1stgen_tn

Thought I would share my work here. Only thing required here is a drill, jigsaw w/metal blade, hacksaw, "foil" tape, and of course a bonez intake.

First off, you need to do the "rat's nest removal" before you can this.

1. Take your hacksaw and cut off all the metal tubes (as close as you can) off the bottom of the air box. If you have a grinder, you may want to grind the remaining down smooth.
2. Take your air filter and use it as a template to mark where you want your cutting circle to be. I allowed a circle 1/2" bigger than the diameter of the filter (too much is better than too little)
3. Drill a elipticle hole close to where you want to cut, just big enough to fit the jigsaw blade into (a starting point for jigsawing)
4. Jigsaw the circle out. Again, if you have a grinder you'll probably want to grind the remaining down smooth.
5. Using the "foil" tape, cap off all metal tubing on bottom of air box (what's left of it anyway)
6. Install your K&N filter and bonez lid. (Sorry, no pic b/c I haven't got these yet)

That's basically it. Fairly simple for the common man and no really special tools required. The metal on the factory air box is really thin and pretty easy to cut. Depending on your metal cutting skills, this can look really quite nice after painting.
I don't claim to be the best at metal work, but I think it turned out alright. The result SHOULD end up with more air going into your Nikki Carb and maybe a little bit more power because of it.

1stgen_Tn

1stgen_tn

Oh yeah, you will also need to remove that grey "box" on the side of the air box before using the jigsaw.
(sorry for not looking up actual names of this stuff, but you get the idea)
This can be removed by drilling out the rivets that attach it to the air box.

Here is a "before" picture. the "after" picture should follow by the end of the week.

Rx7carl

Better than stock, but still restrictive. The design of the stub stack that connects to the carb is very restrictive. I give you an A for inginuity and effort though.

1stgen_tn

Thanks.

So what would be less restrictive? The Racing Beat "mushroom" shaped intake?

Hey Rx7Carl, since I have your attention, how many CFMs do you this might gain?

Rx7carl

On a guess Id say yes. My custom homemade box flowed considerably more and its similar to the RB piece. Search for my old arr box mod thread.

Cant say for sure. It will be significant over the stock box though.

1stgen_tn

LOL. Funny about the misspelling of the "arr box"... Smart guy with a sense of humor, You're alright Carl!

Now, after reading your thread... I take it you expect the full 315 cfm's from your intake. So, I'm guessing mine would be in the 290-300 range maybe?

How far did you get with this? Do you have any pics with it installed?

Thanks again for your continuing help on improving the well, "mostly stock" 12A.

This club reminds me of a commercial. It think it was BASF. It said, "We don't make ALOT of things you buy.....we make alot of the things you buy BETTER."

edwin-82/rx7

iTrader: (1)

can u post a link to that thread? i'm dumb

1stgen_tn

Try this:

https://www.rx7club.com/showthread.p...hlight=arr+box

edwin-82/rx7

iTrader: (1)

found it right after the post



doesn't make much sense to have that bonez cap with the old arr box still sorta surrounding it, huh?

Rx7carl

Really funny thing is it wasnt on purpose.

Yea, that might be a fair guess. on the airflow.

Slow progress. No pics. Im more trying to make something thats useable to most folks without too much fabbing.

Well I love to tinker. I think too many people just wanna bolt on new parts. Im more of an old skool hot rodder. I like to modify whats there. And theres alot of room for improving the hp if you know how, where and what to modify.

edwin-82/rx7

iTrader: (1)

btw rx7carl loved the tutorials

finding it hard to get a 3l220 belt tho, again haven't been looking too hard

i'm kinda lazy like that

1stgen_tn

Well, then maybe maybe my idea wasn't so bad after all then. I mean, you're pretty much using what you've already got. You don't necessarily have to use the Bonez parts if you have access to some sheet metal and just cut the top lid out yourself, and get a threaded rod from a hardware store for an extension.

Too bad I don't have 1/4 mi. times (or dynos) to compare before/after to but I will post if I think I notice any gain from it. It's gotta help though, ecspecially for someone using a Sterling.

1stgen_tn

Edwin, if you're talk'n about that "yoohoo" belt, I had to special order mine at my local parts store (in my case, O'Reilly's) I believe they said it was a compressor belt.

edwin-82/rx7

iTrader: (1)

yeah theres a parts america or something next to the place i work and they didn't have it and couldn't get it (go figure). also didn't have and couldn't get about 1/2 of the other parts on the tutorial list. bastids.

OnlyOnThurs

About The Racing Beat white "mushroom" shaped intake....what kinda of improvement will you see after installing it...man for about 70 bucks for that thing and if it actually does some good improvemments i think its well worth it......

edwin-82/rx7

iTrader: (1)

can u use a k&n with that mushroom one?

84stock

iTrader: (5)

I used the racing beat power pulse air celaner on my 12a with a K&N and was happy. It didn't sound any different, although I thought it would. But it did work well and increased my power band up a little higher. Not a big seat of the pants difference though. You wanna notice a difference, get a header! Best bang for the buck!

1stgen_tn

Yeah, Power Pulse......that's the name for it! I'm quite certain that you can use the same K&N on it.

cdrad51

You can. I just put the RB air filter assembly box, and I had a K&N filter which I'm now using with it.

cdrad51

So how did it go with this? you should have gotten the Bonez intake today.

1stgen_tn

Yeah, I got it. Haven't got a K&N yet though. That'll come next week probably. I'll take another pic when I install the K&N.

However, even with a stock paper filter I felt a WORLD of difference! I couldn't believe it.... Not much to be noticed UNTIL you get to 4,000 RPM. Then, acceleration I would have to say got 2X better. I mean, from 4k to redline, the acceleration time had to be cut in half! Can't wait to slap that K&N in there! My advise is for ANYONE running headers with a Nikki carb is to either get a RB PowerPulse or do this mod. You're not getting the full potential of headers (freeing up you engine) till you do this...

Oh, and with a modded Nikki.......It's gotta be even better!

cdrad51

It is

frigidmonkey

a side note on the power pulse....well two side notes, if you have one thats in an engine fire, the paint will peel off but theres nice shiney aluminum that can be polished under there, lol. the other note, this ones a little more important.... IF you are dumb enough to put an edelbrock performer on top of a RB intake manifold, you cant run the power pulse, the hood wont close, and thats WITHOUT a spacer, glad I had one of those edelbrock triangular shaped foam bastards lying around

1stgen_tn

Lol =d