EdwardNorth

Hey all,

I'm just wondering if the SRMotorSports cold air intake is the exact same design as the M2 cold air intake. It looks identical and both use K&N filters. The only difference I see is the M2 one is made of carbon-fiber and the SR one is powdercoated aluminum.

Anyone using the SR one right now?

Thanks!

Riccardo

iTrader: (1)

I think they are very similar...but I think the CF makes a big difference as I think it shields from heat much better than aluminium and is probably lighter

Is this correct ?

evot23

iTrader: (17)

I don't think CF is a good insulator from heat. Either box is good but I would line the inside with a thermal barrier.

ZeroBanger

the M2/Rx7fasion box are almost exact. The M2 is a little taller though. Both boxes sit above the radiator fan, so the hot air goes in the boxes, the temp increase inside the box while sitting at a stop light is insane.

You can buy aluminum insulation tape and it helps alot to line the box between the radiator fan housing and the box. It helps but doesn't eliminate it.

Sprockett

Did M2 ever fix that problem they had where the box wouldn't stay closed? I thought I remembered hearing about how the box came open and the filters fell out or something way back when I was looking at that thing. Did they ever resolve that issue?

evot23

iTrader: (17)

I've heard of the filters falling off but nothing about the box top coming off. I was very happy with my M2 CF box.

Riccardo

iTrader: (1)

Here is a review and comparison of the M2 in Scuderia Sciriannis site

"...Comparison
Date: Wed, 02 Jun 1999 09:31:35 -0400
From: David Disney (disney7@icx.net)

Cold Air Intake Review

The products tested in this review are:

Stock FD3S Intake
Mostly Mazda Intake (M2)
Pettit Intake


I wish I could have tested one of the PFS intakes - just couldn't afford to buy a third unit just for testing. Anyone know how it is designed or where it gets its air from?

I'm assuming that the Pettit/N-Tech units are similar as well as the M2/Rx7Fashion intakes. If there are significant differences between them let me know.

Here is how the tests were performed. The car was driven through two areas. The first area was a rural highway where the air temperature was 75 degrees F. The second area was a cool valley area where the air temperature was 68 degrees F. Data was taken in both areas at 60 mph. Additionally, upon finishing the road tests, the car was allowed to sit at idle until the temperature readings stabilized. This was done to see the effect of the airbox while sitting in traffic.

The car was brought up to operating temperature and then shut off for several minutes before leaving for measurements. This was done to allow everything in the engine compartment to heat soak so that it would be nice and warm and the effect of fresh incoming air could be seen. I used a thermistor placed about one inch away from the filter element for temperature readings. On the aftermarket intakes, the sensor was placed between the dual cone filters (above one and below the other).

I did my best to drive the car in a similar fashion in all three runs trying the same speeds/throttle usage at the same points on the roads.

Here is a table of my findings, with comments below:

Temperatures are in degrees F.

STOCK M2 PETTIT
IDLE 147.4 137.5 162.3
HIGHWAY 97.7 112.5 124.2
VALLEY 90.8 104.2 122.9

As you can see, the stock airbox performs best with regards to intake temperature with exception of idle temps. I believe the thick plastic of the stock box heat soaks pretty badly.

The Pettit intake's temperature did not drop much when going from the highway to valley area. This tells me that most of its air is being sucked from the engine bay. Also, any speed above 30 mph didn't cause significant changes in the temperature. It got really hot when the car wasn't moving.

The M2 intake's temp did drop when going from the highway to valley area, which would indicate that it is getting fresh air (though not as fresh as the stock box). I could also tell a difference in intake air temp based on speed. The faster I went, the cooler the intake air (dropped by about 5 degrees from 60mpg to 80mph, went back up 5 degrees from 80mph to 60mph). Also, the temperatures in the M2 box dropped/stabilized very quickly at idle and when the car was shut off. I didn't take readings of how long it took the temp to stabilize, but it seems to bleed off heat much better that either the stock or Pettit units.

Bear in mind that I paid no attention to the amount or velocity of the air entering the intake systems. I am sure that the aftermarket units allow more air in more quickly that the stock box. The intake ducting for the stock box is restrictive and the stock systems contains at least three ninety degree turns.

So, here's my opinion.

If you are worried about intake temps, keep the stock airbox and put a K&N element in it.

If you want more air to get to the turbos and are willing to put up with slightly higher intake air temps, go with an enclosed box like the M2 or Rx7Fashion. The sealed boxes force the air to be drawn from the crack between the radiator and frame rail. While this isn't really a great source of ram air, at least it isn't engine compartment air. Oh, the M2 box isn't actually sealed. It has an opening in the front/side area (probably to make it easier to install). This opening is mostly blocked off when the unit is installed, but I suspect it may take advantage of any fresh air that leaks in around the headlight/hood seams. I believe the Rx7Fashion unit is completely sealed (except, of course, the hole in the bottom where it gets air).

Do not go with an open type system such as the Pettit/N-Tech. There is no way in hell that it will draw in fresh air. They will draw air from the engine compartment. They will not magically only use the air that flows up from under the nose of the car. Also, this air from under the nose of the car would be ok, except that they are depending on ram air. You just won't get much ram air from there. It can't come from below because of the engine under cover. It has to come from the nose of the car, make a left hand turn at the radiator and squeeze between the crack between the radiator and the frame rail.

Let me reiterate. Don't buy the Pettit/N-Tech systems if you want fresh air. They should not be calling them Fresh/Cold Air Intakes. If they had ever tested the intake temps they would know better. I'm sure these units are great for getting more/less restrictive air, but they should be calling them something else. Even the manufacturers of the sealed boxes (M2/Rx7Fashion) should probably change the name, as they bring in warmer air than stock.

Below are some notes I typed up regarding the Pettit and M2 intakes:

Pettit:

If you take a look at Pettit's web page you will find a description of their cold air intake. Below is an excerpt.

"Outstanding design features include two big K&N lifetime filters (one for each turbo), a unique cold air duct which draws in cool outside air (rather than superheated engine compartment air), our unique EAM manifold which routes emission and accessories discharge to a third K&N filter (virtually eliminating turbulence from the main induction tract), thus maximizing intake velocity and flow."

OK. Let me describe their "unique cold air duct". It is a piece of aluminum that wedges between the radiator and the K&N air filter assembly. It basically keeps the extremely hot air that exits the radiator from radiating up directly on to the filter assembly. That's it. There is no "duct". Their method of providing fresh air is to remove the foam padding that goes between the radiator and the frame rail on that side of the car and hope that some fresh air will enter here. Not much chance of that. You won't get much fresh air from under the car. Because the engine undertray caps that area off fairly well. You won't get much air from the front of the car unless it decided to take a left turn around the radiator and flow into the crack between the radiator and the frame rail. Yes, some air will enter here, but not much. You also won't get jack if the car isn't moving.

This thing might provide a very small amount of fresh air if you are doing Mach I down the interstate. If you are stuck in traffic, you are sucking up massive amounts of very hot engine compartment air. There is no way that the filters are going to draw in fresh air (that has to make a couple of ninety degree turns to get to the filters) when it is much easier to use the toasty engine compartment air that is available all around them. After driving the car at moderate levels, the air filters are extremely warm to the touch. They won't burn you, but you wouldn't find it comfortable to leave your hand there.

Also, the intake hoses for the turbos (the two large hoses that the K&N filters attach to) are completely unsupported. They just tied them together with their connectors and left them to flop around freely. No, they can't go far in that cramped area, but they hang there on their own weight.

I also didn't like the fact that you have to strap the EAM manifold (the silver piping) to the upper radiator hose to hold it in place. I don't know why I didn't like this; it just seemed like a crappy way of doing something.

Now, understand that I am slamming Pettit's Intake, but I am not slamming Pettit. They have some extremely nice, helpful people there and I'm sure their other products are great.

Mostly Mazda:

I liked this unit. The construction was very nice. Installation was easy (much easier that the Pettit unit). It seems to push the primary turbo host back just a bit further than I'd like, but I haven't had any trouble with it. It would have been nice if they had included some instructions with it, but it wasn't hard to figure out. They could have thrown in an allen wrench also (to remove the top of the box with). Finally, the filters could have been mounted a little lower in the box as it is, the top of the box mashes the upper filter when you tighten the box top down. This sounds like several gripes, but I would recommend the unit to a friend. Also, the M2 box sounds much better than the Pettit unit. Pettit uses an odd hose with sound baffles to silence the air pump discharge. It sounds like a cow in pain most of the time. The M2 box uses a different method and is much quieter. I can still hear it slightly, but passengers have never noticed it. Blow off valve noise is a little louder with the M2 unit, but not objectionable.

________________

Here are my comments on Dave's review.

Nice review.

I had a few comments on it based on my experiences with the M2 intake, which I have on my car.

If you adjust the filters in the M2 intake to mount at an angle, the top will not mash them down. In fact, it won't even touch them. The filters have an angled neck on them (the rubber piece the hose clamp goes around).

My intake gets so hot I am surprised it doesn't glow after a bit of spirited driving. (But then so does anything under the hood - the car just runs hot.) I think that the M2 unit would have a very high idle temp compared to the others if you measured idle temps after a hard run. (But then again, the others might get just as hot.)

Other gripes I had about it: MM should have supplied new hose clamps. The stock ones were almost impossible to get back on. Also, the hose for the airpump does not reach. You need to go to your local auto parts store and buy about a foot of hose.

I had such fun installing mine :-) that I wrote up installation procedures on it. Go to my site, and to How-to --> Engine (Other) --> Intake Installation.

But the bottom line is that is a very high quality unit, and does what it is supposed to. I would buy again from MM if I had it to do over.

Anyone have the Tri-Point unit for comparison purposes?

In regard to the N-Tech unit, doesn't Nick provide instructions in how to open up passages for fresh air? His also looks to be a lot better sealed than the Pettit unit, so it would draw less hot air from under the hood and more fresh air. Plus it is cheaper. --Steve

________________

I am thinking of getting some of the insulating material racer supply places sell. It is basically a reflective insulation-padded sheet of material that should reflect some of the heat away from the intake. You can even get the self-adhesive kind, or get the standard kind that you need to glue on with a silicone adhesive.

Another idea is those "space blankets", aka emergency thermal blankets that are basically a sheet of the same kind of foil they use to insulate spacecraft. I have a couple of these sitting around from camping. It might be worth cutting one up as an experiement. They are about $10 at outdoor stores. --Steve

Rated R1

You need to look at the date of Dave's review. It is almost 5 years old. The design of the M2 box has changed since then. The new CF box is not open at the top like the aluminum was, and the filters that M2 sent with their box back then didn't have quite the angle that the newer ones do.

I don't think space blankets will work very well in this application. We need to insulate against conductive heat transfer, these do not work very well in this type of application. They do a good job on radiation heat transfer insulation though. I think a better material might be something like the material that the cheap sunshades are made of (if they can hold up to the heat).

aREX4X

So what's the best solution for cold air-induction WITH a FMIC? Does it no longer matter because the intercooler's cooling abilities are so much greater than the stock intecoolers to cool the hotter compressed air that is going into the engine, or does it still play an important part?

X...

Riccardo

iTrader: (1)

I agree the test is a bit old, but it does giove an indication
I unfortunately do quite a bit of start stop driving, hence I think the M2 is good for me

7racer

I'm not sure of the cold air induction for a FMIC....

However, this was the exact reasoning I was looking at this kit...

https://www.rx7club.com/forum/showth...hlight=Autoexe