13B TII vs N/A
 

I'm curious if there's any real difference between the NA and TII versions of the engine aside from lower compression rotors. Also what's the main tranny difference? I intend to swap to a TII but I'll end up going into the engine before I do it. Most swaps are 75-90psi compression anyway and places sell them as "GOOD" If that's the case I can get a n/a engine and build that then add the turbo parts to it. There's a car at a local yard that's a TII. Really it's the ONLY FC in a yard within 100 miles. I can get my hands on the smaller parts before they crush it. It's been there over 6mo and the engine is untouched besides the intercooler and hood are gone. If i get the manifolds and turbo, wiring and ecu, maf and boost sensor then build up an engine. Main reason is idk if i'll have $300 (ontop of the fact theyre only open 8-11:30 on weekends) for an engine/trans before they crush it.

Re: 13B TII vs N/A
 

Entire drivetrain is bigger and more durable to handle abuse from high horsepower. Turbos have LSD, bigger sway bars, front and rear brake calipers are different, and the voltage meter is now the boost meter.

Re: 13B TII vs N/A
 

well i've got all that being a GXL. I plan to do a JDM TII swap. Seems i'll need the trans from a TII. What about the engine? Are the rotor housings the same? I was gona turn my NA engine into a backup TII by changing out the rotors to either TII or FD rotors, putting better apex seals and stationaries as a backup slow build til my JDM stock TII swap goes

Re: 13B TII vs N/A
 

The engine internals are pretty much identical from what I know, so it's safe to do have the NA as backup.

FD rotor is lighter from what I know though, best to confirm that before getting the rotors.

Re: 13B TII vs N/A
 

but the FD rotor will still work in the 13b housing right? I want lighter for faster revs

Re: 13B TII vs N/A
 

It will, but it doesn't necessary make the rev go faster.

You should get a aluminum flywheel to get the faster rpm, aluminum driveshaft, bigger diameter exhaust pipe for high flow (3" to 3.5").

Lighter rotor means you will have to adjust the timing, TPS, and also some mapping with the ECU. If you know what you're doing then go right ahead, but I suggest do more research on this.

Re: 13B TII vs N/A
 

Sounds like that wont be worth it til im ready to make big power later on. Ive considered the 3 things u mentioned since they can all be used on the turbo model. Does this engine need backpressure? Thats y im procrastinating getting a nice exhaust system with cat and egr delete. Ontop of the $650 price tag lol anything else we can do for a faster rev? 2nd gear taking a minute to redline with the pedal floored is pathetic

Re: 13B TII vs N/A
 

Just put in a lightweight flywheel, and it'll rev much more faster.

Re: 13B TII vs N/A
 

Even an n/a RX-7 isn't THAT slow. Is everything else up to snuff? Before I started a bunch of go-fast mods, I'd be sure that what I had was tuned up and in good condition.

Re: 13B TII vs N/A
 

Just go with what you have on the exhaust system for now, it's better if you save up the money and get a complete good system (whether pieced together or custom made).

Flywheel and driveshaft is model specific, so get the turbo one since that's what you're going with.

Also, you can get a closer ratio transmission gears, one popular mod is using the miata tranny. Aside from that, change the final gear ratio to 4:30, that will also assist in faster rev. However, horsepower will suffer a bit.

2nd gear taking a minute to redline sounds ridiculous.... stock one doesn't take that long, so something must either be loose or worn out. Also, if you're talking about going from stop-to-redline with 2nd gear, then it does take quite an effort for the engine to rev up at the lower rpm range.

Re: 13B TII vs N/A
 

Even easier way: get smaller wheels and tires. I autocross with 15" wheels with low-profile tires, acceleration was was faster than with 17" wheels with meatier tires. Sure, top speed will suffer, but how often are you going 100+mph?

Re: 13B TII vs N/A
 

it seems to get better as it gets driven. I know it sat awhile before I bought it. I noticed putting a new set of plugs helped alot. The fuel filter is new. All the fluids are fresh. I've got an intake gasket leak. That could be holding me back too. I've got kind of a weak spot from 3700-4000. I had to idle up the engine to keep it from stalling when i let off the gas. That could also be injectors. I've gota pull the plenum off i'll check injectors while i'm there. Also i'm running the factory 15s on 60 series tires. I'm sure an alum driveshaft and some lighter wheels would aid a bit. I know i've got a bad throwout bearing so i'll invest in a clutch and flywheel eventually. It chatters a little bit too. Is there much that can be done to lighten the car? I know it's heavy compared to 240s and miatas. I can feel the weight powering out of corners

Re: 13B TII vs N/A
 

Check your secondary fuel injectors, the weak spot/hesitation you get from 3700-4000 is due to the injectors being clogged. See here: FC3S Pro v2.0:* Problems #1, Engine - 3,800 / 4,000 RPM Hesitations
And here: FC3S Pro v2.0:* Problems #1, Engine - Bogging at 3,800RPM to 4,000RPM

As for the low idle issue... there can be many things, so follow here: FC3S Pro v2.0:* Problems #1, Low idle

15" rims with 60 profile is fine, aluminum driveshaft and flywheel would help with the faster rpm you want to reach, rims wise you would have to go smaller to decrease the rotating diameter.

Miatas are different class, so you shouldn't be comparing the FC with them. 240s are about the same as FC, but the KA24DE has more torque compared to the NA 13B, therefore it would make you feel that FC is heavier.

Get the car completely restored with fresh engine, drivetrain, differential & rear end, plus new bushings and new springs & shocks, you will feel the true rotary rocket spirit coming from the car.

Re: 13B TII vs N/A
 

i know the drivetrain is pretty good. The engine (dont laugh) doesnt burn any oil or smoke. The oil has probably 1500 miles on it and is still a pretty gold color. I've put over 500 miles on the car since I bought it and havent had to add oil and i redline the car at least once while im driving it only when warmed up. I just changed the nasty tranny oil and diff oil and added limited slip addative. This eliminated my low speed accel while turning chatter. I think my biggest hickup is my intake gasket leak. I can spray brake cleaner on the front of the upper plenum and it'll bog the engine down. I have gaskets ordered but being what the car is they arent something the stores keep on the shelf or even in the warehouse so i'll be fixing that next weekend along with cleaning my secondaries because i'm sure theyre nasty. The previous owner (older fella) babied the car so i know he rarely took it over 3500rpm. On the same note tho he took care of the car. It's got new tokicos, new brakes, new radiator, new alternator/starter, new OEM driveshaft and mufflers. The underbody is rust free, the undercoat is even still tacky. The front control arm bushings are wearing but all the other rubber is in decent shape. I guess driving my sentra SER daily i want this car to be peppy. The sentra has a p/w ratio of 14.4:1 with a quick revving QR25 and 6-speed. The engine responds well to heavy load low RPM say 30-45 mph accelerations in 5 or 6 gear with ease where the rx has to be downshifted. the n/a rx has a 16:1 so it's not quite as fast. It's pretty crazy how expensive the mods can be for the rx. It's gona cost me 1500 just to get a new clutch with lighter flywheel (mine chatters and throwout is whining), a good 3" exhaust (mine has factory dual setup) and an aluminum drivehsaft. Question is, is it worth it? I read rotaries react well to mods. I know just changing my spark plugs made a huge difference. Felt like i put an exhaust on a piston engine. Also how do rotaries react to removing emissions garbage like the air pump and evap canister, egr etc

My main reason for considering miata is theyre similar. Balanced rwd great handling cars. My biggest thing is miatas are cheaper to work on and parts are more readily available. The engine is pretty much bulletproof too. Convertible is nice but i have a working sunroof on my FC. But the biggest thing is miatas can be dropped into the 1700 lb range.. that's light making any mods more effective. Their forums are much livelier too. No offense since I always find the info im looking for up here or rx7club, big difference is rx7club makes u do more searches.

Also dont forget the KA weighs as much as the rx's whole driveline. Also nissan didnt focus on balance like mazda does. The KA powered 240s are very front heavy making them abuse tires and lose traction when braking into corners. Most guys swap in a SR due to it's factory build for turbo, ability to handle 300hp without internals and about 250-300 lbs less. The guys i work with have SR 240s exept one who just got his but he plans to stick KA. I'd love to get the TII with all the lighter mods and put it up against the stock SR 240. All he has is the stock setup with 1-piece driveshaft and super low springs

Re: 13B TII vs N/A
 

Check the OMP to see if it's working properly, that might explain why oil is slowly getting lower. I drive mine daily at a pretty spirited fashion, so pretty much I have to check almost once a week or two weeks. It really depends, I have heard others who say their engine don't consume oil.

You've done a quite a bit of research, which is good... I spend a good portion everyday just reading up a lot of different stuff on both the forums and websites. And since we are also drivers, it's easier to know what is actually right or wrong based from our own experience. Also getting connections with local rotary specialist would be one of the most helpful thing, get familiar with them and raise your questions, these mechanics love to share their thoughts with us who are passionate about rotary.

Removing emission related stuff will make the rotary run smoother and quicker... after all, rotary is intended for racing, not daily driving (see the owner's manual, DD is consider 'special driving' that requires a different maintenance method). A lot of people remove the emission stuff, but to be honest, is it necessary? Depending on where you are, law enforcement are bound to give you hassle, given that rotary is loud by nature, removing emission just makes it more obnoxious or high profile, may not be worth it. So this is going with your question, is it worth it?

Worth it or not really depends on you, I say that not to throw the question back at you, but more so everyone has a different direction they pursue after. For my case, I'm working towards the streetable race car that runs on pump gas, DD mostly but track worthy; my mechanic and I are working towards on NA larger streetport, ITB, Microtech, custom one piece exhaust, and a bunch of other things. So the fine line to reach the balance I want is not easy, but it's an on-going project that I insist on pursuing, even though I have doubt myself many many times, is it worth it? (I've spend up to five digits now, and it's still growing)

Miata is nice, I've driven the NA, NB, and NC, even considered to get a NA myself at one point. But I know down the road I will switch to either FC or FD, so may as well just go with it from the start. But that's a different talk all around with the Miata, I'm not a fan of convertibles so it's simply not for me, even though it's a great fun car to drive.

rx7club can be messy, I've been on it since I first got my car, there are way too much useless information on there, and idiots who simply just throw out crap that won't help anyone, not to mention misleading information. But here is pretty dead though... you can see a lot of threads are not active, and there aren't a lot of people around sharing opinions, there are more questions than answers here. I just try my best with my limited knowledge, at most I'm just a more experienced driver and an amateur mechanic, nothing more.

240s are really fun cars, I've driven S13 and S14, both fascinates me with how much potentials can be brought out. But you know what, FC also has lots of potentials against them, just gotta restore it and work on putting in the right upgrades to have it tuned. It gets down to what you want as a whole, cause if you know you will not be satisfied with something, best to just switch to what you will want to have and sick with it, don't settle for something when you can just go with the full package.

Re: 13B TII vs N/A
 

If i was in your situation i probably wouldnt have any issues. There arent any rotary guys in my area. Only one has one and he's part of the omega drifting crew around here. He's running a TII and his is ok not a wow kind of car. I love the engine and how it responds to upgrades and the fact that i can put 3 ppl in the car and it doesnt bog down like my 4 banger does but i hate the lack of support in my area. I'd love to have a rotary powered miata tho. light, convertible and rotary powered :D

Re: 13B TII vs N/A
 

Also ive noticed my hesitation is gone after driving it harder going over 4k more. However i dont have secondary injectors being NA. But the information was interesting

Re: 13B TII vs N/A
 

Do this to clean the 5th and 6th port: Cleaning The 5th and 6th Ports

Re: 13B TII vs N/A
 

Yes, n/a has 2 primary and 2 secondary injectors.

Re: 13B TII vs N/A
 

ah i see theyre hidden. Theyre closer together on turbo models. I may play with those actuators when i do the intake gaskets. I may end up taking the air pump off. I'm just worried the engine may not run right without all it's emissions components since the ecm is tuned to run them... However megasquirt is looking for 86 RX7 N/A models to test ECMs and will give you a free tuned ECM when theyre done. Only catch is I cant drive the car to their shop in GA and leave it for 2 months.

Re: 13B TII vs N/A
 

I drove my '86 n/a with all emissions removed. It ran fine. Back pressure tube was left on, charcoal canister was left on. I also had pineapple racing aux port sleeve inserts, and modded the throttle body.

The mod that had the most negative impact was the throttle body mod. Lots of funky idle issues.

Re: 13B TII vs N/A
 

im more leaning to racing beat headers and cat back (so no cats and with no cats i can remove the air tube and egr) no air pump or evap canister to clean up the passenger side of the engine compartment

Re: 13B TII vs N/A
 

The auxiliary ports need a way to open. On your, that happens with back pressure, using the tube.

The evap canister doesn't take up much space, weighs very little, and without it you'll smell gas fumes all the time.