caymandive

iTrader: (2)

hehe, who posted this video?

http://www.youtube.com/watch?v=RgW24Vh5ons

**edit** nevermind I found the creator back a few pages. Funny!

Cleric

good read here

The supplier for this HC Trap does aknowledge "minimal" impact to flow (which I think the logic has been beaten to death in this thread), but I also have to assume that when Toyota calclulated the flowrate requirements for the engine at WOT and at max engine speed, this was taken into consideration thus they determined what minimum filter surface area was needed with all restrictions in place to prevent the engine from starving. Of course if one were to replace the exhaust system or go forced induction, then increased flowrates are required at which point may put the stock intake system at the point of diminishing returns thus justifying the need to modify the stock intake system with something aftermarket and less restrictive.

From my fluid dynamic days I know flowrate = velocity x area. The surface area of the filter is a lot larger than the area of the intake tube/throttle body so while it can be easy to assume the filter is very restrictive and worth doing away with, if enough filter surface area is present and the engine is not starving for air then I would be surprised to see any noticeable performance benefit removing the filter. I guess the only way to really quantify this would be to take engine power measurements from a dyno and determine the pressure drop seen downstream after the filter.

nabbun

Actually, I have had a similar 2ndary filter on my Toyota Solara (which I took out.)

Read the very last post in this thread:

http://www.solaraguy.org/viewtopic.php?t=15925

We needed to do this and the vacuum trick to improve our engine's throttle response.

Toyota does these things to make our rides quieter when the rpm is low for a more "luxurious" ride =P

I traded it in for the IS 250 AWD and I'm so very glad I did.

I hated the Solara for 2 reasons:

The looks were fine but, the engine's throttle lag and handling sucked!


Edit - Performance gains on our cars should be minimal because the intake's design, as a whole, is sorta restrictive.

If there was a better, complete meaning from where the air gets sucked in > air filter > throttle body > intake manifold > ported and polished intake valves, design then yes, you can make more power.

But in our case, you are only removing the hydrocarbon filter and leaving the stock intake in place, which is an already restrictive design, so slightly better air flow yes but, no performance gains but more emissions =)

caymandive

iTrader: (2)

But if you swap out the stock air filter with a more free flowing filter such as the HKS Super Hybrid Filter, that restriction goes away. I have already begun modding my stock intake similar to what Gernby has done, but with a few changes.

I removed the hydrocarbon filter carefully and lined it's frame with velcro tape so that I can easily swap it in and out for track purposes. Also just ordered the HKS Hybrid Filter that I'll run when the hydrocarbon filter is pulled out. There is definitely a gain to be had by removing these intake restrictions in conjunction with a more free flowing exhaust.

Since I'm fairly certain the HKS filter or any other aftermarket filter does not filter as well as the stock one and I'd like to remain as environmentally friendly as possible, I will only use this setup for track days and keep it in stock configuration the rest of the time. We'll see how it goes, but it sure can't hurt to try and this is cheap modding.

Gernby

iTrader: (1)

Actually, Blackstone labs reported on my last UOA that my air filtration was very good considering my low silicon level.

caymandive

iTrader: (2)

I'm not too familiar with how to read those lab reports, but what else besides the silicon level would be some indications that the air filter is not pulling enough garbage out of the air and getting into the oil?

Gernby

iTrader: (1)

I don't know of any other indicators about air filtration than silicon, but here is what Blackstone had to say.

caymandive

iTrader: (2)

So what oil have you been running in your car and how many miles are you going before doing oil changes? Good information man!

Larry96815

With the after market exhausts coming in bolt on sections it would be so easy to just unbolt the mufflers at the track. Have you ever tried doing that? In my high school days (60s) I remember we would not even remove the muffler, just swing it aside and had a hanger for the pipe. It would take about two minutes. I remember even using wing nuts on mine so I didn't even need a wrench.

Gernby

iTrader: (1)

That may have worked in the 60's but the "tuned" exhausts that are used today can cause reduction in power if you just remove a section of it due to the change in resonance characteristics that comes from shortening the pipe.

caymandive

iTrader: (2)

Not to mention I don't believe most tracks allow this for reasons I'm not sure. I know for a fact they don't allow cut-outs.

Gernby

iTrader: (1)

I'm sure most tracks around where I live would allow the axle-back to be removed since the pre-muffler / resonator does a pretty amazing job at quieting it down.

nabbun

I want an ARC intake box or something that'll replace the whole intake unit lol

or maybe i'll just create my own short ram with a conical filter and complete heat shield that'll draw in air from the front air dam and the rest of the air can leave the back thru the vent hoods of the new seibon ts hood

Or make a naca duct instead of using the air from the grill =P

I dunno I'll keep thinking and dreaming until I start doing the mods.



Lots of ideas floating around in my little head >_<


Edit - Complete as in sealed

jimmyjazz

Crude flow bench results. SuperFlow 600 flowbench. Just laid the filterson 4.155 bore plate , roughly 500cfm with the stock toyota filter put the carbon filter on, dropped to 470 (roughly). I don't know anything about flowbenches. The owner said 30 cfm divided by 6 cylinders is only 5cfm per cylinder. It's just inconsequential. Lobux, sorry about the 500 instead of 200 they have their bench set up for LS1 andLS6 heads (the boreplate) and I didn't want to cause them too much trouble.

Gernby

iTrader: (1)

500 to 470 is a 6% change. That's pretty damn significant when compared to other mods. I realize that the percent change wouldn't be nearly as large at 200 CFM, but ...