So, i have been an FD owner for about 40 days, give or take. The car is a pristine condition with 30 miles on the meter. But i cant help planning some engine upgrades.

I know the engine has to come out at some point, preferably while it is still working properly to avoid any damage, to get a small overhaul. And while doing so i want to upgrade it a bit, but i have a few requirements i want to uphold:

- Must look more or less stock
- Must pass emissions
- Must be twin turbo

I want to keep the orginality of the car, and not mod i to death. They are so rare here in europe, that i dont have the heart to "rice" it (no disrepsect to those who want it rice, just not my cup). This means i want to go to lengths to keep the engine looking stock, and you need to be a rotary enthusiast to notice it isnt.

Emissions is a MUST. Its going to get smogged every two years, and i want to pass the requirements here. I have a doccument form Mazda about the smog tesing that kinda says i dont need it, but i want to run with as good emissions as i can.

I also want twins. I have looked at different threads debating the twins, sequential vs not sequential, 93 spec, 99 spec BNR and what not, and i am not much wiser. So i have put up a few more goals:

- I will do the OMP mod and run 2-stroke in a separate tank.
- I want to use synthetic oil in the engine itself (this is smart yes?)
- I could do a mild port job, but the car must be able to run on stock ECU with the port.
- I would love to end up at 350-400 reliable HP.
- Water/meth injection is probably a good idea?
- I will most probably use an Apexi ECU since they look OEM (stock harness, stock size, and all i need to do is swap out the lid and it looks all stock)


So i am really looking for a starting point for further research, what my potions are, where the limitations in the stock setup is (Turbos? Intercooler? Exhaust manifold? Exhaust?) and what i can do to work with them, or around them?

What would you guys do with the given limitations? Money is a limitation, but obviously im not doing a "budget build". I want proper and reliable, not cheap)

 

remote 2 stroke feeder kits apparently do not fit with standard twin turbo setup

I use 100% mineral castrol GTX 20W50, even during circuit and drag racing , it is a great cheap oil, change it frequently

I wouldn't go there, and I'm probably not going to.

I have / had similar goals.

First point of call, I have it under good information that the PowerFC lobotomises plenty of OEM emissions functionality, be aware. I use a HKS F-Con in conjunction with the factory 2002 JDM ECU for the exact reason that the emissions equipment can run 100% as factory intended.

To have a good go at emissions legality I would suggest and personally use a Knightsports Metalit Pro-200 catalytic converter. There is no exhaust smell.

You will need upgraded injectors which is difficult because any changes there will more than likely completely mess your CO and HC emissions because you will be either using poorly installed 850cc secondary injectors in your primary holes or removing the factory port air diffusers.

The factory MAP sensor maxes out around 1.15 bar / 16.5-17psi of boost, which is a little close to the set point you will need around 1.05bar / 15psi to achieve your goal.

Intercooling is proving hard to do without ruining the car by cutting it up.

But a somewhat common ultra high quality high dollar theme could be

Autoexe RAM air intake + GReddy SMIC or Quality Japanese V-mount (GReddy, HKS or Knightsports)
GReddy compression tubing and hard piping kit
HKS Twin Power
80mm stainless steel front pipe
Knightsport Metalit Pro200 mid pipe or muffler + cat mid pipe from Re-Amemiya, Revolution or R-Magic
any nice 80mm titanium catback
then your ecu of choice.

I would personally avoid any auxiliary injection and just tune the car to 10.8-11.0:1 air fuel ratio on 93AKI / 98RON pump fuel.

 

Thanks for the input. Lots of names and parts to reasearch

I would prefer to run everything with OEM ECU, if that is possible. What are the 2002 JDM ECU capable of doing without help? If i can get good numbers with that, i would prefer that solution to any other aftermarket system.

 

Congrats on the low mile car!

If you have not done so already, check out the FAQ located at the top of this section. Lots of great information in there.

So we can help you better, what year is yours?

As far as the modifications go, on the factory ecu, it generally is a 3 mod limit. Intakes, exhaust, downpipe. Anything beyond that will need something like the Power FC.

But before doing any modifications, you would want to do the "RELIABILITY MODS." Larger radiator, metal AST, new fuel filter, etc.

A boost gauge would also be required so you can keep an eye on the boost level.

For your power goals, a set of BNR twins, Large Pettit or M2 style SMIC with a proper duct, Pettit or M2 style intakes, 3" exhaust, Larger secondary injectors, and some form of engine management with a tune.

Of course there will be other things needed at that point as well (twin power, clutch, better tires, etc.).

Good luck,
Vince

 

I've been very happy with my 99 turbos. The power, torque and general responsiveness is wonderful. I considered getting BNRs but my goals were for a responsive setup more than top end power. Also BNRs have 2 options on oil seals. One only works with dino oil and will smoke if you try and use synthetic.

If emissions is your goal, I wouldn't bother with a remote OMP. The OEM system works very well and delivers a metered dose of oil. Meaning more oil at high loads and less oil at low loads. I don't think those remote pumps have that capability but I could be wrong. More oil in the combustion chamber at idle and low RPM can generate more emissions in the exhaust.

With regards to power goals, I suggest you read this section of the FAQ: https://www.rx7club.com/3rd-generati...0/#post8003838
400 is not achievable in an emissions legal twin turbo setup.

Save the stock cat for emissions testing. Get a high-flow cat for day to day use. I recommend the Bonez from RX7.com

The stock pre-cat should be removed. Check the FAQ to educate yourself as to why.

A mildly ported motor will run on a stock ECU. I swap in the stock ECU for emissions test and then run the Power FC in between tests.

Regarding ECU selection, keep in mind that a programmable, standalone ECU like the Power FC, Haltech etc are only as good as the tuning. If you do not have easy access to a tuner that is COMPETENT at tuning TURBO ROTARY engines, I'd be reluctant to recommend such a mod. Do more research on that. The 'chipped' ECUs work quite well depending on the mods. I think Pettit still offers theirs. You may have other options in EU from UK and other areas.

Intercooler is a must. Again, the FAQ has a lot of good info on this topic as well.

Start reading

Good luck.

 

What year is your car? It's easy to go nuts with the money. Take your time.

 

If you want to run the OMP adapter for 2-stroke oil...you will have to use a Mikuni OMP found on later model FDs. The earlier model Denso OMP with the adapter will not fit with the twins...but the later model Mikuni OMP + adaper should fit

 

Sry I just had a gallon of beer, im a bit drunk, but by "OMP mod" do you mean using the Rotary Aviation adapter? Or do you actually plan to mod your OMP? If the latter is the case than ignore my above post...

 

You can't get away with much with the 2002 ECU.

If you do a full straight through exhaust system with a high flow cat converter that is the limit I consider OK. The factory airbox seems to pose enough restriction to keep things in check.

For your power goals you are going to need all the typical bolt ons + a minor injector upgrade and ignition upgrade.

 

Stock twins will be able to support your power goal, given you have all the supporting mod like upgraded IC/exhaust/injector/ignition, and a proper tune.

BTW nice daily, my daily is a ZE'ed MX-6

 

I don't even know where to start.

1) stock looking engine bay: given your interest on the power fc in regards to it looking like stock (even though the ecu is hidden from view). I say that you will not be content with any visual mods in your engine bay. Which limits you quite a bit. Meaning no hard pipes, cold air intake, no intercooler... All of the stuff that nets you HP by simply bolting it on. IMO your engine mods should be Adam c's cheap bastard kit and A.I. (to lower your intake charge).

Next is emissions.... Sorry man you are not getting 350-400 with emissions still attached. Nevermind the choke by keeping the engine bay stock. At best you are looking at 260 rwhp with your list of criteria (and that's a lot 35 HP over stock). Stock engine bay (minus Adams mod and AI), dp (note a dp removes the precat and that affects emmisions but only when the car is cold), a hi flow cat, a racing beat exhaust (closest thing to stock), a power fc so you can raise the boost to 12 psi max. Nevermind that the BNRs change the cfm... The thing is that if you truly want the benefit of the bnr's over stock you have to raise the boost. If go past 12 then injector change comes to order. which then you have to tune for which greatly affects how your car burns fuel. Meaning you emissions comes to play again. Now I'm not saying it can't be done, what I am saying is the person that tunes your car HAS to know what they are doing not only with respect to rotaries but also with respect to emissions.

IMO given your list- just leave the car as is.

Btw- the 3 mod rule (then an ecu change) is antiquated. It was proven like 12 years ago that as long as the boost is maintained at 10 psi an ecu change is not warranted.

 

Thanks for some good feedback. This is my first turbo (and wankel) car so there are quite a few new things to learn. My previous research was on the N/A KL V6 engines that came in the Probe, MX6 and 626. Quite a different type of setup.

When i say stock, i know that it wont look like it does today. I just want it to look somewhat like what one could expect from a factory car, that is owned and maintained by an enthusiast. Also, i dont want mods that cant be reversed, making sure the car can go back to 100% stock at some point.

It is kinda hard to explain what i am looking for. If the stock airbox is a problem, i can potentially swap it for a better solution, but i would prefer not to. I know it is not possible to get 100% stock look and 400HP, but i would love to get it as close as i can.
The thing i dont want, is chrome tubes, blue silicone, huge turbo, and all other stuff that screams "tuned ricer". We have very strict regulations for this here, and the inspection we have every other year is have two inspection points where they do a "visual inspection for obvious tuning" and "visual inspection for ECU modifications".

I could go with a FMIC, given that it performs good, and also let me do plumbig so they match the stock tubes fort he SMIC. Aluminium IC and Radiators can be anodized black, and thus they wont be as noticable on my black car. And again, that makes it look "stock" like the black oil coolers. If they are mounted to the stock intake system, and using black hoses, it wont be to obvious when people open the hood. Cover it with the plastic from mazda, or make my own covers from fiberglass, and it will be good enough.

And when i say i want emissions, that follow the same line. I want catalytic converters, but they will have to be made for the power level i want. We have emissions every 2 years, so in the worst case, ill have to put the stock system back on. The stock setup has two cats and an airpump for emissions iirc. Are there any options that will allow me to run this when aiming for 350-400hp?

 

I'm at 325 fully emissions compliant with 99 twins and all stock location hardware. Water injection and I should have 350 pretty handily since my intercooler(greddy smic) seemed to be holding me back more than the cat at this point. Beyond 350, i dont know. I'm going to be replacing my Bonez with a 100 cell metallic cat just for street use and run the bonez for emission testing only. I hope to see 375rwhp while still being an hours work away from swapping back in the Bonez and being 100% compliant.

I'm going to do things one at a time just to see the gains.

Oh and ditch the stock ECU. My car runs so much better with the PowerFC.

This is my engine bay:


Jason

 

I would say your enginebay is somewhat within what i would refer to as "looking stock".
Paint the intake satin black and you are there more or less.