MDittz2ndGEN

What's your guys' experience w/ aftermarket short ram air intakes and cold air intakes?

I'm thinking I'm going to replace my air box with a short-ram air intake if I can find one w/ an air flow meter adaptor, and then swap out my right headlight with one of those ones with the little triangle slot to let air into the engine compartment.

RX7freak08

Like this

MDittz2ndGEN

Exactly. Does that hook up to the metering box below the stock air box? & Does it take out any wiring electronic connections or anything? I haven't looked to see if there's any harnesses coming off the intake or not.

Evil Aviator

A somewhat stock non-turbo RX-7 works just fine with the stock "cold air" intake. In most cases, an attempt to gain more horsepower with a fancy intake will actually yield less horsepower on your car. Many Hondas came stock with idiotic hot-air intakes, so just about anything is an upgrade for them. This is not a Honda.

The headlight intake with the little intake is bullshit. If you want to do it right, you need something like this:
http://www.mazdatrix.com/faqpics/roadrace/ep01123gb.jpg

MDittz2ndGEN

GEEZE that thing is enormous. My car's streetported, that's about it power-wise though. Yeah the stock intake seems pretty nice, it's scoop design looks pretty efficient but makes everything look so cluttered =[ Anyone have a comparison of an aftermarket intake to the stock setup?

slo

iTrader: (1)

waste of money unless you need room for intercooler piping or to help facilitate a swap.

papiogxl

iTrader: (6)

My old ghetto setup. ( I had a standalone, so no MAF). If I were you, I would just modify the inside of the stock airbox for more flow, and leave it alone otherwise.


Evil Aviator don't forget, Honda's intake setup serves a purpose and it isn't power.

RX7freak08

Yeah i know what you mean. I believe it is the same size.

Evil Aviator

Blahaha, a friend of mine did the same thing on his NA Sport. It works great! We measured the "heat soak" on the standalone IAT readout, and it didn't matter a hill of beans once the car got up to about 30mph. A simple deflector would probably solve the 0-30mph heat issue, but I don't think my friend was very concerned with it.

That's the difference between a real sports car and an econo box wanna-be sports car.

NZConvertible

Don't be a sucker for idiotic aftermarket terms. A pod filter that replaces the stock airbox is neither "short" nor "ram". It's just a filter.

stylEmon

iTrader: (2)

Here is my current intake. I think it's a nice set-up over-all, but as NZ suggested, I will be doing some comparisons on this intake VS and shielded box with a short intake runner.

Bizmarkie

Just get a drop in K&N filter.

TeamWireRacing

On a similar note, has anyone found a decent (inexpensive) air intake tube to replace the upper intake tube? I have seen a few for the S4, but not a good one for the S5.

I was thinking of starting with something like this:


and then work downward from there. ISC Racing has this for the S4:


I was hoping to find something like the initial photo at the top, but running from the stock AFM location, up to the throttle body.

Anyone else done something similar?

SCCAITS

iTrader: (3)

There is this from AWR - http://www.awrracing.com/pages/rx/rxexh.html

You can also modify the stock elbow - http://howto.globalvicinity.com/gv_w...=308&co=1&vi=1

And my intake solution but good luck getting it to work on a street car or under IT rules- https://www.rx7club.com/race-car-tech-103/custom-cai-708263/

stylEmon

iTrader: (2)

i got a higgi elbow.

NZConvertible

Why would you even bother replacing it? It's huge for the engine's power potential. If your NA makes enough power for that duct to become a restriction, you'd need to ditch the entire factory intake manifold anyway.

That is truly awful. Not only does it move the AFM closer to the hottest part of the engine and mount it completely cocked up, it's effectively replacing the the stock ~3" duct with one that's only 2.5"x2", about 30% smaller. How is that a step forward?

Evil Aviator

That shop normally makes really good items. They do a LOT of testing in IT/EP racing in a very hot environment, so I am sure that it produced some type of gain in that environment, although it doesn't look like such a great design in my opinion. Maybe they were restricted by race rules?

TeamWireRacing

I don't believe it's a restriction, I think that by smoothing out the airflow into the throttle body I might realize some gains. The inside of the stock tube is hardly smooth.

I'm not defending it. I don't know if it works or not. However, the AFM measures air volume, not air temp. I don't think that there would be any losses due to AFM location. Plus, all the ISC race cars use an insulated aluminum heat shield on top of the header to midigate any such unwanted effects.

As far as the tubing, as you said the stock tube is oversized, so a proper reduction might help in terms of speeding up the intake flow and straight-lining the intake tract. ISC has a chassis dyno on site, so I have no reason to doubt their HP claims. The ITA Miatas they are building are quite fast.

papiogxl

iTrader: (6)

I had a box of thin sheet metal around it, sealed with foam. The most I would see the temps increase was about 15* F above ambient when sitting still for extended periods of time. I had also moved the IAT to the plastic elbow

fc623

im just leaving my stock box in but without the cap (a little good old duct tape to keep the filter down) and im planning on getting a vented t2 style carbon hood. thats it.

Evil Aviator

Actually, the AFM does measure air temp. It's a composite unit that has a temp sensor and a volume flow meter. The ECU uses the two readings to calculate mass airflow in order to inject the correct amount of fuel.

Also, just because something can't measure temperature, it doesn't mean that temperature will not be a factor. Air density (for dry air) = Pressure / (Gas Constant * Temperature). We are all slaves to physics.

Well, the plastic elbow isn't going to make a significant difference vs. a metal elbow, but that is interesting to hear about the sheet metal box.

TeamWireRacing

I stand (actually sitting right now) corrected. Thanks for the clarification.

Right, and I don't disagree with that. I just don't believe that moving the AFM twelve inches up the intake tract is going to drastically change the temp of the intake charge.

I can understand the arguement from both sides, but I don't have the emperical data to support either.

NZConvertible

The losses due to turbulence are directly related to the air velocity, and since the velocity in the stock duct is relatively low due to it's size, so too is the turbulence created by any roughness inside.

Simple common sense says moving an electronic measuring device closer to the engine isn't going to do it any favours, and mounting it on an angle like that has been shown to cause problems. Even if there are no losses, I can't see how there could possibly be any gains either. So why bother?

Making the air move faster by reducing cross-sectional area will always increase the work required to move the air. Basic rule of fluid dynamics. And since this is a non-tuned part of the intake, there are no plus-sides to that added restriction. Basically the smaller the pipe, the less power you'll make. Maybe for the power that particular engine makes there's little to no difference from stock, which again raises the question; why? It's certainly not for aesthetics...

Do they make a claim for that intake set-up?

TeamWireRacing

Yup.


AIR FILTER:
NEW Early 2nd Gen ISC Racing Air Filter Assembly
$300.00
Our NEW intake air filter assembly and modification to the intake piping and air flow meter has shown a consistent 3 to 4 HP gain over our old air filter assembly.