B6T

iTrader: (2)

Sorry... there are some large pictures in this thread... turns out photobucket won't re-size them automatically.

Anyhoo, I've got a nicely prepped '84 GSL-SE with full suspension, street-ported S5 engine running on Electromotive TEC 3 standalone, full exhaust, electric fan, etc. etc. blah blah blah.





Last year I made some tuning changes by switching from staged injection running 640/400cc injectors to running ID1000s as primaries only. I also added an IAC as I had previously been running without and the engine would always stall out and never idled very clean using timing advance to control idle speed. I also installed a new AEM UEGO wideband.

I completely retuned the engine but never was able to get the engine to idle stable and strong. Since I had the aux port sleeves removed, I think port velocity through the primaries wasn't substantial enough to carry the fuel through the port and into the housing without pooling in the port. That, coupled with the wide variance in engine load at idle caused by the rad fan switching on/off resulted in an engine that would still die-out under certain idling conditions.

So to summarize, I was never really able to nail the tune and idle, and I ended up attributing it to the overly complex (but suitable for some applications) S5 intake manifold; with VDI, dual stage throttle body, and aux ports. Also, according to the interwebz, it doesn't flow very well. BUT, there are no longer any off-the-shelf ITB setups or alternative intake systems available on the market anymore.

But then one day I was perusing this forum and came across the following thread:
https://www.rx7club.com/forum/1st-ge...ussion-945202/

So I fired up Solidworks and started to model the ITB and manifold. My plan here was to check fit and position using the complete 13B engine model I have but never got to that point yet. I might use it for a future plenum design but who knows:






Using the model I designed some 60mm length air horns and then 3D printed them on a Makerbot Replicator 2X:






Then a box from the U.K. arrived and I assembled everything together:







Not shown is the foam filter sock I ordered off eBay.


So this is my project so far. I plan on bringing my RX7 home from storage tomorrow if the weather holds up and then beginning the installation.

To do:
- Design and fab some sort of throttle cable mount.
- Find a mounting spot for the IAC motor and housing (Rising RPM for S5 turbo) and potentially 3D print some more parts. I'm thinking of just running two ports into the primary ports in the LIM.
- Tap and install two 3/8"NPT x 6mm push lock fittings into each runner of the intake manifold, run those into a tee, then run that into a vacuum manifold, then run a line from the manifold to the MAP, FPR, and oil injectors. The goal here is to smooth out the pulsations in the manifold so the varying vacuum and MAP signal doesn't cause the EMS to flip out... which may not even be required due to a setting in WinTEC.
- Mount intake air temperature sensor.
- Remove ID1000s and swap in 400cc primaries and ~600cc secondaries.
- Re-plumb engine fuel lines using AN fittings.
- Re-tune engine.

More pictures to follow...

Pettersen

iTrader: (1)

Nice!

What kind of plastic are you printing with?

DarrenTRS

iTrader: (1)

If you don't mind me picking your brain, here are my latest ideas/thoughts on it and I would love to hear what you think.

1. Have you though about making a thermal spacer for the intake manifold (lim/keg or lim/uim)? That makerbot (insanely jealous) would make life easier and it would help control the way that intake (especially the RB upper) soaks up heat. This was more prudent for me with a carb since it would heat soak the carb very quickly but would still be a neat piece.

2. What are your plans for ECU?

3. Any thoughts on possible building an airbox? This one is a longshot but it's something I am going to start on this week with atleast measuring space. My reasoning is using the oval stack filter like with the DCOE or DHLA, when sitting still or low speeds it's just sucking air directly off the top of the engine....also I have come to realize that K&N filters are good for keeping birds out and nothing much better. The idea is to build an aluminum box (thermal reflective tape around) with a top mounted rectangular panel paper filter (honda) so you can use a good filter and it's atleast pulling air from a somewhat cooler place but also with a first gen it's easier to "space" the hood so air flows up and out the top of the engine.

4. This might be answered with your ECU choice but, why the choice of staged injectors vs. 2 sizable injectors n/a (a'la GSL-SE).

5. For the 5+6 ports, I'm not super versed on S5 stuff but have you thought about doing an RPM trigger and using a small horn air-pump to power the actuators? I've seen it done a few times and is hopefully the plan for my S3 setup.

B6T

iTrader: (2)

I already have a UHMW LIM to keg gasket that I made a few years back to serve as a heat isolating element. That being said, I was actually planning on printing a LIM to UIM 'spacer' to serve a few purposes other than preventing heat transfer; the first being a mount for the idle air control motor and rising rpm adaptor block with integrated passages to the primary runners, and second, an integrated vacuum manifold from which I could run lines to the MAP sensor, FPR, etc. However, I don't think I'm going to be doing this just yet. I might design it anyway and see exactly how long it would take on the printer (which doesn't actually belong to me).


The car already has an Electromotive TEC3 standalone installed (picture taken during installation):




I have something rudimentary drawn up in Solidworks, but nothing too exact. I don't have any experience with sheet metal work so this too would have to be 3D printed (in sections too) so it would be challenging. I'd like to eventually install an air box as it solves a lot of the problems you mentioned. Initially I was thinking of a plenum with a ~3" single inlet which would be fed from a cold air duct and filter, but it may be just as effective to run a duct down from the cowl as I believe that is actually a higher pressure region at speed and would provide not only cooler air, but a positive pressure charge. I think the Honda panel filter is a really good idea too.




I currently have two 1000cc Injector Dynamics installed and I'm finding the tuning to be difficult with such large injectors. With the 13B, you need a very small amount of fuel to keep the engine idling at stoich mixture. This requires pulsewidths that border the minimum injector on-time, and is therefore unpredictable at times causing the engine to stall out. Low and mid range loads are also hard to tune because small PW changes equal large AFR changes. Because of this, the ECU needs to be run with minimal open-loop EGO feedback authority, otherwise the engine will hunt as the mixture changes drastically, while still within a minimal PW delta.

The normal solution to these problems is to run smaller injectors. But with our engines, the fueling requirements are such that this is impossible. I reached something like 90% duty cycle at high RPM WOT with these injectors, which is pushing the limits.

So the solution is to run two smaller injectors in place of one large. I have a set of DEKA 640cc/min injectors from an SRT4 that I'm going to try. This should get me the controllability of a smaller injectors since I'm only running a single 640cc injector at idle and low load, while being able to kick in another injector to provide the fueling requirements of the rotary at high loads where injector precision isn't an issue.


My plan is to use one of the programmable outputs from my Electromotive to pull open a pair of 12vdc linear actuators that are mounted in place of the OEM vacuum diaphragms (i.e. McMaster-Carr PN 70155K51).

monty11ez

This is very exciting. I am thinking about doing a similar build for a drift car one of these days.

Rub20B

for the airbox I would print a mold and make it with carbon fiber or glas fiber. some of these 3D printer can print material that disolves with acid..

Romeallo

How much hp and torque do you have? Any turbo or blowoff upgrades?

fidelity101

iTrader: (11)

This is the naturally aspirated forum...

Also pictures above suggest to show no turbo or intercooler.

diabolical1

iTrader: (3)

how is this project coming along?

chuyler1

iTrader: (1)

What ever happened to this project @B6T?

Jager

iTrader: (10)

I believe he put it for sale. Last I saw it was a clean running/driving vehicle.

Super cool.

John J. Garvey

Whatever happened to the car shown in this thread? Did it sell? I thought the engine modifications were top flight. I am always interested in what a well cared for RX7 sold for, as I am in the market for such a car. Respectfully, John J. Garvey