RX7MAVEN

I have uncessfully tried to find a low restrictive air intake system for my 89 nt. When I query the sellers as to how the sensors and additional hoses attach to the system, they are evasive. Is there a non restrictive system that is a direct replacemt. Or ---- should I just fit a K&N replacement filter? The car is strictly for street use.

VacavilleFC

there isn't a intake that is more efficient than the stock one.

kontakt

This guys is mostly right.

The biggest restriction on the intake is pretty much always the AFM. An NA won't outflow the AFM. The only way you could come close is with porting so extreme that you need a standalone computer that removes the AFM anyway.

Any gains you can get from intake are generally from building a true cold air box. As it is, if you put on something like a short-ram intake you will only be drawing hot engine air through the new "efficient" system as opposed to cold air through the stock system.

Flow can be improved on the intake side some, yes, but the exhaust is where the power is.

FYI most guys use the prelude intake you can find all over the place and mod it up. I believe there's a write-up in the archives.

Hope this helps.

VacavilleFC

there was just a huge write up on how changing intake you lost intake pressure and that = a loss in horse power, no matter what combination was tried it all = .5hp loss

kontakt

Link please? I'll believe it on stock ports, and stock exhaust, but it'd be nice to know the specifics fo the debate.

Also... do you mean somehow that you lose intake vacuum? There shouldn't be any intake pressure on an NA.

VacavilleFC

i'm having a conversation about it with my friend right now, i guess pressure was the incorrect term and vacuum was. i'm at his house so i don't have the time to dig up those links at the moment but i'll try to find them later tonite, if you search around though, you will not find one any aftermarket intake that has any proven benefits, and almost all certainly are more prone to heatsoak than the stock one, i have a intake temp monitor installed and i only get 7-10 degrees heatsoak after driving an hour here in cali where it his 100 most summer days. completely stock intake with all plastic shrouds in place

Evil Aviator

The guys at KG Parts should be able to answer your questions.
http://kgparts.com/index.php?page=kgparts

In most cases, well-meaning forum members spend a lot of effort fabricating a "cold air" intake that ends up so convoluted that the bends and length of piping cause a restriction that adversely affects the air pressure.

With respect to this subject, pressure = vacuum. Technically, "vacuum" is an incorrect term for pressure below ambient, but it has become common slang.

There isn't a intake that is more efficient than the stock one, there are many intakes that are more efficient than the stock one lol. Unfortunately, most of those intakes require a new manifold and an aftermarket throttle body kit.

kontakt

I know what you mean. I was mostly just interested to see where people were discussing this. I don't have plans of building a CAI ever on my car. When I need better airflow I know I need it from the block up. I'm going to go bridge on my next motor, with a custom ITB setup. That's of course just one example of what you mention at the end of your post.


I even knew that; unfortunately I was corrected recently enough that I just haven't broken the habit. The slang is fairly useful though, as on a turbo car it's easier to say "I was still running in vacuum" instead of "I was still running below atmospheric" when talking about a boosted car. A lot of people (as depressing as this is) probably wouldn't know what you meant by that anyway.

RX7MAVEN

I am not having a problem. It seems strange that most cars have aftermarket air intake kits available. Most suppliers clain exagerated HP gains. There are only makeshift kits for the 2ND gen 7's.
There does not seem to be an agreement as to the benefits/shortfalls of these systems. I am going to put a K&N filter in my stock system. Thank you all for your replies.

Evil Aviator

I use the slang term too. My point is that you were not wrong.

If you really want to mess with people, call that the region of rarefaction, hehehe.

imloggedin

so whats wrong with a cone and cold air box like most people do? also, how do you expect to keep the stock intake if you want an e-fan??

VacavilleFC

because making a CAI that completely seals against the hood and has a cold air source is extremely difficult, also heatsoak would be a huge problem, any metal used to make it would transfer the heat much faster than the thick black abs plastic.

mazda did not slack on designing our intake system, the stock snorkle already draws cold air from in front of the radiator, removing all that and putting in a cone filter and some sort of heat shielded box isn't as efficient.

the car has been around for 20 years and nobody has designed an intake as efficient as stock, that has any proven benfits. isn't that good enough?? if someone could make one that had proven benefits it would have been done by now

as for putting in a e-fan i see no reason you couldn't still use the stock box and snorkle, you may need to make alittle brace for the snorkle but thats about it.

coldfire

iTrader: (1)

on cars like ours, there is hardly any "tuning" effect for the part of the intake BEFORE the throttle body. the only thing you need to be conscerned about is total flow (CFM).
even the stock intake handles that requirement fine.
the only reason i personally went with a K&N cone type filter is to clean up the look, as i didn't care much for the stock intake funnel.
if you are leaving the filter in the engine bay area like that, be sure to at least block it off from the engine side somehow. i used high-heat matting for that...

NZConvertible

My aluminium heat shield is completely sealed against the hood (thick compressible foam strips stuck to the underside), the holes cut in the sheetmetal provide a source of ambient air with very little restriction, and the filter side of the shield is considerably cooler than the engine side thanks to foil-backed insulation stuck to it. I used aluminium because I had some, but ABS or similar would probably work even better. It's trickier to make nice folds in though.

Very wrong. The poor flow of the stock airbox has been proven. As long as the hot engine bay air is kept out, it would be very hard to not improve on the stock airbox.

There are plenty of FC's driving around with intakes considerably more efficient than stock. There are also many with intakes less efficent than stock. The fact that you can't buy one off the shelf proves nothing.

freemanrx7

I put on the K&N kit for fc's and noticed an improvement in throttle response. The car wanted to go to the redline quicker esp in 1-3 gear.

I felt less low-end power. Fifth gear would not pull as strong.



I won't go back to stock!!!!!!!!!!!!!!!!!!!!