38 replies to this topic

[lookforjoe]

Trying to decide whether to remake my airbox. Filter is a K&N RX-4730 extreme (3" inlet); The current casing is about 6.5" OD, with a slight taper, 3" inlet snorkel. There isn't actually much space between the filter & the casing. What I observe is that the filter gets very dirty around the air inlet, and not so much over the rest of the pleating. Functionally, seems to be OK, just not really happy with the level of finish.





Not much room for a larger can, but 7" should just fit.





While I'm cleaning up everything else in the bay for the new build, I'm thinking about making a nice Aluminum casing, same design, just 7" OD, with a slight taper, to provide a little more breathing space around the filter element.

What I'm not sure about is whether making the casing out of aluminum is a good idea (heat retention?), and secondly, whether additional room around the filter actually makes any difference to the full filter surface area being utilized.

[sconeman]

My take on it is; the way the inlet is set up most of the filtering is being done where that inlet dumps into the canister. I'm sure some of it moves around the sides but It's going for the path of least resistance and that will be straight through. If you could get the inlet at the end (front) of the canister then the air would have no choice but to move around the filter and got through more evenly.

Re: material. Aluminum heats up Fast but it cools off fast too. As soon as cold air hits it it's going to cool off. The lower the thermal conductivity the slower it's going to heat up or cool down. So with a material like black ABS it's going to be slower to cool down. I don't think there is anything wrong with Aluminum. If you use aluminum and insulate it then that would be great but would look ugly and with your huge turbo it's only going to take a split second for everything to cool down to the ambient temp when you get moving. Any insulation will also keep the canister from cooling off fast so keep that in mind.

Edited by sconeman, 02 March 2012 - 04:19 PM.

[Fudge-Brownie]

How about something along this design? Its pretty much what Im doing when I move the battery in the trunk.You can get the cold air right there. And dam I love this engine bay

Edited by dublin14, 02 March 2012 - 04:37 PM.

[T5Hammy]

My take on it is; the way the inlet is set up most of the filtering is being done where that inlet dumps into the canister. I'm sure some of it moves around the sides but It's going for the path of least resistance and that will be straight through. If you could get the inlet at the end (front) of the canister then the air would have no choice but to move around the filter and got through more evenly.

Re: material. Aluminum heats up Fast but it cools off fast too. As soon as cold air hits it it's going to cool off. The lower the thermal conductivity the slower it's going to heat up or cool down. So with a material like black ABS it's going to be slower to cool down. I don't think there is anything wrong with Aluminum. If you use aluminum and insulate it then that would be great but would look ugly and with your huge turbo it's only going to take a split second for everything to cool down to the ambient temp when you get moving. Any insulation will also keep the canister from cooling off fast so keep that in mind.

For the amount of time you spend at a stop light or idling somewhere, I would think better insulation would be the way to go. If the abs prevents the heat from reaching the actual intake for the time at say a stoplight (60 sec or so) then when you start moving again the abs would have a much greater time to cool while driving (assuming you're not bumper to bumper). I figure most of the time when you want performance you spend way more time with air flowing through your engine bay than you do sitting still. Since these cars cool relatively fast after you start moving, I would think that IAT's will be benefitted by the better insulated material.

Now I don't know how fast H's car cools with massive amounts of heat compared to the average setup, but if you want better finish on the ABS setup maybe wrap it in graphite?

How about something along this design. You can get the cold air right there. Dam I love this engine lol

Its clean looking but pretty much looks as efficient as an SR5T, and the accordion duct probably doesn't flow great

[Zappo]

BMC CDA (Picture borrowed from boomin)

[ErikS]

All the way to the bottom of the bay.



Currently its back up to the stock location, but it will go back to this later ...

[lookforjoe]

My take on it is; the way the inlet is set up most of the filtering is being done where that inlet dumps into the canister. I'm sure some of it moves around the sides but It's going for the path of least resistance and that will be straight through. If you could get the inlet at the end (front) of the canister then the air would have no choice but to move around the filter and got through more evenly.

I agree with this. I do actually have the end open behind the headlight, the extreme K&N has air intake through the nose of the cone.

Regarding other suggestions, I'm not doing a battery relocate so any substantial redesigns are off the table.

BMC can is very small compared to what I have.

Lower intake draw is not a good idea anywhere there is heavy rain/ water pooling on the roadway, I already tried that & know the effect. In hot weather, the air temp is higher right off the roadway than at the normal intake point, so again, not really a good idea.


I'm going to go ahead with an aluminium version. As Kristian pointed out, it doesn't retain heat the way the plastic does, and it will look much cleaner

EDIT: I really like Russ's bay, but not that accordian. I'm thinking about adding that extra torque damper idea he used on the passenger side. I have to replace my lower engine mount again as it has ripped off the base plate. That damper would probably relieve some of the stress it sees.

[Fudge-Brownie]

Its clean looking but pretty much looks as efficient as an SR5T, and the accordion duct probably doesn't flow great
[/quote

As long as you get cold air right from the front and make a proper sealed box then I dont see in anyway how that would not be efficent. I used that pick as a general idea, and also wouldnt use an accordian duct to the turbo either. I'll just be extending the 3" CA Sconeman pipe I have now.

Edited by dublin14, 02 March 2012 - 06:18 PM.

[ErikS]

Lower intake draw is not a good idea anywhere there is heavy rain/ water pooling on the roadway, I already tried that & know the effect. In hot weather, the air temp is higher right off the roadway than at the normal intake point, so again, not really a good idea.

So you're saying its a dumb idea in general huh, interesting ...

[Zappo]

My BMC can is bigger than the one in the photo. I have to turn my battery sideways before i can install it.

[lookforjoe]

So you're saying its a dumb idea in general huh, interesting ...

It depends were you live. I did run mine like that for about a year. It was horrible in heavy rain, worrying about whether I was going to choke the filter or worse. Less bends in the inlet tract is always better, I've tried to reduce harsh transitions where possible.

My compromise was to run primary intake up top, with a auxiliary intake next to the foglight area. I had to remove that at some point due to lack of space.

[SKI-R]

Running the same as Zap - sideways (turned 90 degrees) mounted Optima battery to facilitate straightest run through a BMC (mine IS Boomin's old one, so the exact same size as the pic above). Not sure that you actually have room to spin your battery given the CC that you have where the airbox was originally, so the whole idea may be moot.

I concur with Kristian's comments - aluminum, sans insulation. And if that's not sufficient, then FULL custom fabrication - haven't seen you dabble in carbon fibre yet!

[lookforjoe]

My BMC can is bigger than the one in the photo. I have to turn my battery sideways before i can install it.

Have you an idea how much space there is between the filter element & the can inner wall? Just trying to gauge how much space they factored as acceptable....

[T5Hammy]

As long as you get cold air right from the front and make a proper sealed box then I dont see in anyway how that would not be efficent. I used that pick as a general idea, and also wouldnt use an accordian duct to the turbo either. I'll just be extending the 3" CA Sconeman pipe I have now.

Wasn't implying that its inefficient, but with the factory tube from the front to the airbox I don't see a need to relocate the entire box, I was just saying at that point it is mainly preference since they will both be fairly cold.

[Zappo]

Have you an idea how much space there is between the filter element & the can inner wall? Just trying to gauge how much space they factored as acceptable....

I can take mine apart and measure. I have opened it up before, but it is all together now.

[trs80]

This thread needs moar diagrams.

[SKI-R]

Have you an idea how much space there is between the filter element & the can inner wall? Just trying to gauge how much space they factored as acceptable....

IIRC - conical filter on mine, ~1/4" space around the base of the filter, ~1 1/2" around the narrower end....... haven't looked/cleaned in awhile. Away for the weekend, but if you're still looking for concrete numbers on Tuesday (not your typical operating mode, I know) I can get them for you at that point.

More diagrams here:

http://www.bmcairfil...rd_pr3_4_1.aspx

scroll down to the ACCDASP-05 option (I believe that's what I ended up with from boomin), click and you should end up with a general idea on dimensions.

Further review leaves me believing I ended up with the ACCDA85-150 universal kit. The filter I got does not look like their current replacement options ACCDARI-150 (both these items are on the same page as the above link). Looking at the filter dimensions (I'm sure you can scale it reasonably close) I'd guess ~15-20mm clearance between filter and housing wall.

[dougy]

Nice job on remake Hussein. Mine still the same, but I did one for my s60r as well.





well... i guess I should read before posting..lol..I dont think there is anyhing wrong woth what you got.

[boxpin]

Thats the sexiest engine bay I have ever seen.

[the commissar!]

For the record, my SR5T also collects the most dirt directly in front of the inlet tube, but it does collect dirt all around. Lots more room in that box than yours. I figure as the filter clogs, the bulk of the air flow will pass around the area of the filter that is clogged (path of least resistence as Christian said) until the deltaP reaches a level where airflow restriction is topped out then you either get blown out filter or dirt pass-through / IF you let it get that dirty, I know you don't H. but some here probably do