Cold Air Intake suggestions
 

I bought an adaptor/K&N 'style' kit off ebay for about $20.

Search for this........
ADAPTER AIR FILTER SUPRA 86-92 NA

It mounts to the AFM (just remove the factory air box, but save it, cause it costs $250 from Toyota).

I drove the car with just the K&N, sucking hot underhood air into engine. It seemed to have "lost" 10 hp.

I used galvanised sheet metal, and flat plastic (from a new kitchen trash can) to 'box in' the filter so as not to draw hot air into the intake, and to force fresh air in from behind the headlight.

You can use whatever, but that was quick, easy, and cheap.

Now, if I were doing it again, I'd see if I could find a small plastic rectangular trash bucket (right color for matching underhood stuff) that would fit even better.

Next........

I cut away the factory plastic wall to let some of the air coming into the front grill (where air goes to radiator) to also be forced into the area behind headlight so it would go into the big oval hole where the old factory rubber 'snorkle' was mounted to the factory air box.

After boxing the filter in, so it only gets outside air, it feels like it gained 10hp. I could FEEL the hp difference.

Air filtration and location...
 

whats the downside to aftermarket air filters Mr. Fuhrer?

Not all filters are created equally. There are a LOT of reviews on the net which test them and show you their methodology... two which I trust are this one and the one over at bobistheoilguy.com... for which I cannot find the link at the moment. The top three on my list are (in order): Apex'i, AEM DryFlow, STOCK, K&N... the K&N is in the last place there as it filters worse than the first three and it is an oiled filter requiring maintenance (some have had troubles supposedly from the oil the filter is coated with damaging intake sensors... I think they've used too much, but I acknowledge the potential and as such I would only use one temporarily). The Apex'i and the AEM flow extremely well, are made of excellent materials and are 'essentially' maintenance free (you do need to blow them off with a compressor fro time to time, but no washing or oiling is required).

As for my complaint about the location.... air in the engine bay is HOT... hot air = power loss... PERIOD. A less restrictive filter that's sucking up air that is 20?+ hotter than you'd be getting through the stocker without the temperature spike more than costs you any potential benefit. I've seen people do their dyno tests with different filters, I have yet to see one where they do each and every run with the hood actually closed and no fan blowing into the engine bay.... besides, an increase of 5 to 10 HP is crap and honestly dyno test results will vary that much from one run to the next when tested back to back. Generally I ignore any dyno results posted in such tests; Now, if there's pressure differential information included they've got my attention.

Cold Air Intake basic information
 

thank you cre our resident guru.

I'd provide additional photos but there's nothing remotely stock about my intake system... If anyone cares to contribute some, you are encouraged to do so.


I should also add, because I've heard this argued over, that it doesn't matter if the car is turbo or not; Getting cold air in at the filter is very beneficial. An intercooler does NOT make up for hot air coming in, it can only cool so much. Supply a turbocharged system with hot air and the turbo increases the temp to a larger degree than if the air entering was cold... Basically, a turbo fed air at 20C will kick out air at 30C, while one fed air at 40C will kick out air at 60C (not real math, just an easy to follow example). Then, the IC has a limit on its capacity as a thermal exchange (which isn't linear either, but let's pretend it is to keep this REALLY simple)... so we say the IC is capable of reducing temps by 10%, you feed it air at 30C (thanks to our CAI) and it feeds the engine air at 27C, feed it air at 60C and it feeds the engine air at 54C.

Running a real CAI is ALWAYS beneficial... How you provide the cold air is another variable which I'm not going to cover right now.


NOTE: The hypothetical example given above is only to serve as an easy to follow guide. The actual math is quite complex and the example above explains the basics well enough, IMO.

I'll second that recommendation.

I prefer this setup as well. It's much less involved than building a box too.

Definitely not a preferred setup. While BARELY a step above just tossing a filter on the end of the AFM and leaving it open to the engine bay you're still leaving it open to the engine bay heat while the vehicle is at rest when the worst heat soak occurs. Depending on the number of bends and their angle you're probably not seeing any benefit that you would see by simply removing the passenger side fog light and forgetting the duct.

This is what I did for mine to help isolate the air coming in from the engine bay. Although it is a NA, the concept should work for a turbo as well. And as far as making the filter run under the headlight the only advice I would give is to keep it up as high as possible to prevent any chance of hydrolock. But maybe it does not rain that much where you are in utah.

http://www.toyota-supra.info/forums/...albums125.html

You can add a valve to the intake piping to open if the vacuum goes above a certain value (say vac over 22InHg). OR they make cylindrical filters with a clamp on both ends which you can add to the pipe further down... they're small enough that little air will be pulled in through them as long as the primary filter isn't clogged or submerged (AEM makes one).

EDIT: http://www.aemintakes.com/air_bypass_valve.htm

I've logged a few different setups with the MAFT Pro as well other EMS's too; Unless you're doing comparisons of each system on like builds under like conditions it means nothing. Open filters (which is all that yours is at low speed and at rest) see a huge increase in intake temps and it takes a while for the engine to clear out that excess heat. While the car is moving there's enough air moving through the engine bay to negate a good percentage of the benefits. The sum of which is more than enough for most to ensure the good ol' "dryer duct CAI"'s placement it on the "not worth it Civic mods" list; Right beneath the entry for "MASSIVE air filter sitting open in engine bay on the EXHAUST side of the bay no less" but still over a couple dozen slots below #1 "4' aluminum racing wing on FWD car with 98HP"(this really is one of my all time favorites).

Sure, any piping in the bay is subject to some heat soak but when the filter is pulling in cool air it's affect is negligible; Besides, it's nothing a good wrap or ceramic coating won't cure to a very significant degree. My soda is still nice and cool when it reaches my lips through the straw even though it's being pulled through 92? air... But put that soda in pot on a hot stove and it's another story (whether you stick in another, smaller straw and blow bubbles or not).

72?? Isn't wind chill great? You know that even if it's 100? out you can still form ice inside the intake? That's why the TB and ISCV have coolant lines run to them. Sorry to say you're not defying the laws of physics though.

Anyway, the point you're missing is that it could be much better all around for the measly cost of a couple feet of pipe with a bend in it... and it generally involves no more effort to install. Actually, the stock air box is best of all... it breathes just fine for up into the 300's is CAI, easy to replace, has after market filters available and there's no extra work to make it fit. A filter under the fog light is nice as you can fit up to 5"x7" without deleting the fog light... if you delete the fog light you can fit a whopper 7"x 10" or so... I don't remember the specifics but you can fit some real nice, big filters under there.

I'm not trying to sound like a dick (It just comes naturally, really... can't help it); There's really nothing redeeming to this mod... In my opinion it's nothing more than a weak attempt to fix what was broken by deleting a better system.

zMrManz:
Well, an AEM DryFlow will run you about $60. The AEM Bypass Valve will run you about.. you guessed it: $60. The AFM adapter for the AFM will run about $10 on eBay or Amazon. And you'll need to find a piece of pipe that's 2.75" dia (If I remember correctly, hopefully someone else will chime in with a measurement.) with a 90? bend in it and about 6" straight on one side or the bend and 12" coming off the other... Cost will depend where you get it, $10 or $15 give or take. So you're in for less than you'd pay for an Apex'i Power Intake or the K&N FIPK (both just filters sitting in the engine bay).

Use the bypass valve as the coupler to connect the pipe's 12" leg to the AFM, put the pipe through the hole the stock airbox breathed through so it points down. Pull off the fog light, install the filter, put the fog light back in and tighten everything down. If any of the piping is too long then cut as needed; It's not going to be seeing any boost so loosing a rolled bead isn't going to hurt anything (and clean out any metal shavings/dust thoroughly before final assembly and mounting).

I'd buy the adapter plate first so you know what size to get for everything else... anything over 3" and you'll be doing some cutting. All of the MKIII's I've installed full intakes for didn't use the AFM and ran 3" or larger piping... sorry I can't be of more help there.

I STRONGLY recommend you put some rubber between the pipe and the lip of the opening. I've seen piping get cut through creating a nice large turbo killing sliver of aluminum; Since seeing that I usually take some fuel line and cut it lengthwise and glue it to that lip first.

I know that the Spectre ones that most auto part stores sell fit the 7MGTE KVAFM, you do have to drill new holes for it though. Be sure to get the one that says it fits Mitsubishi's and some other cars. It's the one with the thick black spacer (like 1/2"). The other one (with the small spacer) works for the N/A afm