OK tmiked, this is at your request.

I got the used airbox bottom today. I ran two tests. First, I put in the stock airbox with K&N air filter. I went up to 30 mph, and shifted to 3rd gear. At 35 mph, I floored it. The timer started at 40 mph, and stopped at 80mph. I did 2 runs. The times were 5.48 and 5.49. Since the times were so close, I didn't feel the need to do any more runs.

I went home and switched to the modded box, with the same filter. I made several runs, and came up with an average time of 5.27.

After doing the test, and letting my butt dyno give some input, I came to a conclusion: At low rpms, it doesnt matter what intake you have. The engine can only pull a limited amount of air at low rpms. What counts is what happens at higher rpms. With the modified box, I could definitly feel the car pulling harder once that second turbo kicked in. I suspect that the 40- 60mph times were nearly identical. Perhaps a better test would have been 60-90mph.

Anyway, that's what the results are. Now I am curious what others have gotten for 40-80 times. Feel free to post them here.

Adam

 

Good information !

Sounds like it might knock at least 1/2 a second off the 1/4 mile.
I think my car did a 5.67 completely stock.
What is the RPM at 90, maybe we should up the measurement to that. Seems like originally that was right at the rev limit.

I havent checked my cas after mods because I dont have my boost gage installed and I dont want to break anything.
Maybe this weekend.

 

i just cut 8 20mm holes in my factory air box around the chasis leg and the less known gap between the wheel arch lining. it now boosts to 0.8 bar on the first turbo. then 0.8 on second and creeping up to around 1.0 bar if i dare let it go that far. think i`m gonna have to plug it and gaffer tape them all up again. what`s the general thought on this. how do cars with cat back and open induction kits preform???? help....

 

scott,

I'm a little confused as to where you cut the holes. In the bottom of the box, on the side closest to the fender??

If that is where your holes are, that's a good choice. You will want to put in some sort of shield to keep the warm radiator air, and warm turbo area air away from the intake holes. Let me know if you want one of my shields.

This mod will definitely help performance. Not just a little either. To reduce your boost, try installing a manual boost controller:

http://www.rx7turboturbo.com/robrobi...controller.htm

 

Just did the 60-90 test. I'm told that the new M3 runs a time of 4.8. I made 2 runs with an average time of 3.6. I was very surprised to see the times are that much faster than the M3.

 

From an e-mail I received today. Tom installed one of my shields.

Hi,

The installation of the shield was easy and I've had
no problems. I already had the stock intake box
opened up some, but was sucking hot air. I did some
other mods over the winter so it's hard to determine
how much power I gained from this mod. I'm really
happy with the power the car's putting out now.

Tom

 

Has anyone made similar "adjustments" to OEM generation 2 airbox? Any positive results?

 

Yeah, I cut out the bottom of the stock airbox on my first Turbo II. Worked very well Even managed to flow enough extra air to hit the fuel cut in the dead of NY winter. Then I eventually bought an HKS intake. Definitely worthwhile.

 

i tried to see adams box, but the link was down. Got any pics?

 

hello adam
the boost gauge holds at 11 to 11.5 then drops to to about 8.5 to 9 then back up in the 11 area. i guess it not a spike but i know its at least 1 psi to 1.5 psi above bone stock. today i took the car on the freeway for the first time since the mod and wha t a difference. lage time on my auto trans is way down , and the turbos kick right in with very little hesitation this is probably the best thing about the mod i can find so fare. also the air box noise is not bad at all i am getting a nice low tone growl when working the throttle. at idle no noise at all. i dont think i could have gotten more preformance with the high end name brand intakes. and this keeps the smog guys off your but. as you know going threw smog in the los angeles area is a bitch.
thanks again adam.

 

Hi Jeff,

I'm glad you are not getting a spike. No one has ever had a problem with that after installing the kit. Thats a great feeling ......... the first time you stomp on it, and it goes so much better

Congrats

 

Do any of you have boost controllers?

How are you making sure that you aren't going lean?

 

If the stock computer can handle boost up to 14.7 lbs, does this mean that no matter how much air is being supplied to the car (fresh air intake), and the boost is kept under 14.7; the stock computer will adjust the fuel/air mix to prevent lean running conditions?

I ask this not because I want to run 14 lbs, but because I want to be sure that if I do the fresh air mod to the airbox, I will not run lean.

 

The stock computer (ECU) is set up to run 10 psi safely. Anything over that can put you at risk of running lean. I believe the stock ECU will hit fuel cut at around 12 1/2 psi, so you can't run 14 psi on the stock ECU for very long. You would probably hit fuel cut by 6000 rpm's.

My mod is safe with the stock ECU at 10 psi. If you want to run higher boost, you should upgrade your fuel computer to make is safe. I believe that a boost controller is a good idea when you start modding your car.

 

Spring additions to car(only power mods):
Cheap bastard intake
K&N filter
Ceramic coated downpipe w/ new O2 senser.

Results: One test drive later, and it is fantastic. Spool is quick and the upper power is better. I'm getting ~11-12 pounds on the boost gauge. Like 11.5-10-11.5 or something, I need to do a few more test runs. Feels GREAT. Before I do anything else power wise, I'm getting a boost controller.

The Cheap Bastard Intake was cake to install. The foam along the radiator was terribly degraded and crumbly. The shield fit fine first time. Easy instructions for measuring and placing the screw hole. Slipped right on, and everything went back together fine.

My overflow tank tubing was just a little tight around the back of the heat sheild. Another 1/2" back and it wouldn't have been able to make it around. But as it was, there is JUST enough give to it that I feel comfortable it isn't under tension, so it fits. No one else mentioned this, so maybe for some reason my tubing was shorter than others. ^_^

I'd have to give it two thumbs up!

 

hello adam
the air box mod is working great.. what I/C upgrade can we use with the stock air box ?. would like to upgrade down the road and want to keep the stock box.

 

Glad to hear that you finally got the kit installed, and that you are pleased with the results.

I did consider the position of the overflow tank line, when designing the mod. I tried to move the shield back as far as I could, to allow as large an intake hole as possible. The overflow line was a limiting factor. If you want to trim away a little bit of tab "A", you will be able to remove, and install the shield a little easier. Of course, now that its in, that won't be much help

 

The Greddy SMIC will fit with the stock airbox, but the fitment is VERY tight. I believe that several modifications have to be made with the Greddy. PM Brentis about the Greddy unit. I chose the Blitz SMIC. Fitment was very good. No problems with my fluidyne radiator either. Mazdacomp makes an intercooler, but I'm not sure that it is any larger that the stock unit.

 

Hey, good to know Adam... I'm looking at adding a SMIC so now I can look at the Blitz as well. Do you know if it performs as well or better than the Greddy.

BTW, thanks for the cheap bastard mod. I have definitely gained some HPs and spool up seems faster. I'll definitely recommend this mod to anyone. But as with an intake some precautions... fuel mixtures and boost need to be addressed. I think you mentioned if you keep boost at 10PSI everything should be fine... I agree. I saw an increase of about 1 PSI and dialed the boost controller back to 10. Everything is nice now. There is a bit more "noise" but its barely noticeable. My GF couldn't tell. Then again, I have heard a bolt fall of my car.

I liked the level of detail you gave the air duct. Like bending the edge up a bit to assure their is minimal to no wear on the rad hose. Good attention to detail. Plus, it fit very well. Simple install... but then again I didn't do it....

So, I give it TWO rotors UP!!!


Thanks Adam

Victor

 

damn server....

 

Hi Victor,

I'm glad you are happy with the airbox mod, and I was happy to install it for you. Just don't tell anyone that I installed it for free ........ oops!!

The Greddy SMIC is larger, and more expensive than the Blitz. If cooling capacity is the only consideration, the Greddy has the advantage. I chose the Blitz because it was a big improvement over stock, while still fitting without difficulty. The Greddy installation is really tight.

With a Pettit ECU, you should be able to run higher boost than 10 psi, and do so safely. I suggest that you check with Pettit to see what they reccommend. I have the M2 stage 3 ECU, and run 13 psi. I would think that you should be able to run AT LEAST 11 psi with no problem.

 

I've started looking at modifying the stock air intake setup and I'm wondering...does anyone know what the rightmost little box on it does (if you are facing into the engine, so the piece nearest to the battery location)? I ripped it off yesterday and it looks like a box to nowhere with a piece of 1/2" or so piping into it?

I'm going to look at running some piping out of the bottom of the airbox to the passenger side front mesh area of the C-West front I have (big opening and single oil cooler so I should use it for something!).

I also noticed there is a gap between the portion of the top piece that goes from the air intake to the intercooler on the intercooler side. Has anyone tried sealing that gap or creating a separate routing system for air to the intercooler?

 

Lots of people have made custom ducting for the intercooler. I believe that Brentis did a bunch of work on custom ducting, so he might be a good source. You may want to send him a PM.

 

Finally installed the CHEAP BASTARD intake mod. It works great!! Installation was a breeze. Best advice on installation is to cut out a large opening rather than several small ones.

It will take a bit to get used to the 'mooing' sound that most aftermarket intakes make, but am pleased with my 'cheap bastard' cold air intake.

Thanks ADAM.

 

Glad the installation went smoothly, and that it is working great for you

I prefer to think of the noise as a growl