N/A to turbo help!
 

Hi guys I am fairly new to rotarys but i have done a lot of research into them, I have a 88 N/A that i bought for $400 and I am adding a turbo kit. heres my question, is there a way to get rid of the flapper maf with a wideband , and the Apexi SAFC (i have no room for it), can i add a 2 bar map sensor, in the intercooler piping? I dont wanna go stand alone because i am going to school and cant afford it yet.

You can't do any of that without a standalone EMS. If you're building a 6-port turbo, don't go cheap. You'll regret it when you blow the engine. A standalone or something like an Rtek 2.x programmable stock ECU would be the only way I would attempt it. An SAFC has no timing control, so all you can do is throw tons of fuel at it and hope for the best. Not the best way to tune anything.

There is no turbo kit for the NA RX-7.

No. A wideband is just a more accurate O2 sensor used for tuning purposes. It has nothing to do with the function of the AFM on the stock ECU.

A S-AFC alters the AFM signal to the ECU to trick it to supplying a different amount of fuel then it normally would. Thus, you need the AFM. The AFM is the primary load input for the stock ECU. It cannot be bypassed or removed.

Sure, but what would you do with it? The stock ECU won't read it.

You can get by with the stock HT-18 on the stock TII ECU. Anything else and you are in standalone territory.

i only plan on running 8 psi daily and 10-12 whenever i need to. So to accomplish this I could get a TII ECU and Rtek 2.x i would be able to do this?

i just did a 6 port turbo build and all i can say is don't cheap out on it. like posted above, you'll regret it. standalone ftw

A Rtek 2.1 converted TII ECU (N332 or N333) would be able to safely run it. Switching the ECU over to MAP based timing, and keeping it very conservative under boost will be ok. You'll need to read up on tuning, so here are some good threads from the Rtek section to get started:

Target AFRs: https://www.rx7club.com/rtek-forum-168/new-target-afr-tables-890528/
Timing Tables: https://www.rx7club.com/rtek-forum-168/new-boost-based-timing-maps-885556/
More tuning info: https://www.rx7club.com/rtek-forum-168/afr-tuning-methods-827389/

You'll also need a wideband 02 sensor/controller, a better fuel pump and larger secondary injectors.

since you have a s4 n/a block and have 9.4:1 comp ration look at my thread here: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s5-6-port-turbo-whos-done-questions-inside-890359/ and look at the 10th post. hope this helps.

Hey thanks for the help guys!!

On what turbo though?

Remember, as I pointed out, there are no turbo kits for the NA RX-7.

If you run a stock HT-18 at 12 PSI, you will make about 250HP and can get by with a stock TII ECU and some minor fuel upgrades (or an RTek).

If you run, for example, a GT40R at 12 PSI, you will make 400HP and neither of those ECUs will cut it.

Perhaps if you tell us your plans, we can offer better advice.

Ok I have a t3/t4 turbo,50mm wastegate, walbro 255, turbo II injectors, wideband 02 controller, getting ready to fab up the 2.5 in down pipe into a 3in catback exhaust. I am almost ready to mess with the ECU. heres pics so far Here

T3/T4 just refers to the flange, not the actual turbo size. So this could mean a loto of things. A full standalone is the "right" way to go if you have a completely aftermarket turbo, but the capabilities of the Rtek 2.x could pull it off. You'll just have to start from scratch with both the fuel and timing tables. It's usually used with stock or hybrid turbos however; some of which are producing 350-400 whp.

Any pictures for those of us who don't have a Facebook account?

As mentioned, T3/T4 doesn't say much. That just shows the turbo is a hybrid of a T3/T4. Could be too small for a rotary, or absolutely massive.

But as I have mentioned several times, there is no bolt on turbo kit for the NA RX-7. In order to fit that turbo, you either need to build your own exhaust manifold, or swap to TII intake manifolds (requires port matching) and then use a manifold designed for a TII.

Sweet! It looks like you have the hard work done. Looks like an eBay manifold with a T4 to T3 adapter? It's nice to know that arrangement provides enough clearance on the NA lower intake, because I've never even thought of that as a solution.

Now the bad news: While I don't know the specs of that turbo, it looks like a T4R'ish compressor housing and wheel. Not exactly the same (fewer blades) but sufficiently larger that you will need to run a full standalone. Go with 680cc primaries, and 1000-1200CC secondaries with a Walbro 255 pump.

Sounds awesome I wish I could see the photos on my phone. I'm in the middle of a 6port turbo build myself. Good luck.