[WRX4ME LE 482]

Alright guys, I have some numbers:



(1)



(2)



(3)


Sorry for the so-so quality pics. I guess it was too bright outside for my phone.

My "cap" of choice for this experiment was a paper towel, folded into fourths. I poked some small holes in it, and secured it very tightly with a piece of string I had laying around. I started out by driving around slowly, just to make sure this would be a safe experiment for my car. I slowly ramped up my loads, checking every once in a while to make sure everything was ok.

Eventually, I felt it safe to do some 2-6k fourth gear pulls at my favorite spot. I did 3 pulls first with my makeshift high-flow "cap", and then put the OEM cap on, and did 3 more pulls. In my experience, I get plenty of cool-down time between runs, so I dont feel doing one "cap" first, or the other really matters.

Also, before anybody asks, my pulls are on a quiet stretch of 4-lane highway about 1/4 mile long that is fairly flat and most importantly has very little traffic. I circle around until no cars are present, then start my run with a clear road ahead.

On the first run, my IAM hit .5. This is totally not unusual for me. My tune is actually excessively safe, but I've got some strange settings (I suspect in my fine-learning tables) which make my IAM drop more often than it should. My main goal was consistency, so I knew I could work it (my IAM) up to a point where it wouldn't likely move again. I was right. I got it to stabilize at .5625 and I started my runs over.

As you can see, the "no cap" runs averaged ever so slightly faster pull times. The 4-6k differences are right about the same as a 10-15 degree drop in fahrenheit. I find it odd that the bigger difference was found in the lower RPM range, which is the area I usually don't care about as much.

It's my opinion that a "filter-cap" mod here would be worthwhile, providing it is proven to be completely safe for the car, and doesn't cost very much.

Also, pic 3 shows the quantity of oil that came out during the entire experiment. Basically, I could have reused that paper towel for dinner.

[WRX4ME LE 482]

Im curious if using a modified "oil cap filter" device would allow you to seal off part of the PCV system, thus avoiding blowby altogether and eliminating problems with oil in the I/C and lowered octane from burning oil vapors.

[bue car]

Originally Posted by WRX4ME LE 482

Alright guys, I have some numbers:



(1)



(2)



(3)


Sorry for the so-so quality pics. I guess it was too bright outside for my phone.

My "cap" of choice for this experiment was a paper towel, folded into fourths. I poked some small holes in it, and secured it very tightly with a piece of string I had laying around. I started out by driving around slowly, just to make sure this would be a safe experiment for my car. I slowly ramped up my loads, checking every once in a while to make sure everything was ok.

Eventually, I felt it safe to do some 2-6k fourth gear pulls at my favorite spot. I did 3 pulls first with my makeshift high-flow "cap", and then put the OEM cap on, and did 3 more pulls. In my experience, I get plenty of cool-down time between runs, so I dont feel doing one "cap" first, or the other really matters.

Also, before anybody asks, my pulls are on a quiet stretch of 4-lane highway about 1/4 mile long that is fairly flat and most importantly has very little traffic. I circle around until no cars are present, then start my run with a clear road ahead.

On the first run, my IAM hit .5. This is totally not unusual for me. My tune is actually excessively safe, but I've got some strange settings (I suspect in my fine-learning tables) which make my IAM drop more often than it should. My main goal was consistency, so I knew I could work it (my IAM) up to a point where it wouldn't likely move again. I was right. I got it to stabilize at .5625 and I started my runs over.

As you can see, the "no cap" runs averaged ever so slightly faster pull times. The 4-6k differences are right about the same as a 10-15 degree drop in fahrenheit. I find it odd that the bigger difference was found in the lower RPM range, which is the area I usually don't care about as much.

It's my opinion that a "filter-cap" mod here would be worthwhile, providing it is proven to be completely safe for the car, and doesn't cost very much.

Also, pic 3 shows the quantity of oil that came out during the entire experiment. Basically, I could have reused that paper towel for dinner.

This is true about the slpash back..

Also look at my cap..it was only 25 about to make...

Very solid.

[importfanatic17]

Wow, so your paper towel lead to faster times. It should be the same with a modified cap that is recirculated (like into an A/O) right? If so, I am going to buy a catch can and do this mod!


Thanks on obtaining some numbers but is it possible that the slightly faster numbers were obtained b/c you started at slightly different speeds?

[ryanwrxduksa]

We need some one with a dyno to do this.

[importfanatic17]

Originally Posted by ryanwrxduksa

We need some one with a dyno to do this.

I don't think it was supposed to be measurable in hp. I think it was earlier discussed that this was relieving pressure and would act somewhat like a lightweight part and provide better drivability without providing a notice on a dyno chart.

[ryanwrxduksa]

Originally Posted by importfanatic17

I don't think it was supposed to be measurable in hp. I think it was earlier discussed that this was relieving pressure and would act somewhat like a lightweight part and provide better drivability without providing a notice on a dyno chart.

If you need X force to accelerate something from 2k rpms to 6k rpms; Then wouldn't doing it faster constitute more power? After all, Road Dynos measure the time it takes to accelerate from X Speed to Y Speed, right? I might be all wrong, just thinking out loud

[WRX4ME LE 482]

Im pretty meticulous about how I perform my tests, though I will be the first to say I cannot possibly be perfect. I get in the same lane, on the same road, going the same direction. I get my car in the range of 1500-1800 rpms in 4th gear (which means im going the same speed each time). I use a tree as a marker. Right when I get to it, I floor it, and hold until around 6200 rpms. When I get the numbers back home, I only measure performance from 2000 rpms up to 6000 with a formula I wrote in MS Excel. Then I split it up into its different components.

I feel like 3 runs gets me a pretty good average of what to expect at that temperature. It's amazing how big a difference temperature makes. On this test, my best 4-6k times were around 6.5 seconds. At 42 degrees, I've attained 5.2s multiple times with around 17 psi as my max boost (19 psi max in this test). If my IAM had been full, I would've more than likely seen around 6.1-6.2 this time.

[importfanatic17]

Originally Posted by ryanwrxduksa

If you need X force to accelerate something from 2k rpms to 6k rpms; Then wouldn't doing it faster constitute more power? After all, Road Dynos measure the time it takes to accelerate from X Speed to Y Speed, right? I might be all wrong, just thinking out loud

But not in horsepower. Think about if you had a stock STi that did the 1/4 in 13.4. If you strip out a ton of weight, you will be faster in the 1/4 but you will not have more power...

[ryanwrxduksa]

Originally Posted by importfanatic17

But not in horsepower. Think about if you had a stock STi that did the 1/4 in 13.4. If you strip out a ton of weight, you will be faster in the 1/4 but you will not have more power...

Doh!

[importfanatic17]

Originally Posted by WRX4ME LE 482

Im pretty meticulous about how I perform my tests, though I will be the first to say I cannot possibly be perfect. I get in the same lane, on the same road, going the same direction. I get my car in the range of 1500-1800 rpms in 4th gear (which means im going the same speed each time). I use a tree as a marker. Right when I get to it, I floor it, and hold until around 6200 rpms. When I get the numbers back home, I only measure performance from 2000 rpms up to 6000 with a formula I wrote in MS Excel. Then I split it up into its different components.

I feel like 3 runs gets me a pretty good average of what to expect at that temperature. It's amazing how big a difference temperature makes. On this test, my best 4-6k times were around 6.5 seconds. At 42 degrees, I've attained 5.2s multiple times with around 17 psi as my max boost (19 psi max in this test). If my IAM had been full, I would've more than likely seen around 6.1-6.2 this time.

Don't get me wrong, I appreciate what you have done for us but I am just trying to find inconsistencies so that we can figure out if this is a worthy mod. From your info it is but I'll let some other people that know more about cars chime in about this before I say too much.

[WRX4ME LE 482]

^No worries Import. Pick it apart as best as you can!

Over the past year of tuning my car I have found this to be a good method of determining whether a particular change is positive or negative.

Oh, and what you said earlier about weight is true. A massively lightened, otherwise stock STi may have the same hp as stock, but in my tests it would finish faster.

I honestly think this mod may be worth at least .2 in the quarter.

[jagstyle]

online source for cheap oil cap?

[bue car]

i plan to get a dyno run soon just to see where i am at... ill have this tested then

[WRX4ME LE 482]

K&N Crankcase Vent Filters

Check out the ones on the bottom. They may be too small though. And, I have no idea of the price...