Brentis

sounds fugly. No offense.

Kento

None taken. It works just as well, and no one can see it anyway. I'm just not all that impressed with most of the intake mods that are available with regards to keeping out engine heat.

adam c

iTrader: (2)

Kento,



When I first decided to do an airbox mod, I was going to do one similar to yours. I saw a mod on Steve Cirian's web site, and thought I would follow it. I pulled out the box and started looking at everything. I looked at all kinds of ways to run piping here and there. Eventually I decided that any piping would be restrictive, and might act like a vacuum cleaner, sucking up everything. Instead, I decided to open up a larger intake area where air could flow from several cool air openings. I created a shield to keep out the engine heat, and allow cool air to come in. It's a nice clean install, and works really well. A couple of people on this site have installed them. A few of my friends have them too. All with good results.

Thanks for your input.

Adam

adam c

iTrader: (2)

I drove down to Pismo Beach this afternoon. My friend Brian lives there with his 94 FD. He has an M2 set up with intake, DP, CB, intercooler and ECU upgrade. The last time I saw his car, I really didn't know much about any of this stuff. I was really curious about his intake. He unscrewed the top and showed me where it pulled its cold air from. Surprise!!! The exact same place as this intake mod. Actually, I was a little surprised. So that's why it works as well as it does.

adam c

iTrader: (2)

quote:
--------------------------------------------------------------------------------
Originally posted by James Paventi
There are lots of picks in this thread.

Also, this airbox has my vote for best ghetto mod. It works great, my turbos spool noticeably faster and when I installed my Fluidyne radiator the airbox mod still worked great. Actually, it’s clean enough that it’s hard to call it a ghetto mod.

James
--------------------------------------------------------------------------------



Agreed, I have done some extensive testing on my stock box to get my trap, then modified it tested it to get my trap. then I got an rx7fasion (same as M2) intake and then got my trap, then I modified it and got my trap.

stock airbox no mods to the air box
Average trap 104.X
Best trap 104.X

stock airbox mods to the airbox
Average trap Low 105's
Best trap mid 106's.

Rx7fasion airbox (unmodified) and midpipe instead highf flow cat
average trap 105
Best trap 106's

Modified RX7fasion Airbox same mods as above
Best trap 109.86
worst trap 109.56

I have backed this up with about 50 timeslips, btw. This is not just doing 1 or 2 runs, I had substantial timeslips. Your trap speed does not lie. What I found was that the stock airbox (though boring) has the exact same HP potential of the aftermarket cold air boxes. You will notice I had to modify my cold air box to really get a good trap.

I just made a new modification to the hose that I routed from the nose of my car, and I expect to get 111-112 traps next weekend.

here was my writeup and details.

https://www.rx7club.com/forum/showth...&highlight=trap


__________________
Stats:
16.4 @ 82 MPH
0-60 8.2 (timed with stop watch)
Getting a M2large IC, hoping it will get me into the sweet 15'S!!!

MODS:
============
Power FC
BLITZ SMIC
Nitto 555 R
Koyo Radiator
DP- MP- Catback
strut tower brace
high flow fuel pump
Competition Toe Links
ACT Street/Strip Clutch
Archos 20Gig MP3 player
Competition Trailing arms
1200 CC secondary injectors
Modified Rx-7 Cold air intake
Leatherseats.com Leather seats
RX7.COM Performance brake pads
Autometer Boostgauge, Analog Clock
Brembo front/rear slotted/drilled rotors


Soon to come:
----------------
M2Large Intercooler

Last edited by ZeroBanger on 12-21-02 at 06:23 PM


12-21-02 06:19 PM



ZeroBanger
No Life.

Status: Offline!
Registered: Jun 2002
Location: San Leandro, CA (bay area)
Posts: 800
By they way, my post above was not a test on Adam's mod. My point is that my testing has proved that these types of systems will work as good or better than the aftermarket boxes.

adam c

iTrader: (2)

Zero Banger,

I think it's very interesting that the stock box mod with the more restrictive high flow cat is as good as the RX7 Fashion with the less restrictive midpipe. That tells me that the stock modded airbox is better than the RX7 fashion.

Did you keep your stock intake, or seal the hole and just use the new opening underneath?

My mod keeps the stock intake and adds an additional intake underneath with an aluminum shield. Several members have tried it with good results.

Adam

ZeroBanger

Actually, the rx7fasion box (same as M2) is far superior. The box very sturdy and will insulate from heat 100 times better. If you notice, the rx7fasion intake trapped about the same as the modded stock intake did. When I modified the rx7fashion box, it trapped far above what the modified stock box did.

The big difference is the rx7fasion box is smaller, which gives you better airflow to the primary/secondary turbos.

Just my opinion.

adam c

iTrader: (2)

Using your results, It looks like a modded stock air box, with a mid-pipe, would be faster than a unmodded RX7 Fashion/M2 intake with the same mid-pipe. This assumes that the setup with the midpipe would be faster than the setup with the high flow cat.

Did you keep the stock intake when you modded your box?

Adam

adam c

iTrader: (2)

You also mention that the RX7 fashion box is smaller, so it provides better airflow. If it is smaller, then it will hold less air. If there is less air available, how can there be better flow. Thats like saying a 2" exhaust will flow better than a 3".

I have seen the M2 intake. It's underside opening is very similar to my modded stock air box. The advantage to my mod is that it still uses the stock intake ducting. This now provides 2 sources of cool air.

ZeroBanger

well we cant prove that theory that a Modded stock airbox with a midpipe is faster than an unmodded rx7fasion/m2 box. I would bet it would be a little better.

What do you mean..did I keep the stock intake when I modded my box? I'm confused what you mean by that.

Let me say it this way...I will answer your other post with this.....

The RX7fasion is better because it is smaller, I believe that. The other box is bigger and does not have direct airflow. We have K & N cone filters with the M2/Rx-7fashion, the paper filter (even with a K & N) is never going to be as efficient.

Ok, I left the stock intake ducting in place and then added my own. its VERY difficult to modify your stock box to ram air into it. I was able to get a thick vinyle hose that had a 3 inch opening, it was flexible, so I could put it between my radiator and the chassis and route it into the bottom of the box. From there I could put a Home Depot pipe opening with a 5 or 6 inch tip. This would sit in the mouth of the car.

With the RX7fashion box , the box is smaller so its not restrictive as to how big the hose is that you can route into the box. I have 2 different hoses going into the intake now, 1 from the mouth of the car, the other from the area where the 2nd oil cooler would be if I had an R1.

The Metal box keeps the intake temps far better than the stock plastic one does too.

adam c

iTrader: (2)

I meant the stock intake ducting. It looks like you figured that out.

Airflow: A smaller box is not going to give you better airflow. The best airflow would be with open filters. Many people choose not to do this because of the warm air they ingest. This is the old "cool air vs more warm air" debate.

Heat: If you put a plastic and an aluminum air box in a 200 degree oven (similar to a RX7 engine compartment) they will both heat to 200 degrees. One may cool more quickly than the other, but the temperatures will remain close. As the air passes thru the box quickly, and generally has contact only with the filter, I do not believe a small temperature difference of the box will produce any measureable difference.

I like the idea of running some ducting to the area near the air box. I don't know about running it into the box. I have been concerned that I might suck up some rocks or debris, (or even water) and damage the filter. Have you had any problems of this sort?

Adam

ZeroBanger

by doing what I did, I get the best of both worlds. I ram air into my intake box, I promise you I get more air that the manifold can injest.

I believe the smaller box is better. The air has no choice but to be directed to the turbo intake hoses.


Adam, I have no problem with any rocks getting in there, that would be nearly impossible. the air goes in the filter then has to go in an upward spiral, the rock would fall out before it made it in.

Now as far as debris, I can tell you that you need to clean your filters more often, originally I pressed the small 3 inch hose up against the filter and within a week or so of heavy driving you can see it clogged. Thats a product of more airflow. I since changed it so the air hose is about 1 inch below the filter.

We have had some heavy *** rains here in cali and I've been driving my car, rain DOES collect in the bottom of the hose and I have to drain it. I will likely put a few small pin holes to use as a drain.

The bottom line is the more air IN the more power out. You can get more air in with the smaller box cause it allows you to use a larger hose. For example I could only get a single 3 inch hose in the stock box, for the new box I use one of the OEM Intercooler hoses, its about 2 times as big...and I also use a 3" hose....I could not do that with the stock air box.

ZeroBanger

Adam..what is SLO? Is that San Lorenzo? If you are in northern cali, let me know. I will run tests on your box for you at the track and compare to mine if you have one to spare.

adam c

iTrader: (2)

My mod opens the bottom of the box so that it breathes like the M2, plus I have the stock intake ducting. It pulls air from the front and the underside of the car, with very little restriction. The hole is about 12 square inches (not counting the stock inlet). How big is your hole?(not meant to be funny)

After about 2 months, I pulled out the box to examine the filter. It was very clean. I just put in back in without doing anything to it.

SLO=San Luis Obispo. It's on Hwy 101 about half way between LA and SF.

Adam

ZeroBanger

I don't know what your design looks like and really its unfair to compare the two designs without doing a test, the key is how you are bringing the air in box and how much. There comes a point where its overkill.

adam c

iTrader: (2)

I agree. The system can only accept so much air with the stock twins.

The only box I have is the one in the car. That's too bad. I would like to see some results.

Thanks for your input, Adam

wickedrx7

iTrader: (14)

I did the same thing, its been a few years so I don't remember the cost, but i know it wasn't much and it was easy.

http://briefcase.yahoo.com/wickedrix

GoRacer

iTrader: (2)

I saw Adam C's setup on James's car and like it alot! Too bad I threw my stock stuff away, all I needed was another bottom peice. The previous owner drilled it full of 3" holes and the Racing Beat stuff was broken to crap.

I think it can be improved: If the shield can have a flat sheet to cover the inside/bottom of the box. Then the rectangular tube through the hole downward, instead of being under the box. You would also use some heat blanket stuff sandwiched in between the sheet metal and the bottom of the air box. ...James's foam idea may improve it pretty good to.

Just noticed WickedRX7's box. Looks like a home depot version of the M2. Very nice job guys.

adam c

iTrader: (2)

Thanks GoRacer. Glad you liked the mod.

When I designed this, I didn't want to "copy" any other intake. I wanted something different. In addition to peformance, this mod was designed to:
1. Be easy to install
2. Be easy to remove the airbox without effecting the mod.
3. Avoid hoses and tubes running anywhere.

A number of people have them installed, with good results. James was one of the first.

adam c

iTrader: (2)

wickedrx7,

I like the setup you have. Is it difficult to get the airbox in and out with that shield on there?

My shield attaches to the frame and rests on the radiator hose. It stays in the car when you remove the box.

tmiked

I wish somebody would publish some before and after 40-80 third gear times. The comparison would be good information.
The trap time post was great but i dont go to the strip often.

Thanks

adam c

iTrader: (2)

I am trying to buy a stock bottom section from a guy on the forum right now. If I get it, I will do the 40-80 test and publish the results. I am curious to see the difference too.

adam c

iTrader: (2)

Thanks Dave. Glad you like the mod. Did you ever race that girlfriend of yours, in the Mustang GT, with your boost working right.

jons3rdgen

I am doing a similar mod but I have the dkuct going from the right side to the small opening in the chasis up to a hole in the bottom of the airbox. I am using 2" plastic pipe lick the kind for a shop vac and using 2" rubber pipe for pluming to fit through the chasis and it is very hard to see the mod unless you know what to look for

adam c

iTrader: (2)

Sounds like you are adding some air to your flow, but not as much as you could. If you have a 2" tube, you will have just over a 3 square inch area that air can come in. This is if the tubing isn't partially collapsed anywhere (to fit thru a narrow opening). If it is collapsed some, then you are restricting some of your flow.

My mod has an opening of about 12 square inches to give maximum airflow. It has no restriction on air to the filter.