Cold air box...
 

Hey guys, just wanted to see what sort of interest there was in a less expensive alternative to the mariah cold air box, still utilizing stock mounting locations and etc. but perhaps incorporating the stock intake 'vent' (the portion 'before' the filter box) in conjunction with the mariah-type system...

...any suggestions on materials would be great too.... I was thinking fiberglass (FG), carbon fiber (CF), and sheet aluminum (Al) as options...

cut the small triangle section out beside the rad. run a 3" pipe through and mount the filter in the bumper :D

What about a 5" pipe, lol thats all i got to use right now, AL and will flex any way u want it to, i found it.

Could someone plzz give em a link to Miriah motorsports website.

This is the $120 mariah cold air box (just the box, no filters / adaptors included....) :eek:
http://www.mariahmotorsports.com/ima...irbox_fipk.jpg

What is the difference from a regular K&N filter cone filter, and the Fuel injection performance kit ?

sooo, are you gonna make those?
I will buy one if the price is good. :)

What kind of Heat resisting qualities do FB & CF have?
I think a combo (CF AL) would insulate better and look better.

And did you say you have 5" pipe going from the Duct Inlet down through the radiator shroud into the grill? I was thinking that would conform to the shape of the hood when closed. Let me know what you have setup and how it works.

Also I think a good idea would be to have the CAB enclosed, like theres a top over the Mariah one. Maybe have it cylindrical, so that air is drawn from the grill and goes to and around the filter. This idea is certainly the most versatile, as it's not a good idea to drive in the rain if you have your filter exposed to direct airflow. I am thinking water would have a much harder time getting all the way up into the filter if its still in the engine bay.

lol, No i don't even have a 7 yet (god i wish i did). But i do have a Piece of 5" Aluminum flexible ducting (like for your clothes dryer type, but aluminum) How well would that work (i have a feelign not well) i jus grabbed it from the trash from a construction site, so me and my friend could mess with it, to make home made cold air intake (lmao) we put it on my friend mikes moms car, and my other friend 86 Izuzu pickup, mounted teh front of the tube under the front bumper, slight performance increase once ur above 25mph (hey its free)

DC mina: yup, I am planning on making atleast one for my own personal use. Depending on how it turns out, and the kind of interest in it, I could see making a few to sell. (at significantly less than the Mariah box) I was just looking for some responses as to materials and design... would you want one exactly like the mariah box, or would you like it to incorporate the stock intake 'vent'? (just wonderin...)



WilTaylor: The bottom of the hood acts as a "top" to the cold air box, if you notice in the mariah picture there is weather stripping around the top, this seals with the bottom of the hood, in effect creating a top, while still allowing cold air in throught the front (from perhaps a vented headlight cover :D) and the side... ...By cylindrical you mean having both the top and bottom open to air?



TriTurboGen3: the idea of running a duct from the bumper to the filter element is a good one, and effective too... but that aluminum pipe will offer significant restriction if it were a 'sealed' unit (due to the corrugation... bumpy = slow (in general...)) ....however, as you say, it's free, so why not eh? ;) :D

Anyone else have some input before I get started on my prototype?

Id be interested in buying one. I just made my own and it looks liek garbage but it gets the job done for now.


But i rather spend a bit of money and have a perdy one :)

Hey, I'll try... lol... not sure what it's gonna look like till it's done though...lol.... :D

OK - Here's a slightly silly cold-air box idea I came up with at an AutoX last weekend - Ram Air.

If you relocate the airbox *BESIDE* the IM, and mount it so it has a good seal on the hood with a scoop, wouldn't that work? After all, with the sub-zero tank gone, there's plenty of room on that side of the motor.

I have a spare steel hood and spare intake that I'm thinking of trying it on.

Pro:
Stock air cleaner/AFM can be reused
Short run to the intake-one 90 degree bend
Air direct from outside the engine.

Con
Cutting torch required (is that really a con? AR! AR! AR!)
Scoop on hood could be rice (sorta)
Lots of work.

Comments?

Z

Interesting idea. I think it would work, but I think that area of the hood is not a high pressure area (there is an aerodynamic profile of the RX-7 floating around somewhere, anyone?) ...but if I remember correctly from the discussion about the diagram, that was because there was laminar flow over that section... a hood scoop MAY be able to suck in enough air to make it worth while... I'll check the diagram when I get home...

BTW, i have just been looking at your autocross car, it looks soooo bloody sweet :D ...how low is it??

There is a low pressure area on the hood. And yes, a hood scoop will draw air into it.

:)

James

I can make one out of CF if there is market for it, just like the Mariah box, or better, including molding, for about $70. I have a great idea for keeping it insulated, too.

It's stock ride height - I have not got around to the suspension work yet. I just got the ports working correctly (they snap open now).

I saw that diagram - if the opening is far enough back and close to the windshield, there's a positive pressure area there. This is going to be some eyeball engineering at it's best. :)

Yes - the area at the end of the hood/base of the windshield is a high pressure area.

And what I meant by cylindrical is this: Imagine your air filter. Now imagine a bucket around it for example- I think that if air were to come in from the top and immediately be forced in a circular motion down, around the filter, it would be more effective that entering into that big open space the Mariah box creates. I dont have one, but I figure that the weatherstripping is more for keeping the heat out than for creating positive flow into the intake. Not sure if that makes any sense. I am curious to see what happens here.

WilTaylor: I see what u mean now, a box with a curved bottom? that sorta idea? I think that would improve airflow if it were a closed system, but as it stands, the cold air box is more of a heatshield than anything else...

i mounted mine in the front bumper! it works great! so many glory stories about it.. i did a write up about it awhile back called " lowered intake temps by half " ask questions if you are intrested.. this is the best intake design by far!

https://www.rx7club.com/forum/attach...&postid=821774

sorry for the size.. that was a ruff copy of what it looks like now.. i was just testing it out... pm me if you are intrested and i could try and find more recent pics!!

I have been called the Almight Cold Air Box Master and for a good reason. I think my box looks much nicer than Mariah's. Look at this thread https://www.rx7club.com/forum/showth...hreadid=101026

Yes almighty king and master of cold air boxes he is!!!

- D