Extremely nice work.

 

I know the laws for AZ what i'm doing leaves all the emssions stuff intact for now, sadly

 

man this thread grew fast, and i can see why! noice work. Great documentation too. about how long do you think (time) before she runs?

 

The TII intake is a little similar to the NA's dynamic chamber in reverse. There is a direct line from the primary throttle butterfly to the primary runners, and then the secondary runners connect to a plenum of sorts which is fed by the secondary throttle plates. I would assume the RE intake is similar but the casting is much more round (it really looks like a plenum).


Should be running by this spring/summer. I'll be driving it around on the stock turbo but won't really be showing it off until I get the big turbo on there and it's tuned. I'm so sick of seeing standalone equipped RX-7s driving around trailing clouds of black smoke I can't subject anyone else to another untuned car...

 

Very impressive!! I wish I had the time/talent/money to do something like that. I'll have to satisfy myself with the stock manifold I've been polishing the exterior of, and portmatching the bits to the gaskets.

Can't wait to see it all together.

Vince

 

Why did you go with the runner length and size that you picked Aaron?

 

Aaron, you are my idle..... I wish I had the ability to undertake something like this.

 

Idol, spell check please

 

Nice work !!

only wish you had done this later (once all up and running) so we could see the increase in HP and flow compaired to the stock one.

but bloody nice work !!

 

1 thing i wanna know!!!! how much money you got rapped into that???? seriously.

 

Niiiice. I'd be too squeamish to trust my own work on thse kinds of things! One of my friends custom fabbed an entire turbo system for his Benz 190E 2.6 along the lines of what you do. Keep it up!

 

I chose the diameter in order to match up with the stock lower intake and gasket. The length was chosen about a year ago based on a few books I read (forget what the titles are now, got them from the library). Basically the plenum needs to be approximatelyt 70% of engine displacement and the intake runners approximately equal in length to exhaust runners. Longer runners make power lower due to higher velocity but choke higher up, shorter runners make power higher up due to less restriction.

Yeah, but that would have required replumbing the secondary injectors and retuning the whole car...

Not counting the throttle body, there's less then $100 of materials in that intake. The major component is TIME.

 

Dont you ever do anything the easy way?

 

hey you have any pics of it on the car done? if so please post!!! amazing work man i love it

 

If you've seen that you've probably seen this too. Nice internal velocity stacks just like you want.

http://www.sdsefi.com/air12.html

Not quite right. Runner length does affect flow (longer = more restriction), but for a given airflow it doesn't affect velocity, only cross-sectional area does. Longer runners make more power at lower rpm because the longer the runners are the lower the resonant tuning point occurs. Shorter runners make more power at higher rpm because the resonant tuning point occurs at higher rpm. Skinny runners make good low rpm power because the higher velocity results in more swirl in the chamber for better air/fuel mixing and more efficient combustion, but like you said costs power at high rpm due to the restriction.

See attched photo.

 

Man, that's a lot of work!!!!

 

Veeery interesting. Thanks a bunch for that one!

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Aaron, I must say this is just the next thing in a growing list of what I've come to expect from you. Your attention to detail and persistance in producing only the highest quality workmanship is not only a continuous inspiration but an increasing respect.

I look forward to seeing what you come up with next, and certainly to working on more automotive projects with you in future.

Do it once. Do it right. Or do it over.

My hat's off to you man.

 

Bump. This should be archived -- along with the other one -- and continuously updated.

 

Where did you get the flange? I was planing on making a LIM with a FD UIM, I have a friend that is a machinest. How do you feel about the FD UIM paired with a custom LIM for the 13b 4prt motor? Would it be worth wile to make a UIM as well? Consider the TII UIM flows much betor then the 13b 6prt motor.

 

Since when has anyone ever accomplished anything by going the easy route?

I have so far resisted the urge to install the intake on the car since I still need to deal with the primary fuel lines and metering oil lines. I don't want to be pulling it on and off too much.

Yes, I saw it after I had finished with mine. That SDS page is one of the most useful sites on the Net for things like this. Too bad their EFI systems aren't very good.

That makes more sense...I had it half right.

I drew up the flange in CAD and had it cut out on a water jet machine.

No idea. I have not done it but others have. I've never seen a back to back dyno comparison, only "butt dyno" numbers.

For what? You mean both a custom upper and lower intake? No point in doing a customer lower intake becuase there's really nothing that goes on down there. It's just a set of runners.

I doubt that's the case since the runner diameter and chamber size are exactly the same. The S5 has bigger runners in both NA and TII forms.

 

That was my T-II manifold! Damn that's an old picture. I cut that one in half, hollowed it out into a large single chamber, and welded it back up. It definitely changed the way the car drove.

 

How so? I would assume that low throttle and off idle would suffer but top end should be uneffected. Am I right?

 

I've cut apart every type of stock manifold, experimented with them, made changes to them, tested them, and run them. I'm going to agree with you. The TII upper does not flow more than the n/a uppers. Look back at the photo. That one is an S4 manifold. Look at the primary runners and how small the area is after the primary throttle plate. It's very small. It's terrible for flow. An S4 upper manifold has much more open area leading into the primary ports. The air doesn't have to turn as sharp in them. It's a tossup on the secondaries but the n/a primaries definitely flow better. On the S5 manifolds, the n/a upper is definitely better as it is better than the S4 upper. That manfold in the picture was hollowed out into one large plenum chamber, welded back up and tested. Throttle response was different. It is a bit more touchy on the throttle. Very similar to the single 75mm Mustang throttlebody with the custom manifold that I built. It was still a little more drivable than the single though but not much. Top end power got better, low end worse. I originally tried it with the stock ecu with fair results but it was much different with a standalone.

I do have to ask, why did you taper down the primary runners mid way through? Why didn't you just use the smaller size all the way into the plenum chamber? The lack of transition would actually have let it flow better and it would have been less work.

 

The NA manifold has to make several 180 degree bends during its process. Where the TII only makes one 120degree bend or so. Even though the runners are the same diameter the overall length and angles are less on the TII.

My purpose for the LIM is to remove all them block offs make it look much bettor is all it was for. As well you could make the runners a tad larger. The UIM was a tossup my original plan was to use the FD UIM for 1 it dose not have the TMIC holes on it, so the FD UIM looks bettor. I have not seen any performance increases that are stated outside of a few butts that say moderately bettor. I am going a lot of looks and would like performance with it but not willing to sacrifice performance for looks.

 

Awesome job, looks sweet! good luck with everything else!