would anyone suggest i use K&n'S INTAKE kit for 86-88 nonturbo rx7, or just a drop in k&n filter using the stock airbox and equipment. the kit sells for $188. a K&N filter sells for $62. ive heard that the stock intake works just fine and an aftermarket intake is useless. anyone comment please. thanks alot.

 

On your N/A, I would just use the drop-in. But I'm sure others will have different opinions.

 

Drop in.

 

you could buy an adapter off ebay for like 10$ and get your own filters, it would be like 100$

 

your going to lose some hp with a cone filter if you dont build a box for it.

a drop in filter will be better. if you want, ill sell you mine. i have a drop in k&n filter that i havent been using.

 

drop-in,

the problem with aftermarket intakes is heatsoak, underhood temps are alittle over 127 F. the stock intake does a perfect job of drawing cold air in from in-front of the radiator keeping intake temps about +10 degrees over the outside temp(ie it's 75 outside yoru intake temp should be about 85), all aftermarket intakes suck air from within the engine bay at 127f. which would you prefer??.

some people have purchased the headlight lid with which has a hole pressed into it, but it's nowhere near the diameter of the original intake piping. i think most likely even with this the majority of air is gonna be pulled from the engine bay which isn't good.

alot of people like to argue with me on this but as far as i know i'm the only person with an intake temp sensor/gauge installed


the only possibly upgrade i've found would be to use an s5 afm which flows an extra 100cfm compared to the s4.

 

drop in filter. An NA doesn't need more air than the stock airbox can supply.

 

In my tests, a stock airbox drew in hotter air than a regular cone filter sitting on the AFM... so I don't buy the lost horsepower thing and yes I know there's a dyno floating around.

I concluded that this was due to where the stock box draws air from and heat soak of the actual box.

A cold air box or tru CAI is the best alternative.

I noticed increased response and performance with a cone setup. The engine may not need more air, but it certainly puts it to use if you give it more air.

To say it doesn't need more air is like saying it doesn't need a turbo. You can give it all the extra air you want as long as you supply the fuel to match.

 

heatsoak of the stock box is only a factor if your driving your car for a bit, stopping for under an and then driving again, because the fan is not running to push the hot air out, and not giving it enough time to dissipate on it's own. under constant driving there is very little heatsoak through the stock plastic. [



the stock air box draws air in from in front of the radiator how is that worse than having an open filter in the engine bay??



the stock intake is a "true CAI"


thats simply not the case the engine does not compensate for extra air, the engine can only compensate up to the limits of the afm thats telling it how much air has passed through it. now if you have standalone or some way of tuning the car that would be the case but what we're discussing is just the intake[




a dyno would not be conclusive unless the car was completely stock with only the intake changed between runs, even then a slight difference in temperature can make 2 runs with the same setup completely different , we're talking a difference of 1-5hp+- , something you wouldn't even notice with your buttdyno

 

thanks alot i appreciate all feedback, looks like i stick with the drop in.

 

you need to explain these "Tests" of yours, cus you reasoning is erroneous.

the only reason why you NOTICED increase performence was simply because there was more noise coming from under the hood.

drive around with a cone filter for a while, and then put the stock **** back in. youl definitely notice a difference.

 

I bought the kit for 2 cars. I Would do it again! I noticed the car responded much better and wanted to go to the redline faster. If you can spend the money then go with the kit.

Looking at the kit(adapter) it has the best design for the afm to suck in air.

 

make alot of since, i agree 100% thanks.

 

quoted for truth.

Doing a proper ambient air intake or cool air intake will likely cost at least $170. 100 for a vented headlight cover, 50 for a cold air box (if you can find one used, much more new), and $25-30 for an eBay cone filter and adaptor.

I don't know why people have such a hard-on for K&N; while their filters are reuseable, my experience with them is that they actually provide slightly less power than a less-restrictive paper filter.

 

the vents, they do nothing.

 

I rock the drop in. Didn't feel like putting in a lot of work to get a intake that might be better than the stock air box.

 

If you cut your headlight assembly, they allow ambient air to enter the cone filter, especially if you have a cold air box that's sealed against the hood. True, it's not the BEST intake method, but it's the easiest to purchase and put together. The vent ABSOLUTELY helps, even if not as much as most people say.

 

no that is not true, the problem with this forum is there is a huge amount of disinformation on it because of people posting and not really knowing what there talking about,

the vented headlight cover is a waste, the opening is half the size of the intake tube, if you did that and sealed the box completely you'd be taking in way less air than stock (making things worse not better) if you didn't seal it, theres higher pressure inside compartment than outside so it would do nothing, it wouldn't suck air. and it's not a scoop so it's not drawing any air on it's own really because the low pressure on the outside.

i wish people could get it through there heads that rx7's are not civics, just because it's good for one car does not mean it's good for the other

 

^ agreed. Mazda did their homework with the stock intake system. I've had both, and definitely prefer stock with the K&N drop in.

 

"Tests"? Way to be a dick about it.

I posted the tests up. If you're so worried about it, here:

https://www.rx7club.com/showthread.p...ht=cone+filter

My reasoning has nothing to do with this. I used a lab grade thermocouple placed before the AFM on every test.

If I were to be as presumptuous as you, I would assume that your information is nothing more than some parroted BS you heard on a forum, but then again I try not to assume **** about people before I hear the story.

 

ive heard from alot of people the stock box is the way to go, i appreciate ur feedback.

 

First of all, I proved that first statement false years ago with real hard numbers. Yes, I did a seperate test to see if the stock box cooled off on a country road in the afternoon. It did, but only slightly.

That aside... I don't know about you, but I don't auto-x on a country road. It's usually on blazing hot asphalt after waiting in grid. Heatsoak.

Second, numbers don't lie. The stock box was as hot or hotter than a regular cone.

So, the engine can't compensate for extra air, but it can compensate for what the AIR FLOW METER reads. That's a self defeating statement.

I'm not saying it makes some huge difference. In fact, the main thing I noticed between the stock box, cone, and my CAI was the response after sitting in grid (due to heat soak), not some seat of pants dyno experience.

Yeah, the stock snorkel takes in air from in front of the radiator. Have you looked up there? Where is the direct path of fresh air? I can't find it.

You know, I'm all for discussing this... but don't just tell me I'm wrong because you think I am... especially when I've put the effort in to get numbers to back up my statements.

 

you didn't perform any "test" you took a digital thermocouple and stuck the sensor near your intake, and took it out to the track, i have one permanently installed in my DD with the sensor installed in the intake piping, isolated in the middle.

unless you completely isolate the sensor, keeping it away from the walls and not touching anything your data is not correct, which you said you just stuck it in behind the filter meaning it wasn't attached to anything but the wire and that was jammed in there also

you said yourself it yourself that the stock intake was 10-15 degrees cooler, on the 80 degree day.

you also tried to compare on "test" on a 100degree day with another on an 80degree day thats idiotic. your "Info" is complete bullshit.

and why in the hell did you hack up your brake vent?? and you put a mist thingy right there. what happens when you have red hot glowing piece of metal and you splash water on it??? IT WARPS or it explodes. not only that but the heat from the brakes would also be going directly into the intake any time your stopped

do you really think that 20 dollars worth of pepboys parts is better than the millions mazda put into engineering our cars??

your mod is a hackjob and your info is not correct

 

also, your tests are for a cold air intake. not a simple cone filter and adapter setup. that is what we are talking about.

i to have done tests. where i took a thermo sensor with a temp read out, and well... my findings where not too surprising.

i had my sensor taped to the inside lid of the cold air box. since its only like... 5 inches from the afm. i also took temp readings from the drop in at the coupler.

guess which one was getting colder air? as much as 20f?

 

get an aftermarket one and ditch that nasty stock intake tube and your golden. this is coming from a guy that has owned two na rx7's and has used them both. the aftermarket revs quicker and if you get some cold air in there (turbo hood...left light vent...drill a hole in the metal) its really nice.

dont forget, with more intake, u should clear out the exhaust.

gutting the cats is where all the hp has been hiding