 Trader Rating: (0)	Re: No Oil cap more horsepower I'm certain if the cops around here were anything like Cally cops, they wouldn't like it at all... Glad they're not. I would like to get out and do some more testing and tuning, but my brokeness and gas prices and g/f in labor are making it difficult...

06-11-2008, 07:44 AM	#146
*bue car* Platinum Member Car: 07 STi Blue Fav Mod: stock :] Location: Torrance, California Posts: 489 Join Date: Sep 2007 Trader Rating: (1)	Re: No Oil cap more horsepower Congrats on the little one man! Also i carry my normal cap in my glove box for just that reason. If I was pulled over, I would say i was running tests (Hence the aggressive driving) and simply put the OEM back on

06-11-2008, 11:43 AM	#148
RAPTR Professional STI Driver Car: My journal Fav Mod: Tank the Terrier! Location: Walnut Cr, CA/Boulder, CO Posts: 448 Join Date: Jun 2006 Trader Rating: (3)	Re: No Oil cap more horsepower ^link to where someone sells that?

06-11-2008, 08:20 PM	#150
bluedemon_II Professional STI Driver Car: 04 Sti Wrb on Silver Location: Hatillo, Puerto Rico Posts: 498 Join Date: Jul 2007 Trader Rating: (0)	Re: No Oil cap more horsepower That actually looks nice This ad is not endorsed by this member. Please register or login to hide this ad.