I'm designing a new rotorhead product, keeping it nice and simple - a Cold Air Intake to replace the stock box on a GSL-SE or the entire blue intake pan on a 12A model.





This single wall will seal nicely along the bottom, and I plan to create a bulb seal (similar to the rubber strip that runs along the inside of a car door opening) to seal the top to the hood, creating a box that draws air in from in front of the rad, not the engine compartment.

Mods neccessary to mount this CAI are:

-drilling a hole in the strut tower for 1 additional bolt
-cutting a hole in the right side rad mount wall to feed in the air

From the CAI wall on back, there'll be 2 different pipe designs; one droppong to mate with the air intake sensor on the SE model, and one rising to the carbureator on the 12A.

No firm pricing yet but I anticipate around $40 (filter not included)

please give me your opinions.

 

this is already available through bonez for the SE.

but Im interested in what you plan to do with the carb intake.

I just put a edelbrock filter on there and it works great.

 

you think you can make this avaible for a 79 RX-7?

 

The Bones intake isn't CAI - it sucks hot air from your engine compartment with no wall. It's just an adapter to fit a cone filter.

EDIT: Rotary performance lists the Bonez kit for $130!!!
Sure it includes a $50 K&N, but...



Josh Carpenter is helping me with computer measurements, and (in theory) it should fit all SA and FBs, unless there's something terrifically different about SA frame/engine compartment design

 

I applaud your efforts on the 12A version! Nice work!

When you get it done, could you post dyno results please?

 

might want to include in plans to remove the plastic from the filter.

i would just create a mockup out of cardboard since it is easy to work with then use foam to seal to the bottom and the hood when shut.

 

hehehe that was Josh buying the filter for test-fitting and leaving it in the plastic to return it if it wasn't what would work best...

The problem with foam is it lets particles through and makes a lousy filter/wall. I'd prefer rubber, as in the bulb seal, to create an airtight seal that forces the CAI to draw air from outside, not the engine compartment

 

you will see no to very little gain without an exhaust system. the motor will not breath any better without being able to exhale any better. the only gains i see are for the 12a since it normally pulls hot air and this will give it a cooler, more dense charge. again it will be very marginal without exhaust.

 

rubber is good. i was going the cheap route with a closed cell foam. you aren't really filtrating with it and the amount of air coming through is neglegible. however it will desintegrate far quicker.

 

Manntis, tube diameter? Most of the cone filters I see are 3" outlets. Also, does moving the filter that far away affect the power/torque curve at all? The air columm having to travel from a restrictive filter all the way to the inlet under high throttle (launch from standing start) I would think might cause a flat spot.

 

A stock SE has the same length of inlet pipe after the filter, that's why it uses broad, flat filters.

The key is a restriction (filter) causes a pressure drop, so you increase the total area substantially to compensate for it at the restriction. By using a cone filter (gobs of surface area) or the broad K&N drop-in filter for a stock SE airbox you prevent a measurable pressure drop.

The air travels that length on an SE with no problem, so I don't see 12A's being snobbish about it. In addition, you're no longer sucking in hot engine compartment air as on the 12A stock setup so you're getting a higher PPM oxygen particle content per volume.

 

Manntis. Carl and I are doing up a CAI next weekend - we already have the supplies, and the total cost of goods is somewhere less than $20 (keeping with our "low budget" theme). You have my email - feel free to write and I'll give you advanced overview of what we're doing so that you can see if you want to integrate any of it into your product.

 

sounds cool, Tom, keep me posted

 

Manntis-
I applaud your efforts on designing a much needed performance upgrade for us 12A guys. I'll be one of the first people to buy one when they get done!

-Fred

 

I'd also like to point out that if you actualy do try to buy one of teh Bonez' unit from RP that they probably won't have it. They use a overflow tank & bracket off a 12a car that they scrounge from junkyards and they just don't have them...


In fact, I'd also liek to point out that with the exception of a few parts that are readily available elsewhere, RP does nothing for 1st gens. They refuse to work on them anymore peiord unless you want them to do a Spec7 motor refresh ($3,500) Or you are spending a couple grand on a halteck setup or something.

 

Manntis, I love the idea! A well done Cold Air Intake for both 12A and 13B cars - Good one.

I have been designing my Turbo exhaust from day one with a Cold Air Intake in mind.




I was planning on building the same thing you are, but with a 4" inlet for the Turbo. If you end up building these, I definately want one, but with no hole cut out for the filter, as I will likley weld a 4" pipe to it from the Turbo.

Your design is very good and simple. I recommend that you fasten it another way other than using drilling a hole to the top of the strut tower though. People running Strut tower braces may not be able to utilize it, or they just don't feel like drilling their pretty car.

By the way, check out Max 7' Cold Air Box too.
It has some good ideas that have kinda been tweaking in my head.

 

The hole in the strut tower is in the side, Alex, not the top and the thing that inspired this project is the fact that I can't mount a strut tower bar over the stock plastic box without having to remove the strut tower bar every time I need to re-oil the K&N filter.

 

Dyno redults are negligable because CAI is designed for a moving car with fresh air slamming into it at highway speeds. Things a dyno can't duplicate no matter how many fans you have going.

 

Alright Mantis... As long as you are going to be looking into this, I highly suggest you pay attention to what this guy did for the 2nd gens... Well worth teh effort I feel.

https://www.rx7club.com/forum/showth...hreadid=101026

 

Ok then Manntis. Hey whats the dia of the outlet of the K&N? ANd whats the flow numbers in CFM? Filter area in sq in? Not busting you *****, dont be offended ok? I think yours will be great for the buy it, bolt it on and go crowd. That said I think theres mucho better ways to do this, but you have to have some fab skills to do it.
Oh and that 2nd gen one looks really professional gls-se! too bad the engineering is so poor .Unless theres more to it, its still sucking underhood air from around all the openings. Mines really ghetto, but it works fandamntastic! And yes I've done the R&D to be sure that I have a real CAI, not a look alike

 

When I finally get th 13B engine in my car I will develop a CAI for sure... Since turbo is planned for later on, I will probable end up with something as Directfreaks car.

 

Wow, Manntis, people really like it.

My notes on what's been posted so far:
1) Ours should be slightly better performing than Max 7's, due to having the huge-*** K&N in a bigger box instead of the cramped enclosure he built - No Offense intended, Max, I've already ogled your site and admire greatly your fabrication skills.
2) Ours should be rather cheap to manufacture, remember that you can custom-craft anything but mass and even low-volume production puts "a few" limits on what's feasible.
3) Please refer to your own personal Seat-of-Pants dyno for proper results, i.e., real-world testing is the best.
4) One thing that is cool is that this will be an easily removable, very lightweight, and inexpensive mod.
5) That clear plastic FC box looked ridiculous, no offense intended. What's the melting point of that plastic, eh? How about discoloration? Not to my taste. Once I get my friend Charlie to get online we'll see a proper metal FC CAI.

Hey pratch & Carl, hold on as I have some measuring to do!
- Josh

 

Josh, what plastic one? ANd measure what? How bout testing different configurations using a gtech on the same car, same day, same conditions?

 

Manntis check or pay attention to the picture that DF posted. Thats one good way to go about it, and it looks easy to fab. just not sealed on top. the red FB with that flip-top air box i must say,,thats pretty cool looking, again not sealed on top. Dyno results ?? i don't think so.
How about a new project instead,,fab. a affordable front
and rear strut brace..??? maybe ?? but if your hell bent,,,
what about california emissions type setup for the 12a with the stock nikki, was that in the master plan ??
again thats just my 11/2 cents.

 

Keep in mind this is the first 'design', and it will change before reaching production