Cone intake on a NA
 

I have read now mulitple times for different cars that using a cone intake actually has made the HP lower, and I am wondering if anyone has proof (like Dyno time, or track time) showing that a cone intake actually provides more HP for a NA FC.

Intresting on my V6 Toyota Tacoma, the 2nd gen K&N cone tube intake kit (which runs an almost identical route over the engine that the FC intake does) turned out to have an average of 6 HP less (over the rev band) than the stock filter case, with a K&N panel filter.

Same thing on my SC400 with an aftermarket rice style HKS intake.

So I am again wondering if there really is any proof that the cone filter replacement is worth the investment on a FC.

Thats an interesting question... I wish I knew the answer. I don't have access to a dyno, but when I put my cone on, I didn't notice much difference, hardly any really. It does look nice though, lol.. I'm curious how a filter that is supposed to flow better than stock lowers hp?


~Jesse

I don't think a cone filter does a whole lot on it's own. If you have headers and no cats, I'm sure a cone filter could only help to create a free flowing air system.

Obviously more restriction than stock or warmer air from the engine area is raising intake temps.

As far as exhaust, I do have headers on my truck, but have been reluctant to do them on the FC due to noise on the NA FC models.

I just put a come intake on my NA not too long ago & didn't notice any gains at all. I didn't notice any declines in performance either though. I would say you might be trading cooler air for more air if you don't build a cold-air box. That is next up for my car, plus a home-made ram-air system. Then we will see what happens.

Well here's my opinion on the subject and I'm not a expert by far. So if anything I say is incorrect feel free to correct me. The cone air filter will allow more air to pass through then a stock system. Due to a larger surface area and less of a restrictive passage. This helps out greatly if you have a aftremarket cat-back system. Lets say Racing Beat for example. That should raise the hp say 10% maybe more with that cone air filter. However that would decrease due to the hot air it would be coming from the heat of the motor. Kinda of sucks that Rotary's can get pretty hot. So most people get around that buy having a cold air box. That's why I'm still using the stock air box untill I get that cold air inlet headlight cover and build a cold air box. Remember folks just my opinion and what I hear from other people. Hope this helps out a little.

Sully

I got a K&N cone and adapter from ebay. I dont know how accurate this is, however the auction said that when put on a stock 86 gxl w/140k on the engine it made something like 6.7 hp and 5.4 ft lbs on the dyno. As i said i don't know how accurate this is or if the engine was hot at the time(probably not). It seemed to make a small diff on mine while cold, but i dont have a cold air box yet so we'll see.

To Mike (AE Turbo)
 

Cool picture in your signature, where can I get a full size copy
of it? Really shows the 13B engine well...

Thanks

I put an HKS intake on my stock 88. felt no difference. then put my RB header/presilencer on.(kept the stock original Y pipe and mufflers, going to get something custom there) Removed Air pump Etc. I think i felt a change but that feeling didnt last long. Maybe the custom Mufflers etc will make a difference but who knows. I heard that set adds up to 40hp to the wheels dyno prooved but who knows. I dont think you feel a real change unless its a big change. im gonna most likely get a donor 89+ Tll and street port etc. need big big change.

I dynoed my GTUs in three configurations: (1) Stock, (2)Cone Intake, and (3) RB downpipe and presilencer, plus cone. Stock, I put down 124rwhp (rear wheel horse power), with the torque curve peaking very low (~3K) and sloping off quickly. With the cone intake, the peak power only went up to 125hp, but the torque curve shifted up in the power band. This gave me more usable power; just not more peak power. Regardless, it was less than obvious without dynoing the car. Then, when I added the DP/PS, the power jumped to 147.3 rwhp with a table-top flat torque curve from 3k-8K. This is very good for a car with the stock exhaust manifold and stock cat back. I also have a fresh air headlight cover and a cold air box, neither of which will show benefits on the dyno so much as they will on the street, due to the ram air effect of actual driving.

Here are some pics of my intake setup, including my fiberglass cold air box:

Intake Setup

the cone makes the engine breath easier

Blake:
that cold air box looks REALLY good. :cool: How did you make that thing? do you have a how-to on how to make one like yours?

Cool blake,

That's the kinda info I was looking for

Great Job!
 

Very clean, and professional, do you have a set of patterns that
you could share with us?

That is pretty much what the doctor ordered...

I had a regular 2.5x4 small size cone intake on my car. Didnt gain anything at all from stock. So I put the stock one back on, but instead of fitting the original one back on. I took my spare one, cut out the middle part. So all i have left is a bracket that holds the air filter. With this setup, I actually gain more noise and power in any RPM. The difference is amazing just from cutting the stock air box cover. If you have a good clean filter (K&N) and a spare cover, i definitely would recommand this setup

Well a cone filter, or an open filter, actually should increase hp a little bit, but will lower torque -- at least that is the case on cylinder combustion engines... most of the time just an open air element will provide little to no NOTICIABLE power increase...The intermediate driver wont even feel hp gains unless they are over 5...

Introducing the Qualley Performance Cold Air Intake System!

Dyno Proven!

Easy to Install!

Great Looking!

Cheap!

:bigthumb:

Re: To Mike (AE Turbo)
 

Here's the copy I found on Yahoo Japan. It's a Japanese magazine ad for the FC. I rearranged it and added my car for my sig.

https://www.rx7club.com/vforums/atta...&postid=222868

Well, my only arguement against that is that you're leaving the intake exposed, right next to the exhaust. Hot air = less dense

So while you could get more air, the temperature of the air may or may not prevent you from actually getting more to the engine. A cold air box like Blake's probably helps significantly.

If nothing else, it's great from an ease of maintenenance standpoint, which is why I have one.

That and the little fucker is noisy. For a while I thought it was my belts makin' all that noise at idle. Then I stuck my ear down next to the filter and noticed that it was actually the intake making all the noise. It isn't noisy like an AEM CAI on a Honda, but it's definitely noticeable over the stock air box.

Hey, I hate to be the lone dissenter on this, but my son installed a Bonez kit from RP on his '88 NA, and both of us noticed an immediate improvement, especially below 4000 rpm! No other mods to the car. Why? I don't know, maybe the original air filter was dirty or something????

Irv, Keith's dad

I agree with Irv, Keith's dad. I noticed a bit of a change when I put my cone filter in. It seems to pick up a little better in the lower rpm range.

yeah,

putting my cone air intake on my 91 vert, I noticed an increase in power in the lower rpm range, along with an increase in engine note (not quite enough for me, though). Have a straight pipe for replacing my main cat, going on next week.

89 TII and 91 vert.

Would it be cool to put a stock K&N replacement?

i too noticed a pickup at low rpm's with the addition of a cone filter (Apexi setup). a little more power at low revs, and the car seems to run smoother...kind of like when you change out your plugs. plus i love the sound of it :).

i added a K&n and i dont know if it added or lost horsepower, but i know for sure it helped the throttle response time... this was all after a complete borla exhaust so i didnt really notice a power change.

If you think about it..
A stock filter was designed to be perfect for that car..

So if you add a high flow, the car still only needs X air to run at its peek preformance... so the other air is going to waist.. unless you have tuned the motor and added aftermarket products that now it can use that extra air..
I dont know, this is pretty much coming out of my ass..
but it makes sence..


aswell, your filter doesnt regulate how much air flows into your intake.. your air flow meter does.. so there can be tons of air going through the filter, but if your AFM isnt letting it by, its not going anywhere..

StinkyFatPig, you are correct, that did come out of your back side. The stock intake system on nearly all cars is intended for the most saleable balance between quite and powerfull. In addition, the AFM does not control intake, it meters (measures) it. The throttle body controls the engines ability to inhale within the limits of the other existing components. A greater mass air charge will always allow for more power (assuming enough fuel is available). The reason most intake mods don't see much improvement at first is simple. A cone intake increases the volume of available intake charge, but if the temp rises too much, the decreased mass due to thermal expansion (I've been out of school too long to quote the exact physical law) will reduce the total intake charge mass to or below that of the stock intake system. Cold air boxes overcome this by insulating the intake charge from the heat of the engine bay.

ohhh, so thats why i havent noticed anything after i put on my cone filter.....i was wondering what the deal was...:p:

I think the cone itself does increase gains. BUT i think that the hot air in the compartment lowers if not overcomes the gains. Get a CAI under the panel away from the heat and maybe you'll see a few HP.

yeah i think im gonna buy the mariah CAI box, ive tried to make my own, its hard!

Most people seem to have figured out it's the higher air temp that negates most of the gains of a pod filter. Unless there's some way of ensuring only ambient temp air is sucked in you're loosing potential performance, and worse, increasing the chance of detonation, particularly on a turbo. Remember most of the air entering the engine bay comes through the radiator, so it's far too hot.
I posted this a while ago:

...a duct of at least 3" diameter pulling air from the front of the car and directing air to a pod filter cut off from the engine bay by a shield is an excellent idea, as the more ambient temp air the filter inhales, the more power the engine will make. The lower temp of the air will be detected by the air temp sensor in the airflow meter and the ECU will then calculate the higher mass of the colder air. More air mass means more fuel injected, and more air and fuel means more power...

...assuming 20ºC air with 60% RH, heating this to 40ºC (typical underbonnet temp) drops its density from 1.19kg/m3 to 1.11 kg/m3, a drop of 6.7%.

This would be approximately how much power you'd lose! I've measured temps much higher than this in the engine bay, so it's probably even worse in some situations.

damn, now that i've found this out, my #1 thing to get is the Mariah Cold Air Box, i should be geting it within this month, so maybe i'll make a writeup on how to simmer up your own creation similar to this one with dimentions and all! because i've tried to make my own or make one someone else made a writeup on, but its too hard, and not one freakin writeup i've seen has the dimentions.....so this will be a first!

for those n/a guys that made their own, what materials do you guys use to make the box? it's just basically make a box that fits, and secure it, right?

Light gauge aluminium sheet is perfect. It's easy to get, easy to work with and it looks good.
First get a bit of cardboard, trim it to a rough shape (but bigger than you need). then trial fit it to work out where you need to trim. Repeat this process until you have the shape you want, then use it as a template to mark out the aluminium sheet.

Couldn't you just build a cold air intake box for yourself by cutting down (and cutting circles out of) a plastic battery housing box from Murray's?

someone posted pictures a couple months ago (I forgot who) of the cold air box he made out of aircraft aluminum and a piano hinge. after he got tons of requests he started mailing out templates for it, and the templates and instructions absolutely kick ass

here is my take on what you originally saw. most cars have the most restriction in the exhaust or are equal in restriction between the intake and exhaust. even if the exhaust manifold is decently designed you have cats and restrictive mufflers to deal with.

so you slap a cone filter that can flow better on there. your engine can breath easier but can't exhale any easier, so no gain. now you also have that filter sitting in the hot engine compartment, as was previously said. so you are not really pulling anymore air through, due to the still restrcitive exhaust, and you are now breathing hot, less dense air. so of course, you are going to see a drop in power (but you gain the cool cone filter honk). cold air box will help some but basically bring you up to stock as the engines ability to pull in more air lies in a free flowing exhaust. that is why you here of upgrading the two as a unit. even gran turismo upgrades the two together. moral of the story is upgrade the exhaust first or get both together. and cold air is good air. :)

Every month i go to the local store and check out Import Tuner... I check out the power pages and not once have i ever seen a cone filter upgrade decrease horsepower. There are atleast 72 examples that im talking about because ive only been reading it for 2 years and it has usually shown an upgrade of 3-5hp and 10-15 on forced induction cars.

This is how I have dealt with the hot air!

https://www.rx7club.com/forum/attach...&postid=776583

https://www.rx7club.com/forum/attach...&postid=776585

I can't say whether or not the original installation of the filter made a noticeable difference. I did however notice an increase in performance when I made that modification to the intake. You need cool air! I bet the people who have lost horsepower after adding a cone filter were in the summer months. I can't see how changing the filter could lower power over the stock intake unless the outside temps were very extreme.

mariah cai box
 

You guys are talking about getting this mariah cai box. where are these available. Internet?

Tim

here

http://www.mariahmotorsports.com/

Archive anyone? :)https://www.rx7club.com/forum/showth...threadid=95492

Note that he had some minor exhaust mods.

I purchased the cold airbox and the NACA headlight cover. The only thing about the airbox its made out of firberglass and it has the original look of fiberglass. I painted the cold airbox engine black paint and I think it looks good that color. I also added a grill to the opening of the headlight.
I did not notice a diffrence in performance when I installed these.
Afterwards I also installed the bonez high-flow cat and I can hear and feel the difference.

Al
87 "Beatup" N/A :cool:

o damn, thanks for the archive i wanna do the intake swap now...

Samps:
How's cooling with just that single elec. fan and the stock rad? Where are your temps?

Temps stay at half way on the crappy stock gauge. But this car is only driven for fun so it never sits in traffic or even driven slowly around a mall parking lot. I probably could get away with running without a fan. Otherwise it cools just fine. :)

Hey, thanks for the props.

All must kneel in the presence of the Exhalted Air Box Master!

I replaced my stock intake with a cone filter and I did experience a perceptible increase in low-end response. When I created the (beautiful) air box, the difference was even more positive.

https://www.rx7club.com/forum/attach...postid=1288970
https://www.rx7club.com/forum/attach...postid=1288983
https://www.rx7club.com/forum/attach...postid=1288986

Guess i'll revive this thread from the dead. I saw a picture of a headlight with a vent that leads directly to the intake, where can I find one of these things?

Does anyone have some measurements that they would like to share, im going to build a cold air box myself...
HAPPY NEWYEAR---KIM