O 16581 72452 5

I just helped a friend with this mod on his hyundai with aid of an S-AFC, worked out very well, and very inexpensive (couple of bottles of JB weld) He had an extra intake and extra throttle body sitting around. This now makes me want to do this modification when i get my engine back together and dropped into a miata, not only does it give the engine a modified look, but helps alot with performance. I'm going to try to use a big bore throttle body for say a civic and try it out sometime in the future. I was sworn to secrecy by him, but i can't keep it. We drilled out his intake manifold and JB welded the throttle body on, we connected the butterflies together with a bike brake cable, then took the signal wires from his MAFs and connected them together, ran the signal wire of the extra maf to his S-AFC, did some tuning on the S-AFC and it worked out very well, it needs some tuning of the fuel curves still to perfect this mod. If anyone has any extra parts laying around and has a GSL-SE, i'd suggest doing this. I hear S-AFCs don't work with SEs because of voltage reasons, but maybe with use of a Haltech or other ECM would work out great.

13B4port

where would you attatch the extra throttle body? and wouldn't it effect the DEC? or harm the air flow? i donno. please go into a little more detail man? it's kinda funky idea, never heard of it for a little engine.

O 16581 72452 5

It would attach directly parallel to the first throttle body on the opposite side.

DEC?

I'm really unsure about all of the details of it, but it requires a S-AFC atleast to process the two MAFs/AFMs so i don't see how it would harm the air flow at all, it's all metered air entering the engine.

13B4port

dynamics effect chamber. thats where you are saying you're goin to connect it? right where the BAC(bybass air control valve) is? the DEC bassically compresses the air, as manntis put it in a thred a while back"kinda like a puesdo turbo". it gets all of 1-2 psi, i think. wouldn't that new TB harm this effect? but it sounds neat. was there a big power gain from it being done on that other car?

O 16581 72452 5

I felt a power increase on his car, i doubt it would effect the DEC much, but it potentionally could. A good idea would be using a spare DEC or 2nd gen DEC, whatever you can come across for practically free and just test it out, see how you like it. You will need an S-AFC or some sort of EMS.

purple82

Can you draw a paint picture or something? It's not clear on how you are setting this up.

rotarygod

iTrader: (1)

Since the dynamic effect chamber on the GSL-SE (or every other RX-7 for that matter) is not symmetrical in shape, it will be next to impossible to do this. Also sice all 3 throttleplates do not go to the same common chamber you will really have issues with making this work. While the GSL-SE throttlebody is embarassingly small, the air flow meter is even smaller in area. You probably will not be able to just wire 2 afm's together like the maf's were on that Hyundai. Even if you were to pursue this you will need to: completely fabricate an entirely new dynamic chamber, get ahold of another GSL-SE throttlebody, figure out where to bring the intake hose for the other throttlebody from, figure out how to make 2 afm's work together (good luck here!). Then once you figure all of this out you will still probably end up using that bastard child bandaid called the S-AFC to make it all approach even functioning correctly which it still won't. Don't forget that there are only 2 fuel injectors on the GSL-SE. An S-AFC can't help you after the injectors are maxed out so you will need to add more injectors. Add all this up in price and what do you have? $1000? Maybe more? Why not just get a Microtech computer for a couple hundred less than this which is the proper way to tune. this alone will add 10%+ more horsepower over stock and probably more after other things are done to the car. If you still want more airflow, adapt a 2nd or 3rd gen throttlebody to the GSL-SE. The total price will be very comparible to what you propose but will function much more smoothly and properly and be much more driveable. If you do it and it works, more power to you and good for you! If I were a betting man however, I'd bet against you. Never-the-less go for it and tell us how it turns out.

13B4port

hey i got the throttle body and intake/DEC from my old gsl-se engine. you want them? i'll give em to ya real cheap. like 20 dollars plus s/h. pm me if you want them. i want to soo you do this. i bet it would work if you connected the 2 intakes after the DEC's. jsut connect the 4 pipes together. i want to see this done, go for it. i got parts for ya

O 16581 72452 5

Thank you rotarygod for not acting like the people in the 2nd gen forum about this. I was only considering this incase i could come upon spare parts for next to nothing and after buying a Haltech or other EMS. AFMs or MAFs can't be wire together without some sort of chip or S-AFC to recognize it.

O 16581 72452 5

I can't afford anything right now, 13b4port, i'm trying to save up every bit of money i can get with parting my car to buy a Miata, i'm jobless. Thanks for the offer and support. i just don't have a running rotary at the moment. I'm wanting to do this expirement on a streetported 13b miata. .

rotarygod

iTrader: (1)

I had hoped I didn't write that in an offensive way. I guess I didn't.

O 16581 72452 5

No, you didn't, you gave me support and listed what could set me back.

Mr BiG G

Could u draw a paint pic or sumtin...i'd really like to see how this setup looks like...i haven't quite understood wat exactly u wanna do...

thanx,
Gufran

O 16581 72452 5

http://www.capa.com.au/kits_hyundai.htm
Scroll to the bottom and you'll see what his set-up looks like, it's not his car, but it closely resembles his air intake set-up.

AdrenalifeRX7

Is the power increase even worth it?

O 16581 72452 5

Click on the small picture of the dyno they have for a larger version, i didn't feel that dramatic of an increase on his car, but there definately was one. He still needs to dyno it to tune his S-AFC properly. Also his second throttle body wasn't sealed and had a massive vacuum leak.

Mr BiG G

That seems pretty kool...basically it's just increasing the air flow by a whole lot...so if u did that and ported ur intake manifold or put an FD intake manifold on ur SE motor (IF that works) u would have some nice hp gains....it's basically like putting a bigger throttle body and increasing the intake manifold pipe diameter and porting the inside of the intake manifold....someone should most definately try this....

later,
Gufran

purple82

It's not exactly the same as a larger single throttle body. Since you still have two smaller intake tubes, your intake velocity is higher than a single big tube would be. This would help keep some of the low rpm cylinder filling.

The problem that I see is that these intake manifolds are designed to take in air from one side and feed it equally (more or less) to all 4 cylinders if it's designed right. If you intake air from the wrong side of the manifold without modifying the manifold, the cylinder intake air distribution won't be right. This might lead to some long term reliability problems.