Best DIY intake?

[turntaker]

I have been looking at cheap mods to do to improve thee sound and intakes seem to be a popular mod. ( I have already done a SE muffler swap)., However there are so many different opinions. What are the best options in terms of cost and sound/effectiveness.

Would you recommend a cold side intake? I have read that the Swiss cheese mod is quite popular but I do not want to suck in hot air into the engine.

[hks_kansei]

Power will be stuff all difference unless you're also tuning the engine to suit.

Sound wise, loudest is the firewall intake.

Otherwise you can just put a pod where the airbox is and shield it, or make a custom box like a ddm works one

Or as you said, a coldside intake.

I have a coldside on mine, it sounds nice, looks nice, but no power diff at all.
Also makes the car run like a bag of sh*t when it's too cold outside (air temp sensor gets frost on it occasionally)

[turntaker]

Yeah not looking for power gains or anything, just sound.

How cold does it get where you live. Didn't think cold side intakes would cause this issue.

If that's the case I may go with a shielded pod in the same location as the air box

[Magpie]

The one made using Tupperware!

[hks_kansei]

Coldsides don't cause the issue, it's more a matter of where you mount the air temp sensor (a separate sensor for nb, na have it built into afm)

On mine the sensor is just up under the rad support, in front of the filter, so not ideal (I got lazy)

If you buy a pre made intake, or drill out the elbow and mount the temp sensor post-filter it shouldn't have the issue.

Temps here get fairly cold but no snow or anything.
We get some pretty bad frost though.

[smy0003]

The Tupperware job is probably my favourite. When you think about it, it's a cheap solution using a material that is designed to freeze and hold boiling liquid.

I used a 45deg bend of 2.5" aluminium with an open pod filter. Very loud, most likely sucked in hot air.

Sent from my LG-H815

[turntaker]

The Tupperware job is probably my favourite. When you think about it, it's a cheap solution using a material that is designed to freeze and hold boiling liquid.

I used a 45deg bend of 2.5" aluminium with an open pod filter. Very loud, most likely sucked in hot air.

Sent from my LG-H815

Was yours a cold side intake?

[Cus]

My opinion: One with as few bends as possible. I just pulled my DIY one off my car, it was hurting economy even though it was delivering fairly-ambient air into the engine, there were way too many bends of far to tight a radius.

[Magpie]

http://mx5cartalk.com/forum/viewtopic.php?style=3&p=877363#p877363

[bartmanftw]

You also want to keep the intake around the same length as the stock one. Shortening the intake too much will cause a dip in torque down low in the rpm range.

[turntaker]

You also want to keep the intake around the same length as the stock one. Shortening the intake too much will cause a dip in torque down low in the rpm range.

Hmm yeah good point

[aka_juffa]

http://www.autospeed.com.au/cms/A_110680/article.html

[Alex 2550]

Hey turntaker, couple things on cowl intakes, coldside intakes and crossover tubes to help you out as i did a fair bit of research before making mine.
swiss cheese air box the yanks talk a heap about but will suck hot air and many who have done it regret it and change it back, yes it makes noise but the other reason the yanks like it as they are restricted on cowl intakes because they drive on the wrong side of the car and the brake master cylinder is there
cowl intakes add between 5-10rwhp from what has been documented many times and seen from dyno days. save arguments lets split the difference and be generous say 7hp at the wheels. (barely noticeable on the "Butt dyno")

My cowl intake is cheap without the heat shield tape but not as effective, throttle response mildly better, above 5,000rpm there is more pull than before no doubt but it is a small amount (air box snorkel restriction? no curves? colder air?), fuel consumption has improved. pod is enclosed so boys in blue wont give you grief.


down sides,
-its loud with soft top up, louder with hard top on, no top its actually quite a nice growl. it is louder and deeper than a loch stewart cowl intake and similar to a mania but more cc volume due to the larger diameter i used.
-takes about 5 minutes to clean leaves out of the filter (like the mania). mine is garaged so not a big issue but if you park near trees it would really annoy you, clog up air filter quicker and reduce performance but this has been discussed many times on cowl intakes.
-bloody big hole in your firewall.

bottom line would i do it again- yes i would, my wife doesn't like the noise as much .

crossover pipes,
My AFM will be gone soon and i intend to get an NB crossover tube to replace my NA8 one (better design, mazda changed it for a reason).
I expect that these will remove more of a restriction and net me a couple HP but will be hard to measure as the computer will be different.

i think the large volume crossover pipes on the market would benefit max HP at max RPM on a dyno but most if not all are metal and run between the radiator and motor so bonnet closed and longer running times heat soak will kill that small gain in the real world.
Documented many times on here and other forums is that the hermholtz (sorry on spelling) chamber on the mazda factory pipe does help mid range torque and would contribute to the shortside/large crossover pipe torque dip.
short coldsides have been shown to slightly reduce midrange torque and really there isn't that much to lose in the first place. air velocity would probably come into play here as well as the hermholtz.
real performance messurements of large crossover tubes and cowl intakes is probably a "what is your trap?" kind of question rather than a "make a difference on the dyno?" one.
this will take into account and show heat soaking of components and engine bay air temps. it will also show the benefit from cowl intakes of the pressurised area under the windscreen that isn't seen on a dyno, dont get me wrong it wont be 20 psi more like an 8th of a bees fart but might be something that explains why so many people think these make a larger difference than the dyno shows, i wonder at what speed there is enough pressure to actually makes a difference?.

anyway here is how i did mine and best of luck with it all.
viewtopic.php?style=3&f=29&t=72551&hilit=cowl+intake
if you need to hear it PM me and ill get it to you, the vid in that topic has expired.

[SuperMazdaKart]

Consider this, K&N Typhoon kit for $55.09 & free post. http://www.ebay.com.au/itm/Universal-Typhoon-Cold-Air-Intake-Induction-System-Kit-With-Air-Box-Filter/302050517425?_trksid=p2047675.c100009.m1982&_trkparms=aid%3D777003%26algo%3DDISCL.MBE%26ao%3D1%26asc%3D20140117125611%26meid%3D3fbe42e992c84f1c8f25e7f25678e25a%26pid%3D100009%26rk%3D5%26rkt%3D10%26sd%3D172349438449 . Couldn't even assemble a copy for any cheaper.

[smy0003]

The link you posted is a generic eBay knockoff

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