I swapped a JDM TII S5 engine in my 1990 vert. The swap did not come with the stock JDM air box. The air box from my USDM N/A engine does not fit over my air flow meter. The hole in the air box where the air flow meter is supposed to fit, is way to small on the N/A USDM box. The hole on the air box is about 70mm in diameter. But the diameter of the JDM TII S5 air flow meter is closer to 90mm.

Now, I have tried to buy a JDM TII air box from people on this forum. Everytime I get someone who knows for sure that it is a JDM TII air box, sells me an airbox that is identical to my N/A USDM air box, with the 70mm opening on the bottom for the air flow sensor.

Can anyone here tell me if I was lucky enough to get the only large size air flow meter that mazda ever made on their JDM FCs, or did I just get ripped off for the third time?

P.S. I have 3 air boxes for sale

 

Trace the hole out and cut it bigger

 

There is not enough room in the plastic that comes out of the bottom of the box. The air flow meter is much bigger than the piece where the hole is.

 

is there a part number on the air flow meter?

 

There is a sticker that looks as if it had a number and barcode on it, but it is worn beyond legibility.

 

maybe that maf was upgraded before u got it and the previous owner ditshe dteh air box cause they ran into the same problem u have

 

I bought the engine from a salvage yard in Japan. It looks like the stock afm from my N/A, except its bigger. If it was upgraded, what car could it have come from? Or is there an aftermarket supplier?

 

alot of times u use a factory maf thats off of another car. my current daily driver is an s13 w/ sr20det and a lot of guys will swap out the maf for one out of a z32. looks the same just bigger. could it be off of an FD?

 

Not sure, but worth checking out. I'll post some pics of it on here tomorrow night. Maybe someone will be able to identify it.

 

definately could be off a FD because we all know they use AFM and it is not a speed density setup. thats why people could put dp and remove cats on them and never have to worry about popping engines...

or that the afm is from a 929?

 

i kinda get the feeling this thread is sarcastic and if all FD's are speed density than sorry, but i thought at least the earlier ones were afm. ( not an FD guy)

 

I heard FDs were speed density.

Just because a AFM will fit or plug into the harness and be bigger, does not mean you will get more power. Can the bigger AFM flow more? Yea, but will the ECU calcualte the airflow correctly? Nope. You will possibly run lean or rich depending on how the AFM is calibrated internally.

 

Screw the stock airbox, just slap an aftermarket filter on the end of that sucker.

 

^ BAD IDEA! Search, and you will know why

 

+1

 

the bigger afms, are from the cosmo's and the v6 626/mx6 cars

 

I searched, and couldn't find any info on why an aftermarket intake is a bad idea. I just want the stock box so that everything looks stock under the hood. I took pictures of my afm and will be posting them when I get back home from school.

 

Can anyone help identify this? If it is from another car, wouldnt the turbo inlet duct be different also?

 

Adding a cone filter to the end of the intake in the engine bay without heat shielding or any way of providing fresh air will only make you loose power.

 

Maybe you got a LUCE motor.

I've seen a couple of them come through the shop as "TII Motors".

Same.. but sliiiightly different.

 

... This isn't entirely true. Most of the power benefit you get from an intake is from the much larger amount of air a cone is able to pull in than the stock snorkel. It might not be ideal to such up all that engine bay air, but it's not terrible either.

Would fresh/cool air be better? Yes. Will you "loose power"? No.

 

pfffttt, got me. im not an fd guy. just throwin ideas out there

 

So no one can identify the afm from these pictures? Is there any other way I could figure out what is going on? If the afm is from a different car, then so is the S shaped tube going from the afm to the intake of the turbo. Because the inlet side of that tube is larger than the n/a afm. Does anyone here have an afm from an fd or a 929 that they could tak a picture of? That might help. You see how I have my air filter attached to the turbo inlet duct. Its ugly, and was only a temporary fix that has been there too long.

 

FD's DO NOT HAVE AIR FLOW METERS

For stock series 5 rx7 airflow meters, turbo and NA look identical and fit the same airbox. The only way to tell is the sticker on it...n35X XX XXX will be an NA, and n37X XX XXX will be a turbo.

Sounds to me like you got a 13bt out of an early cosmo or something. I believe the pre 13b-re cosmo got the 13bt, with an oddball mix of s4 and s5 and non-rx7 peripherals. I am not a mad tyte JDM fanboy though, so I am not 100%.

Just find an air filter that fits on the end of it and if you are worried about the hot air build a box around it or feed a pipe through to the front of the radiator. It's not going to run any differently. The stock airbox flows pretty horribly according to tests I've seen, and even if you did find the stock airbox from a cosmo or whatever, it would not fit your rx7 chassis anyway so I don't see the point of this goose chase.

You have a bit of a unique setup but that doesn't mean it is an issue. As long as it runs normally you are good to go, you are making an issue of nothing.

 

This is probably what you have: https://www.rx7club.com/old-school-other-rotary-63/my-daily-driver-1990-hc-royal-classic-luce-factory-13bt-auto-508087/